Initial Environmental Examination
Project number: 41076-048 July 2021
Philippines: Improving Growth Corridors in Mindanao Road Sector Project
TAWI-TAWI BRIDGES – Nalil-Sikkiat Bridge (Tawi-Tawi Bridge No. 1)
Prepared by the Department of Public Works and Highways (DPWH) for the Asian Development Bank. ABBREVIATIONS
AASHTO - American Association of State Highways and Officials ADB - Asian Development Bank A&D - Alienable and Disposable CENRO - Community Environment and Natural Resources Office CNC - Certificate of Non-coverage CO2 - Carbon Dioxide CR - Critically Endangered CSC - Construction Supervision Consultant DAO - Department Administrative Order DBH - Diameter at Breast Height DENR - Department of Environment and Natural Resources DED - Detailed Engineering Design Consultant DEO - District Engineering Office DOH - Department of Health DPWH - Department of Public Works and Highways ECA - Environmentally Critical Area ECC - Environmental Compliance Certificate ECP - Environmentally Critical Project EHS - Environmental, Health and Safety EIA - Environmental Impact Assessment EIS - Environmental Impact Statement EMB - Environmental Management Bureau EMP - Environmental Management Plan EO - Executive Order EPRMP - Environmental Performance Report and Management Plan ESSD - Environment and Social Safeguards Department of DPWH FGD - Focus Group Discussion GHG - Greenhouse Gases GOP - Government of the Philippines GRC - Grievance Redress Committee GRM - Grievance Redress Mechanism IEC - Information, Education and Communication IFC - International Finance Corporation IEE - Initial Environmental Examination IEER - Initial Environmental Examination Report IUCN - International Union for Conservation of Nature LGU - Local Government Unit Ncm - Normal Cubic Meter NO2 - Nitrogen Dioxide PAGASA - Philippine Atmospheric Geophysical and Astronomical Services Administration PCCP - Portland Cement Concrete Pavement PCDG - Prestressed Concrete Deck Girder PD - Presidential Decree PEISS - Philippine Environmental Impact Statement System PM - Particulate Matter PPTA - Project Preparatory Technical Assistance PR - Project Road RA - Republic Act RCBC - Reinforced Concrete Box Culvert RCDG - Reinforced Concrete Deck Girder RCPC - Reinforced Concrete Pipe Culvert REA - Rapid Environmental Assessment RF - Relative Frequency RMC II - Roads Management Cluster II
ROW - Right of Way SPS - ADB Safeguard Policy Statement of 2009 TA - Technical Assistance TSP - Total Suspended Particulate TSS - Total Suspended Solids UPMO - Unified Project Management Office VU - Vulnerable WHO - World Health Organization
This initial environmental examination is a document of the borrower. The views expressed herein do not necessarily represent those of ADB's Board of Directors, Management, or staff, and may be preliminary in nature. Your attention is directed to the “terms of use” section of this website.
In preparing any country program or strategy, financing any project, or by making any designation of or reference to a particular territory or geographic area in this document, the Asian Development Bank does not intend to make any judgments as to the legal or other status of any territory or area.
Table of Contents
ABBREVIATIONS ...... I TABLE OF CONTENTS ...... III LIST OF TABLES ...... V LIST OF FIGURES ...... VII EXECUTIVE SUMMARY ...... VIII I. POLICY, LEGAL AND ADMINISTRATIVE FRAMEWORK ...... 13
A. ENVIRONMENTAL LAWS, REGULATIONS AND GUIDELINES IN THE PHILIPPINES ...... 13 B. EIA SYSTEM IN THE PHILIPPINES ...... 15 C. ADB’S SAFEGUARD POLICY STATEMENT REQUIREMENT ...... 18 II. DESCRIPTION OF THE PROJECT ...... 20
A. OVERVIEW ...... 20 B. LOCATION ...... 21 C. PROPOSED BRIDGE CONSTRUCTION WORKS ...... 23 D. BASIC DESIGN OF THE PROJECT BRIDGE ...... 23 a. Selection of Design Elements ...... 23 b. Climate Change Adaptation ...... 24 E. ROAD SAFETY ...... 25 F. CONSTRUCTION METHODOLOGY ...... 26 III. DESCRIPTION OF THE ENVIRONMENT ...... 26
A. LAND ENVIRONMENT ...... 26 a. Topography and Slope ...... 26 b. Land Classification ...... 27 c. Existing General Land Use ...... 28 d. Geology ...... 28 e. Soils ...... 29 f. Climate and Meteorology ...... 30 B. FRESH WATER RESOURCES ...... 31 C. AIR QUALITY AND NOISE ...... 31 D. MARINE ECOLOGY ...... 32 a) Secondary Information ...... 32 b) Baseline Survey for Marine Ecological Assessment ...... 36 c) Coral Reefs ...... 36 d) Reef Fish Community ...... 37 e) Seagrass/Seaweeds ...... 40 f) Mangrove Community Structure ...... 41 g) E.2.6. Plankton Community ...... 42 h) Benthos Community ...... 43 i) Water Parameters ...... 44 j) E.2.9 Water Current and Circulation ...... 46 k) Conclusion and Recommendation ...... 47 E. SOCIOECONOMIC RESOURCES ...... 49 a. Population ...... 49 b. Age and Sex Structure ...... 51 c. Age Dependency Ratio ...... 52 d. Migration ...... 52 e. Mother Tongue ...... 53 f. Religious Affiliation ...... 53 g. Education ...... 54 h. Educational Institutions and School Facilities by Level ...... 55
i. Teachers and Student Population ...... 57 j. School Population and Children out of School ...... 57 k. Housing ...... 60 l. Health ...... 61 m. Social Welfare ...... 63 n. Sports and Recreation ...... 64 o. Public Order and Safety ...... 64 p. Agriculture ...... 65 q. Fisheries and Aquatic Resources ...... 66 r. Trade and Commerce ...... 66 s. Tourism ...... 67 F. THE ENVIRONMENT SECTOR ...... 68 a. Solid Waste Disposal ...... 68 b. Sanitary Toilet Facilities ...... 68 c. Areas for Conservation / Protection ...... 68 d. Water and Watershed: Present and Future Water Demand ...... 71 G. THE INFRASTRUCTURE SECTOR ...... 71 IV. ANTICIPATED IMPACTS AND MITIGATION MEASURES ...... 74
A. PRE-CONSTRUCTION...... 75 a. Encroachment on Environmentally Sensitive Areas ...... 75 b. Impacts and Risks to Biodiversity Conservation ...... 75 B. CONSTRUCTION ...... 76 a. Inadequate Disclosure of Project Information and GRM ...... 76 b. Local Air Pollution ...... 76 c. Noise ...... 77 d. Impacts due to Spoils Disposal ...... 78 e. Impacts from Operation of Borrow Areas and Quarries ...... 79 f. Erosion and Unstable Slopes ...... 79 g. Impacts to Marine Water Quality and Ecology ...... 79 h. Loss of Vegetation ...... 81 i. Occupational Health and Safety Hazards ...... 82 j. Public Health and Safety Hazards ...... 82 k. Traffic Obstruction ...... 83 l. Accidental Discovery of Artefacts ...... 83 m. Damage to Properties ...... 83 n. Impacts to Livelihood ...... 84 o. Unanticipated Environmental Impacts ...... 84 C. OPERATION PHASE ...... 84 a. Air Quality ...... 84 b. Noise ...... 85 c. Induced Impacts ...... 85 V. INFORMATION DISCLOSURE, CONSULTATION AND PARTICIPATION ...... 86 VI. GRIEVANCE REDRESS MECHANISM ...... 88 VII. ENVIRONMENTAL MANAGEMENT PLAN ...... 90 VIII. CONCLUSION ...... 119 IX. APPENDICES ...... 121 APPENDIX 1. MARINE ECOLOGICAL ASSESSMENT ...... 122 APPENDIX 2. GRIEVANCE INTAKE FORM ...... 166 APPENDIX 3. PROJECT SEMI-ANNUAL ENVIRONMENTAL MONITORING REPORT OUTLINE ...... 168 APPENDIX 4. APPROVED/SIGNED REA AND ENVIRONMENTAL CATEGORIZATION ...... 170 APPENDIX 5. PUBLIC CONSULTATION ATTENDANCE SHEETS ...... 179
List of Tables
Table 1. Major Environmental Laws and Regulations in the Philippines ...... 13 Table 2. Environmental Laws and Decrees in the Philippines ...... 13 Table 3. Philippine Environmental Agreements to the International Treaty ...... 15 Table 4. Laws and Regulations regarding EIA in the Philippines ...... 15 Table 5. EIS and IEE Requirements for Road and Bridge Projects ...... 18 Table 6. Category Classifications on the Environment based on SPS 2009 ...... 19 Table 7. Subproject Scope and Coverage ...... 23 Table 8. Summary Road Safety Problems and Measures ...... 25 Table 9. Land Classification of Bongao, Tawi-Tawi ...... 27 Table 10. Existing Land Use ...... 28 Table 11. Land Area distribution by barangays in Bongao, Tawi-Tawi ...... 29 Table 12. Monthly temperature and rainfall based on historical weather data ...... 30 Table 13. Mangrove Cover and Condition by Barangay ...... 32 Table 14. Coral Cover and Condition by Barangay, Bongao, Tawi-Tawi ...... 33 Table 15. Seagrass Cover, Condition and Species Composition by Barangay ...... 35 Table 16. Percentage cover of different benthic components in the proposed Nalil-Sikkiat Bridge ...... 37 Table 17. Composition and biomass ((mt/km2) of fish species found in the proposed Nalil- Sikkiat Bridge ...... 38 Table 18. Categories of sites according to species richness as adapted from Hilomen et al. (2000) ...... 40 Table 19. Categories of sites according to fish abundance as adapted from Hilomen et al. (2000) ...... 40 Table 20. Categories of sites according to fish biomass as adapted ...... 40 Table 21. Global Positioning System (GPS) coordinates of mangrove sampling stations in the proposed Nalil-Sikkiat Bridge ...... 41 Table 22. Mangrove species in the proposed Nalil-Sikkiat Bridge Location ...... 42 Table 23. Seedlings and saplings recorded in the proposed Nalil-Sikkiat Bridge ...... 42 Table 24. Cell Density of plankton in the proposed Nalil-Sikkiat Bridge location ...... 43 Table 25. Average water parameters in the Sikkiat side ...... 44 Table 26. Average water parameters in Pakias side ...... 45 Table 27. Range of water parameters for marine organisms in the tropics ...... 45 Table 28. Sampling points if water current in the proposed Nalil-Sikkiat Bridge ...... 46 Table 29. The population of Bongao, Tawi-tawi by barangay and by census year, 1980- 2015 ...... 49 Table 30. Population Density per barangay and location by major island group ...... 50 Table 31. The distribution of population by age group and by sex, 2015 ...... 51 Table 32. Household Population by Mother Tongue, Year 2010 ...... 53 Table 33. Elementary Schools in Bongao, Tawi-Tawi ...... 56 Table 34. Names & Nos. of Pre-Schools, Both Government & Private, Bongao, Tawi-Tawi 56 Table 35. Number of Teachers per Public Secondary School in Bongao, 2014 ...... 57 Table 36. Total Enrollment of Bongao Public Elementary Schools per District, 2013- 2014 58 Table 37. Total Enrollment of Public Secondary Schools, Department of Education ARMM Bongao, Tawi-Tawi ...... 58 Table 38. Proportion of individuals of schooling age and their attendance to school, 2015 . 58 Table 39. Out of School Children and Youth by Barangay and by Rank ...... 59 Table 40. Housing Projects in Bongao as of March 2017...... 60 Table 41. The Leading Causes of Mortality in Bongao, Tawi-Tawi for 2015...... 61 Table 42. Weight of children in Bongao below 5 years old, CY 2015...... 62 Table 43. The programs and services provided by the MSWDO, 2016 ...... 63 Table 44. Crimes and other offenses in Bongao, 2016 ...... 64 Table 45. Agricultural Croplands and Crop Production in Bongao, Tawi-tawi, 2015 ...... 65
Table 46. Approximate Distances of Ecologically Sensitive or Protected Areas from the Bridge Sites ...... 69 Table 47. List of Roads by Classification and Length, Bongao, Tawi- Tawi ...... 71 Table 48. Summary of Environmental Impacts Screening for Tawi-Tawi Bridge No. 1 ...... 74 Table 49. Summary Matrix of Public Consultation ...... 86 Table 50. Summary Matrix of Public Consultation ...... 87 Table 51. Impact Mitigation Plan ...... 91 Table 52. Environmental Monitoring Activities during Construction ...... 113 Table 53. Responsibilities for EMP Implementation ...... 115 Table 54. Cost for Environmental Management and Monitoring ...... 117 Table 55. Appendix 1-1 Percentage cover of different benthic components in the proposed Nalil-Sikkiat Bridge ...... 130 Table 56. Appendix 1-2 Composition and biomass ((mt/km2) of fish species found in the proposed Nalil-Sikkiat Bridge ...... 133 Table 57. Appendix 1-3 Categories of sites according to species richness as adapted from Hilomen et al. (2000)...... 135 Table 58. Appendix 1-4 Categories of sites according to fish abundance as adapted from Hilomen et al. (2000)...... 135 Table 59. Appendix 1-6 GPS coordinates of seagrass/seaweeds sampling stations in the proposed Nalil-Sikkiat bridge...... 137 Table 60. Appendix 1-7 Percentage cover (%/m2) of seagrass in Nalil-Sikkiat bridge ...... 138 Table 61. Appendix 1-8 Global positioning System (GPS) coordinates of mangrove sampling stations in the proposed Nalil-Sikkiat bridge ...... 140 Table 62. Appendix 1-9 Mangrove species in the proposed Nalil-Sikkiat Bridge ...... 140 Table 63. Appendix 1-10 Seedlings and saplings recorded in the proposed Nalil-Sikkiat bridge ...... 141 Table 64. Appendix 1-11 Cell density of plankton in the proposed Nalill-Sikkiat Bridge ..... 145 Table 65. Appendix 1-12 Average water parameters in the Sikkiat side ...... 148 Table 66. Appendix 1-13 Average water parameters in Pakias side ...... 148 Table 67. Appendix 1-14 Range of water parameters for marine organisms in the tropics 148 Table 68. Appendix 1-15 Sampling points of water current in the proposed Nalil-Sikkiat Bridge ...... 151 Table 69. Appendix 1-16 Matrix of compliance of the baseline survey ...... 154
List of Figures
Figure 1. Flow of EIA Process ...... 17 Figure 2. Location of the Proposed Three (3) Bridges in the Province of Tawi-Tawi ...... 22 Figure 3. Location of the Proposed Nalil-Sikkiat Bridge in the Province of Tawi-Tawi ...... 22 Figure 4. Topographic Map of Bongao, Tawi-Tawi ...... 26 Figure 5. Municipal Boundary of Bongao ...... 27 Figure 6. Geologic Map of Bongao, Tawi-tawi ...... 29 Figure 7. Precipitation / Rainfall by month in Bongao ...... 31 Figure 8. Map showing the different sampling stations in the proposed Nalil-Sikkiat bridge 36 Figure 9. Population by Age Group, CY 2014 ...... 52 Figure 10. Ethno-linguistic groupings in Bongao, 2015 ...... 53 Figure 11. Religious affiliation of the population in Bongao, 2010 ...... 54 Figure 12. The literacy rate in Bongao, Tawi-Tawi, 2010 ...... 54 Figure 13. The location of school facilities in Bongao, Tawi-Tawi, 2015 ...... 56 Figure 14. The location of informal settler areas in Bongao, Tawi-tawi, 2017 ...... 61 Figure 15. Geographical Locations and Distribution of Ecologically Sensitive or protected areas ...... 70 Figure 16. Projected Water Requirement per Day, 2017-2026 ...... 71 Figure 19. Appendix 1-1. Map showing the proposed Nalil-Sikkiat Bridge ...... 125 Figure 20. Appendix 1-2 Map showing the different sampling stations in the proposed Nalil- Sikkiat bridge ...... 126 Figure 21. Appendix 1-3 Percentage cover of the main benthic groups in the proposed Nalil- Sikkiat Bridge ...... 131 Figure 22. Appendix 1-4 Average mangrove stands per hectare in Sikkiat side...... 142 Figure 23. Appendix 1-5 Average mangrove stand per hectare in Pakias side ...... 142 Figure 24. Appendix 1-6 Average height (meters) of mangrove in Sikkiat side ...... 143 Figure 25. Appendix 1-7 Average height (meters) of mangroves in Pakias sided ...... 143
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EXECUTIVE SUMMARY
1. The Government of the Philippines has approached the Asian Development Bank (ADB) for financial and technical support for the Improving Growth Corridors in Mindanao Road Sector Project (IGCMRSP).
2. Transportation is a key sector in the Philippine economy with roads being the dominant subsector. The national road network comprises 29,630 kilometers (km), or 14% of the total road network and includes the main trunk roads, the national primary arterial roads, and national secondary roads. An efficient road subsector is crucial for the Philippines’ economic growth and poverty reduction. Despite its importance to the national economy, the road subsector has not received adequate funding. Expansion or improvement of the network has been limited in recent years, and many roads deteriorate prematurely due to inadequate maintenance. Government funding for the road network has been increasing in recent years; however, about 23% of the national road network is in poor condition and in need of rehabilitation. This contributes to the rising number of road accidents in the Philippines. The increasing impact of climate change, particularly flooding, is having a negative effect on the road network. The road network in Mindanao is less developed than the national network. While 82% and 89% of the national roads in Luzon and the Visayas are paved, only 70% of the national roads in Mindanao are paved.
3. The project supports the Government of the Philippines’ priorities for improvement of the country’s road network and development of Mindanao.1 It also supports the key objective of ADB’s strategy for the Philippines of helping the country achieve high, inclusive, and sustainable growth.2 The project is consistent with ADB’s Strategy 2020 through its focus on improving the delivery of infrastructure services as well as investing in physical assets.3 The project supports regional cooperation and integration by contributing to the implementation of the ASEAN Highway and BIMP-EAGA Priority Infrastructure Projects. It supports ADB’s Sustainable Transport Initiative by addressing climate change and road safety, and it is included in ADB’s Philippines Transport Sector Assessment, Strategy, and Road Map.4
4. Use of the sector loan will enable the government to achieve inclusive economic development by concentrating road improvement subprojects in Mindanao and will provide flexibility in determining the most appropriate location for subprojects given changing political and security conditions in Mindanao. The project meets all the requirements for a sector loan:5 (i) the government has a sector development plan and the institutional capacity to implement it, (ii) its policies applicable to the sector are appropriate, and (iii) DPWH has demonstrated capacity.
5. The project is considered Category B for environment based on ADB's Safeguard Policy Statement (SPS 2009). The project will promote connectivity in the region and improve an estimated 300 km of national primary, secondary, and tertiary roads in Mindanao. The improvements will include paving earth roads, replacing damaged road sections, widening existing roads, adding surface overlays, construction of new bridges, and replacing and strengthening existing ones. The project roads will be designed with features to strengthen resilience to climate change. Among the structural and non-structural features included are elevated pavement levels, enhanced slope protection, and improved maintenance of drainage structures. Road safety on these roads will be improved through road safety community awareness campaigns.
1 National Economic and Development Authority. 2011. Philippine Development Plan, 2011–2016. Manila. 2 ADB. 2011. Country Partnership Strategy: Philippines, 2011–2016. Manila. 3 ADB. 2008. Strategy 2020: The Long-Term Strategic Framework of the Asian Development Bank, 2008–2020. Manila. 4 ADB. 2010. Sustainable Transport Initiative: Operational Plan. Manila. 5 ADB. 2003. Sector Lending. Operations Manual. OM D3/BP. Manila. The project will fund water and sanitation subprojects, applying ADB's safeguards, procurement, and disbursement processes, as per OM D3.
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6. This initial environmental examination (IEE) was prepared in accordance with SPS 2009 for the proposed Nalil-Sikkiat Bridge (Tawi-Tawi Bridge No. 1) in the Province of Tawi- Tawi.
7. This is one of three (3) proposed bridges6 in Tawi-tawi that are aimed to bring the development in the island through improved connectivity between the islands in the municipality of Bongao. The three (3) proposed bridges aim to provide a direct route between the existing major growth center (Bongao) and future growth center in Panglina Sugala and Papahag Island. Papahag Island is proposed for development for large scale seaweeds processing plant which is the top raw material produced in Tawi-Tawi, and housing site project for the local population according to the local government of Tawi-Tawi. This proposed Tawi- Tawi Bridge No. 1 is necessary to be sited in the location instead of alongside the existing concrete bridge for the following reasons: a) It is well protected from strong winds from the open sea; b) In the existing bridge, the navigation height (of about 5 meters) and width (25 meters) is limited only to pass small vessels (boats/ships); b) the actual channel width of the existing bridge is between 250 to 260 meters but the bridge length is only 60 meters that caused the accumulation of drift sand at the mouth of the Bongao Channel making the sea depth shallower; and c) locating alongside the existing concrete bridge will be limited by the navigation height requirements of the Bongao airport (bridge elevation cannot be raised as much as in the proposed new bridge location). In addition, traffic congestion is anticipated along the only existing main road that currently connects the two islands during the construction period thereby disrupting the economic activities of the two islands (albeit on a short-term basis only).
8. In addition, the first ecozone for Tawi-Tawi was approved in May 2017 according to the Philippine Economic Zone Authority (PEZA) will be located in Kulape in the town of Panglima Sugala. The first approved private economic zone in the island of Tawi-Tawi will consist of 218.9 hectares. There is also a proposed port development, the Malassa International Port, to address the economic potential of the island province because it is in the path of international shipping containers. Similarly, the construction of the bridges will open up potentials in the tourism and fishing industry. The strengthening of local and regional market connectivity therefore in this corridor can encourage more investors to come in and do business in the country. The development of these industries could spur the economic activities that would boost the mediocre economy of the province and further enhance the quality of life of its people.
9. There are four major existing bridges in the Municipality of Bongao. These are the concrete bridge connecting Bongao Island and Sanga-Sanga Island; the steel bridge at Suwangkagang, Pasiagan, and the two bridges in Barangay Lapid-Lapid. The proposed Bridge No. 1 will connect Barangay Nalil in Bongao Island to Barangay Pakias in Sanga-Sanga Island over the Bongao Channel through the existing municipal roads of mixed condition (generally concrete paved for the most part in the Barangay Pakias site and unpaved road in the Barangay Nalil side). It is a major bridge serving as an alternate shortest access directly connecting the economic activities of Bongao Island to Sanga-Sanga Island.
10. This proposed bridge is necessary to be sited in the location instead of alongside the existing bridge for the following reasons: a) It is well protected from strong winds from the open sea; b) In the existing bridge, the navigation height (of about 5 meters) and width (25 meters) is limited only to pass small vessels (boats/ships); b) the actual channel width of the existing bridge is between 250 to 260 meters but the bridge length is only 60 meters that caused the accumulation of drift sand at the mouth of the Bongao Channel making the sea depth shallower; and c) locating alongside the existing bridge will be limited by the navigation height
6 The other two (2) bridges are the following: Tongsinah-Paniogan Bridge (Tawi-Tawi Bridge No. 2); and Malassa-Lupang Pula Bridge (Tawi-Tawi-Bridge No. 3)
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requirements of the Bongao airport (bridge elevation cannot be raised as much as in the proposed new bridge location). In addition, traffic congestion is anticipated along the only existing main road that currently connects the two islands during the construction period thereby disrupting the economic activities of the two islands (albeit on a short-term basis only).
11. The IEE was undertaken to:
(i) Provide project information and relevant environmental baseline data for the project; (ii) Assess potential environmental impacts of the project; (iii) Identify mitigation measures to minimize negative impacts; (iv) Provide information on the consultations undertaken and the framework for a project level grievance redress mechanism (GRM); and (v) Develop a robust environmental management plan (EMP) which specifies mitigation and monitoring measures, institutional responsibilities and reporting requirements.
12. An environmental assessment and review framework (EARF) had been prepared to serve as a guide to ensure compliance of subprojects with the environmental assessment requirements under ADB’s Safeguards Policy Statement, 2009 (SPS) and the Philippine Environmental Impact Statement System (PEISS).
13. Project Description. Tawi-Tawi Bridge No. 1 - Nalil-Sikkiat Bridge has a gross length of 540.80m. The bridge span is 380.80 m over the Bongao Channel from its first approach in Sikkiat (Sanga-Sanga) at Km 0+031.00 to the second approach through the main bridge ending at Nalil (Bongao) at Km 0+509.80 The existing two-lane, PCC pavement road that will connect to the main bridge is classified as a National Secondary Road are still in good condition that is not generally paved with narrow width for the most part. According to the DPWH, this existing road connecting to the proposed bridge will be improved at the same time as the bridge. This new bridge construction will be a Pre-stressed Concrete Deck Girder (PCDG) structure, AASHTO Type IV-B and Type VI Modified) with twelve spans. The bridge approach roads are 160-m in length and are included to be constructed in this contract package. To decongest the existing Tawi-Tawi circumferential road and the proposed new bridge has a shorter route coming to and out of the Poblacion, Bongao.
14. Existing Environmental Conditions. Areas along the bridge approaches do not traverse or is near ecologically sensitive and/or protected areas. Five (5) areas (refer to table Table 46 and Figure 15) that had been identified7 by the local government unit are located about three (3) kilometers (nearest is the Bongao Peak or Bud Bongao) to more than fourteen (14) kilometers away (Ungus Marine Protected Area). The bridge approaches roads are 160-m in length and are generally characterized as having terrain located in the level to gently sloping areas with 0-8% slope gradient. Since bridge alignment is located in an underdeveloped rural setting, there are no major local sources of anthropogenic emissions. The lack of industrial development suggests that air pollution and noise sources which would normally elevate background levels are not present in the area. However, due to the current unpaved condition of the existing road where the bridge approach roads will be connected, dust will be continually generated and resuspended during dry construction days leading to occasional visible level of suspended particulates. During the rainy season, water quality will be affected by siltation and mud carried into the channel. The unpaved roads were already present before the design plan was established. The BARMM LGU decided to construct a road towards the proposed Tawi-Tawi bridge.
15. A baseline survey employing various methodologies (discussed in Chapter V of the
7 Kindly refer to the detailed discussion under the Environment Sector (paragraph 184, item G(s) of this document.
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Marine Ecological Survey) was undertaken for marine ecological assessment of coral reefs, coral reef fishes, seagrass/seaweeds, mangroves, phytoplankton, benthos, water quality, water current and circulation. Three (3) sampling stations for coral reefs reef fishes, six (6) sampling stations for seagrass/seaweeds and twelve sampling stations (12) for mangroves community structure. The sampling stations for water quality, plankton and benthos is the same with the sampling station for coral reefs. The sampling stations for coral reefs, reef fishes, seagrass/seaweeds, benthos, plankton and water parameters were located nearest the area where the proposed bridge piers will be established based on the maps and coordinates that was provided by DPWH. The mangroves sampling stations were also located adjacent to the proposed bridge approaches that will be directly affected by the construction activities. Results showed that the coral reefs recorded good cover condition while the other marine resources are very minimal. The following observations were made: (1) good species diversity of coral reefs (37% hard coral cover, Gomez, et.al., 1981 and Licuanan, et. al., 2017); (2) poor coral fishes (27-47 species per 1000m2 , Hilomen, et. al., 2000 and biomass of only 6.98mt/km2 , Nanola, et. al., 2006); (3) minimal species of seagrass and seaweeds (mean of 2.18 to 2.43%/m2, Saito and Atobe, 1970; English et. al. 1997, and Fortes, 1986); (4) minimal species of mangrove stand (5 in the Barangay Nalil side and only 2 in the Barangay Pakias side, Arroyo 1977; Fernando and Pancho, 1980) and cutting of mangrove observed; (5) water parameters are within the tolerable limits for the recruitment, growth, survival and development of marine organisms (details in the Marine Ecological Assessment Report); (6) plankton (1,257cell density of phytoplankton, 84 cell density of zooplankton, English et. al. 1997) and benthos population (three (3) infauna groups buried in the sediment recorded in the proposed bridge) are very minimal; (7) water current is 0.15m/sec; and (8) water circulation is favorable for coral growth and development. Lobophyllia corals, was found in small and scattered population in the vicinity of the proposed bridge (only 0.4% cover out of the 37.13% total cover of hard corals). It is a very popular stony coral for aquarium due to its wide variety of colors and textures. This genus however, includes one endangered species, the Lobophyllia serratus. This is proposed to be investigated further prior to start of construction with marine experts from the Mindanao State University-Tawi-Tawi College of Technology and Oceanography (MSU-TCTO) so that mitigation measures can be further enhanced, if necessary. Water circulation in the area is controlled by physical forces at the open boundaries, namely the river inflow, the groundwater inflow, the wind, and the oceanic forces like tides, fluctuations of the mean sea level like storm surges, the waves, and the net oceanic currents. Sedimentation, siltation, low water visibility and substrate characteristics limit or prevent larvae settlements, recruitments, growth and development of other marine organisms in the proposed bridge location.
16. Anticipated Impacts and Environmental Management Plan. The project will involve bridge construction with multiple bored piles to be driven into the channel waters, significant adverse environmental impacts will be discussed in the EMP. The mangrove trees to be cut to make way for the bridge piers and embankment for the approach roads will be minimal and shall be offset through replanting within the immediate vicinity of the bridge site location. The cutting and replacement planting of mangrove trees shall be coordinated by the Department of Public Works and Highways (DPWH) through its implementing agency (the UPMO) and its Contractor with the Ministry of Environment, Natural Resources and Energy (MENRE) through its Environmental Management Services (EMS).
17. Other potential environmental impacts related to construction activities are: (i) impacts to the channel waters through the potential release of bored wall stabilization materials (or maybe polymers or bentonite); sedimentation at and near pier construction sites, (ii) construction noise, (iii) local air pollution due to construction activities, (iv) oil and other hazardous materials releases, (v) vehicular traffic congestion and public access disruption, (vi) hazards to the public due to construction activities, (vii) pollution and health risks arising from workers camps, and (viii) occupational health and safety at work sites.
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18. Mitigation measures have been developed for the negative environmental impacts related to construction activities for inclusion in the works specifications to ensure their implementation. To mitigate negative impacts arising from the Project, an environmental management plan detailing mitigation measures, monitoring activities and responsibilities for implementation has been prepared as part of the IEE. DPWH will include the EMP in the bid and tender documents for civil works to ensure that the Project will be carried out consistent with the EMP requirements. Contractors are required to prepare a contractor’s environmental management plan (CEMP) aligned with the project EMP to be approved by DPWH and CSC prior to start of construction and ADB will be provided a copy. During construction, DPWH will be assisted by a construction supervision consultant who will also undertake monitoring of the environmental performance and compliance of contractors.
19. Information Disclosure and Consultation. Public consultations were conducted in the barangays in December 2019. These were attended by local government officials and residents of the project location. Continuous consultation and information disclosure with the stakeholders will be conducted during subproject implementation, as needed.
20. Grievance Redress Mechanism. A project-specific grievance redress mechanism (GRM) will be established8 to receive, evaluate and facilitate the complaints/grievances of affected persons on the sub-project’s environmental performance. This mechanism will be disclosed to the host communities prior to commencement of site works. A framework is presented in the IEE with additional details to be provided and documented in the CEMP prior to the commencement of the construction activities.
21. Conclusion. Based on the screening and assessment for potential environmental impacts and results of the marine ecological survey and assessment, the project is not anticipated to have significant negative environmental impacts. The project can be implemented in an environmentally acceptable manner provided that the EMP is enforced.
22. Site visit was very limited during the preparation of the IEE due to travel restrictions imposed by the government to curb the spread of COVID-19. Recommendations are included in this IEE for some activities to be pursued prior to start of construction, to strengthen environmental management. Further investigation of critical marine ecological resources identified in the baseline survey that might possibly be affected by construction, particularly the Lobophyllia corals, is recommended prior to start of construction to ensure impacts are mitigated.
23. Should there be significant changes in the project design or the scope of work during construction and the location, the IEE, environmental assessment and EMP will be updated or a new IEE and EMP will be prepared to assess the potential impacts, evaluate the alternatives, and outline mitigation measures and resources to address those impacts. The updated or newly prepared documents will be submitted to ADB for review, clearance and public disclosure.
8 At any appropriate DPWH Office that maybe established because there are no DPWH Offices under the BARMM area in the meantime.
xii INITIAL ENVIRONMENTAL EXAMINATION Tawi-Tawi Bridge No. 1: Nalil-Sikkiat Detailed Engineering Design for Road Improvement and Institutional Development (RIIDP) and Future Financing
I. POLICY, LEGAL AND ADMINISTRATIVE FRAMEWORK
A. Environmental Laws, Regulations and Guidelines in the Philippines
24. Major laws regarding the environment in the Philippines are shown in Table 1. These environmental-related laws were formulated under the Presidential Decree (PD) No.1151 as an environmental policy and PD No. 1152 as an environmental regulation in relation. Since the project is within the Bangsamoro Autonomous Region in Muslim Mindanao (BARMM), applicable environmental guidelines from the Ministry of Environment, Natural Resources, and Energy (MENRE) shall be followed in the application of Environmental Compliance Certificate (ECC).
Table 1. Major Environmental Laws and Regulations in the Philippines
Title Contents Presidential Decree (PD)No.1151 Philippine Environmental Policy Presidential Decree (PD)No. 1152 Philippine Environmental Code9 Presidential Decree 1586 Establishing an Environmental Impact Statement System including other environmental management related measures and for other purposes. Presidential Proclamation No. 2146 (1981) and No. Proclaiming certain areas and types of projects as 803 (1996) environmentally critical and within the scope of the Environmental Impact Statement System established under PD 1586. EMB Memorandum Circular 2014-005 Guidelines of coverage screening and standardized requirements under the PEISS amending relevant portions of Environmental Management Bureau (EMB MC 2007-002. Source: Environmental Management Bureau (EMB: https://emb.gov.ph/laws-and-policies-environmental-impact- assessment/)
25. Major environmental laws are set out for natural resources, protection of wildlife and biodiversity, forest resources, mining, coastal and marine, ambient air, water quality, waste and disposal, land use and resettlement, conservation of historical and cultural assets, environmental assessment, and national integrated protected area system. The laws and decrees applicable to the Project are summarized in Table 2.
Table 2. Environmental Laws and Decrees in the Philippines
Category Title/Outline Natural Presidential Decree (PD) Requiring all individuals, partnerships or Resources 1198 corporations engaged in the exploration, development and exploitation of natural resources or in the construction of infrastructure projects to restore or rehabilitate areas subject thereof or affected thereby to their original condition
9 https://lawphil.net/statutes/presdecs/pd1977/pd_1152_1977.html
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Category Title/Outline Ambient Air Republic Act (RA) 3931 An Act creating the National Water and Air Pollution Commission (also includes definitions ad penalties related to pollution) PD 1181 Providing for the prevention, control and abatement of air pollution from motor vehicles and for other purposes PD 1160 Vesting authority in Barangay captains to enforce pollution and environmental control laws and for other purposes RA 8749 Philippine Clean Air Act of 1999 Water quality RA 9275 Philippine Clean Water Act of 2004 DENR Administrative Order Classification of water and use (DAO) 34 Waste Disposal PD 825 (1975) Providing penalty for improper disposal of garbage and other forms of uncleanliness and for other purposes PD 1152 (1977) Philippine Environmental Code (Objective: To achieve and maintain such levels of air quality as to protect public health and to prevent to the greatest extent practicable, injury and/or damage to plant and animal life and property, and promote the social and economic development of the country)
RA 6969 (1990) An Act to Control Toxic Substances and Hazardous and Nuclear Wastes, Providing Penalties for Violations thereof, and for their Purposes DAO 36 Series of 2004 Procedural manual of DAO 92-29, a (DAO 04-36) comprehensive documentation on the legal and technical requirements of hazardous waste management RA 9003 Ecological and Solid Waste Management Act of 2000 DAO 01-34 Implementing Rules and Regulations (IRR) of RA 9003 Forestry/Flora PD 705 Revised Forestry Code of the Philippines DENR Memorandum Order Uniform Replacement Ratio for Cut or no. 05 of 2012 Relocated Trees Joint Memorandum Circular Guidelines for the Implementation of the No. 2 series of 2014 DPWH- DENR-DSWD Partnership on the Tree Replacement Project
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Category Title/Outline Environmental PD 1586 (1978) Establishing an environmental impact Assessment statement system including other environmental management related measures and for other purposes Presidential Proclamation Proclaiming certain areas and types of 2146 projects as environmentally critical and within the scope of the environmental impact statement system established under PD 1586
Source: Environmental Management Bureau (EMB: https://emb.gov.ph/laws-and-policies-environmental-impact-assessment/)
26. The Government of the Philippines (GoP) has ratified international treaties, agreements, and protocols in relation to environmental social considerations which are listed in Table 3.
Table 3. Philippine Environmental Agreements to the International Treaty Title Year Washington Treaty Convention on the international trade in endangered species of wild flora and fauna (1981) Convention on biological diversity (1993) Framework convention on climate change (1994) Source: PPTA (TA-8574 PHI: Improving National Roads for Inclusive Growth in Mindanao Project (41076-045)
B. EIA System in the Philippines
27. In the Philippines, all private or public projects or activities which are envisaged to potentially have a negative impact on the environment are subject to an Environmental Impact Assessment (EIA) by the Philippine Environmental Impact Statement System (PEISS). EIA is the preliminary analysis of the potential impacts of the project on the environment. Aware of the possible negative effects of the implementation of industrial and other activities, the GoP has instituted measures to encourage the use of EIA as a planning and decision-making tool.
28. PEISS is a set of laws, regulations, administrative orders and guidelines concerned with the EIA. Table 4 shows some of the important laws and guidelines.
Table 4. Laws and Regulations regarding EIA in the Philippines
Title Outline Philippine Environmental An act establishing and centralizing the Environmental Impact Statement Impact Statement System (EIS) System under the National Environmental Protection Council (EISS), Presidential (NEPC), which merged with the National Pollution Control Commission Decree (NPCC) in June 1987 to become the Environmental Management Bureau No. 1586 (1978) (EMB). Presidential It proclaims Environmentally Critical Projects (ECPs) to have significant Proclamation No. 2146 impact on (1981) and No. the quality of environment and Environmentally Critical Areas (ECAs) as 803 (1996) environmentally fragile areas within the scope of the EIS System.
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DAO 96-37 (revised Devolved responsibility for EIS to the EMB-Regional Office and further to become DAO 92- strengthened the Philippine EIS System (PEISS). Placed emphasis on 21) promoting maximum public participation in EIA process to validate the social acceptability of the Project. DENR Administrative Revised Procedural Manual (2007): Provides for implementation of rules Order No. 30 Series of and regulations of Presidential Decree No. 1586, establishing PEISS. 2003 (DAO 03-30) Also, provided detailed definitions of technical terms and detailed information regarding procedures, related laws and regulations EMB Memorandum Guidelines for Coverage Screening and Standardized Requirements Circular 2014-005 under the Philippine Environmental Impact Statement System (PEISS) amending relevant portions of MC 2007-002 DAO 2017-15 Guidelines on Public Participation under the PEISS Source: PPTA (TA-8574 PHI: Improving National Roads for Inclusive Growth in Mindanao Project (41076-045)
29. The procedures of EIA process are shown in Figure 1. The process stages are categorized as: i) pre-study stage (screening and scoping); ii) EIA study stage; and iii) post- study stage (review, decision-making and monitoring).
16 INITIAL ENVIRONMENTAL EXAMINATION Tawi-Tawi Bridge No. 1: Nalil-Sikkiat Detailed Engineering Design for Road Improvement and Institutional Development (RIIDP) and Future Financing
Source: Revised Procedural Manual for DENR Administrative Order No. 30 Series of 2003 (DAO 03-30)
Figure 1. Flow of EIA Process
30. According to PD 1586 (1978), the EIA process covers projects which are considered environmentally critical projects (ECPs) or projects in environmentally critical areas (ECAs) presumed to have significant impacts on the environment.
31. A road project with more than 20 km-long new road construction in total is classified as Category A which requires preparation of an environmental impact statement (EIS) in order to obtain an environmental compliance certificates (ECC) from the Environmental Management Bureau (EMB) of the Department of Environment and Natural Resources (DENR). The criteria of ECPs related to the project are shown in Table 5.
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Table 5. EIS and IEE Requirements for Road and Bridge Projects Not Covered (may Covered (Required to secure ECC) secure CNC) Project Description IEE Checklist Category A: ECP Category B: Non- Category D: PD (Part EIS ECP EIS I only) 3.4.1 Roads, new NATIONAL ROAD: PROVINCIAL ALL TYPES OF construction >= 20 km ROAD and OTHER ROADS: > 2 km but (length with no TYPES OF ROADS: < 20 km, (length with critical slope) OR >= >= 20 km no critical slope) OR <=2 km 10 km (length with (length with no > 2 km but < 10 km critical slope) critical slope) OR >= (length with critical 10 km (length with slope) critical slope) 3.4.2 Roads, > 50 % increase in widening, > 50 % increase in capacity (or in terms rehabilitation capacity (or in terms of length/width) > 50 % increase in and/or of length/width) AND > 2 km but < capacity (or in terms improvement AND >= 20.0 km, 20.0 km, (length None of length/width) but (length with no with no critical <= 2 km increase in critical slope) OR >= slope) OR > 2 km length 10.0 km (length with but < 10.0 km critical slope) (length with critical slope) <= 50 m 3.4.3 Bridges and Regardless of viaducts (including >= 5 km but < 10.0 >= 10.0 km > 50 m but < 5.0 km length for elevated roads), km footbridges or for new construction pedestrian only 3.4.4 Bridges and > 50 % increase in > 50 % increase in viaducts (including > 50 % increase in capacity (or in terms capacity (or in terms of elevated roads), capacity (or in terms None of length/width) but length/width) but rehabilitation and/or of length/width) OR < total length of 10.0 < 2 km increase in improvement >= 10.0 km km length 3.4.5 Roads- Regardless of flyover/ cloverleaf/ None None None length and width interchanges 3.4.6 Pedestrian All underpass All overpass passages None None projects projects 3.4.7 Tunnels and sub-grade roads >= 1.0 km < 1.0 km None None and railways Source: PPTA, based on the “Revised Guidelines for Coverage Screening and Standardized Requirements, EMB Memorandum Circular No. 2014-005 dated July 2014.
C. ADB’s Safeguard Policy Statement Requirement
32. The ADB’s process of determining a road project’s environment category is through accomplishment of a rapid environmental assessment (REA) checklist taking into account the type, size, and location of the proposed project. Based on SPS 200910, a project could be classified under one of the four environmental categories (A, B, C or FI) as shown in Table 6. Tawi-Tawi Bridge No. 1 - Nalil-Sikkiat is considered Category B.
10 The Safeguard Policy Statement (SPS) builds upon the three previous safeguard policies on the environment, involuntary resettlement and indigenous peoples, and brings them into one single policy that enhances consistency and coherence, and more comprehensively addresses environmental and social impacts and risks. The SPS aims to promote sustainability of project outcomes by protecting the environment and people from projects' potential adverse impacts by avoiding adverse impacts of projects on the environment and affected people, where possible; minimizing, mitigating, and/or compensating for adverse project impacts on the environment and affected people when avoidance is not possible; and helping borrowers/clients to strengthen their safeguard systems and develop the capacity to manage environmental and social risks. (https://www.adb.org/documents/safeguard-policy-statement)
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Table 6. Category Classifications on the Environment based on SPS 2009 Category Application Projects with potential for significant adverse environmental impacts that is A irreversible, diverse or unprecedented. These impacts may affect an area larger than the sites or facilities subject to physical works. An environmental impact assessment (EIA) is required Projects judged to have some adverse environmental impacts, but of lesser degree B and/or significance than those for category A projects. Impacts are site-specific, few if any of them are irreversible, and in most cases mitigation measures can be designed more readily than for Category A projects. An initial environmental examination (IEE) is required. Projects likely to have minimal or no adverse environmental impacts. No C environmental assessment is required although environmental implications are still reviewed. Projects are classified as category FI if they involve investment of funds to or through a financial F1 intermediary. Where the FI’s investment have minimal or no adverse environmental risks. The FI project will be treated as category C. All other FI’s must establish and maintain an environmental and social management standard must comply with the environmental safeguard requirements specified in SPS 2009 if the FI’s subprojects have the potential for significant adverse environmental impacts. Source: ADB Safeguard Policy Statement (June 2009)
33. This IEE was prepared in accordance with the requirements of ADB SPS.
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II. DESCRIPTION OF THE PROJECT
A. Overview
34. The Government of the Republic of the Philippines requested the Asian Development Bank (ADB) to provide Technical Assistance (TA) to prepare the Improving Growth Corridors in Mindanao Road Sector Project. This project supports the Government of the Philippines’ priorities for improvement of the country’s road network and development of Mindanao, including the government’s agenda for Mindanao in the Philippines Development Plan (PDP) 2011-2016. This project extends ADB’s long standing assistance in Mindanao with a recent focus on the road sector including institutional development and now improving national roads for inclusive growth.
35. Mindanao is the second largest island in the Philippines, with a population of nearly 25 million people. Despite being rich in natural resources, Mindanao has the highest poverty incidence of the Philippines’ three island groups (Luzon, Visayas, and Mindanao), with a rate of 39%,11 due in large part to civil conflict and low economic growth. Although significant development has occurred in recent years, a number of infrastructure targets in the government’s Mindanao 2000 plan have not been achieved, due to the lack of coherent plans, inadequate government financial resources, and underinvestment, especially by the private sector.12
36. The road network in Mindanao is less developed than the national network. While 82% and 89% of the national roads in Luzon and the Visayas are paved, only 70% of the national roads in Mindanao are paved.10 This is compounded by a wider set of issues such as constrained growth of regional economic corridors through Mindanao and reduced support to regional cooperation and integration, as well as the lack of the necessary physical, institutional and governance capacity to support the full delivery of a quality national road network.
37. The impact of the project will be improved mobility, connecting accessibility and safety, and reduced poverty in the project area. The outcome will be reduced transport cost and improved accessibility. Transport on and investment in the national road network will become more efficient. The increased efficiency will be measured by reductions in travel time, vehicle operating costs, and road accident rates; improvements in the road surface condition; and improvements in governance in the transport sector and in DPWH's assessment, communications and administration capabilities. The Project's impact will be an accessible, affordable and safe road network in the project area.
38. Three (3) bridges13 have been proposed in Tawi-Tawi Province. These are aimed at decongesting Bongao Island (the capital of Tawi-Tawi) by bringing the development in the mainland through improved connectivity between the islands/municipalities of the province. The three (3) proposed bridges aim to provide a direct route between the existing major growth center (Bongao) and future growth center in Panglina Sugala and Papahag Island. Papahag Island is proposed for development for large scale seaweeds processing plant which is the top raw material produced in Tawi-Tawi, and housing site project for the local population according to the local government of Tawi-Tawi.
39. In addition, the first ecozone for Tawi-Tawi was approved in May 2017 according to the Philippine Economic Zone Authority (PEZA) will be located in Kulape in the town of
11 ADB. 2010. Making a Difference in Mindanao. Manila. 12 MinDA. 2011. Mindanao 2020 Peace and Development Framework Plan 2011-2030. 13 The other two (2) bridges are the following: Tongsinah-Paniogan Bridge (Tawi-Tawi Bridge No. 2); and Malassa-Lupang Pula Bridge (Tawi-Tawi-Bridge No. 3).
20 INITIAL ENVIRONMENTAL EXAMINATION Tawi-Tawi Bridge No. 1: Nalil-Sikkiat Detailed Engineering Design for Road Improvement and Institutional Development (RIIDP) and Future Financing
Panglima Sugala. The first approved private economic zone in the island of Tawi-Tawi will consist of 218.9 hectares. There is also a proposed port development, the Malassa International Port, to address the economic potential of the island province because it is in the path of international shipping containers. Similarly, the construction of the bridges will open up potentials in the tourism and fishing industry. The strengthening of local and regional market connectivity therefore in this corridor can encourage more investors to come in and do business in the country. The development of these industries could spur the economic activities that would boost the mediocre economy of the province and further enhance the quality of life of its people.
40. This initial environmental examination (IEE) was prepared in accordance with SPS 2009 for the proposed Tawi-Tawi Bridge No. 1 - Nalil-Sikkiat Bridge in the Province of Tawi- Tawi.
B. Location
41. The proposed Tawi-Tawi Bridge No. 1 is located in the Province of Tawi-Tawi as shown in Figure 2. This bridge has a combined gross length of 540.80 lineal meters consisting of a bridge length of 380.80 lineal meters and approach roads with a combined length of 160 meters. The Tawi-Tawi Bridge No. 1 - Nalil-Sikkiat Bridge has a span of 380.80 m over the Bongao Channel from its first approach in Sikkiat (Sanga-Sanga Island) at Km 0+031.00 to the second approach through the proposed main bridge ending at Nalil (Bongao) at Km 0+509.80 with a gross length of 540.80m. The existing two-lane road that connects to the proposed bridge is classified as a National Secondary Road that is not entirely paved with narrow width for the most part but in generally good condition. According to the DPWH, this existing road connecting to the proposed bridge will be improved at the same time as the proposed bridge. This new bridge construction will be a Pre-stressed Concrete Deck Girder (PCDG) structure, AASHTO Type IV-B and Type VI Modified) with twelve spans. The bridge approach roads are 160-m in length and are included to be constructed in this contract package. The selection of the location of the bridge was based on technical considerations, most economical location on account of the short distance to cross the Bongao Channel with the least involuntary resettlement and marine ecological impacts.
42. There are four major existing bridges in the Municipality of Bongao. These are the concrete bridge connecting Bongao Island and Sanga-Sanga Island; the steel bridge at Suwangkagang, Pasiagan, and the two bridges in Barangay Lapid-Lapid. The proposed Bridge No. 1 will connect Barangay Nalil in Bongao Island to Barangay Pakias in Sanga-Sanga Island over the Bongao Channel through the existing roads of mixed condition (generally concrete paved for the most part in the Barangay Pakias site and unpaved road in the Barangay Nalil side). It is a major bridge that will be constructed serving as an alternate shortest access directly connecting the economic activities of Bongao Island to Sanga-Sanga Island. This proposed bridge is necessary to be sited in the location instead of alongside the existing concrete bridge for the following reasons: a) It is well protected from strong winds from the open sea; b) In the existing bridge, the navigation height (of about 5 meters) and width (25 meters) is limited only to pass small vessels (boats/ships); b) the actual channel width of the existing bridge is between 250 to 260 meters but the bridge length is only 60 meters that caused the accumulation of drift sand at the mouth of the Bongao Channel making the sea depth shallower; and c) locating alongside the existing concrete bridge will be limited by the navigation height requirements of the Bongao airport (bridge elevation cannot be raised as much as in the proposed new bridge location). In addition, traffic congestion is anticipated along the only existing main road that currently connects the two islands during the construction period thereby disrupting the economic activities of the two islands (albeit on a short-term basis only).
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Source: Detailed Engineering Design (TA-8574 PHI: Improving National Roads for Inclusive Growth in Mindanao Project (41076- 045) Figure 2. Location of the Proposed Three (3) Bridges in the Province of Tawi-Tawi
Source: Detailed Engineering Design (TA-8574 PHI: Improving National Roads for Inclusive Growth in Mindanao Project (41076-
Figure 3. Location of the Proposed Nalil-Sikkiat Bridge in the Province of Tawi-Tawi
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045)
C. Proposed Bridge Construction Works
43. The bridgeworks to be undertaken are as summarized below.
Table 7. Subproject Scope and Coverage Total Road Project Province Municipality Length Project Scope (Barangay) (km) a) Construction of approach road with a total length of 160m;
b) Construction of the bridge
Tawi-Tawi structure itself that is 380.80
Bridge No. 1 - Sikkiat (Sanga-Sanga), and lineal meters; Tawi-Tawi Nalil-Sikkiat Nalil, Municipality of c) Installation of guard rails,
Bridge Bongao) warning signs, regulatory signs, 540.80 informatory signs, pavement m markings, slope protection work (rubble concrete). Source: Detailed Engineering Design, 2019.
D. Basic Design of the Project Bridge
a. Selection of Design Elements
44. One of the chief best practices set of design standards practiced worldwide is the “Policy on Geometric Design of Highways and Streets, 2001, AASHTO”. This set of standards is also recommended to adopt as design standards for Philippine national highways by “Highway Safety Design Standards Manual – Part 1: Road Safety Design Manual, 2012, DPWH”.
45. Design speed is used to determine individual design elements, such as stopping sight distance and horizontal curvature. The combination of a design traffic volume and a topography condition, namely flat topography, rolling topography, and mountainous topography, leads to determination of design speeds of roads. A design speed determines corresponding horizontal minimum radius, vertical maximum gradient, super elevation, and sight distances. Topographic conditions will be decided for each section of the project roads.
46. Other elements are less related to design speed, such as pavement and shoulder width and clearances to walls and traffic barriers. Typically, an arterial road warrants a higher design speed than a local road. A road located in flat terrain warrants a higher design speed than one in mountainous terrain.
47. The design elements for the Tawi-Tawi Bridge No. 1 and approach roads are summarized below:
1. Hydraulic Conditions – 3.270m MHHW and 3.780m (HWL) 2. Vertical Clearance (VC) – 13.790 m 3. Vessel Hight (HV) - 9.000m 4. High Water Level (HWL) – 3.790 m 5. Freeboard K(m) – 1.000
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6. Bridge Type – PCDG (AASHTO Type IV-B and Type VI Modified) Twelve Spans 7. Design average daily traffic: 1000-2000 8. Topographic condition: Level to gently sloping 9. Design speed: 60 km/hr 10. Classification of road for design: national secondary Minimum radius: 130 m Maximum grade 6% 11. 5. Lanes: 2 x 3.35 m/6.7 m 12. Shoulders: 1.5 m (each side) 13. Right-of-way: 20 m
b. Climate Change Adaptation
48. It is most effective to design and construct a climate resilient bridge and approach roads than retrofitting at a later stage when problems appear. Using climate projections based from the results of the PRECIS model run in 2010 by PAGASA14 to evaluate future requirements instead of basing on historic climate patterns is significantly more cost effective. The following adaptation measures have been included in the project design, as appropriate, to make all project bridges and roads of the DPWH more resilient to climate change impacts:
• Bridges: review design storm return periods, raise bridge if freeboard in inadequate, reinforce bridge piers and abutments at risk from scouring, provide retention dams upstream to reduce flood flows • Road pavement: improvement of road surface and subsurface drainage systems and raise pavement levels • Road drainage: increase size of side drains, consider alternative drain section, increase water retention capacity of drains, use of water capture and storage retention ponds • Culverts and cross drainage pipes: increase capacity of hydraulic structures, increase the number of cross drains, use apron rather than catch pit at pipe entrance to avoid clogging by debris, downstream protection of outlets to reduce scouring
49. A 10% increase15 in the design of road structures had been adopted to meet the requirements specified in the Design Guidelines, Criteria and Standards. Other adaptation measures to be implemented for the project are described below: • Regularly clear out debris from cross drainage pipes, culverts, and riverbeds under bridges. Although this was stated for bridges over rivers, this applies as well to bridges under sea channels and are very effective if regularly undertaken during periods of heavy rain. This will become part of the regular bridge maintenance budget of the district DPWH. • Establish mangrove and sea grasses and encourage seaweed farming along coastlines to reduce storm surge impacts. This will require collaboration with DENR under their Mangrove and Beach Forest Development and Management Program. Vegetative materials sourced from approved nurseries. These are effective when fully established in reducing coastal wave action and storm surge impacts.
14 Source: PPTA, February 2016 from PAGASA, February 2011: Climate Change in the Philippines. Downscaling to a grid resolution of 25km x 25km allowed detailed Regional profiles to be prepared for each region. Climate data over the period 1971- 2000 was used as the baseline data and formed the control run to establish the model’s bias. Climate change projections Zamboanga Sibugay: 1) baseline for seasonal temperature increase in degrees C is DJF – 27.1, MAM – 27.9, JJASON – 27.5; seasonal rainfall change in % is DJF – 284.1, MAM – 290.5, JJA – 597.2, SON – 674.1; 2) Change 2020 (2006-2035) for seasonal temperature increase in degrees C is December to November - 1; seasonal rainfall change in % is DJF – 9.9, MAM – 6.6, JJA – 6.5, SON – 14.8; 3) Change 2050 (.2036-2065) for seasonal temperature increase in degrees C is DJFMAM – 2, JJA – 1.9; and SON – 2.0; seasonal rainfall change in % is DJF – 4.8, MAM – 10.3, JJA – 22.0, SON – 8.9. 15 Information provided by Detailed Engineering Design Consultants, Detailed Engineering Design and Tendering of Asset Preservation (AP) and Road Improvement (RI) Projects of the Road Improvement and Institutional Development Project (RIIDP) and Future Financing, 2018.
24 INITIAL ENVIRONMENTAL EXAMINATION Tawi-Tawi Bridge No. 1: Nalil-Sikkiat Detailed Engineering Design for Road Improvement and Institutional Development (RIIDP) and Future Financing
• Raise embankments where road passes close to the shoreline. Consider 82 cm sea level rise coupled with a projected maximum storm surge height and 30cm freeboard. There may be portions of the bridge approach roads that would be subject to this. This would require provision of suitable subbase materials, machinery and labor and are effective to ensure coastal road unaffected by storm surges.
E. Road Safety
50. During the PPTA, results of the review carried out on selected project bridges and road safety measures in Western Mindanao were incorporated accordingly into the bridge design including their approach roads. The review was aimed to identify potential road safety hazards and to incorporate measures in the detailed design to improve safety aspects of the project. The same measures were applied in the design considerations for this bridge project. The road safety audit followed the key criteria of the ADB Road Safety Audit for Road Projects (2003).
51. The PPTA Road Safety team discussed these findings to determine the potential safety risks and found that most of defects are observed across Western Mindanao. A series of suggested measures were identified for consideration to help avoid or mitigate safety issues. Problems related to geometric design will be solved by following DPWH design standards. Measures considered in the detailed design are shown in Table 8.
Table 8. Summary Road Safety Problems and Measures No. Problem Design Measure 1 Road signs and Setting up warning and guide signs, arrow marks and providing pavement markings delineation lines clearly along every road. 2 No light signal Providing traffic signals at key intersections 3 Poor pavement Improvement of the quality of pavement and provide delineation or without delineation pavement markings. 4 Stalls and residential Removal of stalls to help reduce obstructions and encroachment houses beside the road 5 Small vertical crest Improving vertical curves to suit safe design criteria/requirement with poor sight distance 6 Sharp curve and Installation of chevron signs where required and speed limit signs. insufficient chevron Improvement of the vertical alignment to provide sight distance signs requirement 7 Dangerous side Setting up guardrails between the road and ditches ditches close to road 8 Parking along the Prohibiting of the use of carriageway as parking to ensure safe, carriageway efficient and smooth vehicular flow 9 No warning sign in Installation of advance warning signs on construction sites so the construction sites drivers can get advance information beforehand 10 Slope-slide prone Planting of grass and installing the necessary slope protection zone facilities. Conduct of geotechnical investigation to determine the most appropriate slope protection structures 11 No guard rails at high Installation of guard rails on all locations with embankment height embankments and exceeding 2.0m steep side slope 12 Block-type guard- Changing to guard rails, which function to guide a deviating walls stones vehicle back to the lane. 13 Y-type intersection Changing a crossing angle of 2 roads at merging section to more than 70 degrees. Improve intersection layout; provide proper “channelization”
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No. Problem Design Measure 14 Shortage of sight Moving hazards: trees, fences, poles etc. Improve the horizontal distance and vertical alignment. Source: PPTA. NB: In the PPTA workshop held on 29 April 2015, participants of a road safety discussion group suggested to add a few more recommendations in addition to the above: first, road safety education for students and local residents, and second, widening of shoulder of 1.5m (minimum) for emergency, provision of turn-outs/lay- bys
F. CONSTRUCTION METHODOLOGY
III. DESCRIPTION OF THE ENVIRONMENT
A. Land Environment
16 a. Topography and Slope
52. The Tawi-Tawi Bridge No. 1, Nalil-Sikkiat Bridge is a proposed new bridge over the Bongao Channel connecting Sanga-Sanga Island to Bongao Island where the main seat of government of the province is also located. It is located in the Municipality of Bongao that is generally flat with low-lying hills, white sandy shorelines, reefs and deep harbors. Bud Bongao is the municipality’s highest mountain range at an altitude of 340 meters above sea level. Bongao Island is enclosed by Tawi-Tawi Bay, Bongao Channel, Sanga-Sanga Channel, Pandan Bay, Manalik Channel and is traversed by the Simanale Bay that cuts Sanga-Sanga Island from Tawi-Tawi mainland.
Source: Comprehensive Land Use Plan of the Municipality of Bongao, Tawi-Tawi.
Figure 4. Topographic Map of Bongao, Tawi-Tawi
16 Excerpted description from the Environmental Impact Assessment (EIA), TA-8574 PHI: Improving National Roads for Inclusive Growth in Mindanao Project (41076-045), February 2016.
26 INITIAL ENVIRONMENTAL EXAMINATION Tawi-Tawi Bridge No. 1: Nalil-Sikkiat Detailed Engineering Design for Road Improvement and Institutional Development (RIIDP) and Future Financing
Legend: - Municipaliy of Bongao, Tawi-Tawi
Source: GoogleMap, Municipality of Bongao. Figure 5. Municipal Boundary of Bongao
b. Land Classification
53. The Municipality of Bongao has a total land area of 16,595 hectares.16 Almost half of these or 7,250 hectares is alienable and disposable land. 3,562 hectares or 22% of the total land area is considered as agricultural with another 1,698 as land potential for agriculture. Forest land comprises 20% with 2,500 as unclassified forest land and 740 hectares as established forest land reserve. Out of this, 33.7% or 1,091.55 hectares is noted to be mangrove forests or areas. Bongao still has 855 hectares of unclassified land. Possibly, these are due to either accretion or changes in sea levels that led new lands to appear. These will be properly classified once the cadastral survey is finished and the municipal boundaries are finalized
Table 9. Land Classification of Bongao, Tawi-Tawi
Classification Land Area (in has) Alienable and Disposable Land 7,250 Unclassified Forest Land 2,500 Established Forest Land Reserve 740 Agricultural Land 3,652 Potential Agricultural Area 1,598 Other unclassified land 855
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TOTAL 16,595 Source: Comprehensive Land Use Plan, Bongao, Tawi-Tawi (2017-2026).
c. Existing General Land Use
54. Of the total land area, only 24% is utilized. Agricultural area accounts for the largest share with 3,652 hectares. Residential area follows with 253 hectares. This does not include around 76.28 hectares of the sea occupied by the Sama Dilaut (or Badjaos), an indigenous group of people known for being sea settlers. Commercial areas rank third with 43 hectares. These are mostly located in Bongao Island. Areas devoted for government institutions and military reservations also account for 34 hectares and 26 hectares, respectively. Cemeteries and dumpsite have the least share with 2.5 hectares and 0.5 hectares each.
Table 10. Existing Land Use
Existing Land Use Area(in hectares) Residential Area 253.0 Commercial Area 43.0 Agricultural Area 3,652.0 Institutional Area 34.0 Military Reservation Area 26.0 Cemeteries 2.5 Dumpsite 0.5 Total 4011.0 Source: Comprehensive Land Use Plan, Bongao, Tawi-Tawi (2017-2026).
55. There are no industrial lands in Bongao as seaweeds culture and fish drying are the only main industries. Fish drying is generally household-based industry. Those involved in this industry would just utilize open spaces in the neighborhood particularly in the beaches or in their yards. The products are then delivered to a consolidator who has a stall in the municipal market or has access to the markets in Zamboanga City, Cebu or Manila. The areas devoted to seaweeds culture is presented in the Water Use subsection below.
d. Geology
56. Rock Formation. The municipality has two (2) geological characteristics. Almost all of Bongao’s land territory is made up of Late Miocene to Pliocene Clastic Rocks. These are formed between 7.6 million to 2.6 million years ago. The upper portion of the municipal territory is made up of Recent Alluvium composed of beach deposits, sand, gravel and clay. Recent alluvium covers the northern to northwestern of Sumangat, Luuk Tulay, Mandulan, Lakit-lakit, Tubig-Basag and Sanga-Sanga.
28 INITIAL ENVIRONMENTAL EXAMINATION Tawi-Tawi Bridge No. 1: Nalil-Sikkiat Detailed Engineering Design for Road Improvement and Institutional Development (RIIDP) and Future Financing
Source: Comprehensive Land Use Plan, Municipality of Bongao, Tawi-Tawi
Figure 6. Geologic Map of Bongao, Tawi-tawi e. Soils
57. The Municipality of Bongao has clay and loam soils that are the dominant soil types in the Municipality of Bongao. However, its coastal areas have sandy soil type. Table 1 below shows that the barangays with wide areas with clay and loam soils suitable for planting. Other barangays, especially those situated along the shorelines have sandy type of soil.
58. The roads, bridges and ports are also accounted in the land uses. There is a total 120.4 kilometers of roads in Bongao; a 2-kilometer airport; and, a 1.25 kilometer municipal government-operated sea port. The barangay with the biggest land area is Lapid-Lapid covering 1,411 hectares. This is followed by Tarawakan with 1,321; and, Mandulan with 1,304. Lapid-Lapid and Tarawakan are both located in the mainland Tawi-tawi while Mandulan is in the Sanga-Sanga Island. The smallest barangay in terms of land area is Tongsinah with 15 hectares followed by Tubig Mampallam and Lamion with 24 hectares and 26 hectares, respectively. Tongsinah is located in the Pababag Island while the other two are located in Bongao Island. Table 11. Land Area distribution by barangays in Bongao, Tawi-Tawi
Land Area Land Area Rank Barangay Rank Barangay (in hectares) (in hectares) 1 Lapid-Lapid 1,411 19 Pahut 220 2 Tarawakan 1,321 20 Ungus-Ungus 167
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3 Mandulan 1,304 21 Pababag 165 4 Luuk Pangdan 974 22 Sanga-Sanga 152 5 Silubbog 847 23 Tubig Boh 119 6 Pagatpat 797 24 Ipil 117 7 Kamagong 778 25 Paniongan 109 8 Luuk Tulay 667 26 Lato-Lato 99 9 Lakit-Lakit 529 27 Pagasinan 92 10 Karungdong 523 28 Simandagit 63 11 Sumangat 490 29 Lagasan 47 12 Masantong 469 30 Pag-asa 45 13 Malassa 372 31 Tubig Tanah 34 14 Muntay-Muntay 343 32 Poblacion 34 15 Tubig Basag 282 33 Lamion 26 16 Pasiagan 273 34 Tubig Mampallam 24 17 Nalil 256 35 Tongsinah 15 18 Pakias 248 Source: Comprehensive Land Use Plan, Bongao, Tawi-Tawi (2017-2026).
f. Climate and Meteorology
59. Bongao's climate is classified as tropical. Based on the Köppen-Geiger system, Bongao can be classified as “Af” or a “wet equatorial climate” characterized by “a consistently high temperatures (around 30 °C [86 °F]), with plentiful precipitation (150–1,000 cm [59–394 inches]), heavy cloud cover, and high humidity, with very little annual temperature variation”9.
60. Atmosphere Temperature. The average temperature in Bongao ranges from 22.6º to 31.3º centigrade with hottest months from April to October while the cold months are from November to March. However, these past few years, there are reports of increase in temperature reaching to as high as 40 º centigrade and is observed to be getting hotter day after day. This phenomenon is not unique to Bongao as other countries also report the same due to climate change.
Table 12. Monthly temperature and rainfall based on historical weather data
Janua Februa Marc Apr Ma Jun Jul Aug Septem Octob Novemb Decem ry ry h il y e y st ber er er ber 26. 27. 26. 26. Avg. Temperature (°C) 26.1 26.1 26.4 26.9 26.8 26.7 26.5 26.3 7 2 8 7 Min. 22. 22. 22. 22. 22. 22. Temperat 22.4 22.6 22.4 22.5 22.6 22.6 6 6 6 6 9 6 ure (°C) Max. 29. 29. 30. 30. 31. 31. Temperat 31.1 31.3 31.3 31 30.5 30 6 6 2 9 5 1 ure (°C) Source: https://en.climate-data.org/location/21228/#climate-graph
61. Relative Humidity. The humidity rate prevailing in the municipality is 75% during clear sky and 85% during cloudy sky vary by 1.1 °C.
30 INITIAL ENVIRONMENTAL EXAMINATION Tawi-Tawi Bridge No. 1: Nalil-Sikkiat Detailed Engineering Design for Road Improvement and Institutional Development (RIIDP) and Future Financing
Source: https://en.climate-data.org/location/21228/#climate-graph
Figure 7. Precipitation / Rainfall by month in Bongao
62. Cloudiness. The Municipality of Bongao, being part of a small island province in the southernmost part of the country, has no major industries that produce air pollution. Hence, most of the times especially during good weather, the area has clear horizons.
63. Rainfall. Rainfall in Bongao is evenly distributed throughout the year at an average of 18.04 mm. Between the driest and wettest months, the difference in precipitation is 78 mm.
64. Wind Direction. Prevailing winds is in easterly direction with a speed of 2 knots.
B. Fresh Water Resources
65. Surface Run-off. Bongao, being made up of small islands has minimal problems on significant floods. Surface run-off easily flows down to the sea during downpours. There are no rivers in Bongao except a small one in Barangay Tarawakan. There are also a few creeks but these dry out during the dry season. These creeks are overflows from the small lakes in Sanga-Sanga Island.
66. Groundwater Resources. The main water supply in the Municipality of Bongao comes from underground sources. Bongao Water District has developed several deep wells in Sanga- Sanga Island that supply 12 of the 35 barangays with piped water. Almost all barangays in the municipality have dug wells that serve as water source, though, most of them dry up during dry seasons.
C. Air Quality and Noise
67. There were no available secondary data for air quality and noise in the project area. During the detailed engineering design, primary data collection/field sampling was not undertaken due to inability to secure reasonable logistical quote from third party service providers. This baselining activity shall be pursued instead during the pre-construction stage as part of the CEMP preparation.
68. Both sides of the bridge approach roads are predominantly occupied by croplands mainly of coconuts, and the remaining areas are made up of sparsely distributed settlements and grassland/shrub/open lands. Further, the lack of industrial development suggests that air
31 INITIAL ENVIRONMENTAL EXAMINATION Tawi-Tawi Bridge No. 1: Nalil-Sikkiat Detailed Engineering Design for Road Improvement and Institutional Development (RIIDP) and Future Financing pollution and noise sources which would normally elevate background levels are not present in the area. As such, it is expected that the average ground level concentrations of sulfur dioxide (SO2), nitrogen dioxide (NO2), and particulate matter (PM10) will not exceed the values in the International Finance Corporation (IFC) guidelines (EHS Guidelines of April 2007) which are 20 µg/Ncm, 40 µg/Ncm, and 20 µg/Ncm, respectively. Baseline measurements to be collected by the Contractor for air and noise however is recommended prior to the start of the construction period. The results will be included in the Contractor’s Environmental Management Plan (CEMP).
69. To minimize dust generation and resuspension during the bridge construction period, speed limit of up to at least 20 kph in populated areas along the alignment shall be informed to all motorists and contractor vehicle and equipment operators through signages prior to approaching each way of the sensitive receptors. In addition, regular watering at least every 4 hours shall be undertaken by the Contractor during dry construction days in these areas.
D. Marine Ecology
a) Secondary Information17
70. Coastline. Bongao, being surrounded by waters, has a long coastline and seawaters rich in natural resources. The length of coastline for the three major islands and the barangays situated in Tawi-Tawi mainland is 116.76 kilometers. The coastlines facing the Sulu Sea are generally sandy beaches, while those facing the southern portion, particularly the bay areas and the channels that cut the islands, are mangrove areas.
71. Mangrove Forests. Mangroves play a significant role in coastal stabilization by trapping sediments thereby promoting land accretion and preventing erosion and excessive shifting of coastlines. Mangroves also provide habitat for marine species such as fish, crabs, shellfish, prawns and edible snakes and worms. The mangrove cover in the municipality is as shown in the table below.
Table 13. Mangrove Cover and Condition by Barangay Mangrove Species Barangay Cover Condition Dominant Specie Common Name Composition (in%) Bongao Island Lamion no habitat Nalil 34.00 fair 6 Rhizophora Apiculata Bakhaw Lalaki Pag-asa 15.00 poor 3 Rhizophora Apiculata Bakhaw Lalaki Pahut 37.00 fair 11 Rhizophora Apiculata Bakhaw Lalaki Pasiagan 47.00 fair 8 Rhizophora Apiculata Bakhaw Lalaki Poblacion negligible Simandagit 25.00 poor 1 Sonneratia Alba Pagatpat Tubig Mampallam no habitat
Tubig Tanah 25.00 poor 3 Rhizophora Stylosa Bakhaw Bakaun Pababag Island Lagasan 31.00 fair 8 Rhizophora Apiculata Bakhaw Lalaki Pababag 39.00 fair 12 Rhizophora Apiculata Bakhaw Lalaki Tongsinah 25.00 poor 7 Avicennia Officinalis Apiapi Sanga-Sanga Island Karunddong 42.00 fair 11 Rhizophora Apiculata Bakhaw Lalaki Lakit-Lakit 59.00 good 3 Brugeira Farviflora Langarai Lato-Lato 25.00 poor 9 Rhizophora Apiculata Bakhaw Lalaki Luuk Pangdan 30.00 fair 8 Rhizophora Apiculata Bakhaw Lalaki
17 Comprehensive Land Use Plan of Bongao, Tawi-Tawi, 2017-2026.
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Mangrove Species Barangay Cover Condition Dominant Specie Common Name Composition (in%) Malassa 29.00 fair 7 Rhizophora Apiculata Bakhaw Lalaki Mandulan 66.00 good 8 Rhizophora Apiculata Bakhaw Lalaki Pagasinan negligible Pakias 20.00 poor 5 Rhizophora Apiculata Bakhaw Lalaki Paniongan negligible Sanga-Sanga 23.00 poor 7 Sonneratia Caseolaris Pedada Tubig Basag 24.00 poor 1 Exoecaria Agallocha Buta-Buta Main Island of Tawi-Tawi Ipil 57.00 good 12 Rhizophora Apiculata Bakhaw Lalaki Lapid-Lapid 91.00 excellent 4 Rhizophora Apiculata Bakhaw Lalaki Luuk Tulay 69.00 good 9 Rhizophora Stylosa Bakhaw Babae Masantong 16.00 poor 6 Brugeira Gymporrhiza Busain Muntay-Muntay 75.00 good 9 Rhizophora Apiculata Bakhaw Lalaki Pagatpat 51.00 good 11 Rhizophora Apiculata Bakhaw Lalaki Silubbog 47.00 fair 10 Rhizophora Apiculata Bakhaw Lalaki Sumangat 74.00 good 8 Sonneratia Alba Pagatpat Tarawakan 23.00 poor 9 Rhizophora Apiculata Bakhaw Lalaki Ungus-Ungus 66.00 good 8 Rhizophora Apiculata Bakhaw Lalaki Source: Comprehensive Land Use Plan, Bongao, Tawi-Tawi (2017-2026).
72. Approximately 1,091.55 hectares in Bongao are mangrove areas and these are scattered in 28 coastal barangays. The only coastal barangays with no mangrove areas are: Lamion, Tubig Mampallam, Poblacion, Pagasinan and Paniongan. Overall, the average mangrove crown cover is 40% and generally classified as being in “fair” condition. Barangay Lapid-Lapid, though, showed having excellent crown cover with
73. Coral Ecosystem. Coral reefs are among the most biologically diverse and economically valuable ecosystems. They provide habitats, spawning and nursery grounds for economically important fish and other marine species; generate jobs and income to local economies dependent on fishing, marine recreation and tourism; protect coastlines from storms and erosion; a source of new medicines; and, are hotspots of marine biodiversity.
74. Bongao has a rich coral ecosystem. Based on a study conducted by the Fisheries Improved for Sustainable Harvest or FISH Project in 2006, the average coral cover in the municipality of Bongao is 46.3%, which is classified as being in “Fair condition”. Human activities like fishing, seaweed harvesting may affect the existing condition since then. There are 42 species of coral found in Bongao waters belonging to 32 genera, 14 families and 5 orders. There are no municipal-wide accessible current information to compare changes that had occurred over time. The information provided here relied on secondary information available in the Municipality’ Comprehensive Land Use Plan (CLUP).
75. Thirty-three (33) of the thirty-five (35) barangays of Bongao are coastal areas. Of the coastal barangays, seventeen (17) or more than half have good coral cover condition – that is, with more than 50% coral cover. The areas with the highest covers are Sanga-Sanga, Muntay-Muntay, Lagasan, and Silubbog. A presence of butterfly fishes was observed in some of these areas indicating relatively healthy coral reefs.
76. Fourteen (14) barangays are considered as having a fair coral condition while only two – Pag-asa and Tubig Mampallam – are in poor condition.
Table 14. Coral Cover and Condition by Barangay, Bongao, Tawi-Tawi
Barangay Coral Cover (in %) Condition Species composition Sanga-Sanga 69 Good 26
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Barangay Coral Cover (in %) Condition Species composition Muntay-Muntay 68 Good 18 Lagasan 66 Good 19 Silubbog 65 Good 26 Luuk Tulay 63 Good 18 Pagasinan 62 Good 11 Pagatpat 60 Good 19 Tubig Tanah 59 Good 15 Malassa 59 Good 12 Sumangat 59 Good 12 Lakit-Lakit 56 Good 18 Pababag 55 Good 19 Nalil 54 Good 10 Karungdong 54 Good 9 Tongsinah 51 Good 12 Lato-Lato 51 Good 17 Masantong 51 Good 19 Ipil 49 Fair 18 Pahut 48 Fair 15 Mandulan 47 Fair 19 Luuk Pangdan 47 Fair 12 Ungus-Ungus 47 Fair 25 Tubig Basag 42 Fair 14 Pasiagan 39 Fair 23 Simandagit 37 Fair 24 Paniongan 36 Fair 11 Tarawakan 36 Fair 23 Lapid-Lapid 33 Fair 14 Poblacion 31 Fair 13 Lamion 24 Fair 17 Pakias 10 Fair 11 Pag-asa 0 Poor Tubig Mampallam 0 Poor Source: Comprehensive Land Use Plan, Bongao, Tawi-Tawi (2017-2026).
77. Seagrass Communities. Sea grasses are flowering plants that have adapted to living in shallow marine waters, such as bays and lagoons. Like coral reefs, they also indicate the health of the marine ecosystem, and provide food, habitat, and nursery areas for marine organisms, stabilize the sea bottom, maintain water quality, and support local economy.
78. Of the 33 barangays in Bongao, only two have pristine sea grass communities and these are Silubbog and Sumangat with 84% and 77.2% sea grass cover, respectively. Dominant species in these areas are Thallasia Hemprichii. Ten barangays have altered sea grass communities and these are the coastal areas facing the Bongao and Sanga-Sanga Islands, and Tawi-Tawi mainland. In addition to Thallasia Hemprichii, the dominant species in these areas are Enhalus Acoroides and Cymodocea Rotondata.
79. Seventeen (17) of the thirty-three (33) coastal barangays have disturbed sea grass communities. Most of these are in the Sanga-sanga Island and Tawi-Tawi Mainland. The dominant sea grass specie is Thallasia Hemprichii. Three barangays are considered to have
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“Emergent” sea grasses. These are Poblacion and Tubig Mampallam both in Bongao Island; and, Luuk Pangdan in Sanga-Sanga Island. 91%, and eight more others, located mostly in the Tawi-tawi mainland, as having good crown cover. The rest are classified as either “Fair” or “Poor”.
Table 15. Seagrass Cover, Condition and Species Composition by Barangay Seagrass Species Barangay cover (in%) Description Composition Dominant Species Silubbog 84 Pristine 4 Thallasia Hemprichii Sumangat 77.2 Pristine 4 Thallasia Hemprichii Pag-asa 30.2 Altered 3 Enhalus Acoroides Nalil 10 Altered 3 Enhalus Acoroides Tubig Tanah 56 Altered 4 Thallasia Hemprichii Lamion 23.3 Altered 5 Enhalus Acoroides Pakias 27 Altered 2 Enhalus Acoroides Karungdong 22 Altered 3 Enhalus Acoroides Paniongan 23 Altered 4 Enhalus Acoroides Tarawakan 35 Altered 1 Thallasia Hemprichii Masantong 6 Altered 2 Cymodocea Rotondata Muntay-Muntay 34.2 Altered 3 Enhalus Acoroides Pahut 50 Disturbed 5 Thallasia Hemprichii Pasiagan 48.3 Disturbed 5 Thallasia Hemprichii Simandagit 60 Disturbed 5 Thallasia Hemprichii Tongsinah 38 Disturbed 4 Enhalus Acoroides Lagasan 34 Disturbed 6 Thallasia Hemprichii Pababag 59 Disturbed 4 Thallasia Hemprichii Malassa 33.5 Disturbed 5 Enhalus Acoroides Mandulan 85 Disturbed 6 Thallasia Hemprichii Lakit-Lakit 53.5 Disturbed 4 Thallasia Hemprichii Tubig Basag 53.7 Disturbed 3 Syringodium Isoetifolium Sanga-Sanga 54 Disturbed 4 Cymodocea Rotondata Pagasinan 50 Disturbed 6 Thallasia Hemprichii Lato-Lato 40.2 Disturbed 5 Thallasia Hemprichii Luuk Tulay 70.3 Disturbed 5 Thallasia Hemprichii Pagatpat 32 Disturbed 5 Thallasia Hemprichii Ungus-Ungus 43.5 Disturbed 6 Cymodocea Rotondata Ipil 39 Disturbed 6 Enhalus Acoroides Tubig Mampallam Emergent Poblacion Emergent Luuk Pangdan 15.6 Emergent 1 Enhalus Acoroides Source: Source: Comprehensive Land Use Plan, Bongao, Tawi-Tawi (2017-2026) from the Analysis of satellite image from Google Earth and validated with data from http://www.globalforestwatch.org/
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b) Baseline Survey for Marine Ecological Assessment
80. A baseline survey was conducted for the proposed bridge site by a Team of twelve (12) researchers on November 10 to 11, 2020 notwithstanding the constraints posed by the COVID-19 pandemic. The following were surveyed: 1) coral reefs; 2) coral reef fishes; 3) seagrass/seaweeds; 4) mangroves; 5) phytoplankton; 6) benthos; 7) water quality; and 8) water current and circulation. Three (3) sampling stations for coral reefs and reef fishes; six (6) sampling stations for seagrass/seaweeds; and twelve sampling stations (12) for mangroves community structure are shown in Figure _ below. The sampling stations for water quality, plankton and benthos is the same with sampling station for coral reefs. Details of the marine ecological assessment can be found in Appendix 1 of this report.
Figure 8. Map showing the different sampling stations in the proposed Nalil-Sikkiat bridge
81. The full report of the baseline survey is presented in more detail in Appendix 1.
c) Coral Reefs
82. Survey results indicated that the average living hard coral cover is 37% as shown in Table _ and Figure _). The 37% hard coral cover is considered in good condition using the
36 INITIAL ENVIRONMENTAL EXAMINATION Tawi-Tawi Bridge No. 1: Nalil-Sikkiat Detailed Engineering Design for Road Improvement and Institutional Development (RIIDP) and Future Financing
Gomez, et.al., 1981 and Licuanan, et.al., 2017 scales and thresholds for evaluating status of reefs in the Philippines. A reef is in “poor” condition if it has a hard coral cover of 0-22%, “fair” if hard coral cover is >22-33%, “good” if hard coral cover is >33-44%, and “excellent” if hard coral is >44% (Licuanan et al., 2017). The major coral genera in the proposed bridge location are Acropora, Echinopora, Euphyllia, Favia, Favites, Fungia, Galaxea, Goniopora, Heliopora, Lobophyllia, Millepora, Porites, and Seriatopora. Most of the coral genera are weedy and stress tolerant except for Lobophyllia. The Lobophyllia genus, sometimes called Lobed Brain corals, are a very popular stony coral for aquarium due to its wide variety of colors and textures. It also includes one species, the Lobophyllia serratus, which is on the IUCN Red List of Endangered Species. The survey report indicates that small and scattered population of Lobophyllia was found in the vicinity of the proposed bridge (only 0.4% cover out of the 37.13% total cover of hard corals. The specific species however was not identified. It is recommended that further investigation should be done prior to construction in consultation with marine experts from the Mindanao State University-Tawi-Tawi College of Technology and Oceanography (MSU-TCTO) to determine if this species is among the Lobophyllia corals found during the survey. This will enable the project to implement appropriate mitigation measures with expert guidance. Protection of this species is the same with the other hard corals. Protection of corals during the bridge construction will be done by the following: (1) minimized sedimentation/siltation, and (2) preventing the discharge of wastewater into the channel and other chemicals during construction.
Table 16. Percentage cover of different benthic components in the proposed Nalil-Sikkiat Bridge Major Category Mean Cover Std. Dev. Std. Error Hard Coral 37.13 8.23 4.76 Algae assemblage 31.39 3.73 2.16 Abiotic 15.25 2.36 1.37 Macroalgae 0.37 0.32 0.19 Halimeda 2.98 2.05 1.18 Other biota 12.87 4.89 2.82
The good coral cover in the proposed Nalil-Sikkiat bridge indicates that the area is suitable for coral recruitment, growth and development. The good category of hard coral could be attributed to the frequent tidal flushing of the channel that connects the Sulu Sea and Sulawesi Sea or Celebes Sea. The water parameters are within the optimum level for coral growth and development. Sedimentation and siltation is observed in the area but the accumulation of sediment and silt on the bottom was minimized by frequent tidal flushing. The tidal flushing reduce sedimentation resulting to the light penetration and transporting sediment away from the coral area. It is therefore important that during the piling works, sediments from the pier and pile cap areas are minimized either by managing with a spill boom; piping slurries to a well-protected siltation pond at the landside before effluents are discharged back to the marine waters; or use borehole stabilization materials that are benign or least intrusive such as polymer instead of bentonite.
d) Reef Fish Community
83. The baseline survey identified thirty-seven (37) species belonging to eighteen (18) fish families with an average biomass of 6.98 mt/km² recorded in the proposed Nalil-Sikkiat bridge as shown in the table below. This cumulative species falls under the poor category (Hilomen et al. 2000). Two indicator fish species belonging to family Chaetodontidae and seven target fish families (Nemipteridae, Scaridae, Siganidae, Balistidae, Haemulidae, Serranidae and Lethrinidae were observed in the area.
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Table 17. Composition and biomass ((mt/km2) of fish species found in the proposed Nalil-Sikkiat Bridge Species Biomass (mt/km2) Amblyglyphidodon aureus 0.173481976 Amblyglyphidodon curacao 0.185700171 Balistoides viridescens 0.067873271 Cantherhines pardalis 0.025434554 Cantherhines pardalis 0.036475791 Canthigaster compressa 0.005248501 Canthigaster compressa 0.009728927 Canthigaster compressa 0.014209352 Canthigaster compressa 0.014209352 Canthigaster compressa 0.014209352 Canthigaster rollandi 0.028418705 Centropyge nox 0.079409185 Chaetodon lineolatus 0.115417577 Chaetodon melannotus 0.166880735 Cheilinus chlorourus 0.093106635 Cheilinus chlorourus 0.031059156 Cheilinus fasciatus 0.06649864 Cheilinus fasciatus 0.05246136 Cheilinus undulatus 0.039347759 Cheilodipterus macrodon 0.103915428 Cheilodipterus macrodon 0.155573233 Cheilodipterus quinquelineatus 0.025492132 Chlorurus sordidus 0.144390107 Chlorurus sordidus 0.107835823 Choerodon anchorago 0.146692026 Chromis viridis 0.120675728 Cirrhilabrus cyanopleura 0.079383198 Coris batuensis 0.01777472 Dascyllus aruanus 0.031468654 Dascyllus aruanus 0.049727618 Dascyllus melanurus 0.010517691 Dischistodus fasciatus 0.077015959 Dischistodus fasciatus 0.079053481 Dischistodus fasciatus 0.097165264 Dischistodus melanotus 0.218137229 Dischistodus melanotus 0.279642747 Dischistodus perspicillatus 0.077830968 Dischistodus perspicillatus 0.058745807 Dischistodus prosopotaenia 0.210237783 Dischistodus prosopotaenia 0.079053481 Dischistodus prosopotaenia 0.167595734 Epibulus brevis 0.023253207 Epibulus brevis 0.023253207 Epibulus brevis 0.029302122
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Species Biomass (mt/km2) Epinephelus merra 0.118282266 Gerres oyena 0.337314367 Gobiodon okinawae 0.001249911 Halichoeres margaritaceus 0.05806304 Halichoeres margaritaceus 0.08667136 Halichoeres melanurus 0.199558763 Hemigymnus melapterus 0.11899871 Hemigymnus melapterus 0.037809133 Meiacanthus grammistes 0.019064899 Myripristis adusta 0.083799385 Myripristis adusta 0.083799385 Nectamia similis 0.019597291 Neoglyphidodon bonang 0.020567581 Neoglyphidodon melas 0.064805989 Oxycheilinus celebicus 0.11997546 Oxycheilinus digrammus 0.07952112 Oxycheilinus digrammus 0.07952112 Parapercis cylindrica 0.051902561 Plectorhinchus chaetodonoides 0.226911744 Plectorhinchus chaetodonoides 0.41763175 Plectorhinchus chaetodonoides 0.066151477 Plectorhinchus vittatus 0.156377358 Plotosus lineatus 2.737977165 Pomacentrus brachialis 0.048217776 Pomacentrus moluccensis 0.095719157 Pomacentrus simsiang 0.072943095 Pseudomonacanthus macrurus 0.327375376 Scarus dimidiatus 0.029441802 Scarus psittacus 0.070004137 Scarus psittacus 0.088394909 Scolopsis bilineatus 0.122088819 Siganus vulpinus 0.3937066 Sphaeramia nematoptera 0.183927387 Synchiropus splendidus 0.036751929 Synchiropus splendidus 0.022765173 Thalassoma hardwicke 0.047567722 Thalassoma hardwicke 0.059587311 Thalassoma lunare 0.064931421
84. The species diversity of these thirty-seven (37) species within a 1000m2 area is under the poor category and fish abundance of 189 individual/1000m2 is under very poor category using the Hilomen et al. 2000 scales and threshold for evaluating status of reef fishes in the Philippines. The reef fish biomass of 6.98mt/km² falls under the very low category using the Nañola et al. 2006 scales and threshold in evaluating status of reef fish in the Philippines. The result indicates that the fish sizes were small and the area is overfished and disturbed marine environment.
39 INITIAL ENVIRONMENTAL EXAMINATION Tawi-Tawi Bridge No. 1: Nalil-Sikkiat Detailed Engineering Design for Road Improvement and Institutional Development (RIIDP) and Future Financing
Table 18. Categories of sites according to species richness as adapted from Hilomen et al. (2000) Category No. of individuals per 1000m2 Very Poor 0 -201 Poor 202 – 676 Moderate 667 – 2267 High 2268 – 7582 Very High > 7592 from Nañola et al. (2006).
Table 19. Categories of sites according to fish abundance as adapted from Hilomen et al. (2000) Category Biomass MT/km2 Very Poor < 5 Poor 6 – 10 Moderate 11 – 20 High 21 – 40 Very High > 41 from Nañola et al. (2006).
Table 20. Categories of sites according to fish biomass as adapted Category No. of species per 1000m2 Very Poor 0 – 26 Poor 27 – 47 Moderate 48 – 74 High 75 – 100 Very High > 100 from Nañola et al. (2006).
85.
e) Seagrass/Seaweeds
86. A total of six 6) sampling sites were established for this purpose – three (3) for the Sikkiat approach; and three (3) for the Pakias approach. Only two (2) species of seagrass (Enhalus acoroides and Halophila ovalis) was observed present in the proposed Nalil-Sikkiat bridge. The average percentage cover of seagrass in Sikkiat and Pakias was 2.18 and 2.43 %/ /m2, respectively. The percentage cover of E. acoroides in Sikkiat (0.48%/m2) is slightly higher than in Pakias side (.09%/m2) while H. ovalis recorded 0.06 %/m2 and 5% /m2 in Sikkiat and Pakias, respectively.
87. On the other hand, there were seven (7) species of seaweeds recorded in the proposed Nalil-Sikkiat bridge location. The seaweeds species are Halimeda sp.,Galaxaura sp., Padina sp., Neomeris sp., Gracilaria sp., Boergesenia sp.and Caulerpa sp. These species thrive in areas with low light intensity, silty and sandy substrates, and they tolerate fluctuations of physical and chemical parameters. Parameters that affect the recruitment and settlement of seaweeds are: water movement/wave action, water clarity, turbidity, and substrate characteristics. These species are naturally growing in the area but are not farmed for commercial purposes. There were no visible and observable seaweed farms within the vicinity of the bridge location at the time of the sampling activities.
88. The development of Enhalaus acoroides in the area is favorable in sandy-muddy and sandy-silted substrates and this species is not greatly affected by turbidity and low light
40 INITIAL ENVIRONMENTAL EXAMINATION Tawi-Tawi Bridge No. 1: Nalil-Sikkiat Detailed Engineering Design for Road Improvement and Institutional Development (RIIDP) and Future Financing intensity due to the long leaves that extended to the surface of the water. Enhalus acoroides is the biggest tropical seagrass and can tolerate low light and highly turbid conditions (Bach et al., 1998) such as the waters of Sikkiat-Pakias bridge. However, the recruitment and development of other seagrass species in the area is affected by sedimentation, siltation, pollution and deposition of physico-chemical substances.
89. The category of seagrass in the proposed Nalil-Sikkiat bridge is emergent wherein the area is characterized by very low species diversity and low cover, largely controlled by extreme fluctuations of physico-chemical conditions. Low species diversity of seagrass and seaweeds in the proposed bridge was affected primarily by the substrate characteristics, turbidity brought by sedimentation and siltation and influx of water from unidentified rivers that drain into the Bongao Channel. This observation conforms to the findings of Fortes (1994) that the lowest number of seagrass species occur at highly turbid water, silted sites where patchy monospecific stand of seagrass, a highly degraded habitat and areas highly protected from waves with muddy substrate. The distribution and species abundance of seagrass is directly affected by the levels of siltation (Agawin et al. 1997, Terrados et al. 1998; Vermaat et al. 1995, 1997) and the reduced underwater light availability can lead to seagrass mortality and reduce biomass (Duarte, 1991). The management of sedimentation and siltation will follow the same approach as discussed above for the mitigation of impacts on the coral reefs during construction.
f) Mangrove Community Structure
90. Six (6) sampling stations were established in the proposed Nalil-Sikkiat bridge to represent the mangrove community in the area as shown in the table below. Mangrove density is higher in Nalil side as compared with the Pakias side.
Table 21. Global Positioning System (GPS) coordinates of mangrove sampling stations in the proposed Nalil-Sikkiat Bridge
Station Coordinates Sikkiat Station 1 N5 02.101 E119 45.415 Station 2 N5 02.100 E119 45.423 Station 3 N5 02.084 E119 45.414 Station 4 N5 02.086 E119 45.421 Station 5 N5 02.077 E119 45.414 Station 6 N5 02.070 E119 45.416 Pakias Station 1 N5 02.213 E119 45.383 Station 2 N5 02.216 E119 45.393 Station 3 N5 02.213 E119 45.400 Station4 N5 02.214 E119 45.379 Station 5 N5 02.217 E119 45.374 Station 6 N5 02.219 E119 45.366
91. There were five (5) species of mangroves recorded in Sikkiat side and three (3) species found in Pakias side (Table 22). The mangrove species in Sikkiat are Rhizophora apiculata,
41 INITIAL ENVIRONMENTAL EXAMINATION Tawi-Tawi Bridge No. 1: Nalil-Sikkiat Detailed Engineering Design for Road Improvement and Institutional Development (RIIDP) and Future Financing
Rhizophora stylosa, Sonneratia alba, Ceriops tagal, and Bruguiera gymnorrhiza while the mangrove species found in the Pakias side are Rhizophora apiculata and Sonneratia. R. apiculata and had been recorded as the most abundant and dominant mangrove species in the proposed bridge location.
Table 22. Mangrove species in the proposed Nalil-Sikkiat Bridge Location Sikkiat Pakias Rhizophora apiculata R. apiculata Rhizophora stylosa S. alba Ceriops tagal Sonneratia alba Bruguiera gymnorrhiza Total = 5 Total = 2
92. Higher sapling and seedling counts were recorded in Pakias side as compare with the Sikkiat side. The total seedlings in the Pakias side is 27 while 13 seedlings were found in Sikkiat side. There are fifty-three (53) saplings recorded in Sikkiat side while three (3) saplings found in Pakkias side (Table 23). S. alba recorded the highest count of seedling (18) while R. apiculate recorded the highest count of sapling. Table 23. Seedlings and saplings recorded in the proposed Nalil-Sikkiat Bridge Sikkiat Pakias Species seedling sapling seedling sapling 5 27 9 R. apiculata 10 2 C. tagal R. stylosa 4 6 11 18 S. alba B. gymnorrhiza 2 1
93. In Sikkiat side, Rhizophora apiculata recorded the most dominant (516.67/ha) mangrove species in the area followed by Sonneratia alba (83.33/ha), C. tagal (50/ha), R. stylosa and B. gymnorrhiza (16.7), respectively. R. apiculata recorded 733.33 stand per hectare and 150.0 stand/hectare for S. alba found in the Pakias side. In Sikkiat side, Sonneratia alba was the tallest of all mangrove species with an average height of 5.9 meters, followed by B. bruguiera (4.2 m), R. apiculata (3.9 m), C. tagal (3 m), and R. stylosa (2.4m) (Figure 6). In Pakias side, S. alba was the tallest mangrove with an average height of 4.8 meters while R. apiculata was 2.6 meters.
94. Based on the survey, between 10 to 20 mangrove stands will be affected by the bridge construction. This will not significantly affect the population density of the mangroves in the project area and on the overall mangrove resources in the province. These affected stands will be replaced following government regulations. This replanting activity shall be coordinated by the Contractor with the equivalent BARMM DENR Office.
g) E.2.6. Plankton Community
(i)
95. There were 1,257cell density of phytoplankton recorded in the area while zooplankton recorded 84cell density as shown in Table 24. Sikkiat side recorded 603 cell density and 654 recorded in Pakias side. There are 22 genera of phytoplankton recorded in the area and the most dominant is Skeletonema followed by Coscinodiscus, Ceratium, Lauderia and
42 INITIAL ENVIRONMENTAL EXAMINATION Tawi-Tawi Bridge No. 1: Nalil-Sikkiat Detailed Engineering Design for Road Improvement and Institutional Development (RIIDP) and Future Financing
Thalassionema. Zooplankton is higher in Pakias side with 654 cell density while 603 cell density in Sikkiat side.
Table 24. Cell Density of plankton in the proposed Nalil-Sikkiat Bridge location Sampling Stations Genius Composition Sikkiat Pakias Cell Density Cell Density Asterolampra 17 22 Asteromphalus 3 10 Basteriastrum 27 23 Ceratium 60 49 Chaetoceros 30 25 Coscinodiscus 60 62 Cylindrotheca 18 14 Eucampia 20 10 Gambierdiscus 12 15 Goniodoma 14 18 Gonyaulax 13 28 Guinardia 15 42 Lauderia 40 37 Pleurosigma 30 51 Prorocentrum 19 25 Protoperidinium 20 33 Pyrophacus 5 8 Rhyzosolenia 34 30 Skeletonema 65 76 Thalasiosira 16 20 Thalassionema 55 27 Tintinnopsis 30 29 Total 603 654 Zooplankton 60 24
96. The phytoplankton and zooplankton abundance in the area is low due to the physical and chemical characteristics of the area. Based on the result of the marine ecological assessment study, the living organisms like fishes are in the poor category. The abiotic factors considered as the main causes of plankton population variation. This conforms to the findings of Ayad (2002) and Dejen et.al., (2004) that salinity, and turbidity, has been identified as critical factors in the development of zooplankton. The main deleterious effect of suspended sediment to the population of zooplankton appear to reduce intake of nutritious particles due to the proportionately higher ingestion of abiogenic seston (Tester and Turner, 1989) or phytoplankton food uptake limitation (Gasparini et al., 1999). The zooplankton is mainly dependent to phytoplankton for their food. The abundance of phytoplankton is not directly related to the population of zooplankton in the area. The effect of abiotic factors and the introduction of waste water and other anthropogenic activities might affect the population of zooplankton.
h) Benthos Community
97. Survey results revealed that there are three (3) infauna groups (buried in the sediment) recorded in the proposed bridge. The infauna groups are Polychaetes, Annelids and Nematods while seven (7) epifauna species (live on the surface of the sediment) are Coenobita, Echinoderms, Asteroids, Ascidians, Mollusks and Holothurians and Poriferans. Benthos is the community of aquatic organism that lives in above or near the bottom of lake, sea, river streams or any other aquatic environment. Benthos plays a big role in the ecosystem
43 INITIAL ENVIRONMENTAL EXAMINATION Tawi-Tawi Bridge No. 1: Nalil-Sikkiat Detailed Engineering Design for Road Improvement and Institutional Development (RIIDP) and Future Financing like decomposition, nutrition, remineralization, food source and increased oxygen in the bottom. They constitute a vital link in the food chain and energy flow, serve as food for other higher organisms such as fish and play a vital role in the circulation of nutrients (Oben et al., 2003).
98. Benthos population is very minimal due to the physical and chemical characteristics of the water, substrate structure, siltation, pollution and human disturbance. The substrate characteristics directly affect the benthic populations in the Nalil-Sikkiat bridge. Sedimentation and water turbidity limit the adaptability, settlement, recruitment, growth and development of benthos organisms. Berry et al. (2003) stated that suspended sediment directly affects invertebrates include, direct impacts due to abrasion, interference with respiration and ingestion by clogging of filtration mechanisms, and in extreme cases mortality from smothering and burial. The distribution of infauna and epibenthic species is impacted indirectly through light attenuation affecting feeding efficiency, behavior (avoidance and drift), and habitat alteration occurring from changes in the composition of substrate (Donahue and Irvine 2003; Waters 1995; Zweig and Rabeni 2001; Berry et al. 2003). Increases in suspended sediments resulted in increased drift and significantly altering the distribution of benthic invertebrates in streams (Herbert and Merkens 1961; Berry et al. 2003).
i) Water Parameters
99. The sampling stations for the water quality is the same with the sampling stations of coral reefs. Two sampling stations with ten replicates were established in the two areas. Table 9 presents the water parameters in the Sikkiat side of the bridge. The readings of water parameters between the surface and middle of the water are similar (Table 25). The identified physico-chemical parameters were selected because these are the major limiting factors for the recruitment, survival and development of marine organisms. These physico-chemical parameters affects the species composition, their abundance and productivity18.
100. The average surface water temperature is 31.8 oC while 31.50 oC in the middle, the pH at the surface water and middle water column were both 8.8, water salinity at the surface water and middle water column were both 34.1 ppt, dissolve oxygen is 8.0 in the surface and 7.0 in the middle, total dissolved solid (TDS) (g/L) at the surface water and middle water column were 36,400 and 38,900, respectively. The water transparency is from 3.55 m in Sikkiat side and 4.25 m in Pakias side with an average of 3.9 meters.
Table 25. Average water parameters in the Sikkiat side
Parameters Surface Middle Temperature (oC) 31.8 31.5 pH 8.8 8.8 Salinity (ppt) 34.1 34.1 DO 8.0 7.0 Total Dissolved Solid (mg/L) 36,400 38,900 Note: Refer to Footnote 17 for the WQG parameters to be measured.
101. The table below shows the average water parameters in Pakias side. The surface
18 A separate water quality sampling activity to meet the DENR Water Quality Guidelines shall be conducted following approval by the DPWH of the request by the DED Consultant. This shall address the requirements during the construction and operation phases from which possible pollutant discharges shall be monitored. The sampling parameters for the marine assessment was limited only to the capability of the handheld instruments used during the sampling activities and only for those deemed necessary to determine the limiting factors for the purpose mentioned above. However, it was later agreed by UPMO management, that the 10 primary parameters will be included in the EMP of this IEE. Hence, the baseline data will be conducted and included in the CEMP.
44 INITIAL ENVIRONMENTAL EXAMINATION Tawi-Tawi Bridge No. 1: Nalil-Sikkiat Detailed Engineering Design for Road Improvement and Institutional Development (RIIDP) and Future Financing water and middle water column has an average temperature of 32.1 °C and 31.3°C, the pH values at the surface water and middle is 8.8; water salinity reading at the surface is 32.0 ppt and 33.1 ppt in the mid water column, dissolve oxygen measurement is 8.0 mg/l in the surface and 7.5mg/l in the mid water column and total dissolve solid measurement is 39,800 mg/l in the surface and 39,800 mg/L in mid water column.
Table 26. Average water parameters in Pakias side
Parameters Surface Middle Temperature (oC) 32.1 31.3 pH 8.8 8.8 Salinity (ppt) 32.0 33.1 DO (mg/L) 8.0 7.5 Total Dissolved Solid (mg/L) 39,800 39,800 Note: Refer to Footnote 17 for the WQG parameters to be measured.
102. The ranges of water parameters for marine organisms in the tropics are presented in Table 27. Marine organisms have different ranges of water parameters since they have the ability to adopt changes in their environment. Sudden changes on the level of water parameters affect the reproductive mechanism, feeding habit, growth and development of fish and other invertebrates.
Table 27. Range of water parameters for marine organisms in the tropics Parameters Range of Values Temperature (oC) 24-32 pH 7.5-8.5 Salinity (ppt) 33-37 DO (mg/L) 5-20 Total Dissolved Solid (mg/L) 30,000-40,000 Note: Refer to Footnote 17 for the WQG parameters to be measured.
103. Temperature. The water quality parameters recorded in the proposed Nalil-Sikkiat bridge are within the tolerable and optimum limit for marine organisms. Water temperature ranges from 31.5 to 32.1oC were recorded and the normal range of surface temperature varies between 24°C and 32°C (75°F to 89°F). The water temperature is favorable for marine organisms for their growth and development.
104. Salinity. The salinity of the water recorded ranges from 32.0 to 34.1 parts per thousand. The normal range of ocean salinity ranges from 33 to 37 parts per thousand (NWS, Jetstream/Seawater), with an average of 35 parts per thousand. The salinity level of the water in the proposed Sikkiat-Pakias bridge is lower than the normal ranges of salinity in the open ocean. This is because of the influx of fresh water from the community. However, some marine organisms tolerate lower salinity and most aquatic species can adopt different salinity levels like some reef-building corals require very saline water ranging from 32 to 42 ppt.
105. pH or Hydrogen ion concentration. Hydrogen ion concentration of pH and measurement of acidity in seawater. The average pH level recorded in the proposed Sikkiat- Pakias bridge was 8.8. This data is within the optimum pH level of seawater.
106. Dissolved Oxygen. The dissolve oxygen content of the water in the proposed bridge recorded ranges from 7 mg/l to 8.0 mg/l. The dissolve oxygen content of the water is within the normal ranges of dissolve oxygen in other areas. The dissolve oxygen needed by the marine organisms living in the bottom or substrate is ranges from 1-6 mg/l while 4-15 mg/l dissolve oxygen level needed by marine organisms living in the shallow portion of the sea. If
45 INITIAL ENVIRONMENTAL EXAMINATION Tawi-Tawi Bridge No. 1: Nalil-Sikkiat Detailed Engineering Design for Road Improvement and Institutional Development (RIIDP) and Future Financing the dissolved oxygen levels of seawater drop below 5.0 mg/l, aquatic life is under stress. The lower the concentration of dissolve oxygen, the greater the stress and if dissolve oxygen levels drop to 1-2 mg/l for a few hours, it resulted to large fish kills (Lenntech BV).
107. Total dissolved solids (TDS). The total dissolve solid recorded in the proposed Nalil- Sikkiat bridge is within the optimum level of concentration from 36,400 mg/l to 39,800 mg/l. The normal total dissolve solid of marine water is more than 35,000 mg/l.
j) E.2.9 Water Current and Circulation
108. Water current. Water current was measured in forty (40) points around the proposed bridges as shown in Table 28. The average velocity of the water current during the sampling period is 0.15 m/sec. Typical maximum current speeds in tidal inlets are approx. 1 m/s, whereas tidal current speeds in straits and estuaries can reach speeds as high as approx. 3 m/s. The current in the area is primarily wind generated.
Table 28. Sampling points if water current in the proposed Nalil-Sikkiat Bridge
Replicate Rate (m/s) starting point end point
1 0.09 N5 02.131 E119 45.402 54⁰ NE 2 0.10 N5 02.130 E119 45.401 2⁰ N 3 0.05 N5 02.135 E119 45.398 44⁰ NE 4 0.07 N5 02.140 E119 45.395 99⁰ E 5 0.09 N5 02.147 E119 45.400 42⁰NE 6 0.06 N5 02.142 E119 45.404 93⁰ E 7 0.08 N5 02.149 E119 45.407 81⁰ E 8 0.08 N5 02.152 E119 45.416 336⁰ NW 9 0.10 N5 02.151 E119 45.419 49⁰ NE 10 0.10 N5 02.143 E119 45.423 58⁰ NE 11 0.10 N5 02.143 E119 45.422 65⁰ E 12 0.14 N5 02.138 E119 45.421 65⁰ NE 13 0.08 N5 02.131 E119 45.415 8⁰ N 14 0.11 N5 02.113 E119 45.412 358⁰ N 15 0.07 N5 02.110 E119 45.403 46⁰ NE 16 0.02 N5 02.110 E119 45.401 223⁰ SW 17 0.09 N5 02.104 E119 45.392 69⁰ NE 18 0.04 N5 02.103 E119 45.388 122⁰ SE 19 0.10 N5 02.113 E119 45.377 190⁰ S 20 0.04 N5 02.118 E119 45.376 203⁰ SW 21 0.08 N5 02.132 E119 45.375 189⁰ S 22 0.05 N5 02.138 E119 45.376 216⁰ SW
46 INITIAL ENVIRONMENTAL EXAMINATION Tawi-Tawi Bridge No. 1: Nalil-Sikkiat Detailed Engineering Design for Road Improvement and Institutional Development (RIIDP) and Future Financing
Replicate Rate (m/s) starting point end point
23 0.06 N5 02.153 E119 45.384 164⁰ SE 24 0.06 N5 02.158 E119 45.384 167⁰ SE 25 0.05 N5 02.160 E119 45.385 143⁰ SE 26 0.09 N5 02.169 E119 45.387 150⁰ SE 27 0.07 N5 02.175 E119 45.384 131⁰ SE 28 0.04 N5 02.180 E119 45.388 169⁰ S 29 0.08 N5 02.201 E119 45.407 26⁰ N 30 0.13 N5 02.202 E119 45.410 18⁰ N 31 0.11 N5 02.199 E119 45.412 51⁰ NE 32 0.07 N5 02.197 E119 45.411 84⁰ E 33 0.10 N5 02.193 E119 45.410 56⁰ NE 34 0.09 N5 02.191 E119 45.408 86⁰ E 35 0.06 N5 02.184 E119 45.411 39⁰ NE 36 0.04 N5 02.187 E119 45.412 60⁰ NE 37 0.08 N5 02.189 E119 45.411 47⁰ NE 38 0.10 N5 02.184 E119 45.404 60⁰ NE 39 0.08 N5 02.182 E119 45.401 60⁰ NE 40 0.03 N5 02.181 E119 45.401 3⁰ N
109. Water circulation. The proposed Nalil-Sikkiat bridge is located in a channel that connects the Sulu Sea and Celebes Sea also known as Sulawesi Sea. Water circulation in the area is controlled by physical forcing at the open boundaries, namely the river inflow, the groundwater inflow, the wind, and the oceanic forcing like tides, fluctuations of the mean sea level like storm surges, the waves, and the net oceanic currents. Hydrologic cycle or water cycle in the channels is responsible for transport of food, nutrients, and pollution downstream.
k) Conclusion and Recommendation
110. The present state of coral reef in the proposed bridge is in good condition while the other biological resources is in imperiled status. The marine biological component except coral reefs is characterized by low species diversity The coral reefs are located mostly in the middle of the channel which is characterized by good water movement. Due to the sparse and scattered presence of Lobophyllia coral species during the survey, it is recommended that further investigation be done prior to construction in consultation with marine experts from the Mindanao State University-Tawi-Tawi College of Technology and Oceanography (MSU- TCTO) to determine if the Lobophyllia serratus species is among the Lobophyllia corals found during the survey. This will enable the project to implement appropriate mitigation measures with expert guidance.
111. Sedimentation, alteration of habitat and deposition of waste materials are among the end result of human activities in the area. The result of these anthropogenic activities and the deposition of organic and inorganic substances greatly affect the recruitment, growth and development of some marine biological resources. Negative impact on sedimentation
47 INITIAL ENVIRONMENTAL EXAMINATION Tawi-Tawi Bridge No. 1: Nalil-Sikkiat Detailed Engineering Design for Road Improvement and Institutional Development (RIIDP) and Future Financing includes: loss of important or sensitive aquatic habitats, decrease in fishery resources, loss of recreation attributes, loss of coral reef and reef fish communities, changes in fish migration, increases in erosion, circulation changes, increases in turbidity, prevent marine organism recruitment, settlement and development, loss of submerged vegetation, and coastline alteration. Sedimentation and siltation are detrimental to bottom-dwelling organisms through burial effect. The minimal population of benthic organisms like fishes, marine plants, benthos and plankton is mainly attributed by the deposition of suspended sediments resulting to the alteration of habitat and low light penetration. There are fishermen in the area but some of them, are fishing in the open sea. The channel is used by the residents primarily as passage in going to Bongao and nearby areas. At the time of the sampling activities, no seaweed farms were visible and observable. Any seaweed farms that maybe found to be located near the bridge site during construction shall be relocated so this will not be affected by the construction activities.
112. It is strongly suggested that extra precautions be set in place prior to the construction activities in the area due to the presence of good coral resources. These shall be incorporated in the Contractors Environmental Management Plan and operationalized through the submission of Method Statement for review and approval by the DPWH and its Construction Supervision Consultant. Bridge construction activities (i.e. bored piling and concrete pouring works) that may cause sedimentation shall be minimized by putting sediment traps or fine nets before any construction activities shall commence. The bridge construction activities shall not further contribute to the negative impacts of the current coastal development or coastal activities/ activities of the population in the coastal area such as but not limited to the following: the establishment of houses in the coastal area or in the marine waters (which is not favorable for the marine organisms); discharges of solid wastes and waste waters to the marine environment, and discharge of oil and grease and other pollutants from the different boats that passes through the channel (the marine environment serving as garbage area of the residents).
113. Mangrove replanting shall be undertaken to replace the mangroves that will be affected by the bridge pier and approach road embankment. This will also help stabilize the bridge structures (e.g. abutments/embankments), and the roots will effectively reduce wave action and prevent soil erosion.
114. Patches of seagrass will be affected during the construction of bridge piers in the area. The Contractor shall identify the exact locations of seagrass beds that will be affected by the bridge piers and confine the activities within the affected space. In addition, the Contractor shall be required to relocate affected patches to adjacent area prior to the setting up of the cofferdams to naturally re-grow.
115. In the proposed Nalil-Sikkiat bridge, the diversity of coral reefs is not positively correlated with the fish community. This is maybe due to the anthropogenic activities in the area. Several studies supported these findings. The coral species richness and live coral cover had no influence on the diversity and abundance of fish communities in some studies (Luckhurst and Luckhurst 1978; Mc Manus et al. 1981; Roberts and Ormond 1987). While in other studies, the fish characteristics were positively correlated with the live coral cover (Carpenter et al. 1981; Sano et al. 1984, 1987; Bell and Galzin, 1984 & 1988). The variability in the relationship between fish and coral communities maybe attributed to some ecological and methodological factors. Fish population can be used as an indicator if coral reef is healthy but there were cases that even if the areas do not have good coral cover, high species fish diversity are still present. Fish abundance and biodiversity may vary because of water quality and presence of food source in a certain area.
48 INITIAL ENVIRONMENTAL EXAMINATION Tawi-Tawi Bridge No. 1: Nalil-Sikkiat Detailed Engineering Design for Road Improvement and Institutional Development (RIIDP) and Future Financing
E. Socioeconomic Resources
a. Population
116. The Municipality of Bongao accounts for 25.7% of the total provincial population. The municipal population is characterized as a young and ethno-linguistically diverse population. Based on the 2015 census, the municipal population is 100,527 from at least nine Philippine ethno-linguistic groups in addition to the Chinese, Malaysians and Indonesians who settled in the area. This diversity is due to Bongao’s strategic location as a door to countries in Southeast Asia particularly its proximity to the rich state of Sabah in Malaysia.
117. Bongao has six urban barangays – Poblacion, Tubig Boh, Lamion, Pag-asa, Tubig Tanah, and Tubig Mampallam. All of these are in Bongao Island. These barangays were considered as urban barangays because they meet any of the following criteria:
• Each of them has a population size of 5,000 or more; • Each has at least one establishment with a minimum of 100 employees; or • Each has five or more establishments with 10 to 99 employees, and five or more facilities within the two-kilometer radius from the barangay hall.
Table 29. The population of Bongao, Tawi-tawi by barangay and by census year, 1980- 2015 Population by Census Year Barangay 1980 1990 1995 2000 2010 2015
Bongao Poblacion 6,565 6,419 7,139 7,193 11,158 12,503 Ipil 537 554 602 820 1,100 1,165 Kamagong 1,124 1,209 1,277 931 985 Karungdong 755 540 979 1,094 1,720 1,819 Lagasan 751 1,028 1,026 1,277 1,444 Lakit-lakit 843 949 1,052 723 1,102 1,121 Lamion 3,412 2,532 4,639 4,882 6,409 7,090 Lapid-lapid 2,377 1,745 1,382 1,587 1,709 1,810 Lato-lato 389 642 700 620 574 833 Luuk Pandan 1,345 1,785 1,788 2,014 2,376 2,652 Luuk Tulay 1,857 1,002 788 817 1,056 1,088 Malassa 378 552 678 632 1,045 1,118 Mandulan 589 494 764 808 1,870 1,991 Masantong 633 672 720 847 938 Montay-montay 914 815 1,101 1,268 1,410 Nalili 962 986 1,361 3,154 4,637 Pababag 484 704 783 1,193 1,505 1,639 Pag-asa 1,464 1,628 4,398 5,648 6,835 Pag-asinan 622 738 903 1,207 1,662 Pagatpat 406 587 699 749 958 Pahut 1,290 387 705 1,042 1,145 1,649 Pakias 242 442 624 1,299 1,450 Paniogan 416 94 314 533 692 906 Pasiagan 718 678 816 1,390 1,639 3,310
49 INITIAL ENVIRONMENTAL EXAMINATION Tawi-Tawi Bridge No. 1: Nalil-Sikkiat Detailed Engineering Design for Road Improvement and Institutional Development (RIIDP) and Future Financing
Population by Census Year Barangay 1980 1990 1995 2000 2010 2015
Sanga-sanga 1,520 1,580 1,878 2,550 2,961 3,755 Silubog 980 854 832 902 1,393 1,514 Simandagit 233 644 716 1,612 2,008 8,584 Sumangat 912 757 933 1,050 1,120 Tarawakan 720 1,553 1,590 1,673 2,319 2,630 Tongsinah 1,244 594 737 761 982 1,015 Tubig-basag 371 619 663 855 1,231 1,418 Tubig-tanah 1,133 2,354 4,121 5,090 5,742 Tubig-Boh 1,477 1,643 1,844 4,988 7,440 Tubig-mampalam 2,084 3,799 4,817 5,074 5,295 Ungus-ungus 861 287 469 649 786 1,001 Source: Comprehensive Land Use Plan, Bongao, Tawi-Tawi (2017-2026).
118. These barangays are also the high population density areas with Poblacion having 36,991 population per square kilometer; Tubig Boh with 31,130, Lamion with 27,588; Tubig Mampallam with 15,574; Pag-asa with 15,122; and, Tubig Tanah with 4,825. Other barangays with high population density, though not considered as urban, are Simandagit (13,712), Nalil (1,811) and Pasiagan (1,212) all in Bongao Island; Tongsinah (6,678) and Lagasan (3,046) both of Pababag Island; and Sanga-Sanga (2,470) and Pagasinan (1,801) both of Sanga- Sanga Island. The rest of the barangays have population densities below 1,000 per square kilometers. The sparsely populated areas are Pagatpat with 120, Kamagong with 127 and Lapid-Lapid with 128. All of these are in the Tawi-tawi mainland.
Table 30. Population Density per barangay and location by major island group Population Density Classification Barangay Name Location (per sq.km.) Bongao Poblacion Bongao Island 36,991
Tubig-Boh Bongao Island 31,130
Urban Lamion Bongao Island 27,588 Tubig-Mampallam Bongao Island 15,574 Pag-asa Bongao Island 15,122 Tubig Tanah Bongao Island 4,825 Simandagit Bongao Island 13,712
Tongsinah Pababag Island 6,678
Lagasan Pababag Island 3,046 Sanga-sanga Sanga-Sanga Island 2,470
Nalil Bongao Island 1,811 Pagasinan Sanga-Sanga Island 1,801
Pasiagan Bongao Island 1,212 Ipil Tawi-tawi Island 996
Pababag Pababag Island 993 Lato Sanga-Sanga Island 841
Paniongan Sanga-Sanga Island 831
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Population Density Classification Barangay Name Location (per sq.km.) Pahut Bongao Island 750
Ungus-ungus Tawi-tawi Island 599
Rural Pakias Sanga-Sanga Island 585 Tubig Basag Sanga-Sanga Island 503 Montay Tawi-tawi Island 411 Karungdong Sanga-Sanga Island 348 Malassa Sanga-Sanga Island 301 Luuk Pandan Sanga-Sanga Island 272 Sumangat Tawi-tawi Island 229 Lakit Sanga-Sanga Island 212 Masantong Tawi-tawi Island 200 Tarawakan Tawi-tawi Island 199 Silubog Tawi-tawi Island 179 Luuk Tulay Tawi-tawi Island 163 Mandulan Sanga-Sanga Island 153 Lapid Tawi-tawi Island 128 Kamagong Tawi-tawi Island 127 Pagatpat Tawi-tawi Island 120 Source: Comprehensive Land Use Plan, Bongao, Tawi-Tawi (2017-2026).
b. Age and Sex Structure
119. More than half or 50,982 of the municipal population is female. The proportion of females is very high in the age ranges 15-29, and 70-74. The percentage of females in those age ranges is between 53% and 54%.
Table 31. The distribution of population by age group and by sex, 2015 Population by Sex Age Group Both Male Female Sexes All Ages 100,527 49,545 50,982 Under 1 2,170 1,131 1,039 1-4 12,126 6,100 6,026 5-9 14,604 7,377 7,226 10-14 13,333 6,556 6,777 15-19 12,322 5,756 6,567 20-24 9,375 4,419 4,955 25-29 8,555 4,039 4,516 30-34 6,033 2,949 3,084 35-39 6,238 3,024 3,215 40-44 4,773 2,480 2,293 45-49 3,735 1,906 1,829 50-54 2,602 1,377 1,225 55-59 1,752 964 788 60-64 1,236 670 566 65-69 755 393 362
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Population by Sex Age Group Both Male Female Sexes 70-74 493 227 266 75-79 193 92 100 80 and 231 98 133 over Source: Comprehensive Land Use Plan, Bongao, Tawi-Tawi (2017-2026).
120. Bongao’s population is generally young. Those aging 29 years old and below accounts for 72% or 72,485 of the total population. Those aging between 5 to 9 years old accounts for 14.53% of the total population followed by the 10-14 age group with 13.26%, and the 15-19 age group with 12.26%. The age groups with the least numbers are the 75-79 and 80 and above with 0.19% and 0.23%, respectively.
Source: Comprehensive Land Use Plan, Bongao, Tawi-Tawi (2017-2026) Figure 9. Population by Age Group, CY 2014
c. Age Dependency Ratio
121. Given the age structure of the municipal population, age dependency ratio is 1:1. Age dependency, which accounts for the population aging 17 years old and below is 49,671 or 49.4% of the total population. The population aging 18 years old and above (or majority age population) is 50,856 or 50.6% of the total population.
d. Migration
122. The rapid growth of population at the rate of 4.84% in Bongao may not only be attributed to the natural growth but also migration as crude birth rate is only 195 per month based on 2015 data. Bongao, as the urban growth center of the Province of Tawi-Tawi enjoys the presence of almost all socio-economic amenities not found in other island municipalities. These include the facilities for health, education, business and commerce, transportation and
52 INITIAL ENVIRONMENTAL EXAMINATION Tawi-Tawi Bridge No. 1: Nalil-Sikkiat Detailed Engineering Design for Road Improvement and Institutional Development (RIIDP) and Future Financing the like. The municipality is also an economic gateway and an environment tourism area. Add the relatively stable peace and order situation of the municipality that people not only from other island municipalities of Tawi-Tawi but also from other provinces want to live in Bongao.
e. Mother Tongue
123. The population of Bongao comes from diverse ethno-linguistic backgrounds. Based on the 2010. Census of Population, 71.82% of the population is Tausug followed by 15.35% Sama. The figure in 2015 changed with the conduct of the Rapid Community-Based Monitoring System. It appears that the Tausug ethno-linguistic population declined while that of the Sama population increased. This can be explained by the migration of the Tausugs to the Malaysian State of Sabah and the movement of the Sama from the restive province of Sulu. The values, however, may still increase as 21% of the population did not make a response.
Table 32. Household Population by Mother Tongue, Year 2010
Mother Tongue Household No. % of Total Household
Tausug 10,117 71.82 Sama 2,162 15.35 Cebuano 582 4.13 Tagalog 310 2.2 Ilocano 225 1.6 Batangueno 211 1.5 Ilonggo/Hiligaynon 183 1.3 Bicolano 169 1.2 Waray 127 0.9 Total 14,087 100
No Response 21%
3%
Tausug Sama 56% 20%
Figure 10. Ethno-linguistic groupings in Bongao, 2015
f. Religious Affiliation
124. 86.84% of the population belongs to Islam while Catholics account for 9.30% of the
53 INITIAL ENVIRONMENTAL EXAMINATION Tawi-Tawi Bridge No. 1: Nalil-Sikkiat Detailed Engineering Design for Road Improvement and Institutional Development (RIIDP) and Future Financing population. The high percentage of Muslims can be traced to the historical background of Bongao. As presented in Section 2, Bongao was a cradle of Islam, and that it is among the few areas that were never colonized by the Spaniards.
Others, 0.3
Jehovas Witness, 0.4 Christian Islam, 86.84 Alliance , Catholics, 9.3 1.36 Iglesia ni Kristo, 1.8
Figure 11. Religious affiliation of the population in Bongao, 2010 g. Education
125. Educational Attainment and Literacy Rate. The Municipality of Bongao has an increasing literacy rate due to the increasing number of educators and facilities being made available to the population. From 60.3% in 1980, literacy rate increased to 79.84% in 2010. Literacy rate is higher among females (51%) than males (49%). The difference is due to the fact that the males, even at a younger age, are already focused on income- generating activities such as fishing hence making education a secondary priority.
Figure 5-1. The literacy rate in Bongao, Tawi-
tawi, 2010
18.61 19%
Literate 79.84 81%
Figure 12. The literacy rate in Bongao, Tawi-Tawi, 2010
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h. Educational Institutions and School Facilities by Level
126. Bongao is the center of education facilities in the province. Located in the municipality are the five (5) tertiary institutions, twelve (12) secondary schools, forty-three (43) elementary/primary schools, and seventy-six (76) pre-schools.
127. Tertiary Institutions. Of the five tertiary institutions in Bongao, three are private colleges/institutes, one is a state university and another is a state college. The government institutions are the Mindanao State University-Tawi-Tawi College of Technology and Oceanography (MSU-TCTO) located at Barangay Sanga-Sanga, and the Tawi-Tawi Regional Agricultural College (TRAC) at Barangay Nalil. The privately owned tertiary institutions are: the Mahardika Institute of Technology at Barangay Lamion; the Abubakar Computer Learning Center located at Barangay Simandagit; and, the Tawi-Tawi School of Midwifery at Barangay Tubig Boh.
128. Secondary Schools. The twelve (12) secondary schools in the municipality are composed of eight government-run schools and four privately owned institutions. Of the eight government-run schools three are managed by the state university/college. These are the MSU Science High School and the MSU Preparatory High School both at Barangay Tubig Mampallam; and the TRAC High School Department at Barangay Nalil. The other five are under the Department of Education and these are Tawi-Tawi School of Arts & Trade at Barangay Poblacion; the Tawi-Tawi School of Fisheries also at Barangay Poblacion; the Boloboc Science and Technology National High School; the Pagasinan National High School at Barangay Pagasinan; and the Sanga-Sanga National High School at Barangay Pahut.
129. The privately owned high schools are the Abubakar Computer Learning Center at Barangay Simandagit, the Mahardika Institute of Technology High School Department at Barangay Lamion, and, the Bongao Advent Academy at Barangay Tubig Boh.
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Source: Comprehensive Land Use Plan, Bongao, Tawi-Tawi (2017-2026).
Figure 13. The location of school facilities in Bongao, Tawi-Tawi, 2015
130. Primary/Elementary Schools. Of the 43 primary and elementary schools in Bongao, 36 are under the Department of Education, two are under the state universities, and the rest are privately managed. Almost all of these are concentrated in the Bongao Island. The municipality has been subdivided into four school districts, namely: Bongao Central District, District I, District II and District II. Bongao Central District oversees eight primary/elementary schools; Districts I and District III both have seven primary/elementary schools each; and, District II has 14.
131. The state university-managed elementary schools in the municipality are the MSU- TCTO Child Development Center-Laboratory Elementary School located at Barangay Tubig Mampallam, Notre Dame of Bongao Elementary Department at Barangay Poblacion. The privately owned primary and elementary schools, meanwhile, are the Notre Dame of Bongao Elementary Department at Barangay Poblacion, Bongao Discovery Learning Center.
Table 33. Elementary Schools in Bongao, Tawi-Tawi Number of Elementary Schools Operator/Manager Schools Bongao Central District schools 7 DepEd Tawi-Tawi Bongao District I schools 8 Dep Ed Tawi-Tawi Bongao District II schools 14 Dep Ed Tawi-Tawi Bongao District III schools 7 Dep Ed Tawi-Tawi MSU-TCTO Child Development Center- 1 State university Laboratory Elem School (MSU-TCTO ) Notre Dame of Bongao Elementary Department 1 State university (Notre Dame of Bongao ) Bongao Discovery Learning Center 1 Private Bongao Adventist Elementary School 1 Private Bongao Advent Academy 1 Private Mahardika Institute of Technology Elementary 1 Private Department Abubakar Learning Center Elementary 1 Private department. T o t a l 43 Source: Comprehensive Land Use Plan, Bongao, Tawi-Tawi (2017-2026).
132. Pre-school. There are 76 pre-schools existing in Bongao most of which are attached to elementary schools. The 36 elementary schools of the Department Education have their component pre-schools or kindergarten schools. MSU-TCTO CDC-LES, Notre Dame of Bongao elementary department, Seventh-Day Adventist Kinder School, Bongao Alliance Kindergarten, Bongao Discovery Learning Center and Mahardika Institute of Technology Elementary Department have also their respective pre-schools. The rest of the pre-schools are operated by the Department of Social Welfare and Development through its Day Care Centers. Most schools are located in Bongao Poblacion and neighboring barangays.
Table 34. Names & Nos. of Pre-Schools, Both Government & Private, Bongao, Tawi-Tawi Number Elementary Schools of Operator Schools Bongao Central District 7 Dep Ed Tawi-Tawi
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Bongao District I 8 Dep Ed Tawi-Tawi
Bongao District II 14 Dep Ed Tawi-Tawi
Bongao District III 7 Dep Ed Tawi-Tawi
MSU-TCTO Child Development Center- 1 state university Laboratory Elem School Day-Care Centers 34 DSWD/public Notre Dame of Bongao Elementary Department 1 private Bongao Discovery Learning Center 1 private Bongao Adventist Elementary School 1 private Bongao Advent Academy 1 private Mahardika Institute of Technology Elementary 1 private Department T o t a l 76 Source: Comprehensive Land Use Plan, Bongao, Tawi-Tawi (2017-2026).
133. Other Schools. The Department of Education Tawi-Tawi has also established the Alternative Learning System (ALS). The ALS is a parallel learning system that provides a practical option to the existing formal instruction particularly to those who does not have or cannot access formal education in schools.11 It includes both the non-formal and informal sources of knowledge and skills. In Bongao, the ALS caters to out-of-school youth, rebel returnees, victims of calamities and adult illiterates.
i. Teachers and Student Population
134. Bongao Central District has a total of 243 teachers in its eight (8) component elementary schools based on its record in 2014. Other school districts have no data available. There are also 102 public secondary teachers in Bongao in the five secondary schools being operated by the DepEd. The highest number is in the Tawi-Tawi School of Art and Trade with 42 teachers of various specialization followed by the Tawi-Tawi School of Fisheries with 30 teachers. Boloboc Science and Technology National High School has the lowest number of teachers with 7.at Barangay Poblacion, Bongao Adventist Elementary School at Barangay Tubig Boh, Bongao Advent Academy at Barangay Tubig Boh, Mahardika Institute of Technology Elementary Department, and, Abubakar Learning Center Elementary department.
Table 35. Number of Teachers per Public Secondary School in Bongao, 2014
Total Number of Public Secondary Schools Teachers Boloboc Science and Technology National High School 7
Pag-asinan National High School 12 Tawi-Tawi School of Art and Trade 42 Tawi-Tawi School of Fisheries 30 Sanga-Sanga National High School 11 Source: DepEd ARMM Bongao, Tawi-Tawi 2014
j. School Population and Children out of School
135. For the School Year 2013-2014, Bongao has a total of 18,606 enrollees. 3,376 of these are in kindergarten and 15,230 are in Grades 1 to 6. Almost one-third of the enrollees for kindergarten is in Bongao District 1 while most of the enrollees for Grades 1 to 6 are in Bongao Central. Female enrollees are higher in number compared with the male enrollees in all the public kindergarten and elementary schools in Bongao. the highest is in Bongao District II
57 INITIAL ENVIRONMENTAL EXAMINATION Tawi-Tawi Bridge No. 1: Nalil-Sikkiat Detailed Engineering Design for Road Improvement and Institutional Development (RIIDP) and Future Financing where gender parity index is 1.16. Gender Parity Index is calculated as the quotient of the number of females by the number of males enrolled in a given stage of education is used by international organizations particularly the United Nations Educational, Scientific and Cultural Organization (UNESCO). The index describes attempts to eliminate gender disparities in primary and secondary education and emphasizes the plight of girls in unequal access in third world countries.12
Table 36. Total Enrollment of Bongao Public Elementary Schools per District, 2013- 2014
Number of Pre- Number of Parity Index schools/ Kindergarten Grade 1-6 District Elementary (Kindergarten and Kindergarten Enrollment Enrollment Schools Elementary) Schools Bongao 7 583 7 4,375 1.01 Central Bongao 8 1,033 8 3,999 1.03 District I Bongao 14 783 14 3,690 1.16 District II Bongao 7 977 7 3,166 1.06 District III Total 3376 15,230 Source: DepEd ARMM Bongao, Tawi-Tawi 2014
136. In the public secondary schools, enrollees in 2013-2014 is 3,454. Almost all of these came from the Tawi-Tawi School of Art and Trade, and the Tawi-Tawi School of Fisheries.
Table 37. Total Enrollment of Public Secondary Schools, Department of Education ARMM Bongao, Tawi-Tawi Public Secondary Schools Total Number of Enrollment
Boloboc Science and Technology National High School 172 Pag-asinan National High School 380 Tawi-Tawi School of Art and Trade 1,506 Tawi-Tawi School of Fisheries 1,236 Sanga-Sanga National High School 160 Source: DepEd ARMM Bongao, Tawi-Tawi 2014
137. Out of School Children and Youth. Despite the number of schools, 19.87% of children aging 6-12 years old and youth aging 13-16 years old are out of school. This is equivalent 19.87% of the children population who are not attending elementary school and 28.21% of the teenage population who are not attending high school.
Table 38. Proportion of individuals of schooling age and their attendance to school, 2015 Category 6-12 Years Old 13-16 Years Old In-School 80.13 71.79 Out-of-School 19.87 28.21 Source: RCBMS 2015
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138. In 2015, Barangay Lamion ranks first in Bongao with 705 children aging 6-12 years old who are out of school. Tubig Tanah follows with 408; Simandagit with 382, Pag-Asa with 310, and Poblacion with 255. Lamion, likewise, ranks first with 1,041 youth aging 13-16 years old who are not attending high school. This is followed by Tubig Tanah with 403, Poblacion with 668, Simandagit with 577, and Nalil with 494. Only Luuk Tulay shows 100% compliance in ensuring that its children and young people aging 6-12 years old and 13-16 years old to be in school. Table 39. Out of School Children and Youth by Barangay and by Rank
Out-of-school children Out-of-school youth Area (6-12 y.o.) Rank (13-16 y.o.) Rank Bongao Poblacion 255 5 668 3 Ipil 61 17 51 32 Kamagong 45 22 70 28 Karungdong 86 13 206 12 Lagasan 31 27 96 25 Lakit 38 25 170 14 Lamion 705 1 1041 1 Lapid 68 14 113 19 Lato 24 30 45 33 Luuk Pandan 134 7 113 19 Luuk Tulay 0 35 0 35 Malassa 100 11 94 26 Mandulan 49 21 110 21 Masantong 38 25 101 23 Montay 28 29 58 31 Nalil 127 9 494 5 Pababag 68 14 64 30 Pag-asa 310 4 445 6 Pagasinan 94 12 233 9 Pagatpat 127 9 99 24 Pahut 8 34 168 15 Pakias 131 8 210 10 Paniongan 19 33 34 34 Pasiagan 62 16 185 13 Sanga-sanga 21 31 157 16 Silubog 57 19 123 17 Simandagit 382 3 577 4 Sumangat 54 20 209 11 Tarawakan 30 28 65 29 Tongsinah 41 23 119 18 Tubig Basag 39 24 263 8 Tubig Tanah 408 2 903 2 Tubig-Boh 61 17 102 22 Tubig-Mampallam 171 6 410 7 Ungus-ungus 21 31 72 27
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Source: RCBMS 2015, Source: Comprehensive Land Use Plan, Bongao, Tawi-Tawi (2017-2026).
k. Housing
139. Based on the 2015 Census of Population and Housing, Bongao has a total of 17,636 households. Of this number, 97.41% have their own houses with only 2.59% as renters. The high percentage of house ownership is due to the housing projects of the local government unit in partnership with the national government agencies. As of 2015, Bongao has fifteen housing projects nine of which are made up of concrete materials, and six are made of light materials.
Table 40. Housing Projects in Bongao as of March 2017. Housing Projects with Concrete Materials Housing Projects with Light Materials 1. Old Housing Project in 1. Barangay Sanga-Sanga Barangay Tubig Boh 2. Barangay Pahut 2. New Housing Project in 3. Barangay Pakias Barangay Tubig Boh 4. Barangay Simandagit 3. Daira in Barangay Tubig Boh 5. Badjao Village Barangay Pag-asa 6. Kasulutan. 4. GNA in Barangay Lamion 5. ACS in Barangay Simandagit 6. NDB Housing in Barangay Nalil 7. Sea Orchid in Barangay Nalil 8. Triple R in Barangay Nalil 9. Barangays Nalil and Pasiagan housing project Source: Comprehensive Land Use Plan, Bongao, Tawi-Tawi (2017-2026).
140. Not all of the housing units, however, are made of durable materials. Based on Rapid CBMS data, 9.14% of the houses in 2015 are makeshift houses with materials that can be easily destroyed by strong winds or heavy rains. Most of these houses can be found in Barangays Pag-asa, Simandagit, Tubig Tanah, Poblacion and Tubig Mampallam. 46% of those considered as makeshift houses are owned by informal settlers. Informal settlers are those who occupy the land that is not theirs without the landowner’s permission or government properties and prohibited areas such as the danger zones, waterways, seashores and even the seas.
141. Informal settlers in Bongao would likely occupy the seas primarily because it is a tradition of one of the major indigenous group of people in the municipality – the Sama popularly known as the Badjaos. These informal settlers occupy 76.28 hectares of the sea based on 2017 pixel analysis of satellite maps from Google Earth. These are generally located around the Bongao Island (except the western portion); the southern portion of Sanga-Sanga Island; the Mandulan area also of Sanga-sanga Island; and some areas in the foreshore of Barangays Tarawakan and Sillubog.
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Source: Comprehensive Land Use Plan, Bongao, Tawi-Tawi (2017-2026).
Figure 14. The location of informal settler areas in Bongao, Tawi-tawi, 2017
142. 2.59% also of the total households are renters. Most of the renters are in the Bongao Island and this is because of the commercial activities and educational facilities in the area. The renters are highly concentrated in the barangays of Tubig-Mampallam, Poblacion, Pag- asa, and Lamion. There are also renters in Barangays Sanga-Sanga and this could be due to the presence of airport as well as the MSU.
l. Health
143. The leading causes of mortality for 2015, meanwhile, is as follows:
Table 41. The Leading Causes of Mortality in Bongao, Tawi-Tawi for 2015 No. Causes of Mortality 1 Septic shock 2 Cardio Pulmonary Disease 3 Pneumonia 4 Sepsis Neonaturum 5 Dengue Fever 6 Respiratory Arrest 7 Pulmonary Tuberculosis 8 Acute Infection 9 Acute Kidney Failure 10 Bacterial Meningitis Source: Bongao RHU, Source: Comprehensive Land Use Plan, Bongao, Tawi-Tawi (2017-2026).
144. Rate of Malnutrition. In 2015, a total of 13,538 children below five (5) years of age participated in Operation Timbang program. Of this number, 98.28% or 13,306 were found to be in normal weight for their age while the rest are either underweight or overweight.
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145. 191 or 1.41% is considered as underweight. Of this number only 46 are considered to be severe underweight. 41 are also considered as overweight and this constitutes 0.30% of the total number of children.
Table 42. Weight of children in Bongao below 5 years old, CY 2015.
Severe Underweight Underweight Normal Overweight Age (in Male Female Total Male Female Total Male Female Total Male Female Total months) 0-5 0 2 2 2 2 4 507 493 1000 0 2 2 6-11 4 2 6 8 16 24 609 684 1293 2 1 3
12-23 3 6 9 19 5 24 1,084 1,013 2097 3 4 7
24-35 4 6 10 9 10 19 1,000 1,054 2054 7 6 13
36-47 4 5 9 8 12 20 1,127 999 2126 5 4 9
48-59 4 5 9 14 14 28 1,277 1,193 2470 2 2 4
60-71 0 1 1 17 9 26 1,197 1,069 2266 2 1 3
Total 19 27 46 77 68 145 6,801 6,505 13306 21 20 41 Source: Comprehensive Land Use Plan, Bongao, Tawi-Tawi (2017-2026).
146. In terms of distribution by sex, there are more underweight females than males. More than half of the overweight children are likewise males. Consistently, the females also tend to be malnourished. There are 36 cases of malnutrition equally divided into moderate and severe malnutrition. 66.7% of the malnourished children below five years old are females.
147. The cases of malnutrition are found in 14 barangays. Tubig Tanah and Tubig Boh are noted to have the highest number of cases of malnutrition with five each. Ipil, Sanga-Sanga, Tubig Basag, Pasiagan and Tongsinah have one cases each.
148. Health Resources, Facilities and Services. The Rural Health Unit provides the following programs and services:
• Maternal and Child Health (Pre- Natal, intrapartum, post-partum) • Expanded Program on Immunization • Family Planning • Regular Consultation and Check-up • TB DOTS • Laboratory Services (sputum examination, malarial smear, blood type) • Dental Services • Nutrition Health for 0-5 years old (Garantisadong Pambata, Operation Timbang) • School-based Immunization and Deworming • Non-communicable Disease Cure Program • Communicable Disease Cure
149. The Rural Health Center has its family planning program to help parents properly decide the number of children to have and the family planning method to avail of. It also has a Maternal and Child Health Program that conducts pre-natal checkup among pregnant women, and follows them until the baby is born. When babies are born, these are automatically enrolled in the Expanded Immunization Program to ensure that they have proper and complete
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150. Waste Disposal. Hospital waste is currently disposed of along with the regular wastes as currently there is no special waste disposal for hospital waste.
m. Social Welfare
151. Programs and Services. Bongao has a Municipal Social Welfare and Development Office (MSWDO). It is headed by the MSWD Officer and is assisted by staff. The MSWDO services different types of clienteles including: children, women, persons with disability (PWD), senior citizens, indigenous people (IPs) and other marginalized members of the community. The programs and services provided by the MSWDO are the following:
Table 43. The programs and services provided by the MSWDO, 2016
Target No. of Beneficiaries Served Programs and Services Clientele/Beneficiaries 2014 2015 2016 Day Care Service Childre 1,086 1,650 1,650 Supplemental Feeding (DCC) n 1,086 1,650 1,650 Supplemental Feeding – 3,139 3,139 236 Supervised Neighborhood Play Children in Conflict with the Law 3 6 22 Organization of Kalipunan ng Women 25 25 30 Liping Pilipina Violence Against Woman and 4 20 12 Children (VAWC) Solo Parent 100 150 167 Pre-Marriage Counseling (PMC) for 11 20 27 Couples Out-of-School Youth (OSY) Youth 30 38 47 Person with Disability (PWD) 50 102 74 Organization of Senior Citizens (no. 1,040 1,203 1,397 Senior Citizens of members) Social Pension for Indigent Senior 269 475 675 Citizens Emergency Relief Assistance Displaced Families 190 210 300 Trafficked In-Person 516 490 369 Deportees 1,000 675 377 Pantawid Pamilya Program Indigents 5,300 5,289 5,328 Modified Conditional Fund Transfer Indigenous People 1,080 2,765 3,829 Payapa at Masaganang Cooperatives 4 w/ 235 8 w/ 410 2 Pamayanan members MNLF (PAMANA) members Sustainable Livelihood Program Women - - 28 groups w/700 members Source: Comprehensive Land Use Plan, Bongao, Tawi-Tawi (2017-2026).
152. Social Welfare Organizations. There are three accredited organizations in Bongao that assists the MSWDO. These are the Tawi-tawi Family Life Foundation, Inc., (TFLF) that provides family life education, counseling; the Local Organization of Senior Citizens that provides access to financial assistance to elderly and physical fitness activities to keep the
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n. Sports and Recreation
153. The municipality has several recreation and sports facilities. These are either owned or operated by the barangays or by the schools.
154. Type, number and location of sports and recreational facilities. Just like any typical Filipino community, the people of Bongao also love basketball and thus, each barangay maintain a basketball court. Some of these are covered while the rest are not. The courts, though sometimes not in conformity to standard sizes, are considered as necessary not only for the sports activities but also of social activities of the barangay residents. The barangays with covered courts are: Tubig Boh, Pag-asa, Poblacion, Tubig Tanah, and Simandagit.
155. There is also a convention center in Tubig Mampallam, the Datu Amilbahar Convention Center within the MSU-TCTO Preparatory High School campus; a gymnasium in Barangay Nalil inside the Tawi-Tawi Regional Agricultural School campus; and, a gymnasium in Sanga- Sanga in the MSU TCTO campus. All facilities are owned by the academe but are also being used by the communities surrounding it for sports and recreation.
o. Public Order and Safety
156. Bongao is considered one of the most peaceful municipalities in the Bangsamoro Autonomous Region in Muslim Mindanao (BARMM). To sustain these and ensure proper coordination of different peace- enforcement agencies, the municipal government organized the Municipal Peace and Order Council (MPOC). The MPOC is composed of the local government unit of Bongao, the Philippine National Police (PNP), the Armed Forces of the Philippines, and other interested stakeholders. The MPOC convenes from time to time to assess the situation and recommend policies for common understanding and guidance of the stakeholders concerned.
157. Total Number of Police personnel and facilities. Bongao Police Station has a total of 59 PNP personnel that are assigned in the PNP station at Barangay Pag-asa, in the market, and some strategic areas in the municipality in order to have police visibility. The PNP station has 1 Mahindra Mobile Patrol and 3 handheld ICOM Radio as their communication facility.
158. Types and volume of crime in the LGU. Bongao is a peaceful place and this is manifested by the report of PNP Bongao which was able to record only 87 crime incidents in the first three quarters of 2016. Based on the report, traffic related crime and physical injury topped in the list of crime incidents. There are also reported cases of robbery, motornapping, murder and comprehensive dangerous drug violations.
Table 44. Crimes and other offenses in Bongao, 2016
Number Classification Offense of Cases Crime Murder 8 Homicide 4 Physical Injury 15 Rape 2 Robbery 10 Motornapping 10 Non-Index Crime Traffic Incidence 18
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Number Classification Offense of Cases Special Laws Anti-Trafficking in Person 1 Child Abuse 2 Comprehensive Dangerous Drugs 13
Comprehensive Law on Fire-arms and 4 Ammunition T O T A L 87 Source: Comprehensive Land Use Plan, Bongao, Tawi-Tawi (2017-2026).
159. Fire-fighting personnel and facilities. Bureau of Fire Protection in Bongao has only seven (7) personnel. It has only 1 fire truck available to combat fire incidents.
160. Occurrence of fire and response time. In 2014, there were 8 fire incidents that occurred in the municipality. In 2015, 15 fire incidents were recorded and in the first three quarters of 2016, there were already 5 fire incidents that happened.
161. Number and Location of Existing Security and Detective Agencies. Business establishments, big or small, need security services to safeguard the owners and the business from bad elements. That is why there are 3 Security Agencies that are operating in the municipality and their offices are located at Barangays Sanga-Sanga and Poblacion. These security agencies are: Black Arrow, SSS, and RIBUSA.
p. Agriculture
162. Bongao has 4,651.626 hectares of land devoted to agriculture. These are located in Sanga- Sanga Island and Tawi-Tawi mainland. The agricultural lands are planted with cassava, rice, corn, banana, variety of fruits and vegetables.
163. Agricultural Croplands and Crop Production. The biggest portion of the agricultural land is devoted to cassava being the staple food of the people. It occupies a total of 2,769 hectares with another 1,200 hectares as potential cassava plantations.13 The major areas for cassava plantations are in Barangays Lapid-Lapid, Sumangat, and Luuk Pangdan. As of 2014, there are 406 cassava farmers in the municipality.
164. Banana and mango plantations rank next with 300 and 200 hectares, respectively. Both banana and mango farms can be found all over Bongao, though the latter are more notable in Barangays Tubig Basag, Nalil and Pahut. Sweet potatoes and fruit trees like lanzones, durian, jackfruit and marang occupy two hectares each and these are scattered in the different barangays of the municipality. Cassava also has the highest volume of yield which averages 9 metric tons per hectare. This is followed by banana and calamansi with 5 and 4 metric tons per hectare, respectively. The least in terms of yield are upland rice and corn with 2 metric tons per hectare.
Table 45. Agricultural Croplands and Crop Production in Bongao, Tawi-tawi, 2015 No. of Hectares Volume of Average
Service Potential Yield per ha. Yield per Commodity Barangays Covered Area al area (mt) Hectare (MT) Irrigated Rice 8 5 23.2 2.9 Lapid-Lapid Lowland Rain fed Montay-Montay, Luuk Rice 13 20.4 20.4 2.4 Pangdan, Sumangat, Silubbog Upland Rice 2 20 20 2 Luuk Pangdan, Sumangat Corn 30 10 60 2 sporadic
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No. of Hectares Volume of Average
Service Potential Yield per ha. Yield per Commodity Barangays Covered Area al area (mt) Hectare (MT) Lapid-Lapid, Sumangat, Luuk Cassava 2,769 - 24,786 9 Pangdan & other barangays Banana 300 30 1,815 5 sporadic Calamansi 10 15 40 4 sporadic Rubber 10 15 18 1.8 Lapid-Lapid, Sumangat Mango 200 70 729 2.7 Lupah Pula, Tubig Basag, Nalil, Pahut & other barangays Lanzones 2 3 35 7 sporadic Durian 2 3 19 3.8 sporadic Jackfruit 2 3 25 5 sporadic Marang 2 3 11.5 2.3 sporadic Sweet Potato 2 2 28 4 sporadic Vegetables 28 10 64.4 2.3 Tubig Basag, Luuk Pangdan, Sumangat & other barangays Source: MAO Bongao, Tawi-Tawi, PAO Tawi-tawi, Source: Comprehensive Land Use Plan, Bongao, Tawi-Tawi (2017-2026).
165. Number and Volume of Production by type of livestock & poultry. Almost half of the livestock produced in Bongao are goats with 1,580 heads. The goats are easy to take care and sell especially during Muslim special occasions where offerings are made during prayer or duwa’a. Following goats are cattle and dogs with 868 and 795 heads, respectively. The least number of livestock animals is carabao with only 100 heads. There are no records of swine production because the municipality is predominantly a Muslim population. 77% of the poultry animals in the municipality are chicken. Ducks and turkey are also grown but only in minimal number.
q. Fisheries and Aquatic Resources
166. The municipal waters of Bongao not only provide rich fishing grounds for the local fishermen but also for the culture of seaweeds. Fishing is a major income-generating industry in Bongao. There are 9,501 registered fishermen in the municipality and 86 registered boats. A greater number is unregistered most of whom are occasional fishermen and/or those who have other seasonal jobs.
167. The portion of the Bongao Channel where the proposed Bridge No. 1 will be located serves as a major crossing point to the neighboring island of Sanga-Sanga on account of its short distance. There are no major fishing and aquaculture activities in this area because fishing takes place in the open sea. Navigation which is the most beneficial use in this part of the channel, will allow vessel passage through this area unhampered both during construction and operation since navigation height of the bridge had been adequately provided in the bridge design. During bridge construction, mitigating measures will be done as in Table 53: Impact Mitigation Plan.
r. Trade and Commerce
168. Financial Institutions and Insurance. Bongao is the financial center of Tawi-Tawi. There are three banking institutions operating in Bongao and serving the banking needs of the people of Tawi-Tawi. These banks, all located at Barangay Poblacion, are: Land Bank of the Philippines, Philippine National Bank/Allied Banking Corporation, and, Metrobank. In addition to the banks, there are also companies that accept money transfers. These include the ML Lhuillier with four branches, LBC with two branches, Cebuana Lhuillier, and, Palawan Pawnshop. There are also pawnshops that operate in the municipality by providing loans to the people. Lastly, there are also insurance companies with offices also in Bongao and these are the PNB Beneficial Insurance System and Social Security Service.
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169. Trading. Wholesaling is practiced by some department stores and groceries especially to those buyers from the island-municipalities. However, there are also a number of small- scale retailers in the different barangays serving the basic needs of the population. The stores sell goods from Zamboanga and other parts of the country, and from Malaysia, Indonesia and other neighboring countries. Most prominent products are: rice, canned goods, sugar, cooking oil, noodles flour and biscuits.
170. Transportation. Bongao is likewise the communication and transportation hub of the province. There is one regular daily flight from Zamboanga to Bongao through the Sanga- Sanga Airport. The number of flights doubles during peak season. Commercial boats also ply Zamboanga and Bongao every Tuesday, Thursday and Saturday. A number of cargo boats passing through Jolo and Siasi also operate in Bongao, along with a number of sea vessels for rent. There are also motor launches ferry passengers and cargoes from the island- municipalities to Bongao and vice versa. The frequency of trips, however, varies depending on the weather, distance and number of passengers. Motor launches from neighboring municipalities of Panglima Sugala and Simunul come to Bongao every day except Friday. Land transportation is also common in Bongao and these are through tricycles and jeepneys. Lately, private cars also ply the municipal and provincial roads. Only the tricycles, however, are regulated by the municipal government as the jeepneys and cars are regulated by the Land Transportation Office.
171. Communication. Bongao is home for the Provincial Post Office, and the mail and cargo delivery companies – LBC and JRS Express. Mobile companies like PLDT, GLOBE and SMART also operate in the municipality. In addition, a local telephone company also serves Bongao – the Bongao Nationwide Telephone Service Company. There are also two radio stations in Bongao – the Radio Ng Bayan and DXGD are the two radio stations operating in the municipality.
172. Personal Service Shops. Bongao also has establishments that cater to the personal needs of the people like the beauty parlors and barbershops, dress and tailoring shops for casual, formal and native attires. Some of them are not really in shops but working in their private homes and cater to neighbors, friends and relatives. Bongao has no funeral parlors because the Muslims who are majority of the constituents bury their dead loved ones immediately within 24 hours after death. Christian families, on the other hand, usually bring the body of the dead at their respective residences where families and friends come to pay a visit until burial schedule.
173. Community and Security Services. There are 3 Security Agencies that offer security services to government and private offices and establishments. These are the Black Arrow, SSS, and RIBUSA. These agencies have offices in Barangays Sanga-Sanga and Poblacion.
s. Tourism
174. Tourism is a new industry in Bongao and the prospective tourist areas are still being developed. The private sector is also trying to cope up and have started to establish the support industries like the hotel and restaurant businesses.
175. Tourist Areas. There are at least four existing tourism destinations in Bongao. These are the Bud Bongao – a local conservation area being a monkey sanctuary and a sacred mountain for the natives both Muslims and Christians; the Baloboc Cave and Rock Shelter, an anthropological and archaeological site in Barangay Lakit-Lakit that is currently attracting historians and other enthusiasts; the Lapid-Lapid Mangrove Eco-Park, a mangrove forest conservation area; and the Tango Island, an islet surrounded by white sandy shorelines and rich marine habitat making it an excellent site for snorkeling and scuba diving. There are also
67 INITIAL ENVIRONMENTAL EXAMINATION Tawi-Tawi Bridge No. 1: Nalil-Sikkiat Detailed Engineering Design for Road Improvement and Institutional Development (RIIDP) and Future Financing a number of white sandy beaches which includes Kasulutan Beach, Pasiagan Beach, Sanga- Sanga Beach, and Pababag Beach. Likewise, the five marine sanctuaries namely the Lagasan-Pababag MPA, the Ungus-Ungus Fish Sanctuary, Pasiagan Fish Sanctuary, Ipil Fish Sanctuary, and the Lakit-Lakit MPA/Fish Sanctuary can also serve as a marine tourism destination particularly for those interested not only in the marine environment per se but also in marine ecology management.
F. The Environment Sector
a. Solid Waste Disposal
176. The general practice is for each family to dispose of its own garbage. Others maintain compost pits, there are those who resort to burning, and a significant number, particularly the members of an indigenous population, would just throw all their wastes to the sea. In all those practices, no waste segregation is observed.
177. Eventually, barangays were enjoined to develop communal compost pits. These, though, did not improve the situation so the Municipal Government of Bongao, under the leadership of Mayor Jimuel Que, has started institutionalizing proper waste disposal system thru its Solid Waste Management Program (SWMP). A Solid Waste Management Committee has been created for the purpose though a Solid Waste Management Plan has yet to be enacted.
178. The SWMP is still on its initial stage and currently services eleven barangays. The local government under Mayor Jimuel S. Que, has just acquired four solid waste management equipment to be used exclusively for the program, and has entered into a lease contract agreement for the establishment of a new controlled-dumping site. The site is currently being developed albeit delays are being experienced due to the peace and order situation affecting Mindanao.
b. Sanitary Toilet Facilities
179. Because most of the houses in the municipality are built along the coastal areas, many have no sanitary toilet facilities. For those who have toilets, most have no septic tanks. Human wastes are directly thrown to the sea. Of the 17, 636 total number of households, only 6,877 households or 38.99% have sanitary toilets.
c. Areas for Conservation / Protection
180. There are no protected areas that can be found within the area albeit Tawi-Tawi is a Key Biodiversity Area (KBA) with an estimated 293 species of terrestrial and marine fauna of various taxonomic group being listed in the IUCN Red List within a 50 km of the area of interest19 . In general, the municipal government wants to conserve and protect all its land and water resources particularly its marine environment being the source of livelihood of a significant number of the population. But given the limited manpower and fiscal resources, the following have been raised as the priority conservation areas:
• The Bongao Peak or Bud Bongao which had been declared as Local Conservation Area. It is a monkey sanctuary, and various species of flora and fauna that are unique and could never be found in other mountains. It is also considered sacred by the natives, and a pilgrimage site of both Christians and Muslims. This is between 2.0 to
19 IBAT Proximity Report. Generated under licence 951-16851 from the Integrated Biodiversity Assessment Tool on 31 May 2021 (GMT). www.ibat-alliance.org (Proximity Report generated courtesy of Edwin Lara, Senior Safeguards Officer (Environment), Philippines Country Office, ADB).
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3.0 kilometers away from the bridge location. This will not be directly affected by any negative impacts associated with the bridge construction at the opposite side of the site.
• The Baloboc Cave and Rock Shelter at Barangay Lakit-lakit which is considered as a pre-historic site in the southern frontier of the Philippines. Archaeological excavations undertaken in the Balobok Rock Shelter led to the discovery of ancient artifacts such as polished shell tools made from the valves of a huge clam, red- slipped earthenware shards, animal remains dated by C-14 to be about 8,810-5,190 years ago. These artifacts provide evidence of one of the earliest habitation in the region. This is about 7.0 kilometers (more or less) in the other island of Sanga-Sanga. This will not be directly affected by any negative impacts associated with the bridge construction.
• Lapid-Lapid Mangrove Eco-Park at Barangay Lapid-lapid which is a vast area of mangrove forest densely vegetated with several species of mangroves that grow in the wilds along the coastal area of the barangay. Its thick vegetation can be attributed to the excellent protection being provided by the community people for decades now. Crocodiles and several kinds of birds can also be found in the area. This is about 10.0 kilometers (more or less) in the other island of Ungos-ungos. This will not be directly affected by any negative impacts associated with the bridge construction.
• The Tango Island at Barangay Ungus-ungus. This is an islet surrounded by white sandy shorelines that is excellent for snorkeling and scuba diving because of the existence of giant clams and corals. This is about 9.0 kilometers away from the bridge location. This will not be directly affected by any negative impacts associated with the bridge construction.
• Fish Sanctuaries and/or Marine Protected Areas. Bongao is being considered as a marine tourism destination for the local government’s efforts to preserve its ecology. At present, the LGU has designated five fish sanctuaries/MPAs and these are the Lagasan-Pababag MPA, the Ungus-Ungus Fish Sanctuary, Pasiagan Fish Sanctuary, Ipil Fish Sanctuary, and the Lakit-Lakit MPA/Fish Sanctuary. These areas can be considered as tourist destinations particularly for those interested not only in the marine environment per se but also in marine ecology management. The approximate geographical locations and distribution of these areas are as shown in Table _ below.
Table 46. Approximate Distances of Ecologically Sensitive or Protected Areas from the Bridge Sites
Distance (km.) Ecologically Sensitive or Bridge 2 : Bridge 1 : Bridge 3 : Malassa Protected Areas Paniongan- Nalil-Sikkiat - Lupa Pula Tongsinah a. Bud Bongao or Bongao Peak 2.30 4.70 9.70 b. Boloboc Cave 7.00 6.50 6.60 c. Lapid-Lapid Mangrove Eco-Park 9.60 7.20 3.00 d. Tango Island 8.70 5.90 3.30 e. Fish Sanctuaries e.1. Lagasan-Pababag MPA 3.30 1.00 5.60 e.2. Ungus Ungus MPA 14.30 11.20 6.70 e.3. Pasiagan MPA 3.40 5.40 10.30 e.4. Ipil MPA 12.50 9.20 5.00
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e.5. Lakit Lakit MPA 4.00 5.50 7.80
181. The geographical locations and distribution of these ecologically sensitive or protected areas are as shown in Figure 15 below.
Legend: Fish Sanctuary and/or Marine Protected Areas Bongao Tangao Pasiagan Fish Sanctuary Pabagbag Island Marine Protected Area Baloboc Ungus-Ungus Fish Sanctuary Lapid -Lapid Mangrove Ipil Fish Sanctuary Eco-Park Lakit-Lakit Fish Sanctuary/MPA Bridge Location
Figure 15. Geographical Locations and Distribution of Ecologically Sensitive or protected areas
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d. Water and Watershed: Present and Future Water Demand
182. The Bongao Water District is the major water service provider in the Municipality. As of 2015, however, it only services 13 barangays or 2,463 households equivalent to 32 % of the total population. The other twenty-two (22) barangays or 68% of the households still remain unserved relies on deep well and rain as the major sources of water. This is equivalent to around 7.8 million liters of water per day.20 Water consumption is expected to increase by 160% from 11.98 liters daily in 2017 to 19.22 liters daily by 2026. At present, there are two identified possible sources of potable water supply and these are in the Tarawakan Area (around 30 kilometers from the Poblacion) and the Patal, Karungdong (around 15 kilometers from Poblacion).
per Day Liters Millin In
Source: Comprehensive Land Use Plan, Bongao, Tawi-Tawi (2017-2026)
Figure 16. Projected Water Requirement per Day, 2017-2026
G. The Infrastructure Sector
183. Roads. There are four types of roads in Bongao. These are the national roads, the provincial roads, the municipal roads and the barangay roads. Bongao has a 120.4 kilometer road network. 67.47 kilometers of these or 56.04% are barangay roads, and 47.93 kilometers or 38.81% are national roads. Provincial roads total only to 3.35 kilometers while municipal roads is only 1.65 kilometers long. Barangay roads connect both the residential areas and the farms to the market but even then, almost two-thirds of these are unpaved. On the other hand, all the national and provincial roads are unpaved.
Table 47. List of Roads by Classification and Length, Bongao, Tawi- Tawi Road Condition Road Total (in Percent to Unpaved (in Classification Paved (in km) km) total Roads km) National 47.93 0 47.93 39.81 Provincial 3.35 0 3.35 2.78 Municipal 1.45 0.2 1.65 1.37 Barangay 28.23 46.09 67.47 56.04 Total 80.96 46.29 120.4 100.00
20 Based on a 113.7 liters per capita per day consumption for small towns based on the Philippines Small Towns Water Utilities Data Book
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Source: Comprehensive Land Use Plan, Bongao, Tawi-Tawi (2017-2026).
National Road Provincial Road Municipal and Barangay
Source: Road Network Base Map from Bongao CLUP. Classification of road reconstructed according to the Bongao CLUP and the Comprehensive Capacity Development Project for Bangsamoro Development Plan for the Bangsamoro Final Report Sector Report 2: Infrastructure of JICA (https://openjicareport.jica.go.jp/pdf/12253654_01.pdf).
184. Bridges There are four major existing major bridges in Bongao. These are the concrete bridge connecting Bongao Island and Sanga-Sanga Island; the steel bridge at Suwangkagang, Pasiagan, and the two bridges in Barangay Lapid-Lapid. The existing concrete bridge is along the coast that is continually exposed to winds from the open sea with an actuall channel width that is narrow resulting in drift sand being accumulated at the mouth of the channel rendering the depth becoming shallow. Besides, this concrete bridge has a very low navigation height. The bridge in Barangay Pasiagan does not provide any opportunity to directly connect the two islands of Bongao and Sanga-Sanga because this is located at the other side of the Bongao Island. The two bridges in Barangay Lapi-Lapid will not meet the bridge design requirements and connectivity objectives for the anticipated development of an international port in Malassa.Coastal communities also have wooden footbridges that connect houses and serve as access to the municipality’s road network.
185. Flood Control and Drainage Facilities. Drainage canals have been constructed along the roads of Barangays Tubig Boh, Pag-asa, Nalil, Pahut and Poblacion. There are still many areas that need drainage system for flood control especially during the rainy season.
186. Domestic Water Supply. The municipality is being served by the Bongao Water District which provides water to 13 barangays. The water district relies mainly on underground water system. The rest of the barangays still rely on deep wells and rain as sources of freshwater.
187. Electric Water Supply. The National Power Corporation through the Tawi-Tawi Electric Cooperative Inc. is the major supplier of electric power in Bongao giving access to 13 out of 35 barangays. To date, the NPC provides a total capacity of 7.2 megawatts from its 4-
72 INITIAL ENVIRONMENTAL EXAMINATION Tawi-Tawi Bridge No. 1: Nalil-Sikkiat Detailed Engineering Design for Road Improvement and Institutional Development (RIIDP) and Future Financing unit generator. It operates 24 hours a day with a peak demand of 2.2 megawatts.
188. Transport Facilities. For air transportation, Bongao has an airport in Sanga-Sanga Island with a daily flight during lean season and a twice daily flights during peak season. Bongao also has a municipal port, a wharf, and five fish landing sites that cater to cargoes, passengers, and fishermen. For cargo and passenger vessels, there are regular trips to and for Bongao from other municipalities and barangays, and from Zamboanga City. Barangays also have their respective barangay ports. The municipal road network also serves motorcycles, tricycles, jeepneys and even private cars.
189. Communication Facilities. The municipality has one landline telephone service provider, and is covered by the country’s major telecommunications network such as PLDT, Globe and Smart. ICOM is also available to connect to island-municipalities and nearby areas. Aside from the Philippine Postal Corporation, the municipality is also being serviced by LBC and JRS mail and cargo delivery companies.
190. Waste Disposal System. The Municipal Government of Bongao has started institutionalizing proper waste disposal system thru its Solid Waste Management Program. Proper waste management is being advocated at the local level and the use of sanitary toilets is being encouraged at the household level. With the new Solid Waste Management Program of the municipal government, a controlled dumpsite has been established and regular garbage collection has been set in place.
191. Municipal Cemetery. There are three municipal cemeteries established as a place for human remains. There is a cemetery at Barangay Pasiagan for the Muslims; and, one cemetery each at Pag-Asa and Tubig-Basag for the Christians.
192. Slaughterhouse. There is also one municipal slaughterhouse at Barangay Simandagit. But since the staple viand of the population is fish, the slaughterhouse is rarely used.
193. Public Market. Bongao also has one public market which is located in Bongao Island in the boundary of Barangays Poblacion and Tubig Mampallam. The market is composed of three (3) buildings, two (2) of which are 2-storey buildings for stalls selling dry goods; and a one- storey building or wet goods such as fishes and other marine products.
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IV. ANTICIPATED IMPACTS AND MITIGATION MEASURES
194. The Project is considered environment Category B and significant negative environmental impacts are not anticipated. The impact assessment was conducted for pre- construction, construction and operation phases. Results of the environmental impacts screening are summarized in Table 47. Impact types and magnitudes are indicated for both impacts without the mitigating measures and the resulting situations when mitigating measures will be implemented. The direct impact areas are Barangays Nalil and Pakias that share the bridge length across the channel and host the approaches during their construction. The indirect areas are those barangays that may be traversed by vehicular traffic due to materials deliveries during construction and may include Barangays Sanga-sanga, and Pangasinan at the northern bridge end; and Barangays Pahut, Pasagan, Tubig Boh and Simandagi at the southern bridge end. Sensitive receptors identified during the site visit in 2019 are only residential areas near the bridge landings and approach roads. This will be confirmed prior to start of construction.
195. The screening table uses the symbols “+” for positive impacts and “− “for negative impacts. Symbols for impact magnitudes are “∆” for minor and “” for moderate. The symbol for a minor negative impact is “∆ −”, while a moderate negative impact is “ −“. The second column of the table indicates the type and magnitudes of the impacts without any mitigating measures being applied. The last column of the table indicates the expected impact magnitude after applying the mitigating measures. Hence, a moderate negative impact ( −) will become minor (∆) after applying the mitigating measures. The discussions of each identified issue and corresponding mitigation measures are presented in the succeeding sections.
Table 48. Summary of Environmental Impacts Screening for Tawi-Tawi Bridge No. 1 Without Environmental Impacts and Risks With Mitigation Mitigation PRE-CONSTRUCTION PHASE (Design) ¯ Encroachment on environmentally sensitive areas n/a n/a ¯ Impacts and risks to biodiversity conservation n/a n/a CONSTRUCTION PHASE ¯ Impacts to endangered and/or critically ∆ − ∆ Endangered species ¯ Potential damage to archaeological and cultural n/a n/a ¯ assets ¯ Mangrove vegetation loss and sedimentation within − ∆ ¯ and in the vicinity of bridge pile construction sites ¯ Noise from construction equipment − ∆ ¯ Local air pollution due to construction activities − ∆ ¯ Oil and other hazardous materials releases − ∆ ¯ Vehicular traffic congestion and public access − ∆ ¯ Hazards to public due to construction activities − ∆ ¯ Pollution and health risks due to workers camp − ∆ - Occupational health and safety risks at work sites − ∆ Increased employment opportunity in work sites + + Traffic congestion − ∆ Direct impacts to the Bongao Channel − ∆ - Turbidity due to bored piling activities and − approach road construction ∆ - Removal of between 10 to 20 mangrove stands − ∆ - Livelihood displacement − ∆
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Without Environmental Impacts and Risks With Mitigation Mitigation - Fishing and seaweed farming − ∆ - Damage to corals − ∆ - Damage to seagrass beds − ∆ - Access of marine aquatic wildlife ∆ OPERATION AND MAINTENANCE PHASE Increased risk of road and bridge accidents − ∆ Increased noise levels due to increased vehicular ∆ − ∆ traffic
Increased air pollution due to increased vehicular ∆ − ∆ traffic + + Improved accessibility Notes: n/a = not applicable; ∆ = minor; = moderate; + = positive; - = negative
A. Pre-construction
a. Encroachment on Environmentally Sensitive Areas
196. The existing road and the proposed bridge are located in a corridor that has been transformed already into its present agricultural, grassland, shrub land, with nearby settlements and mangrove vegetation. While a section of the road is adjacent to, and the bridge itself will marginally affect a mangrove area as it traverses through the other side of the bridge approach, the area is not considered an environmentally protected area. The mangrove cover in Barangay Nalil composed mostly of Rhizophora Apiculata, is considered fair. The bridgeworks and the improvement works for the approach road and the construction limit for the bridge will not go beyond the designed length, and width of 15 meters each side of the existing alignment if the DPWH will eventually acquire a 20 m wide ROW for this road.
b. Impacts and Risks to Biodiversity Conservation
197. Available secondary information indicated that the marine waters of the Bongao Channel is characterized with a rich coral ecosystem. The average coral cover in the Municipality of Bongao is more than 46% classified as ‘fair condition”. There are 42 species of coral found in Bongao waters belonging to 32 genera, 14 families and 5 orders. The areas parallel to the road are not undisturbed and over the years the ecological changes due to human activities in those areas have resulted to its present predominantly agricultural landscape. The marine ecological survey indicates that small and scattered population of Lobophyllia corals was found in the vicinity of the proposed bridge within the geographic coordinates N5.03540 E119.75686, N5.03660 E119.75648 and N5.03581 E119.75678. This genus was only found in the Barangay Pakias side with 0.4% of 37.13% total cover of hard corals. The specific species however was not identified. The Lobophyllia genus, sometimes called Lobed Brain corals, are a very popular stony coral for aquarium due to its wide variety of colors and textures. It also includes one species, the Lobophyllia serratus, which is on the IUCN Red List of Endangered Species. It is recommended that further investigation should be done prior to construction in consultation with marine experts from the Mindanao State University-Tawi-Tawi College of Technology and Oceanography (MSU-TCTO) to determine if this species is among the Lobophyllia corals found during the survey. Protection of this species is the same with the other hard corals. The Contractor shall be made aware of its specific location and shall implement appropriate mitigation measures that will ensure this will not be smothered by construction debris and silt resulting from construction activities. Sediment traps or fine nets shall be provided in the vicinity of the coral cover to minimize sedimentation from bored piling works. Collection and removal of these corals shall be likewise prohibited. This shall be committed by the Contractor in its Contractor’ Environmental Management Plan
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(CEMP).
B. Construction
a. Inadequate Disclosure of Project Information and GRM
198. To ensure that host communities of Barangays Nalil and Sikkiat are aware of the grievance redress mechanism and project implementation schedule and activities, these aspects will be communicated by the DPWH with LGU representatives, directly affected persons, and residents of the host communities. In particular, such communication will be carried out by the Environmental Officer (EO) of the Office of the District Engineer with the support of the CSC through consultations with the municipal and barangay officials in advance of activities, when and where noise, dust and other nuisances that may be expected, etc. and how affected persons can access the GRM for environmental concerns related to the project.
199. The consultation for all interested stakeholders, will be conducted by the EO and CSC prior to commencement of site clearing and quarterly thereafter or as agreed with the stakeholders. The EO and CSC should ensure that stakeholders are properly informed and encouraged to attend the consultations.
b. Local Air Pollution
200. Air emissions during construction mainly arise from the operation of construction vehicles and clearing of the approach roadway of base and sub-base materials, rubbles, and operation of quarry pits and hauling of materials. Emissions from rock crushing operations, aggregate drying, concrete batching plants and hot mix plants which will be required for the works may also degrade air quality. Movement of haul trucks during spoil transport will also generate dust and has the potential to affect communities located along the route towards the spoil disposal area. No spoils shall be disposed into the immediate vicinity of the site or anywhere along the Bongao Channel. To minimize dust and gaseous emissions during construction phase, the contractor will ensure that:
a) Regular water spraying/dampening dust emissions from disturbed soil, approach road construction surfaces and haul roads shall be undertaken wherever there are sensitive receptors along the materials haul route. Spraying will be done twice daily or at such frequency as is needed to suppress dust emission to acceptable levels. b) Regular removal of debris and spoil piles and clean-up after completion of the works. c) All vehicles transporting dusty materials will be tightly covered to prevent release of fugitive dust. d) Rock crushing, concrete batching plant, aggregate drying and surface treatment preparation operations (whether bituminous asphalt or spray seal mixes) will be located a sufficient distance (at least 500 m) from habitations and community environments including other sensitive receptors (churches, schools, medical facilities, etc.) to assure that there will be no community impacts from such activities. It is due to fine particles or offensive odor which such facilities generate often reach a point within 500m from the source under certain conditions (e.g. wind strength/direction). Establishment and operation of these facilities must be approved by the relevant authorities (e.g., EMB-DENR, LGUs). e) All equipment, machinery and vehicles used for the project must be well maintained to ensure proper functioning thereby minimizing contribution to air pollution. f) For storage areas of construction materials such as sand, gravel, cement, etc., provisions will be made to prevent materials from being blown away towards sensitive receptors. g) Roads used for the hauling of construction materials will be regularly cleaned to remove tracked mud, cement, etc.
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h) Stockpiling of spoils near sensitive receptors and in the immediate vicinity of the bridge site along the Bongao Channel will be prohibited. i) Asphalt plants, concrete batching plants and crushing plants will be equipped with dust suppression devices such as water sprays, dust collectors, covered conveyor, etc. j) Speed limits (at least 25 kilometers/hour) will be imposed on construction vehicles to minimize dust emission along areas where sensitive receptors are located. k) Burning of all types of wastes generated at the construction sites, work camps and other project-related activities will be strictly prohibited. l) Stockpiles of sand and aggregate greater than 20 m3 for use in concrete mixing will be enclosed on three sides, with walls extending above the pile and two meters beyond the front of the piles. m) Water sprays will be used during the delivery and handling of all raw sand and aggregates, and other similar materials, when dust is likely to be created and to dampen such stored materials during dry and windy weather to avoid impacts to sensitive receptors. n) Cement and other such fine-grained materials delivered in bulk will be stored in closed containers.
c. Noise
201. Noise impacts will originate from the operation of heavy construction equipment. The range of typical noise levels in relation to distance from a construction site is shown in Table _. Sensitive receptors within 100 m from the bridge project may be adversely affected by construction21 noise. Noise levels due to construction activities should not exceed 55 dB(A) near residential areas during daytime and 45 dB(A) for nighttime based on World Health Organization recommendations.
Table _. Construction Noise / Distance Relationship
Distance from Construction Site (m) Range of Typical Noise Levels (dBA)
8 82 – 102 15 75 – 95 30 69 – 89 61 63 – 83 91 59 – 79 122 57 – 77 152 55 – 75 305 49 – 69 Source: Dept. of Transportation (USA) from the Environmental Impact Assessment, TA-8574 PHI: Improving National Roads for Inclusive Growth in Mindanao Project (41076-045), February 2016
202. Construction noise levels are expected to exceed WHO guidelines and would temporarily affect sensitive receptors (SRs) close to the construction zone. Table _ indicates noise levels for common construction machinery.
Table _. Construction Machinery Noise22 Noise Emission Level (dBA) at Distances (m) from Equipment Equipment 5 10 15 20 40 60 80 100 150 200 300
21 For example, when a construction machine with 110 dBA of acoustic power level such as a concrete breaker operates, noise level of 70 dBA is expected to reach at 90 m far from the source, based on an authorized theoretical formulation 22 Source: TA-8574 PHI: Improving National Roads for Inclusive Growth in Mindanao Project (41076-045), prepared by the DPWH for the ADB, February 2016 taken from various sources
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1 Bulldozer 86 80 74 68 64.5 62 60 56.5 54 50.5 2 Excavator 84 78 72 66 62.5 60 58 54.5 52 48.8 3 Loader 90 84 78 72 68.5 66 64 60.5 58 54.5 4 Land scraper 90 84 78 72 68.5 66 64 60.5 58 54.5 5 Mixing Equipment 87 81 75 69 65.5 63 61 57.5 55 51.5 6 Roller 87 81 75 69 65.5 63 61 57.5 55 51.5 7 Vibrator road 86 80 74 68 64.5 62 60 56.5 54 50.5 roller 8 Backhoe 81 9 Compactor 82 10 Concrete mixer 85 11 Crane (mobile) 83 12 Generator 81 13 Jack hammer 88 14 Paver 89 15 Pneumatic tool 85 16 Pump 76 17 Shovel 82 18 Truck 88 Source for Equipment 1-7: Initial Environmental Examination (IEE) of the Proposed Logistics development Project. Government of Mongolia. 2011. Source for Equipment 8-18: Based on Figure 1 – Construction Equipment Noise Ranges. Noise from Construction Equipment and operations, Building Equipment and Home Appliances. US-EPA. 31 December 1971. A blank field indicates no data available.
203. Noise impacts are unavoidable consequence of construction that will be mitigated through implementation of the following measures:
a) Limit the duration of noisy construction activities to daylight hours, whenever possible, in the vicinity of sensitive receptors. b) In areas near houses or noise-sensitive sites, noisy equipment will not be operated during nighttime to early morning (19:00H – 06:00H). c) Workers exposed to high noise levels will be provided with ear plugs. d) The contractors will provide prior notification to the community on the schedule of construction activities. e) Whenever possible, noisy equipment will be completely enclosed which can significantly reduce noise levels. f) Any stationary equipment that produce high noise levels (e.g., portable diesel generators, compressors, etc.) will be positioned as far as is practical from sensitive receptors. g) Construction traffic routes will be defined in cooperation with local communities and traffic police to minimize noise and nuisance. h) Vehicle speeds will be reduced around sensitive receptors. i) Concrete batching plants will be located at least 500 m away from sensitive receptors. j) Temporary noise barriers will be installed along the edge of the road, as necessary, in front of sensitive receptors facing heavy construction activities. k) Prior to undertaking noisy activities, the contractor will consult with village leaders and representatives from the religious sites and schools along the project road regarding construction schedule so as to minimize disturbance to important events such as ceremonies, examination period and the like.
d. Impacts due to Spoils Disposal
204. The Project will generate spoils from the road approach, and bridge construction during the bored piling works. To ensure proper handling and disposal of such materials, prior to excavation, contractors will submit a spoils disposal plan to concerned authorities such as LGUs and DPWH for approval. A copy of the approved plan will be submitted to ADB. The plan
78 INITIAL ENVIRONMENTAL EXAMINATION Tawi-Tawi Bridge No. 1: Nalil-Sikkiat Detailed Engineering Design for Road Improvement and Institutional Development (RIIDP) and Future Financing will show the location of proposed excavation sites, cut locations, fill and/or disposal sites for excess cut. This plan shall form part of the CEMP.
205. The plan will include photographs of the sites and will also indicate the existing land use and capacity of the disposal site. The contractor will ensure that spoils disposal will not take place along the Bongao Channel, will not cause sedimentation or obstruction of channel flow and not cause damage to agricultural land, properties and other productive sites.
e. Impacts from Operation of Borrow Areas and Quarries
206. The approach road of the bridge will require embankment fill and construction materials that will be sourced from borrow pits and quarries. For commercial borrow pits and quarries, the contractor will ensure that only facilities with necessary environmental permits will be used for the project. For project-specific facilities, i.e., those that will be established and solely operated for the project, the contractor will ensure that these are covered by necessary environmental permits. Copies of the permits shall be provided and included in the CEMP.
207. Prior to operation of these facilities, the contractor will submit to the LGU and DPWH a plan showing the location/s of borrow pits and quarries to be used, as well as timeframe and mitigation measures to be implemented to rehabilitate project-specific borrow pits and quarries. The contractor will also ensure that topsoil will be properly removed, stockpiled and preserved for later use during restoration of the borrow pit. Vegetation cover will also be provided during rehabilitation of the site. Upon completion of extraction activities, quarries and borrow pits will be dewatered, signages and fences installed, as appropriate, to minimize health and safety risks.
f. Erosion and Unstable Slopes
208. Soil erosion and unstable side slopes susceptible to landslides are not anticipated along the alignment of the bridge approaches where raising of embankment is required. However, impacts due to soil erosion and unstable side slopes may include: i) increased run off and sedimentation of the Bongao Channel were corals and seagrass beds maybe affected; ii) loss of topsoil that could affect vegetation; (iii) deposition of sediments that will have adverse impacts to the water quality of the Bongao Channel and aquatic organisms; iv) damage to vegetation by burying or gulling; and v) development of unsightly cuts and fills that have been riddled by uncontrolled erosion and gulling. The above impacts will be addressed through:
a) Planting of native species of trees and landscaping along the short approach roads and embankment slopes, as appropriate. b) Construction activities will be carried out intensively during dry season. However, as the area is not generally typhoon-prone, construction work during wet season is likely feasible. c) Slope protection measures (e.g., sodding) will be implemented to avoid impacts to agricultural land and adjacent properties. Areas to be cleared of vegetation for construction will be restricted to the minimum required for immediate works.
g. Impacts to Marine Water Quality and Ecology
209. The potential sources of water pollution associated with different construction activities include excavation and filing, bored piling and pier construction for the bridge works, concrete mixing, refueling facilities, and equipment maintenance. Water from concrete batching plants and casting yards is expected to be alkaline with high concentration of total suspended solids (TSS). All these are anticipated impacts on the Bongao Channel that will be crossed by the bridge. Measures to minimize impacts to marine water quality are as follows:
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a) Control of siltation during bored piling and approach road construction will be achieved through limiting the exposure of areas prone to erosion, as well as providing silt traps or fine mesh nets to especially protect coral species identified during the marine ecological survey. The appropriateness of contractor’ mitigation measure for this impact shall be informed by experts’ advice from the MSU Campus of Tawi-Tawi during the pre-construction stage of the project. Continuous consultation with marine experts is also encouraged. b) Observing proper management of spoils during bored piling works and approach roads embankment by stockpiling away from the work areas and providing bunds while waiting to be properly disposed in locations to be approved by the CSC. c) Transporting spoils immediately to final disposal sites as much as possible to minimize materials carried by surface runoff during rainy days. d) Avoid prolonged stockpiling unless necessary (i.e. topsoils necessary for agricultural re-use where sodding maybe necessary to keep from being washed away during rainy days). e) Bentonite slurry or polymers that maybe finally be decided to be used during bridge construction will be collected and processed in a system of leak-free tank storages. Discharges into the Bongao Channel will be prohibited and compliance closely monitored by the CSC. f) Spillage of bentonite or polymers in adjacent lands will be cleaned up immediately to prevent caking and hardening, or contaminating the marine water brought about by surface runoff during rainy days. g) Prior to establishment and operation of concrete batching plants and casting yards, the contractor will obtain the necessary environmental permits to ensure proper siting away from the Bongao Channel. h) Retention ponds with sufficient specifications/capacity will be constructed for treatment of wastewater (e.g., from washing of equipment such as mixer drums, trucks and chute, contact storm water, etc.) and shall be operated and maintained to ensure that effluent quality will meet applicable standards. i) Equipment service and maintenance yards will be sited away from the Bongao Channel and provided with impermeable flooring and collection sump. j) Watertight receptacles will be provided in all the equipment maintenance shops for waste oil, oily rags, spent oil filters, solvents and oily containers to prevent leaked materials from being washed to the channel during rainy days. k) Disposal of wastes contaminated with hydrocarbons shall not be done in the channel, and will be done only through authorized waste handlers and recyclers. l) Refueling and servicing of equipment will only be carried out in areas away from the channel and adequately equipped to collect leaks and spills. m) Fuel and other hydrocarbons will be stored in a roofed area that has an impervious floor and bund around it. n) Fuel storage area will be located away from watercourses, flood-prone areas and workers camps that may eventually carry materials to the channel during rainy days. o) Spill clean-up materials (e.g., absorbent pads, etc.) specifically designed for petroleum products and other hazardous substances where such materials are being stored and used shall be available to ensure leaked residues are not carried away by surface runoff during rainy days. p) Relevant construction personnel will be trained in handling of fuels/hazardous substances and spill control procedures. q) All storage containers of hazardous materials and wastes will be properly labeled and maintained in good condition. r) Restoration of temporary work sites will include removal and treatment or proper disposal of oil contaminated soils.
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h. Loss of Vegetation
210. The project will require removal of a small number of between 10 - 20 mangrove trees and other vegetation (shrubs, grass, agricultural crops, etc.) to give way to bridge approaches. A tree inventory shall be further conducted based on actual ground staking of the construction limits for both the bridge piers and embankments for the approach roads. This activity shall be. conducted by the Contractor to be used in the application of tree cutting with the equivalent BARMM DENR CENRO which shall verify the number of the trees prior to the issuance of a tree cutting/earthballing permit. This activity shall be conducted prior to the tree-cutting activity during the pre-construction phase of the project as part of the tree-cutting permitting requirement.
211. Since none of these areas are within legally protected areas (as previously discussed elsewhere in this report) or are critical habitats/high biodiversity areas which support survival of critically endangered species, ecological impacts are not considered significant.
212. No compensation for all affected mangrove stands will be paid to affected persons. However, to compensate for the loss of these mangrove stands, the following will be implemented:
a) DPWH will obtain a tree cutting permit in compliance with PD 705 (Revised Forestry Code of the Philippines). No tree cutting will be undertaken without the necessary permit to be issued by the Community Environmental and Natural Resources Office (CENRO) of the DENR. b) The tree cutting program, which will be undertaken by DPWH through a contractor, will be based on the Tree Chart to be prepared by the CENRO. The said chart will be generated through a tree inventory to be conducted by the Contractor detailing the species, diameter at breast height and global positioning system (GPS) reading of each tree. The Tree Chart will also include a site development plan/bridge and approach road alignment plan indicating the location of each mangrove stands to be cut. c) Marking of each mangrove stands (where practicable) will be carried out by the Contractor to be verified by the CENRO staff. Tree cutting can only be undertaken under close supervision of CENRO staff who will be present at the site throughout the duration of cutting activities. Cut trees will be turned over to the CENRO or disposed elsewhere as maybe provided in the tree cutting permit. d) DPWH will undertake replacement of cut mangrove stands in compliance with DENR Memorandum Order no. 05 of 2012: Uniform Replacement Ratio for Cut or Relocated Trees which mandates that "For planted trees in private and forest lands not covered under item 2.1 (i.e., private lands and forest lands exclusively established for tree plantations/timber production purposes) tree replacement shall be 1:50 while naturally growing trees on the same areas, including those affected by development projects shall have 1:100 ratio in support of the National Greening Program (NGP) and climate change initiatives of the Government". Such tree replacement is further mandated in a Joint Memorandum Circular No. 2, series of 2014: Guidelines for the Implementation of the DPWH-DENR-DSWD Partnership on the Tree Replacement Project co-signed by the Secretaries of the DPWH, DENR and Department of Social Welfare and Development (DSWD). e) DPWH will ensure that one of their Environment Specialists and/or that of the Supervision Consultant will closely monitor the tree cutting activities to ensure that these will comply with the provisions of the Tree Cutting Permit and corresponding Tree Chart. As part of the semi-annual environmental monitoring report to be submitted to ADB, DPWH will report on the status of tree cutting, any issues/concerns, corresponding actions and other relevant matters.
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f) To avoid unnecessary impacts to vegetation, the contractor will prohibit cutting of mangrove trees for firewood and for other uses in the Project and will ensure that tree cutting is limited to areas as approved by the CENRO. g) Seagrass beds that will be affected by the construction of the bridge piers shall be relocated to the nearby areas prior to the erection of cofferdams to naturally regrow and revegetate sparsely populated seagrass habitats. Seagrass relocation activities shall be under the supervision of experts preferably from the MSU Campus of Tawi- Tawi to properly guide the contractor of the relocation/revegetation activities.
i. Occupational Health and Safety Hazards
213. Workers will be exposed to safety hazards due to operation of heavy and highly specialized bridge construction equipment, working at heights, performance of other construction activities, etc. as well as health hazards associated with inadequate sanitation facilities and other accommodation amenities, etc. The following measures will be implemented by the contractor to minimize adverse impacts:
a) Use of personal protective equipment (PPE) such as safety shoes, safety hat, goggles, safety belt, ear protection or other garments or equipment designed to protect the wearer's body from injury will be strictly observed during construction. b) Provision of personal flotation devices (PFDs) to all workers working on the bridge to help reduce the risk of drowning when falling into the Bongao Channel. c) Preparation and implementation of a COVID-19 Risk Management Plan following existing guidance from the DPWH, as well as the ADB Guidance on Managing Risk from COVID-19 on Construction Sites and in Workers’ Housing (June 2020). d) Provision of first aid kits that are readily available to workers as well as access to or availability of a health worker to attend to any immediate health needs of workers and in case of untoward incidents. e) Conduct orientation for construction workers regarding health and safety measures, emergency response in case of accidents, fire, etc., and prevention of HIV/AIDS, COVID-19 and other related diseases. f) Installation of adequate drainage in workers camps to avoid water logging/accumulation of stagnant water and formation of breeding sites for mosquitoes. g) Provision of separate clean housing with sufficient ventilation and separate hygienic sanitation facilities for male and female workers h) Provision of reliable supply of water for drinking, cooking and washing purposes at the workers’ camps. i) Proper collection and disposal of solid wastes within the workers’/construction camps consistent with local regulations. j) Provision of fire-fighting equipment at the work areas, as appropriate, and at workers camps. k) Treatment of wastewater emanating from workers camps, construction camps and other project-related activities and facilities consistent with national regulations. l) Use of reversing signals on all construction vehicles.
j. Public Health and Safety Hazards
214. Health and safety hazards may also be experienced by adjoining communities due to activities that will generate elevated noise levels and excessive dust, unsafe construction practices, etc. To protect the health and safety of host communities, the following measures will be implemented by the contractor:
a) Installation of sturdy fencing or barriers/barricades such as G.I. sheets, phenolic boards/plywood, wood fences, filled up used fuel drums with soil or gravel in drainage excavations, concrete jersey barriers or water-filled plastic jersey barriers, bamboo
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fencing, or barbed wire fencing depending on the extent of excavation works) around excavation areas and construction sites. b) Provision of proper signage and lighting at night at the periphery of the construction site to warn and direct traffic and pedestrians. c) Deployment of security personnel in hazardous areas to restrict public access. d) Imposition of speed limits for construction vehicles along residential areas and where there are other sensitive receptors. e) Orientation of drivers on safe driving practices to minimize accidents and to prevent spill of hazardous substances and other construction materials during transport. f) If necessary, provide safe passageways for pedestrians crossing the construction site. g) At construction areas, provide safe access to farmland and other properties.
k. Traffic Obstruction
215. The project will not generally affect land access during the construction stage since the bulk of civil works will be undertaken on bridge works along the Bongao Channel. While hauling of construction materials through the main thoroughfares will be necessary and add to the present volume of traffic, materials transport may be scheduled to also be made along the Bongao Channel through barging. Sea vessel traffic are not anticipated to be affected during construction by making sea lanes in between the bridge piers open following the contractor’ method of construction. The contractor shall be required to prepare and submit a traffic management plan considering both road and sea vessel traffic to ensure potential congestion and access obstruction are avoided. Construction activities may require partial road closures which can cause traffic delays and unsafe conditions for vehicles and pedestrians. The contractor will implement the following to minimize impacts:
a) Prepare and implement an alternate plan to divert some materials delivery using the Bongao Channel following coordination with the LGU and the Philippine Coast Guard where possible. b) Provide signs advising road users that construction is in progress, particularly in areas where vehicles hauling of materials crosses existing roads and where construction related- facilities are located. c) Employ flag persons to control traffic when construction equipment is entering or leaving the work area. d) Post traffic advisory signs (to minimize traffic build-up) in coordination with local authorities.
l. Accidental Discovery of Artefacts
216. In the event of unanticipated discoveries of cultural or historic artefacts (movable or immovable) in the course of the work, the contractor will take all necessary measures to protect the chance finds. Procedures to be followed in case of discovery of artefacts are:
a) Contractor to immediately cease operations at the site of discovery b) Contractor to inform the CSC and Environment Officer of the Office of the District Engineer c) CSC to relay information to DPWH, d) DPWH to notify the National Historical Commission of the Philippines (NHCP) and/or other concerned government agencies for the next steps e) Recommence work only after NHCP has provided official notification accordingly
m. Damage to Properties
217. Local roads will be used to transport equipment, construction materials and spoils. Since local roads are usually unpaved and has low load bearing capacities, use of these roads
83 INITIAL ENVIRONMENTAL EXAMINATION Tawi-Tawi Bridge No. 1: Nalil-Sikkiat Detailed Engineering Design for Road Improvement and Institutional Development (RIIDP) and Future Financing by the project may result to deterioration of the roads which can cause inconvenience to the local communities. Damage to properties such as houses, other structures, agricultural land, water supply facilities, etc. may also occur due to operation of vehicles and equipment, and construction-related activities. The contractor will implement the following measures to address such impact:
a) The contractor will immediately repair and/or compensate for any damage that it causes to properties (houses, farmlands, aquaculture ponds, irrigation canals, etc.), community facilities such as water supply, power supply, communication facilities and the like. b) Access roads used for transport of construction materials and other construction- related activities will be maintained by the Contractor in at least in their pre- project condition for the duration of construction.
n. Impacts to Livelihood
218. Bongao Channel serves as an important navigation route and fishing area of the municipality. However, the area nearest to the bridge alignment is not used for any economic activity such as seaweed farming or fishing albeit fishing is generally a major activity of the whole municipality. The bridge construction activities will not hamper or displace any livelihood activities of the population of the barangays. This may even enhance opportunities for employment of these fisherfolks for skilled or unskilled labor for the project to augment their income and also reduce dependency on fishing, at least for the duration of construction. The Contractor is encouraged to hire local labor from the direct impact areas of Barangays Nalil and Sikkiat, as well as qualified skilled and unskilled laborers from the indirect areas.
o. Unanticipated Environmental Impacts
219. If any unanticipated impacts become apparent during project implementation, the DPWH will update the environmental assessment and EMP or prepare a new environmental assessment and EMP to assess the potential impacts, evaluate the alternatives, and outline mitigation measures and resources to address those impacts. The updated or newly prepared documents will be submitted to ADB for review, clearance and public disclosure.
220. During the construction phase, and prior to the erection of the piers of the bridges, the contractor shall see to it that damages to the marine biodiversity in the vicinity of the bridge location mentioned above are avoided, minimized or mitigated. The Contractor shall incorporate the required sound mitigation hierarchy in its CEMP prior to construction following staking, site inspections and acquiring further information from experts from the academe in the MSU Campus in Tawi-Tawi.
C. Operation Phase
a. Air Quality
221. The impact on air quality during operation stage depends upon traffic volume, traffic fleet including fuel type and prevailing atmospheric conditions. An unstable atmospheric condition disperses pollutants more and results into low pollutant concentrations while stable atmospheric conditions build-up the pollution level. To assess the likely impacts on the ambient air quality due to the proposed bridge project, the prediction of nitrogen dioxide (NO2) and particulate matter (PM) concentrations will have to be carried out at a later time i.e using line source dispersion modeling approach, based on Gaussian equation.
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b. Noise
222. During operations, noise emissions from road vehicles may disturb community life and the living environment. It is anticipated that with the operation of the bridge will catalyze development in the area and will create opportunities to change the land use. Population will be anticipated to increase in the barangays traversed by the bridge and beyond. However, noise impacts from vehicles travelling along this road connected by the bridge are not expected to be significant due to the light traffic loads.
223. Speed bumps may be provided in areas where there are sensitive receptors so as to further reduce noise levels from passing vehicles most especially along the residential areas of Barangay Nalil and Barangay Pakias. In addition, regular maintenance of pavement and traffic management especially near receptors would also further contribute to lower ambient noise levels.
c. Induced Impacts
224. The bridge project will connect to an existing road and there is not likely to be any significant or abrupt change to the current pattern of movements caused by the bridge and approach road construction activities. There could be land use change over time involving land conversions from agricultural to residential and commercial development brought about by increased accessibility and economic activities. The project’s induced impacts will be mainly positive. These benefits include improved and shortened access and connectivity between the two barangays (and the two islands in general) to social services and improved economic development opportunities in the Municipality of Bongao.
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V. INFORMATION DISCLOSURE, CONSULTATION AND PARTICIPATION
225. Public consultations are needed to generate awareness, informed opinions/views, and suggestions/approaches. It is important that misconceptions are clarified and stakeholders are fully aware and informed about the project to eventually stimulate dynamic participation and support in the implementation of the development activities in the locality. It is important that the IEC be produced in local dialect to ensure effective understanding of the target populace. The components of the IEC are the following:
• Dissemination of the outputs of the impact assessment Information on the project design • Information on project implementation and monitoring
226. The proposed project has been presented to stakeholders on 17-20 December 2019 during the preparation of the Project and the detailed engineering phase in connection with the preparation of the resettlement and indigenous people’ plan (RIPP) involving the conduct of perception survey, census, socio-economic survey (SES) and inventory of loss (IOL). The information included the following:
• Brief project description showing the bridge location and its approach roads. • Potential environmental and socioeconomic issues/impacts per project phase • Recommended mitigation and enhancement measures addressing both negative and positive impacts of the project • Participation of the stakeholders in project implementation
227. In compliance with the requirements of ADB’s Safeguard Policy Statement (SPS 2009 and DAO 2003-30, a public consultation was carried out for this bridge project to primarily inform the community about the proposed project and to provide opportunity to the community to participate and make clarifications on pertinent matters related to the project. These were attended by representatives of different sectors and organizations that will be affected by the project implementation. No significant environmental issues were brought up during the consultation besides the issue on resettlement. The issues and concerns raised in the other areas are similar, centering on the issue of resettlement.
Table 49. Summary Matrix of Public Consultation NAME OF GENDER TOTAL DATE VENUE Agenda BRIDGE Male Female PARTICIPANTS Bridge No. 2: Barangay Hall, 15 1 16 Presentation of project Tongsinah- Barangay background, scope, Paniongan Paniongan objectives, benefits, Bridge updates, basic Bridge No. 1: Baran 6 1 2 resettlement policies Nalil-Sikkiat gay 9 5 Bridge (GOP and ADB), cut- Hall, off-date and Baran 12/18/2019 announcement of gay succeeding Nalil resettlement activities. Baran 0 4 4 gay Hall, Baran gay Pakias
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12/19/2019 Bridge No. 3: Barangay 4 2 6 Malassa-Lupa Malassa Bridge Pula Bridge Site
Source: Public Consultation, December 2019.
228. During the public consultation, the summary matrix of issues and concerns is as follows: Table 50. Summary Matrix of Public Consultation RAISED BY RESPONSE BY DPWH AND QUESTIONS AND ISSUES CONSULTANTS Date of project implementation Name unrecorded Dependent on other factors.
1
Will there be a relocation site for Name unreccored This will be identified together with the LGU. those who would be affected by the project.
2
Barangay Chairman of Barangay Chairm Mayor Que said that it would be too late to Barangay Pakias indicated of Barangay change the bridge name at this point. 3 hesitation to attend the meeting Pakias However, he assured Pakias Barangay because the Barangay was left Chairman Ading that the Municipal Council will out in the naming of Bridge No. immediately issue a resolution renaming the 1 Bridge No. 1 as Nalil- Pakias bridge right after the completion of construction of the bridge.
Mayor Que also asked if change of bridge site is still feasible for Bridge No.1,
Consultant said that the design and DED related plans of the bridges are now under review by the Bureau of Designs, DPWH. Observation that the existing Hon. Mayor Que, The development of the local road network road would likely be affected by Municipality of would be undertaken by the regional and local 4 Bridge No.1. Bongao government. There is another plan to construct a new port in front of Papahag Island. Bridge location for the Bongao Channel was selected at the narrowest portion due to bridge construction cost; and location with the least involuntary resettlement and marine ecological impacts. Bridges are cost effective when connected to existing road networks. 229. Source: Public Consultation for the Tawi-Tawi Bridges, December 2019.
230. Public consultation and information disclosure to stakeholders will continue, when necessary, during subproject implementation.
87 INITIAL ENVIRONMENTAL EXAMINATION Tawi-Tawi Bridge No. 1: Nalil-Sikkiat Detailed Engineering Design for Road Improvement and Institutional Development (RIIDP) and Future Financing
VI. GRIEVANCE REDRESS MECHANISM
231. There is no DPWH-DEO in Tawi-Tawi Province. In the case of Tawi-Tawi Bidges, project related environmental complaints will be managed by UPMO RMC II and DPWH Region IX. Prior to the commencement of the civil works UPMO-RMC II will closely coordinate with the LGUs of the Tawi-Tawi Province to establish the grievance redress mechanism to manage complaints/grievances of affected persons on the sub-project’s environmental performance. This mechanism will be disclosed to the host communities prior to commencement of site works and contact information will be posted in the tarpaulin for the information of the host community.
232. A Grievance Redress Committee (GRC) will be chaired by the UPMO-RMC II Project Engineer as a representative of the UPMO-Project Director and will be tasked to resolve any complaint on the project. Members will include the following: (i) the contractor’s highest official at the site such as the Construction Manager or the Construction Superintendent; (ii) Barangay Chairperson; (iii) Environment Specialist of the Construction Supervision Consultant and (iv) the contractor’s environment officer. For the quick filing of complaints, the GRM will use the attached grievance intake form (Appendix 1). The Project Engineer will be responsible for the registration of grievances and communication with the aggrieved party. To facilitate addressing complaints, the project billboards shall include contact details/hotlines of the contact person/s that will receive the complaints located in the campsite offices and in project billboards that will be erected at the starting point of the project.
233. The steps to be followed in filing complaints and the procedures for redress are the following:
(i) complainant will provide the background and file the complaint directly either verbally or in writing to the on-site contractor representative(s), barangay officials and/or the Project Engineer for immediate corrective action; (ii) As the representative of the mplementing office, the Project Engineer then required to act immediately on valid complaints and record such complaints in a complaints registry that must be maintained on site; (iii) complaints that cannot be immediately attended to by the Contractor shall be filed either verbally or writing to the GRC, who will assist the complainant in filling-up the grievance intake form; (iv) within 2 working days, the Project Engineer and the contractor’s Environment Officer, contractor’s representative, and the complainant will discuss if the complaint can be resolved without calling for a GRC meeting; (v) within 3 days of lodging the complaint, the Project Engineer will provide the complainant a written feedback on the process, steps and timeframe for resolving the complaint. (vi) if the complaint cannot be resolved, a GRC meeting with the complainant will be called within 5 working days; (vii) the GRC will have 15 days to resolve the complaint; (viii) the complainant will receive feedback from the Project Engineer within 5 working days after the various steps of the GRM are completed. (ix) if unsatisfied with the decision, the existence of the GRC will not impede the complainant's access to the Government's judicial, administrative remedies or through concerned government agencies (e.g., Community Environment and Natural Resources Office and Provincial Environment and Natural Resources Office of DENR, Regional offices of the Environmental Management Bureau, etc.)
234. The GRC will receive, follow-up and prepare monthly reports regarding all complaints,
88 INITIAL ENVIRONMENTAL EXAMINATION Tawi-Tawi Bridge No. 1: Nalil-Sikkiat Detailed Engineering Design for Road Improvement and Institutional Development (RIIDP) and Future Financing disputes or questions received about the Project and corresponding actions taken to resolve the issues. These reports will be included in the semi-annual environmental monitoring reports to be submitted by DPWH to ADB.
89 INITIAL ENVIRONMENTAL EXAMINATION Tawi-Tawi Bridge No. 1: Nalil-Sikkiat Detailed Engineering Design for Road Improvement and Institutional Development (RIIDP) and Future Financing
VII. ENVIRONMENTAL MANAGEMENT PLAN
235. The Environmental Management Plan (EMP) is the synthesis of all proposed mitigation and monitoring actions, set to a time frame with specific responsibility assigned and follow-up actions defined. It contains all the information for the proponent, the contractor and the regulatory agencies to implement the project within a specified time frame
236. This EMP consists of a set of mitigation, monitoring and institutional measures to be taken for the project to avoid, minimize and mitigate adverse environmental impacts and enhance positive impacts. The plan identifies responsibilities and cost estimates needed for the implementation of these measures, reporting requirements, and capacity building activities, where necessary. The major components of the EMP are:
(i) Mitigation of potentially adverse impacts; (ii) Monitoring of EMP implementation during project implementation and operation; and (iii) Institutional arrangements to implement the EMP.
237. The main objectives of this EMP are:
(i) To ensure compliance with ADB’s applicable safeguard policies, and regulatory requirements of the Government of the Philippines; (ii) To formulate avoidance, mitigation and compensation measures for anticipated adverse environmental impacts during construction and operation, and ensure that environmentally sound, sustainable and good practices are adopted; (iii) To stipulate monitoring and institutional requirements for ensuring safeguard compliance; and (iv) The bridge projects and their respective approach roads and related facilities shall be environmentally sustainable.
238. The identified environmental issues and corresponding mitigation measures and monitoring are provided in Table 51 and Table 52. The responsibilities for implementing the EMP are presented in Table 53. The indicative overall cost for the implementation of the EMP is shown in Table 54. An Approved/Signed Rapid Environmental Assessment and Environmental Categorization is attached in Appendix 4.
239. The Contractor will prepare and submit a contractor’ environmental management plan (CEMP) consistent with this EMP, prior to start of construction. The CEMP should provide details of activities and location of facilities specific to the contract package such as batching plant and construction camp. It should be cleared by DPWH and CSC before any physical activity is started on the site. The CEMP should clearly state that the project will comply with relevant Philippine laws and the ADB Safeguard Policy Statement 2009 (SPS) and the contractor will be responsible for CEMP compliance of the subcontractors.
240. Reporting Requirements. The Environmental Officer of each contractor will provide inputs/data to the CS Consultant, Environmental Officer, monthly for consolidation for the preparation of the Semi-annual Environmental Monitoring Report (SEMR) and subsequently submission of DPWH for disclosure to ADB website. (Appendix 3. Project Semi-Annual Environmental Monitoring Report Outline).
241. The EMP will be updated, when necessary, to include additional mitigation measures or corrective actions to manage and address unanticipated impacts.
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Table 51. Impact Mitigation Plan Environmental Responsibl 23 Responsible Implementation impacts/Concern Proposed Mitigation Measures Estimated cost e for institutions Schedule s monitoring Pre-construction Stage 1. Inadequate a) Before commencement of site clearing and civil Part of Project cost in DPWH/ Environment Mobilization disclosure of works, the grievance redress mechanism (GRM) as a) Pay Item B.11 – Provisional Sum construction project well as project implementation schedule and activities supervision and period prior to information and will be communicated with the LGU representatives of 50 persons x 2 brgy x 250 php/person Soci grievan the host communities. Such communication will be x 4 = Php 100,000 al ce redress carried out through consultations with the municipal consultant (CSC) Safeguards site clearing and mechanism and barangay officials in advance of activities, when Division civil works; and and where noise, dust and other nuisances may be (ESSD) of quarterly or as expected, etc. and how affected persons can access DPWH/CSC agreed with the GRM for environmental concerns related to the
project. The consultation will continue on a quarterly stakeholders basis or as agreed with the stakeholders.
2. Improper a) Engage qualified Environmental, Health and Part of bid cost Contracto ESSD/CSC During the implementation Safety Officer (EHSO) who will ensure compliance a) Pay Item B.7(1)- Occupational r contractor of with environmental, health, and safety statutory Safety and Health Program & Pay a mobilization environmental requirements, contractual obligations and EMP Item B.14- Environmental Review nd period; and as management provisions. Management and Monitoring approv DP often when the Salary = Php 60,000.00 monthly plan (EMP) al: and WH need arise due to
CSC the b) Secure relevant Government Permits such as b) Pay Item B.14- Environmental requirements of but not limited to Environmental Compliance Management and Monitoring the construction Certificate (ECC); tree-cutting/earthballing permit; Permits Cost = Php 5,055.00 per activities. water extraction permit; quarry permit; ECC for ECC Application temporary facilities; water discharge permit; permit to operate generators (Air Pollution Source Installation); building permit; excavation permit; fencing permit; and
other permits that the LGU may require.
23 Contractor should take note of the EMP requirements in the tender documents and provide indicative costs during the tendering process, and preparation of the CEMP based on their experience, best practice, and best judgement to ensure compliance with the EMP requirements
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Environmental Responsibl 23 Responsible Implementation impacts/Concern Proposed Mitigation Measures Estimated cost e for institutions Schedule s monitoring c) Conduct baseline environmental quality measurements for marine water quality to supplement the findings of the marine ecological survey prior to c) Pay Item B.14- Environmental construction following inclusion of this requirement in Management and Monitoring & Pay Item B.11 – Provisional Sum the tender document for the following:. Water Quality: Lump Sum for Water Quality Tests = Turbidity, pH, Heavy metals, BOD5, COD, DO, Oil and Php 332,000.00 grease, TSS, Fecal Coliform, Total coliform
Php 4,000.00 per sampling station During the pre-construction phase of the project, excluding mobilization and specific items to be addressed by that time includes manpower but not necessarily limited to the following:
• for purposes of marine water quality monitoring, the parameters following the Water Quality Guidelines shall be conducted by the Contractor during the pre-construction stage;
• Contractor to confirm the exact location of the affected coral species to be able to apply the appropriate mitigation measures; stakeout the exact locations of the seagrass beds that will be affected by the bridge piers and relocate the affected patches to the nearby areas to naturally regrow/re-vegetate;
• stakeout the abutment and embankment areas of the bridge and approach road to determine the final number of affected mangrove stands and apply for tree cutting permit and replacement planting;
• coordinate with the Mindanao State University (MSU) Tawi-Tawi Campus to make arrangements for marine ecology and water quality monitoring resources during construction, and continuous consultations
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Environmental Responsibl 23 Responsible Implementation impacts/Concern Proposed Mitigation Measures Estimated cost e for institutions Schedule s monitoring with its experts on the protection of marine ecology; and
• Validate anecdotal accounts of the presence of crocodiles wandering in the channels and mangrove areas of Tawi-Tawi since this was not observed during the conduct of the marine ecological survey. c) Pay Item B.14- Environmental d) Prepare and submit a contractor’s environmental Management and Monitoring management plan (CEMP), based on the project EMP and with specific details (location of sensitive receptors, associated facilities, etc.) relevant to the particular contract package or lot, to be approved by DPWH and CSC prior to start of construction. e) The CEMP shall include but not necessarily limited d) Pay Item B.14- Environmental to the following presentation of the following: a) Management and Monitoring Natural Environment Preservation - Soil Management Plan; Waste Management Plan; Surface water, groundwater (if applicable nearest the bridge location) and marine water quality management plan; Mangrove Replanting Plan (even if the number currently is only small); b) Pollution Prevention and Control – Air Quality, Dust, Smoke and Airborne Pollution Management; Noise Management; Environmental Risk Management; c) Social Environment Management and Mitigation – Traffic Management Plan; Disabled and Gender Plan; Occupational Health and Safety Management; IEC Program; Chance Finds Procedure; d) Environmental Impacts Monitoring – Environmental Management Monitoring Reports in compliance with EMB and ADB requirements.
A copy of the CEMP will be submitted to the ADB for review and concurrence.
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Environmental Responsibl 23 Responsible Implementation impacts/Concern Proposed Mitigation Measures Estimated cost e for institutions Schedule s monitoring Construction Stage 3. Local air a) Provide signages informing public and contractor a) Pay Item B.8(1)- Traffic Preparatio ESSD/CSC During the pollution staff to observe speed limit of at least 25 kph in Management n: contractor populated areas (sensitive receptors) of the Contractor mobilization community. a period; and as Review nd often when the approv DP need arises due al: and WH to the CSC requirements of the construction activities. b) Regular water spraying/dampening dust emissions Pay Item B.14- Environmental Contractor ESSD/CSC During dry from disturbed soil, approach road construction Management and Monitoring construction surfaces and haul roads wherever there are days. sensitive receptors (such as houses, churches, businesses, schools, medical facilities) nearby is undertaken. Spraying will be done twice daily or at such frequency as is needed to suppress dust emission to acceptable levels c) Regular removal of debris and spoil piles and Contractor ESSD/CSC As often when clean-up after completion of works. construction activities require. d) All vehicles transporting dusty materials will be Contractor ESSD/CSC During each tightly covered to prevent release of fugitive dust. hauling activities.
e) Rock crushing, concrete batching plant, aggregate Contractor ESSD/CSC During the drying and surface treatment preparation contractor operations (whether bituminous asphalt or spray mobilization seal mixes) will be located a sufficient distance (at period following least 500 m) from habitations and community locational environments including other sensitive receptors guidelines; and (churches, schools, medical facilities, etc.) to during facility assure that there will be no community impacts operation. from such activities
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Environmental Responsibl 23 Responsible Implementation impacts/Concern Proposed Mitigation Measures Estimated cost e for institutions Schedule s monitoring f) Establishment and operation of rock crushing, Contractor ESSD/CSC During the concrete batching plant, aggregate drying and contractor surface treatment preparation operations (whether mobilization bituminous asphalt or spray seal mixes) must be period following approved by the relevant authorities (e.g., EMB- locational DENR, LGUs). guidelines; and during facility operation. g) All equipment, machinery and vehicles used for the Contractor ESSD/CSC During the project must be well maintained to ensure proper contractor functioning thereby minimizing contribution to air mobilization pollution. period; and throughout the construction period until complete demobilization. h) For storage areas of construction materials such as Contractor ESSD/CSC During the sand, gravel, cement, etc., provisions will be made contractor to prevent materials from being blown away mobilization towards sensitive receptors. period; and throughout the construction period until complete demobilization. i) Roads used for the hauling of materials will be Contractor ESSD/CSC During every rainy regularly cleaned to remove tracked mud, cement, days; and every etc. after concrete pouring activities in the work site.
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Environmental Responsibl 23 Responsible Implementation impacts/Concern Proposed Mitigation Measures Estimated cost e for institutions Schedule s monitoring j) Stockpiling of spoils near the Bongao Channel and Contractor ESSD/CSC During hauling sensitive receptors will be prohibited. and stockpiling activities; locational guidance provided during the CEMP preparation. k) Asphalt plants, concrete batching plants and Contractor ESSD/CSC During the crushing plants will be equipped with dust contractor suppression devices such as water sprays, dust mobilization collectors, covered conveyor. period; and throughout the construction period until complete demobilization. l) Speed limits will be imposed on construction vehicles Pay Item B.8(1)- Traffic Contractor ESSD/CSC Throughout the to minimize dust emission along areas where Management construction sensitive receptors are located. period until complete demobilization. m) Burning of all types of wastes generated at the Pay Item B.14- Environmental Contractor ESSD/CSC Throughout the construction sites, work camps and other project- Management and Monitoring construction related activities will be strictly prohibited. period until complete demobilization. n) Stockpiles of sand and aggregate greater than 20 Contractor ESSD/CSC During hauling m3 for use in concrete mixing will be enclosed on and stockpiling activities and three sides, with walls extending above the pile throughout the and two meters beyond the front of the piles. construction period until complete demobilization.
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Environmental Responsibl 23 Responsible Implementation impacts/Concern Proposed Mitigation Measures Estimated cost e for institutions Schedule s monitoring o) Water sprays will be used during the delivery and Contractor ESSD/CSC During materials handling of all raw sand and aggregates, and other delivery similar materials, when dust is likely to be created activitiesand and to dampen such stored materials during dry throughout the and windy weather to avoid impacts to sensitive construction receptors. period until complete demobilization. p) Cement and other such fine-grained materials Contractor ESSD/CSC During cement delivered in bulk will be stored in closed delivery activities containers. and throughout the construction period until complete demobilization. 4. Noise a) Limit the duration of noisy construction activities to Contractor ESSD/CSC Throughout the daylight hours, whenever possible, in the vicinity of construction sensitive receptors. period until complete demobilization. b) In areas near houses or noise-sensitive sites, noisy Contractor ESSD/CSC Throughout the equipment will not be operated during nighttime to construction early morning (19:00H –06:00H). period until complete demobilization. c) Workers exposed to high noise levels will be provided Pay Item B.7(1)- Occupational Contractor ESSD/CSC Throughout the with ear plugs. Safety and Health Program construction period until complete demobilization.
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Environmental Responsibl 23 Responsible Implementation impacts/Concern Proposed Mitigation Measures Estimated cost e for institutions Schedule s monitoring d) The contractors will provide prior notification to the Contractor ESSD/CSC Throughout the community on the schedule of construction construction activities. period until complete demobilization. e) Whenever possible, noisy equipment will be Pay Item B.7(1)- Occupational Contractor ESSD/CSC Throughout the completely enclosed which can significantly Safety and Health Program construction reduce noise levels. period until complete demobilization. f) Any stationary equipment that produce high noise Contractor ESSD/CSC During equipment levels (e.g., portable diesel generators, mobilization compressors, etc.) will be positioned as far as is following practical from sensitive receptors. locational guidelines.
g) Construction traffic routes will be defined in Contractor ESSD/CSC Prior to the cooperation with local communities and traffic commencement police to minimize noise and nuisance. of the construction activities anticipated in the locality. h) Vehicle speeds will be reduced around sensitive Contractor ESSD/CSC Throughout the receptors. construction period until complete demobilization. i) Concrete batching plants will be located at least Contractor ESSD/CSC Prior to plant 500 m away from sensitive receptors. mobilization following locational guidelines.
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Environmental Responsibl 23 Responsible Implementation impacts/Concern Proposed Mitigation Measures Estimated cost e for institutions Schedule s monitoring j) Temporary noise barriers will be installed along the Pay Item B.7(1)- Occupational Contractor ESSD/CSC Prior to the edge of the road, as necessary, in front of sensitive Safety and Health Program commencement receptors facing heavy construction activities. of the activities. k) Prior to undertaking noisy activities, the contractor Contractor ESSD/CSC Prior to the will consult with village leaders and commencement representatives from the religious sites and of the activities. schools along the project road regarding construction schedule so as to minimize disturbance to important events such as ceremonies, examination period and the like. 5. Spoils a) Prior to excavation, contractors will submit a spoils Pay Item B.14- Environmental Preparation ESSD/CSC Prior to the disposal disposal plan to concerned authorities such as Management and Monitoring : commencement LGUs and DPWH for approval. The plan will show Contractor of the activities; the location of proposed excavation sites, cut a guided by the locations, fill and/or disposal sites for excess cut Review CEMP. and, and disposal sites for bridge approach road approval: nd construction spoils. The quantities shall be DPWH determined and monitored during actual a C construction and these could be significant from nd bridge pier piling works as well as approach road S excavation works, The plan will include photographs of the sites and will also indicate the C existing land use and capacity of the disposal site. A copy of the approved plan forming part of the CEMP will be submitted to ADB.
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Environmental Responsibl 23 Responsible Implementation impacts/Concern Proposed Mitigation Measures Estimated cost e for institutions Schedule s monitoring b) The contractor will ensure that spoils disposal will Contractor ESSD/CSC Prior to the not encroach on the Bongao Channel, will not commencement cause sedimentation or obstruct channel flow and of the activities; will not cause damage to adjacent lands, and throughout properties and other productive sites. the duration of the c) Where local residents and villages requests to use activities. spoils as fill materials in their lots and properties, the contractor shall secure a written request and agreement for proper disposal. The Contractor shall ensure that the filling activities shall not cause pollution or sedimentation and/or water ponding by technically assisting property owners in the establishment of adequate bunding and drainage.
6. Impacts from a) For commercial borrow pits and quarries, the Contractor ESSD/CSC Prior to the operation of contractor will ensure that only facilities with commencement borrow areas necessary environmental permits will be used for of the activities; and quarries the project. guided by the CEMP. b) For project-specific facilities, i.e., those that will be Contractor ESSD/CSC Prior to the established and solely operated for the project, the commencement contractor will ensure that these are covered by of the activities; necessary environmental permits. c) Prior to operation of borrow pits and quarries, the Preparation: ESSD/CSC Prior to the contractor will submit to the LGU and DPWH a plan Contractor commencement showing the location/s of such facilities to be used, of the activities. as well as timeframe and mitigation measures to Review an be implemented to rehabilitate project-specific approval: d borrow pits and quarries. DPWH and CS d) The contractor will also ensure that topsoil will be Contractor ESSD/CSC Throughout the properly removed, stockpiled and preserved for duration of later use during restoration of the borrow pit. activities.
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Environmental Responsibl 23 Responsible Implementation impacts/Concern Proposed Mitigation Measures Estimated cost e for institutions Schedule s monitoring e) Vegetation cover will be provided Pay Item 622(3)b- Vegetation, Contractor ESSD/CSC Following during rehabilitation of the site. Vetiver Grass System completion of the civil works activities. f) Upon completion of extraction activities, quarries Pay Item B.14- Environmental Contractor ESSD/CSC Upon and borrow pits will be dewatered, signages and Management and Monitoring completion of fences installed, as appropriate, to minimize health extraction and safety risks. activities. 7. Erosion and a) Undertake planting of native species of trees and Contractor ESSD/CSC Following unstable landscaping along the approach roads and completion of slopes embankment slopes, as appropriate. the civil works activities. b) Construction activities will be carried out Contractor ESSD/CSC During the dry intensively during dry season. However, as the season and as area is not generally typhoon-prone, construction weather permits. work during wet season is likely feasible. c) Slope protection measures (e.g., sodding) will be Pay Item 622(3)b- Vegetation, Contractor ESSD/CSC Prior to the implemented to avoid impacts to agricultural land Vetiver Grass System commencement and adjacent properties. Areas to be cleared of of slope vegetation for construction will be restricted to the protection works minimum required for immediate works. and following completion of the activities. 8. Deterioration a) Limit the exposure of areas prone to erosion so this Pay Item B.14- Environmental Contractor ESSD/CSC During of Marine will not be carried into the channel during rainy Management and Monitoring earthworks, and water days as well as providing silt traps or fine mesh throughout the quality and nets to especially protect coral species and duration of the ecology seagrass beds identified during the marine activities. ecological survey. Continuous consultation with marine experts is also encouraged. b) Observe proper management of spoils Contractor ESSD/CSC During during bored piling works and approach roads earthworks, and embankment by stockpiling away from the work throughout the areas and providing bunds while waiting to be duration of the properly disposed in locations to be approved by activities.
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Environmental Responsibl 23 Responsible Implementation impacts/Concern Proposed Mitigation Measures Estimated cost e for institutions Schedule s monitoring the CSC.
c) Transport spoils immediately to final disposal sites Pay Item B.14- Environmental Contractor ESSD/CSC During as much as possible to minimize materials carried Management and Monitoring earthworks, and by surface runoff during rainy days. throughout the duration of the activities. d) Avoid prolonged stockpiling unless necessary (i.e. Contractor ESSD/CSC During topsoils necessary for agricultural re-use where earthworks, and sodding maybe necessary to keep from being throughout the washed away during rainy days). duration of the activities. e) Bentonite slurry or polymers that maybe finally be Contractor ESSD/CSC During decided to be used during bridge construction will bridgeworks, be collected and processed in a system of leak- and throughout free tank storages. Discharges into the Bongao the duration of Channel will be prohibited and compliance closely the activities. monitored by the CSC. f) Spillage of bentonite or polymers in adjacent lands Contractor ESSD/CSC During will be cleaned up immediately to prevent caking earthworks, and and hardening, or contaminating the marine water throughout the brought about by surface runoff during rainy days. duration of the activities. g) Prior to establishment and operation of concrete Contractor ESSD/CSC Prior to facility batching plants and casting yards, the contractor mobilization. will obtain the necessary environmental permits to ensure proper siting away from the Bongao Channel. h) Retention ponds with sufficient Contractor ESSD/CSC Prior to specifications/capacity will be constructed for commencement treatment of wastewater (e.g., from washing of of pond works; equipment such as mixer drums, trucks and chute, and throughout contact storm water, etc.) and shall be operated the construction and maintained to ensure that effluent quality will period until meet applicable standards. demobilization.
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Environmental Responsibl 23 Responsible Implementation impacts/Concern Proposed Mitigation Measures Estimated cost e for institutions Schedule s monitoring i) Equipment service and maintenance yards will be Pay Item B.14- Environmental Contractor ESSD/CSC During the sited away from the Bongao Channel and provided Management and Monitoring establishment of with impermeable flooring and collection sump. the facility. j) Watertight receptacles will be provided in all the Contractor ESSD/CSC Throughout the equipment maintenance shops for waste oil, oily operation of the rags, spent oil filters, solvents and oily containers maintenance to prevent leaked materials from being washed to shops until the channel during rainy days. demobilization. k) Disposal of wastes contaminated with Contractor ESSD/CSC During wastes hydrocarbons shall not be done in the channel, and disposal will be done only through authorized waste activities. handlers and recyclers.
l) Refueling and servicing of equipment will only be Contractor ESSD/CSC Throughout the carried out in areas away from the channel and operation of the adequately equipped to collect leaks and spills. maintenance shops until demobilization. m) Fuel storage areas shall be roofed with impervious Contractor ESSD/CSC Throughout the floor and bunded around and will be located away operation of the from watercourses, flood-prone areas and workers campsite until camps that may eventually carry hazardous demobilization. materials to the channel during rainy days. n) Spill clean-up materials (e.g., absorbent pads, etc.) Contractor ESSD/CSC Throughout the specifically designed for petroleum products and operation of the other hazardous substances where such materials campsite until are being stored and used shall be available to demobilization. ensure leaked residues are not carried away by surface runoff during rainy days. Hazardous a) Fuel storage areas shall be roofed with impervious Pay Item B.14- Environmental Contractor ESSD/CSC Throughout the materials floor and bunded around and will be located away Management and Monitoring operation of the and wastes from watercourses, flood-prone areas and workers campsite until camps. demobilization.
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Environmental Responsibl 23 Responsible Implementation impacts/Concern Proposed Mitigation Measures Estimated cost e for institutions Schedule s monitoring b) Spill clean-up materials (e.g., absorbent pads, etc.) Throughout the specifically designed for petroleum products and operation of the other hazardous substances where such materials campsite until are being stored. demobilization. c) Relevant construction personnel will be trained in Prior to handling handling of fuels/hazardous substances and spill of hazardous control procedures. materials, etc. d) All storage containers of hazardous materials and Throughout the wastes will be properly labeled and maintained in operation of the good condition. campsite until demobilization. e) Restoration of temporary work sites will include Prior to removal and treatment or proper disposal of oil demobilization. contaminated soils that maybe potentially carried to the channel during rainy days. 9. Loss of f) DPWH will obtain a tree cutting permit in Pay Item 100 (3) – Individual DPWH ESSD/CSC Prior to tree mangrove compliance with PD 705 (Revised Forestry Code Removal of Trees (150mm- cutting activities. vegetation of the Philippines). No tree cutting will be 750mm dia.) and affected undertaken without the necessary permit to be trees along issued by the Community Environmental and the Natural Resources Office (CENRO) of the DENR approach g) Tree cutting can only be undertaken under close Contractor ESSD/CSC During tree road supervision of CENRO, DPWH and CSC staff who cutting activities. alignment. will be present at the site throughout the duration of cutting activities. h) Only trees marked based on the Tree Chart will be Contractor ESSD/CSC During tree cut. cutting activities.
i) Cut trees will be turned over to the CENRO or local Contractor ESSD/CSC During and/or community for disposal. after tree cutting activities. j) In compliance with DENR Memorandum Order no. Pay Item 611 – Refurnishing of DPWH ESSD/CSC During and/or after 05 of 2012: Uniform Replacement Ratio for Cut or Trees tree cutting Relocated Trees, and turn over to the CENRO. activities.
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Environmental Responsibl 23 Responsible Implementation impacts/Concern Proposed Mitigation Measures Estimated cost e for institutions Schedule s monitoring k) Ensure that one of the environment specialists Pay Item B.14- Environmental DPWH/CSC ESSD/CSC During tree and/or that of the supervision consultant will Management and Monitoring cutting activities. closely monitor the tree cutting activities to ensure that these will comply with the provisions of the Tree Cutting Permit and corresponding Tree Chart.
l) As part of the semi-annual environmental DPWH/CSC ESSD/CSC Semi-annual monitoring report to be submitted to ADB, DPWH during SEMR will report on the status of tree cutting, tree preparation and relocation or replacement any issues/concerns, submission to corresponding actions and other relevant matters. ADB. m) To avoid unnecessary impacts to vegetation, the Contractor ESSD/CSC During tree contractor will prohibit cutting of trees for firewood cutting activities. and for other uses in the Project and will ensure that tree cutting is limited to areas as approved by the CENRO. 10. Impacts on a) Prohibit workers from hunting wild animals Contractor ESSD/CSC Duration of the fauna including crocodiles, that based on anecdotal construction accounts of some residents are present in the period. channel during the cold months. b) As much as possible, bridge works will be Contractor ESSD/CSC During the dry scheduled during the dry season to minimize season. adverse impacts to fishery, river water quality and other aquatic resources. 11.Occupation a) Use of personal protective equipment (PPE) such Pay Item B.7(1)- Occupational Contractor ESSD/CSC Throughout the al health as safety shoes, safety hat, goggles, safety belt, Safety and Health Program construction and safety ear protection or other garments or equipment duration. hazards designed to protect the wearer's body from injury will be strictly observed during construction. b) Prepare and implement a COVID-19 Risk Pay Item B.11 – Provisional Contractor ESSD/CSC Throughout the Management Plan guided by DPWH’ and ADB’ Sum construction Guidance on Managing Risk from COVID-19 on duration. Construction Sites and in Workers’ Housing.
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Environmental Responsibl 23 Responsible Implementation impacts/Concern Proposed Mitigation Measures Estimated cost e for institutions Schedule s monitoring c) Provision of personal flotation devices (PFDs) to all Pay Item B.7(1)- Occupational Contractor ESSD/CSC Throughout the workers working on the bridge to help reduce the Safety and Health Program construction risk of drowning when falling into the Bongao duration. Channel. d) Provision of first aid kits that are readily available Contractor ESSD/CSC Throughout the to workers as well as access to or availability of a construction health worker to attend to any immediate health duration. e) needs of workers and in case of untoward incidents. f) Conduct orientation for construction workers Contractor ESSD/CSC Prior to work regarding health and safety measures, emergency deployment; as response in case of accidents, fire, etc., and often as prevention of HIV/AIDS, COVID-19 and other necessary. related diseases. g) Installation of adequate drainage in workers camps Contractor ESSD/CSC During campsite to avoid water logging/accumulation of stagnant establishment. water and formation of breeding sites for mosquitoes. h) Provision of separate clean housing with sufficient Contractor ESSD/CSC During campsite ventilation and separate hygienic sanitation establishment. facilities for male and female workers. i) Provision of reliable supply of water for drinking, Contractor ESSD/CSC During campsite cooking and washing purposes at the workers’ establishment. camps. j) Proper collection and disposal of solid wastes Contractor ESSD/CSC During campsite within the workers’/construction camps consistent operation until with local regulations. demobilization. k) Provision of fire-fighting equipment at the work Contractor ESSD/CSC During campsite areas, as appropriate, and at workers camps. operation until demobilization. l) Treatment of wastewater emanating from workers Contractor ESSD/CSC During campsite camps, construction camps and other project- operation until related activities and facilities consistent with demobilization. national regulations.
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Environmental Responsibl 23 Responsible Implementation impacts/Concern Proposed Mitigation Measures Estimated cost e for institutions Schedule s monitoring m) Use of reversing signals on all construction Contractor ESSD/CSC Throughout the vehicles. construction period. n) Regular coordination with local authorities Contractor ESSD/CSC Throughout the regarding project activities throughout the and DPWH construction construction phase to reduce over-all security risks period. to the project. 12. Public health a) Installation of sturdy fencing around excavation Pay Item B.7(1)- Occupational Contractor ESSD/CSC During excavation and safety areas and construction sites. Safety and Health Program works until hazards completion of the activity. b) Provision of proper signage and lighting at night at Pay Item B.8(1)- Traffic Contractor ESSD/CSC Throughout the the periphery of the construction site to warn and Management construction direct traffic and pedestrians. period. c) Deployment of security personnel in hazardous Contractor ESSD/CSC Throughout the areas to restrict public access. construction period. d) Imposition of speed limits for construction vehicles Contractor ESSD/CSC Throughout the along residential areas and where there are other construction period. sensitive receptors e) Orientation of drivers on safe driving practices to Contractor ESSD/CSC Prior to work minimize accidents and to prevent spill of deployment and hazardous substances and other construction throughout the materials during transport. construction period. f) If necessary, provide safe passageways for Contractor ESSD/CSC Throughout the pedestrians crossing the construction site. construction activity until completion. g) At construction areas, provide safe access to Contractor ESSD/CSC Throughout the farmland and other properties. construction activity until completion.
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Environmental Responsibl 23 Responsible Implementation impacts/Concern Proposed Mitigation Measures Estimated cost e for institutions Schedule s monitoring 13. Road/sea a) Provide signs advising road users that Pay Item B.8(1)- Traffic Contractor ESSD/CSC Throughout the vessel Traffic construction is in progress, particularly in areas Management construction obstruction where the project alignment crosses existing roads activity until and where construction related-facilities are completion. located (i.e. bridge approaches, etc.). b) Employ flag persons to control traffic when Contractor ESSD/CSC Throughout the construction equipment is entering or leaving the construction work area. activity until completion. c) Post traffic advisory signs (to minimize traffic build- Contractor ESSD/CSC Throughout the up) in coordination with local authorities. construction d) Vessel passage are not anticipated to be affected activity until by construction. Navigation lanes shall be made completion. available for passing sea vessels all the time by making bridge piers open in between following the contractor’ method of construction. e) The Contractor shall prepare and submit a traffic management plan addressing both road and sea vessel traffic most especially if barging of construction materials are also anticipated to be significant during construction. 14. Accidental a) Contractor to immediately cease operations at the Contractor ESSD/CSC Immediately discovery site of discovery. upon discovery of artefacts of artefacts. b) Contractor to inform the CSC and Environment Contractor ESSD/CSC Immediately Officer of the Office of the District Engineer. upon discovery of artefacts. c) CSC to relay information to DPWH CSC ESSD/CSC Immediately upon discovery of artefacts. d) DPWH to notify the National Historical DPWH ESSD/CSC Immediately Commission of the Philippines (NHCP) and/or upon discovery other concerned government agencies for the next of artefacts. steps.
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Environmental Responsibl 23 Responsible Implementation impacts/Concern Proposed Mitigation Measures Estimated cost e for institutions Schedule s monitoring e) Recommence work only after NHCP has provided Contractor ESSD/CSC Immediately official notification accordingly. upon NHCP notification. 15. Damage to a) The contractor will immediately repair and/or Pay Item B.14- Environmental Contractor ESSD/CSC Immediately upon properties compensate for any damage that it causes to Management and Monitoring completion of properties (houses, farmlands, aquaculture ponds, damage irrigation canals, etc.), community facilities such as assessment. water supply, power supply, communication facilities and the like. b) Access roads used for transport of construction Contractor ESSD/CSC Throughout the materials and other construction-related activities construction will be maintained by the Contractor in at least in period. their pre-project condition for the duration of construction. c) Contractor to restore areas used for project facilities close to their original state as practically feasible or to the satisfaction of private owners as stipulated in lease contracts. Also cleanup of construction sites immediately after construction. 16.Unanticipat a) If any unanticipated impacts become apparent Contractor, CSC, DPWH Immediately ed during project implementation, the DPWH will ESSD upon environmen update the environmental assessment and EMP or occurrence of tal impacts prepare a new environmental assessment and impact. EMP to assess the potential impacts, evaluate the alternatives, and outline mitigation measures and resources to address those impacts. The updated or newly prepared documents will be submitted to ADB for review, clearance and public disclosure.
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Environmental Responsibl 23 Responsible Implementation impacts/Concern Proposed Mitigation Measures Estimated cost e for institutions Schedule s monitoring b) Implement measures specified in the new or Pay Item B.14- Environmental Contractor ESSD/CSC Immediately upon updated environmental assessment and EMP to Management and Monitoring completion of address unanticipated environmental impacts. impact assessment and agreement on corrective action. 17. Need for a) Implement additional environmental mitigation Contractor ESSD/CSC Immediately upon additional measures, as necessary, to avoid, minimize and/or completion of environmen compensate for adverse impacts due to impact tal construction works and related activities assessment and mitigation performed by the contractor. agreement on measures corrective action. Operation Stage 1. Noise a) As necessary, install traffic calming measures, Pay Item 605(1)-Warning Signs District DPWH Upon e.g., speed bumps in areas where there are Engineering completion of sensitive receptors so as to further reduce noise Office (DEO) roadworks. levels from passing vehicles. b) Undertake regular maintenance of pavement and District DPWH After the defects traffic management especially near receptors to Engineering liability period of contribute to lower ambient noise levels. Office (DEO) the contractor. 2. Bridge and a) Setting up warning and guide signs, arrow marks DPWH Upon Road and providing delineation lines clearly along the completion of safety road. roadworks and hazards during maintenance operation if necessary. b) Provision of traffic signals at key intersections. DPWH Upon completion of roadworks and during maintenance operation if necessary.
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Environmental Responsibl 23 Responsible Implementation impacts/Concern Proposed Mitigation Measures Estimated cost e for institutions Schedule s monitoring c) Approach roads will have vertical curves that suit DPWH During detailed safe design criteria/requirement. design and construction. d) Installation of chevron signs where required and Pay Item 605(2)-Regulatory DPWH Upon speed limit signs. Sign completion of roadworks and during maintenance operation if necessary. e) Approach roads will have improved vertical DPWH During detailed alignment to suit sight distance requirement. design and construction. f) Installation of guardrails between the road and Pay Item 603(3)- Metal DPWH Upon ditches. Guardrail completion of roadworks and during maintenance operation if necessary. g) Prohibit the use of carriageway as parking to DPWH Upon ensure safe, efficient and smooth vehicular flow; completion of coordinate with LGU(s) concerned to improve roadworks and enforcement. during maintenance operation if necessary. h) Provision of pedestrian crossing. Pay Item 612- Reflectorized DPWH Upon Thermoplastic Pavement completion of Markings roadworks and during maintenance operation if necessary.
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Environmental Responsibl 23 Responsible Implementation impacts/Concern Proposed Mitigation Measures Estimated cost e for institutions Schedule s monitoring i) Provision of sidewalks and bicycle lanes where DPWH During appropriate construction works as specified in the detailed design. 3. Solid waste Implementation of related mandates with regard to LGU Upon project build- up provision of solid waste management, health and completion. and sanitary facilities. shortage of health/sanit ary facilities due to influx of migrants 4. Increase in Implementation of related mandates to prevent or DENR Upon project resource minimize illegal mangrove tree cutting and other completion. use (e.g., resource extractive activities (e.g. through close tree cutting) monitoring).
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Table 52. Environmental Monitoring Activities during Construction Aspect Means of Monitoring Frequency of Monitoring Responsible for Monitoring 1. Close supervision of the contractor’s As part of day-to-day project On-going throughout the DPWH/ESSD/CSC implementation of mitigation supervision construction phase measures to minimize or avoid impacts to air quality (particularly dust emission), noise, siltation of surface water and other impacts.
2.Contractor’s environmental Site visit, ocular inspections, Monthly DPWH/ESSD/CSC performance and implementation of interviews with local residents, construction phase environmental coordination with concerned mitigation barangay/s measures specified in the IEE/ EMP 3. Dust Visual observation, interviews with Monthly DPWH/ESSD/CSC local residents, coordination with concerned barangay/s 4. Noise Handheld noise meter, site Monthly DPWH/ESSD/CSC observation, interviews with local residents, coordination with concerned barangay/s 5. Marine water quality and ecology To be discussed with MSU-TCTO, Monthly DPWH/ESSD/CSC interviews with local residents, coordination with concerned barangay/s 6. Air quality, noise, and marine water Field sampling To be undertaken only to Contractor under supervision of quality validate complaints and/or ESSD and CSC during pollution events that are potentially caused by the project
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7. Marine flora and fauna (corals, Field inspection to establish location IEC and field inspection to be Contractor under supervision of seagrass beds, and crocodiles) as per the given coordinates/visual undertaken prior to ESSD and CSC observation, interviews with local construction; On-going residents, coordination with throughout the construction concerned barangay/s prior to the phase; validation and reporting upon receipt of sightings start of construction. (especially for crocodiles wandering near or in the site;
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Table 53. Responsibilities for EMP Implementation Agency Responsibility Department of Public • Executing agency with overall responsibility for project Works and Highways construction and operation (DPWH) of the BARMM • Ensure that sufficient funds are available to properly implement the EMP; • Ensure that Project implementation complies with Government environmental policies and regulations; • Ensure that the Project, regardless of financing source, complies with the provisions of the EMP and ADB Safeguard Policy Statement 2009 (SPS); • Obtain necessary environmental approval(s) from the Environmental Management Bureau and/or other concerned government agencies prior to commencement of civil works; • Ensure that tender and contract documents for design, supervision and civil works include the relevant EMP requirements; • Establish information on an environmental grievance redress mechanism, as described in the IEE, to receive and facilitate resolution of affected peoples' concerns; and • Submit semi-annual monitoring reports on EMP implementation to ADB. DPWH-Unified Project • Project management office with direct responsibility for the Management implementation of civil works, engineering designs and Office (UPMO), Roads project coordination; Management • Ensure that EMP design measures are incorporated in the Cluster II (RMC-II) detailed design; • Ensure that EMP provisions are strictly implemented and monitored during various project phases (design/pre- construction, construction and operation) to mitigate environmental impacts to acceptable levels; • Ensure compliance with environmental permits; and • Include relevant provisions of the EMP in the bid and contract documents for design, civil works and supervision. • Coordinate with DENR-EMB, Local Government Units (LGU), and other concerned agencies related to environmental aspects for maintaining project`s compliance with environmental permits. Environmental and Social • Assist the UPMO-RMC II and CSC in undertaking their Safeguards Department environment-related tasks. (ESSD) of DPWH Detailed Engineering • Incorporate into the project design the environmental Design (DED) Consultant protection and mitigation measures identified in the EMP for the design/pre-construction stage; and • Assist PMO to ensure that all relevant mitigation and monitoring measures from the EMP are incorporated in the bidding and contract documents for project supervision and civil works. Construction Supervision • Prior to establishment of contractor’s facilities and Consultant (CSC) commencement of civil works, undertake review of specific environmental management plans (e.g., Consultant (CSC) spoils disposal plan, facilities development plan, etc.) to be
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Agency Responsibility prepared by contractors to ensure that such plans are consistent with the provisions of the EMP. • Engage environment specialists who will undertake supervision and monitoring of EMP implementation and contractor’s environmental performance; • As part of day-to-day project supervision, closely supervise the contractor’s implementation of mitigation measures specified in the EMP; • Undertake monthly monitoring of contractor’s environmental performance and over-all implementation of the EMP; • Prepare semi-annual environmental monitoring reports (Appendix 3) on status of EMP implementation for submission to ADB; • Based on the results of EMP monitoring, identify environmental corrective actions and prepare a corrective action plan, as necessary, for submission to ADB Contractors • Recruit qualified environmental and safety officer to ensure compliance with environmental statutory requirements, contractual obligations and EMP provisions; • Provide sufficient funding and human resources for proper and timely implementation of required mitigation and monitoring measures in the EMP; and • Implement additional environmental mitigation measures, as necessary, to avoid, minimize and/or compensate for adverse impacts due to construction works and related activities performed by the contractor. Environmental • Review and approve environmental assessment reports Management Bureau required by the Government; and (EMB) of the Department • Undertake monitoring of the project’s environmental of Environment and performance based on their mandate. Natural Resources (DENR), BARMM Asian Development Bank • Conduct periodic site visits to assess status of EMP (ADB) implementation and over-all environmental performance of the Project; • Review environmental monitoring reports submitted by the executing agency to ensure that adverse impacts and risks are properly addressed; and • Publicly disclose through posting on ADB’s website environmental monitoring reports, corrective action plans, prepared by the executing agency during project implementation.
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Table 54. Cost for Environmental Management and Monitoring Number/ Cost per Source of Component Description Cost (Php) Frequency Unit (Php) Funds PRE-CONSTRUCTION PHASE Clearances and Securing ECC from 5,055 for 1 ECC 5,055/ECC DPWH permits EMB-RO ECC Information disclosure and Public consultations during consultations preconstruction and As per 21,000 (for 3 and construction phase, Lump sum DPWH requirement Brgys) information including public disclosure awareness campaign through media Communication will be carried out through consultations with the municipal and barangay officials in advance of activities, when and where noise, dust and other Part of Grievance 50 persons x 2 nuisances may be Project cost in Redress Quarterly brgy x 250 Php 100,000 (for a) Pay Item expected, etc. and Mechanism basis php/person x 4 4 consultations) B.11 – how affected (GRM) = Php 100,000 Provisional persons can access Sum the GRM for environmental concerns related to the project. The consultation will continue on a quarterly basis or as agreed with the stakeholders. Orientation workshop of officials and staff involved in the project implementation on ADB SPS (2009), applicable laws, Meals and Capacity rules and venue Part of the building (part of regulations Php 52,500 per One loan the TOR of the CS on environment. 50,000x project package Consultant) Workshops/ 250/pax x 10 Writeshops will be pax/project conducted by the CS Consultant Team with the supervision of DPWH Team (i.e. Preparation of CEMP, Monitoring
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Number/ Cost per Source of Component Description Cost (Php) Frequency Unit (Php) Funds procedures on EIA compliance, etc.) Contractor’s liability (approx. 4,000/ Depends on Covered Assessment of air Baseline ambient sampling the number of under quality and noise To be noise level survey station designated construction level along determined (24 hr) excluding sampling contract receptors mobilization stations (CEMP) and manpower cost) Lump Sum Turbidity, pH, Heavy for Water Water Quality metals, BOD5, COD, Pay Item B.11 Conduct of Water Quality Tests Tests = Php DO, Oil and grease, Lump sum – Provisional Quality Test = Php 332,000.00 TSS, Fecal Coliform, Sum 332,000.00 Total coliform.
CONSTRUCTION PHASE Application of noise Covered Noise and dust and dust under suppression at As required suppression construction work sites measures contract Wherever Safety signboards, Covered required Traffic temporary under throughout Php management diversions, construction the project 15,357,592.08 barricades, etc. Php contract corridor 383,939.802 (Incase the Covered Compliance with Everyday per mo. Noise level budget is not under the IFC-EHS along nearest x monitoring sufficient, construction Guidelines receptors 36 mo. there is a contract Implementation of Throughout standby Covered occupational health the budget of Php under Hazard to workers and safety construction 50 million from construction measures period the contract contingency in Covered Any Mitigation of any the contract). under unanticipated unanticipated Php construction impact due to impact arising Lump sum 1,535,759.20 cost – project and defect liability 8 contractor’s implementation period insurance Summary of environmental cost Environmental cost included in construction contract plus mitigation for 15,357,592.08 unanticipated impacts Additional environmental management cost not included in construction 566,555 contract Total environmental cost 15,924,147.08
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VIII. CONCLUSION
242. Results of the initial environmental examination show that the project will not cause significant environmental impacts. Adverse impacts that will be experienced during site works are mainly due to dust and noise emissions as well as potential occupational and community health and safety risks. Bridge pier installation for the structure of the chosen alignment will entail mangrove tree cutting and this will be compensated through replanting within the immediate vicinity of the bridge location.
243. The bridge alignment does not pass through legally protected areas, critical habitats or biodiversity sites. In 2006, the average coral cover in the Municipality of Bongao is 46.3%, which is classified as being in “Fair condition. A marine ecological assessment was conducted to determine the status of the marine resources before the construction of the bridge. The baseline marine ecological assessment adjacent to the bridge location indicated the following observations results: (1) good species diversity of coral reefs (37% hard coral cover, Gomez, et.al., 1981 and Licuanan, et. al., 2017); (2) poor coral fishes (27-47 species per 1000m2 , Hilomen, et. al., 2000 and biomass of only 6.98mt/km2 , Nanola, et. al., 2006); (3) minimal species of seagrass and seaweeds (mean of 2.18 to 2.43%/m2, Saito and Atobe, 1970; English et. al. 1997, and Fortes, 1986); (4) minimal species of mangrove stand (5 in the Barangay Nalil side and only 2 in the Barangay Pakias side, Arroyo 1977; Fernando and Pancho, 1980) and cutting of mangrove observed; (5) water parameters are within the tolerable limits for the recruitment, growth, survival and development of marine organisms (details in the Marine Ecological Assessment Report); (6) plankton (1,257cell density of phytoplankton, 84 cell density of zooplankton, English et. al. 1997) and benthos population (three (3) infauna groups buried in the sediment recorded in the proposed bridge) are very minimal; (7) water current is 0.15m/sec; and (8) water circulation is favorable for coral growth and development.
244. Adverse ecological impacts to the marine waters including marine- based livelihood activities are conservatively anticipated from nil to low because the vicinity of the bridge site is not used for fishing and aquaculture-seaweed farming. Anticipated impacts can be mitigated with available bridge engineering technologies and construction methods. To effectively mitigate negative impacts arising from the Project, an environmental management plan detailing mitigation measures, monitoring activities and responsibilities for implementation has been prepared as part of the IEE.
245. The marine ecological assessment survey had been wholly done by experts stationed in the Mindanao State University (MSU) Tawi-Tawi Campus and coordinated by the Metro Manila-based Team Leader who relied on the experts’ integrity in data collection. Validation of site results was hampered due to the travel restriction imposed for the COVID-19 pandemic. The work of the consultant was not validated by DPWH because of travel restrictions imposed by the LGU as well. Lobophyllia was mentioned in the report, but no specific Lobophyllia species was mentioned which is rather unfortunate since this genus includes an endangered species, Lobophyllia serratus. This will be verified prior to construction. The number indicated in the report based on the sampling is rather small, 0.4% of 37.4% hard corals observed.
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246. Other activities to be performed during the pre-construction phase of the project, to be addressed by that time includes but not necessarily limited to the following: 1) for purposes of marine water quality monitoring, the parameters following the Water Quality Guidelines shall be conducted by the Contractor during the pre-construction stage; 2) Contractor to confirm the exact location of the Lobophyllia coral species to be able to apply the appropriate mitigation measures; stakeout the exact locations of the seagrass beds that will be affected by the bridge piers and relocate the affected patches to the nearby areas to naturally regrow; 3) stakeout the abutment and embankment areas of the bridge and approach road to determine the final number of affected mangrove stands and apply for tree cutting permit and replacement planting; 4) coordinate with the Mindanao State University (MSU) Tawi-Tawi Campus for marine ecology and water quality monitoring and effective marine ecology protection and management during construction; 5) validate anecdotal accounts of the presence of crocodiles wandering in the channels and mangrove areas of Tawi-Tawi; and 6) identify and provide details of sensitive receptors in the project area. The results shall form part of the CEMP submission indicating the required mitigation measures. The Contractor shall be required to prepare and submit a Contractor’ Environmental Management Plan (CEMP) prior to the commencement of construction work and shall comply with all applicable government and ADB SPS 2009 requirements.
247. Public consultations involving affected people and local officials have been conducted during the preparation of the IEE/RIPP in compliance with ADB’s information disclosure and consultation requirements. Additional consultations and information disclosure activities will be undertaken as necessary during construction to update stakeholders of project activities and solicit their opinions. A grievance redress mechanism will be established to resolve complaints. DPWH will include the EMP in the bid and tender documents for civil works to ensure that the Project will be carried out consistent with the EMP requirements. During construction, DPWH will be assisted by a construction supervision consultant who will also undertake monitoring of the environmental performance of contractors.
248. Should there be significant changes in the project design or the scope of work during construction and the location, the IEE, environmental assessment and EMP will be updated or a new IEE and EMP will be prepared to assess the potential impacts, evaluate the alternatives, and outline mitigation measures and resources to address those impacts. The updated or newly prepared documents will be submitted to ADB for review, clearance and public disclosure.
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IX. APPENDICES
Appendix 1. Marine Ecological Assessment
Appendix 2. Grievance Intake Form
Appendix 3. Project Semi-Annual Environmental Monitoring Report Outline
Appendix 4. Approved/Signed REA and Environmental Categorization
Appendix 5. Public Consultation Attendance Sheets
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Appendix 1. Marine Ecological Assessment
DRAFT FINAL REPORT
Environmental Baseline Survey
Marine Ecological Assessment in the Proposed Nalil-Sikkiat Bridge, Bongao, Tawi-Tawi
Roger S. Savella Environmental Expert
December 2020
SUMMARY The Government of the Republic of the Philippines requested the Asian Development Bank (ADB) to provide Technical Assistance (TA) for the preparation in Improving Growth Corridors in Mindanao Road Sector Project. This project supports the Government of the Philippines’ priorities for improvement of the country’s road network and development of Tawi-tawi, including the government’s agenda for Tawi-tawi in the Philippines Development Plan (PDP) 2011-2016. This project extends ADB’s longstanding assistance in Tawi-tawi with a recent focus on the road sector including institutional development and now improving national roads for inclusive economic growth.
249. Part of the activities of the project is the conduct environmental impact assessments, which requires primary and baseline data gathering for the terrestrial and aquatic (freshwater and marine) environment. The objective of the biological (terrestrial and aquatic – freshwater and marine) environmental baseline survey/study activities is to establish the baseline condition of the project area where the Sub-projects are located, and which may be impacted by the activities.
250. Twelve researchers conducted field activities on November 10 to 11, 2020 in the proposed Nalil-Sikkiat bridge to conduct baseline survey for marine ecological assessment of coral reefs, coral reef fishes, seagrass/seaweeds, mangroves, phytoplankton, benthos, water quality, water current and circulation. The result of the study provides a clear understanding on the different resources that will be affected by coastal development and proper management strategies will be formulated for the affected marine resources.
251. Results showed that the coral reefs recorded good cover condition while the other marine resources are very minimal. The following observations were made: (1) good species diversity of
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coral reefs, (2) poor coral fishes, category (3) minimal species of seagrass and seaweeds, (4) minimal species of mangrove stand and cutting of mangrove observed, (5) water parameters are within the tolerable limit, (6) plankton and benthos population are very minimal (7) water current is 0.15m/sec, and (8) water circulation is favorable for coral growth and development. Water circulation in the area is controlled by physical forcing at the open boundaries, namely the river inflow, the groundwater inflow, the wind, and the oceanic forcing like tides, fluctuations of the mean sea level like storm surges, the waves, and the net oceanic currents. Sedimentation, siltation, low water visibility and substrate characteristics limit or prevent larvae settlements, recruitments, growth and development of other marine organisms in the proposed bridge location.
INTRODUCTION
252. This report was prepared to present the findings of baseline survey for marine ecological assessment conducted in the proposed Nalil-Sikkiat-Pakias Bridge, Sanga-Sanga Island, Bongao, Tawi-tawi as part of an environmental impact assessment. The following coastal resources were surveyed: (1) coral reefs, (2) reef fishes, (3) seagrass/seaweeds, (3) mangroves, (5) plankton, (6) benthos, (7) water quality and (8) water current and circulation. This was conducted in preparation for the proposed bridge construction that will connect Sanga- sanga Island and Bongao, Tawi-Tawi.
253. Baseline information on coastal resources and other environmental parameters is essential for the establishment of reference points for key indicators on the state of ecological health of the ecosystem. It provides qualitative and quantitative information on the current status of the marine environment before any development project has been implemented. Similarly, baseline information is crucial since it facilitates better understanding on the nature of the fisheries dynamics, biological interactions and state of utilization of the resources. Lastly, baseline study served as reference material to determine the degree and quality of change during and after the implementation of the activity; provides minimum information required to assess the quality of the activity implementation and measure the development results.
254. The result of the study are critical to good project decision making, and for biodiversity management in particular, because they: (1) help identify and prioritize the most important biodiversity elements present within the area of influence of the project (2) provide information that allows for a rigorous and transparent impact assessment process; (3) provide information that allows for early implementation of the mitigation hierarchy; and (4) provide the data for establishing long-term monitoring,
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evaluation and assessment programs. Above all, baseline information is necessary in the planning and implementation of a biodiversity/marine restoration and management programs for those resources affected by development activities.
DESCRIPTION OF THE PROPOSED NALIL-SIKKIAT BRIDGE
255. The proposed Nallil-Sikkiat bridge is approximately 380.80 lineal meters in length separated by approximately 4-meters deep channel of water (Figure 1) varying from 0.5 meters to 3.5 meters. The proposed bridge is located is near the base of PNP-Maritime and the area was used by the community as highway in going to other places and in transporting goods and other commodities. The coastal area is rocky that gradually changed into muddy substrate. Pollution in the form of solid waste was also observed in both sites and saltwater crocodile are frequently sighted in the area.
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Figure 17. Appendix 1-1. Map showing the proposed Nalil-Sikkiat Bridge
256. Figure 2 showed the different sampling stations for coral and fishes, seagrass and mangroves. Three (3) sampling stations for coral reefs reef fishes, six (6) sampling stations for seagrass/seaweeds and twelve sampling stations (12) for mangroves community structure. The sampling stations for water quality, plankton and benthos is the same with sampling station for coral reefs. The sampling stations for corals, fish, seagrass/seaweeds, plankton, benthos and water parameters were located nearest to the proposed bridge alignment based on the map and coordinates that was provided by the DPWH. The mangroves sampling sites were also located nearest to the proposed bridge approaches that will be directly affected by the construction activities.
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Figure 18. Appendix 1-2 Map showing the different sampling stations in the proposed Nalil-Sikkiat bridge
OBJECTIVES OF THE BASELINE STUDY
257. The main objective of the study is to establish a baseline data on the status of biological resources in the proposed Nalil-Sikkiat bridge. The specific objectives are as follows:
(1) Determine the biological resources in the proposed Nalil Sikkiat bridge,
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(2) Determine the status, species composition, abundance and biomass of coral reefs and reef fishes, (3) Determine the community structure of seagrass/seaweed species, and Mangrove, (4) Determine the water quality, phytoplankton and benthos diversity, abundance and composition abundance, and (5) Determine the water current and circulation in the area.
METHODOLOGY
A. Coral Reefs
258. Line Intercept Transect (LIT) method (English et al, 1997) was used in estimating the relative abundance of living things and non-living things particularly the hard corals, soft corals, dead corals, algae, and various reef substrates, which may reflect the health of the reef observed along the transect line. The transect lines were laid parallel to the shore following reef contour or formation at a constant depth. Starting at one end (mark zero), the SCUBA diver observes over the transect line and records the fraction of the length of the line that is intercepted by that lifeform. At each dive site surveyed, two (2) 50 m transect lines were laid using fiberglass measuring tapes. Other site variables were also noted, such as the depth range, visibility, currents, general reef profile and water circulation. The position and location of each station surveyed was taken using a GPS (Global Positioning System).
Percent cover was computed using the following equation:
Total number of points per life form Percent cover (%) =------x 100% Total number of points per transects
259. Reef health had been assessed using the quartile index established by Gomez et al., 1981 and Licuanan, et.al. 2017 wherein the proportion of living hard corals were compared relative to other benthic components (e.g., dead coral, soft coral, algae, rubble, etc.). Coral reefs were classified as poor having 0- 24.9% live hard coral cover; fair (25-49.9% cover), good (50- 74.9% cover) and excellent (75-100% cover).
B. Reef Fish Community
260. The Fish Visual Census (FVC) techniques (English et al. 1997) used to determine the fish species diversity, abundance and biomass in the proposed Nalil-Sikkiat bridge. Fish visual census (FVC) was conducted on the same transect lines surveyed for benthic community. In the survey protocol, observers waited for about 5-10 minutes after the line has been laid, before the actual census was performed to allow for the disturbed fish community
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to return to their normal activity. Starting at one end of the line, all fishes within a 5m x 10m imaginary quadrat were identified up to species level (if possible) and their numbers and estimated sizes recorded. The observer swam and stopped at every 5 meters mark along the line until the end of the transect lie. The faster moving fishes were counted first before the slower ones. Each transect covers an area of 500m2 (50m long x 10m width). The sizes of all fishes encountered within transect line were estimated to the nearest centimeter using the total length (TL). Fish density and biomass were then computed using ReefSum (Uychiaoco 2000). Fish biomass is based from the relationship, W=aLb, where W is the weight in grams; a and b are the growth coefficient values taken from published length-weight data; and L is the length of the fish in cm (English et al. 1997). All fishes were grouped into target, coral indicator, and major species. Target species are the commercially important fishes, coral indicator species are coral-associated, and major species are those that belong to non-commercially important species.
C. Seagrass/seaweeds
261. Data on seagrass and associated seaweeds were gathered inside the 50 x 50 cm quadrats placed at regular intervals along the transect line. The transect line were placed perpendicular to the shore, representing prevailing gradients in water depth, substrate, and exposure to wind and waves. The structure of the plant communities was assessed in terms of their composition, abundance and status in relation to prevailing habitat conditions. The species composition and percentage cover of seagrass/seaweeds was estimated at 10 meters intervals along the transect line using the methods of English et al. (1997). The quadrat was placed on the substratum, and the estimated cover of seagrass/seaweeds in each of the 25 squares was scored using the classes developed by Saito and Atobe (1970). The classification of seagrass/seaweeds bed was determined on the basis of the degree and nature of alteration and their general response to specific habitat conditions using the criteria of Fortes (1990).
D. Mangrove Community Structure
262. The mangrove community structure technique of English et al., (1997) was used to determine the species diversity, abundance, and dominance of mangroves in the proposed bridge. A 10-meter x 10-meter quadrat was established to gather information on the species diversity, frequency and dominance of mangroves in the site. Parameters measured in the community structure of mangroves include species composition and distribution, tree density, and diameter at breast height (GBH). Girth at breast height (GBH) of each tree was recorded by measuring the trees’ circumference 1.3 m above the ground. Saplings (girth less than 4 centimeters and height greater than 1 meter) and seedlings (less than 1 meter in height) are identified and the number of individuals by species is determined by actual count. If the density of sapling and seedlings is very high and uniform, smaller
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subplots can be used (5-meter x 5 meter) would be the minimum size.
E. Plankton Community
263. A plankton net measuring one (1) meter length with 60 cm diameter mouth opening and 20 microns mesh size was used to collect plankton samples. The net consists of a cone shaped gauze bag equipped with a metal ring on the mouth and closed in the narrow end by detachable plankton collecting vessel. The mouth of the plankton net is attached to the towing line by three rope bridles and a weight is attached to the end of the towing cable.
264. Before deployment, the plankton net was rinsed with the sample water and the code end is completely closed by turning the valve into vertical position. The plankton net is slowly lowered horizontal to the water surface and slowly towed horizontally by a low-speed motorboat. The plankton sample is collected by opening the cod end by turning the valve horizontally and put it into sampling bottle. Upon arrival to the laboratory, the samples were analyzed using a light microscope to identify the type of phytoplankton and zooplankton, and cell count to determine the plankton cell density.
F. Benthos Community
265. A sediment core sampler made of acrylic tube, measuring 50 centimeters long and 5 centimeters wide was used to collect sediments for benthos sample. The sediment core was manually pushed into the substrate approximately 30 centimeters of the tube to gather sediment samples. Sampling in hard or coarse substrates was done by gentle rotation of the tube while pushing in order to facilitate greater penetration and decrease core compaction. The top of the tube is capped to provide suction and reduce the chance of losing the sediment. The collected sediment was transferred in 500ml plastic bottles labeled with station name, date and site and the top of the plastic bottle is completely wrapped up with duck-tape to prevent leakage.
266. The wet sieving method was employed to separate the benthic infauna from the sediment. The sediment was transferred into a sieving pan measuring one micron (1.00 ). The sieving pan is fitted onto a basin filled with water and then swirled repeatedly to separate the fines, sand particles, detritus𝜇𝜇 and fauna present in the sediment. Benthic organisms were picked out from the sieving pan, classified, counted and identified down to the species level (English, et.al., 1997).
G. Water Parameters
267. The physical and chemical parameters of the water were analyzed in-situ with the used of Extech DO700. The main purpose of the water quality measurement for the marine environment is to determine if these parameters support the
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requirements of marine organisms in the area. Prior to the actual measurement, the device (Extech DO700) was pre- calibrated to reduce errors on reading of various water parameters. The physical and chemical water parameters measured are: temperature (0C), salinity (parts per thousand), dissolve oxygen (DO), pH (referring to amount of hydrogen in the substance) and total dissolve solid (TDS). Both TDS (and TSS which was not possible to test by the device) brings negative effect to the marine organisms. If the turbidity is higher, there is greater amount of total suspended solid in the water. Unlike 'hardness', the greater the total dissolved solids' content is, the lower the turbidity of the water. The physico-chemical parameters were determined at the surface and in the mid-water level with three (3) replicates. This was done to compare the water parameters in surface and in the mid-level of the water. Probes and electrodes are rinse thoroughly with distilled water in every reading conducted to avoid contamination and errors of the results.
H. Water Current and Circulation
268. Mapping of surface currents will be determine using the 600 KHZ TRDI Acoustic Doppler Current Profiler (ADCP) and time- series current measurements using Nortek ADCP. Water circulation will determine using the DELFT modelling.
RESULT AND DISCUSSION
A. Coral Reefs
1. Result
269. Three sampling stations (N5.03540 E119.75686, N5.03660 E119.75648 and N5.03581 E119.75678) with three (3) replicates were established in the proposed Sikkiat-Pakias bridge, Tawi- Tawi. (Figure 2). The sampling stations were located both sides of the proposed bridge and in the middle of the channel.
270. Using the detailed survey result, the average living hard coral cover is 37% (Table 1 and Figure 3). The 37% hard coral cover is considered in good condition using the Gomez, et.al., 1981 and Licuanan, et.al., 2017 scales and thresholds for evaluating status of reefs in the Philippines. A reef is in “poor” condition if it has a hard coral cover of 0-22%, “fair” if hard coral cover is >22-33%, “good” if hard coral cover is >33-44%, and “excellent” if hard coral is >44% (Licuanan et al., 2017).
Table 55. Appendix 1-1 Percentage cover of different benthic components in the proposed Nalil-Sikkiat Bridge Mean MAJOR CATEGORY Std. Dev. Std. Error cover Hard Coral 37.13 8.23 4.76
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Algae assemblage 31.39 3.73 2.16 Abiotic 15.25 2.36 1.37 Macroalgae 0.37 0.32 0.19 Halimeda 2.98 2.05 1.18 Other biota 12.87 4.89 2.82
271. The major coral genera in the proposed bridge location are Acropora, Echinopora, Euphyllia, Favia, Favites, Fungia, Galaxea, Goniopora, Heliopora, Lobophyllia, Millepora, Porites, and Seriatopora. Most of the coral general are weedy and stress tolerant except for Lobophyllia which is endangered and is only found in the Sulu bioregion (Licuanan et al., 2019). The Lobophyllia Brain Corals, sometimes called Lobed Brain corals, are a very popular stony coral for aquarium due to its wide variety of colors and textures.Small and scatted population of this species was found in the proposed bridge. Protection of this species is the same with the other hard corals. Sediment traps or fine nets shall be deployed over the area to prevent these from being smothered by construction debris and silt resulting from the construction activities. Contractors shall be made aware of the presence of these species and additional mitigating measures shall be applied including but not limited to its unauthorized removal. Should transplantation be necessary, this activity shall be under the supervision of experts preferably from the MSU Tawi-Tawi Campus.
Hard coral Algae assembalge Abiotic Macroalgae Halimeda Other biota
13% 3% 0% 37%
15%
32%
Figure 19. Appendix 1-3 Percentage cover of the main benthic groups in the proposed Nalil-Sikkiat Bridge
2. Discussion
272. The good coral cover in the proposed Nalil-Sikkiat bridge indicates that the area is suitable for coral recruitment, growth
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and development. The good category of hard coral could be attributed to the frequent tidal flushing of the channel that connects the Sulu Sea and Sulawesi Sea or Celebes Sea. The water parameters are within the optimum level for coral growth and development. Sedimentation and siltation observed in the area but the accumulation of sediment and silt on the bottom was minimized by frequent tidal flushing. The tidal flushing reduce sedimentation resulting to the light penetration and transporting sediment away from the coral area.
273. The water parameters in the area suitable is favorable for coral growth and development. This observation conforms to the statement of Goreau, et.al. (1979) & Nybakken (1982), that coral reefs need good conditions favoring the growth and development include water temperature above 18 0C; water depth shallower than 50 meters; constant salinity greater than 30 parts per thousand; low sedimentation rates; sufficient circulation of pollution free water; and preexisting hard substrate.
274. Coral reefs require sunlight because the individual polyps of the coral contain symbiotic algae. The algae need the light for photosynthesis. The key feature of corals is that they are in a symbiosis with tiny dinoflagellates called zooxanthelle. These tiny creatures actually live inside of the corals and are photosynthetic algae which produce food (organic compounds) for the coral while the coral provides them with a place to live, as well as carbon dioxide, some nutrients, protection and access to light. Without this key interaction, the entire coral reef community would not be possible, because the tropical waters are too nutrient-poor to support life. Thus, millions of tiny zooxanthelle produce key nutrients and give them to the corals, which are then distributed throughout the community through nutrient cycling.
275. The water in the area is turbid due to sedimentation and siltation. Turbid water prevented light penetration into the bottom. However, due to frequent tidal flushing, light penetration reach into the coral area. Corals need clear water that lets sunlight through; they don’t thrive well when the water is opaque. Sediment and plankton can cloud water, which decreases the amount of sunlight that reaches the zooxanthellae. Reef-building corals require warm water conditions to survive. Different corals living in different regions can withstand various temperature fluctuations. However, corals generally live in water temperatures of 20–32° C.
276. Corals are sensitive to pollution and sediments. Sediment can create cloudy water and be deposited on corals, blocking out the sun and harming the polyps. Wastewater discharged into the ocean near the reef can contain too many nutrients that cause seaweeds to overgrow the reef. Corals need saltwater to survive and require a certain balance in the ratio of salt to water. This is why corals don’t live in areas where rivers drain fresh water into the ocean (“estuaries”).
277. Substrate type is an important factor influencing coral larvae
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settlement and a possible determinant of coral community structure. Substrates, such as live coral, sediment, macroalgae, encrusting sponges, and loose, unconsolidated substrate are unsuitable for coral recruit settlement. Suitable recruitment habitat includes stable bottom type, limited sedimentation in water column, and absence of large macroalgae. The presence of chemical properties in crustose coralline algae (CCA) and other substrates, such as dead coral, have been shown to encourage coral larvae settlement. Lastly, the daily tidal water flushing in the channel help the coral growth and development by reducing concentration of suspended silt and sediment in the water column resulting to the good light penetration into the bottom which is very essential to the production food and nutrient cycling in the bottom.
A. Reef fishes
1. Result
278. There are 37 species belonging to 18 fish families and with an average biomass of 6.98 mt/km² recorded in the proposed Nalil- Sikkiat bridge (Table 2). This cumulative species falls under the poor category (Hilomen et al. 2000). Two indicator fish species belonging to family Chaetodontidae and seven target fish families (Nemipteridae, Scaridae, Siganidae, Balistidae, Haemulidae, Serranidae and Lethrinidae were observed in the area.
Table 56. Appendix 1-2 Composition and biomass ((mt/km2) of fish species found in the proposed Nalil-Sikkiat Bridge Species Biomass (mt/km2) Amblyglyphidodon aureus 0.173481976 Amblyglyphidodon curacao 0.185700171 Balistoides viridescens 0.067873271 Cantherhines pardalis 0.025434554 Cantherhines pardalis 0.036475791 Canthigaster compressa 0.005248501 Canthigaster compressa 0.009728927 Canthigaster compressa 0.014209352 Canthigaster compressa 0.014209352 Canthigaster compressa 0.014209352 Canthigaster rollandi 0.028418705 Centropyge nox 0.079409185 Chaetodon lineolatus 0.115417577 Chaetodon melannotus 0.166880735 Cheilinus chlorourus 0.093106635 Cheilinus chlorourus 0.031059156 Cheilinus fasciatus 0.06649864 Cheilinus fasciatus 0.05246136 Cheilinus undulatus 0.039347759 Cheilodipterus macrodon 0.103915428
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Species Biomass (mt/km2) Cheilodipterus macrodon 0.155573233 Cheilodipterus quinquelineatus 0.025492132 Chlorurus sordidus 0.144390107 Chlorurus sordidus 0.107835823 Choerodon anchorago 0.146692026 Chromis viridis 0.120675728 Cirrhilabrus cyanopleura 0.079383198 Coris batuensis 0.01777472 Dascyllus aruanus 0.031468654 Dascyllus aruanus 0.049727618 Dascyllus melanurus 0.010517691 Dischistodus fasciatus 0.077015959 Dischistodus fasciatus 0.079053481 Dischistodus fasciatus 0.097165264 Dischistodus melanotus 0.218137229 Dischistodus melanotus 0.279642747 Dischistodus perspicillatus 0.077830968 Dischistodus perspicillatus 0.058745807 Dischistodus prosopotaenia 0.210237783 Dischistodus prosopotaenia 0.079053481 Dischistodus prosopotaenia 0.167595734 Epibulus brevis 0.023253207 Epibulus brevis 0.023253207 Epibulus brevis 0.029302122 Epinephelus merra 0.118282266 Gerres oyena 0.337314367 Gobiodon okinawae 0.001249911 Halichoeres margaritaceus 0.05806304 Halichoeres margaritaceus 0.08667136 Halichoeres melanurus 0.199558763 Hemigymnus melapterus 0.11899871 Hemigymnus melapterus 0.037809133 Meiacanthus grammistes 0.019064899 Myripristis adusta 0.083799385 Myripristis adusta 0.083799385 Nectamia similis 0.019597291 Neoglyphidodon bonang 0.020567581 Neoglyphidodon melas 0.064805989 Oxycheilinus celebicus 0.11997546 Oxycheilinus digrammus 0.07952112 Oxycheilinus digrammus 0.07952112 Parapercis cylindrica 0.051902561 Plectorhinchus chaetodonoides 0.226911744 Plectorhinchus chaetodonoides 0.41763175 Plectorhinchus chaetodonoides 0.066151477
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Species Biomass (mt/km2) Plectorhinchus vittatus 0.156377358 Plotosus lineatus 2.737977165 Pomacentrus brachialis 0.048217776 Pomacentrus moluccensis 0.095719157 Pomacentrus simsiang 0.072943095 Pseudomonacanthus macrurus 0.327375376 Scarus dimidiatus 0.029441802 Scarus psittacus 0.070004137 Scarus psittacus 0.088394909 Scolopsis bilineatus 0.122088819 Siganus vulpinus 0.3937066 Sphaeramia nematoptera 0.183927387 Synchiropus splendidus 0.036751929 Synchiropus splendidus 0.022765173 Thalassoma hardwicke 0.047567722 Thalassoma hardwicke 0.059587311 Thalassoma lunare 0.064931421
2. Discussion
279. Table 3 and 4 showed the species richness and fish abundance categories developed by Hilomen, et al. (2000) and Table 5 showed the biomass category developed by Nañola et al. (2006). These categories used to determine the status of reef fishes in the proposed bridge.
280. The species diversity of 37 species within a 1000m2 is under the poor category and fish abundance of 189 individual/1000m2 is under very poor category using the Hilomen et al. 2000 scales and threshold for evaluating status of reef fishes in the Philippines, and the reef fish biomass of 6.98mt/km² falls under the very low category using the Nañola et al. 2006 scales and threshold in evaluating status of reef fish in the Philippines. The result indicates that the fish sizes were small and the area is overfished and disturbed marine environment.
Table 57. Appendix 1-3 Categories of sites according to species richness as adapted from Hilomen et al. (2000). Category No. of individuals per 1000 m2 Very poor 0 -201 Poor 202 – 676 Moderate 667 – 2267 High 2268 – 7582 Very high > 7592
Table 58. Appendix 1-4 Categories of sites according to fish abundance as
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adapted from Hilomen et al. (2000). Category Biomass MT/km2 Very poor < 5 Poor 6 – 10 Moderate 11 – 20 High 21 – 40 Very high > 41
Category No. of species per 1000m2 Very poor 0 – 26 Poor 27 – 47 Moderate 48 – 74 High 75 – 100 Very high > 100
281. The result of the reef fish assessment in the proposed Nalil- Sikkiat bridge falls under poor category in species diversity, very poor category in number of individuals (Hilomen et al. 2000) and poor category in the total biomass. Despite of the good coral cover, the status of reef fish population in the proposed bridge is in poor category. This showed that there is no mutual dependencies between the reef building corals and reef- inhabiting fishes.
282. The physical characteristics of the substrate influence the recruitment, settlement, growth and survival of marine organisms. Several studies supported these findings, that the complex structural of coral reefs offers shelter to an extremely diverse fauna (Connell, 1978). In most studies, the physical complexity of substratum is positively correlated with the diverse of fish community but not with the fish abundance (Luckhurst and Luckhurst 1978; Talbot et al. 1978; Roberts and Ormond 1987). While in other studies, the fish characteristics were positively correlated with the live coral cover (Carpenter et al. 1981; Sano et al. 1984, 1987; Bell and Galzin, 1984). The variability in the relationship between fish and coral communities maybe attributed to some ecological and methodological factors.
283. Water turbidity also affects the reef fish population in the area. Lloyd et. al., (1987) showed that the productivity of aquatic systems could be reduced by turbid conditions. Increases in turbidity reduced light penetration which led to decreased quantities of plant material and hence reduced primary production, decreased abundance of fish food organisms (secondary production) and decreased production and abundance of fish. The degree of fish population declines is usually associated with the quantity of “fines” within a stream ecosystem (Castro and Reckendorf 1995; Muck 2010). There were a variety of negative impacts pertaining to fine sediments in streams, including: (1) loss of habitat for macro invertebrates,
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i.e., fish prey (Rabeni et al. 2005; Wood et al. 2005), (2) physiological stress and direct physical damage for both fishes and macro invertebrates (Newcombe and MacDonald 1991; Sutherland and Meyer 2007), (3) reduction in or elimination of reproductive habitat for benthic and crevice spawning fishes (Burkhead and Jelks 2001; Sutherland 2007), and (4) reductions in the locating and capturing prey ability of fishes due to visual impairment (Barrett et al. 1992; Zamor and Grossman 2007; Hazelton and Grossman 2009).
3. Relationship between coral reefs and coral reef fishes
284. In the proposed Nalil-Sikkiat bridge, the diversity of coral reefs is not positively correlated with the fish community. This is maybe due to the anthropogenic activities such as fishing and passage of boats in the area. Several studies supported these findings. The coral species richness and live coral cover had no influence on the diversity and abundance of fish communities in some studies (Luckhurst and Luckhurst 1978; Mc Manus et al. 1981; Roberts and Ormond 1987). While in other studies, the fish characteristics were positively correlated with the live coral cover (Carpenter et al. 1981; Sano et al. 1984, 1987; Bell and Galzin, 1984 & 1988). The variability in the relationship between fish and coral communities maybe attributed to some ecological and methodological factors.
285. Fish population can be used as an indicator if coral reef is healthy but there were cases that even if the areas do not have good coral cover, high species fish diversity are still present. Fish abundance and biodiversity may vary because of water quality and presence of food source in a certain area.
B. Seagrass/seaweeds
1. Result
286. Table 6 showed the GPS coordinates of seagrass/seaweeds sampling stations in the proposed Nalil-Sikkiat bridge. Three sampling stations were established in the both sides of the proposed bridge. Only two (2) species of seagrass (Enhalus acoroides and Halophila ovalis) was present in the proposed Nalil-Sikkiat bridge.
Table 59. Appendix 1-6 GPS coordinates of seagrass/seaweeds sampling stations in the proposed Nalil-Sikkiat bridge. Stations Sites Coordinates 1 Sikkiat N5 02 06.4 119 45 25.0 E 2 Sikkiat N5 02 06.4 119 45 24.9 E 3 Sikkiat N5 02 06.3 119 45 24.7 E 1 Pakias N5 02 12.1 119 45 23.3 E 2 Pakias N5 02 12.1 119 45 23.1 E 3 Pakias N5 012 12.2 119 49 22.9 E
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287. The average percentage cover of seagrass in Sikkiat and Pakias was 2.18 and 2.43 %/ /m2, respectively. The percentage cover of E. acoroides in Sikkiat (0.48%/m2) is slightly higher than in Pakias side (.09%/m2) while H. ovalis recorded 0.06 %/m2 and 5% /m2 in Sikkiat and Pakias, respectively.
Table 60. Appendix 1-7 Percentage cover (%/m2) of seagrass in Nalil-Sikkiat bridge Site Species Cover (%/m2) Sikkiat Station 1 5.45 Station 2 0.00 Station 3 1.09 Mean 2.18 Pakias Station 1 0.00 Station 2 7.27 Station 3 0.00 Mean 2.43
2. Seaweeds species
288. There seven (7) seaweeds species recorded in the proposed Nalil-Sikkiat bridge. The seaweeds species are Halimeda sp.,Galaxaura sp., Padina sp., Neomeris sp., Gracilaria sp., Boergesenia sp.and Caulerpa sp. These species thrive in areas with low light intensity, silty and sandy substrates, and they tolerate fluctuations of physical and chemical parameters. Parameters that affect the recruitment and settlement of seaweeds are: water movement/wave action, water clarity, turbidity, and substrate characteristics.
3. Discussion
289. The development of Enhalaus acoroides in the area is favorable in sandy-muddy and sandy-silted substrates and this species is not greatly affected by turbidity and low light intensity due to the long leaves that extended to the surface of the water. Enhalus acoroides is the biggest tropical seagrass and can tolerate low light and highly turbid conditions (Bach et al., 1998) such as the waters of Sikkiat-Pakias bridge. However, the recruitment and development of other seagrass species in the area is affected by sedimentation, siltation, pollution and deposition of physico- chemical substances.
290. The category of seagrass in the proposed Nalil-Sikkiat bridge is emergent wherein the area is characterized by very low species diversity and low cover, largely controlled by extreme fluctuations of physico-chemical conditions. Low species diversity of seagrass and seaweeds in the proposed bridge was affected primarily by the substrate characteristics, turbidity brought by sedimentation and siltation and influx of water from the river. This observation conforms to the findings of Fortes (1994) that the
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lowest number of seagrass species occur at highly turbid water, silted sites where patchy monospecific stand of seagrass, a highly degraded habitat and areas highly protected from waves with muddy substrate. The distribution and species abundance of seagrass is directly affected by the levels of siltation (Agawin et al. 1997, Terrados et al. 1998; Vermaat et al. 1995, 1997) and the reduced underwater light availability can lead to seagrass mortality and reduce biomass (Duarte, 1991).
291. The expansion of seagrass in the deeper part of the area greatly influence by sedimentation and low light intensity. This observation attest to the findings of Duarte et al., (1997) that increased in the sedimentation load of the water effectively decreases light penetration, resulting in the eradication of much of the seagrass beds from deeper areas. Savella, R. (2014) also found out that the seagrass bed with low species diversity located in areas protected from waves, and higher concentration of sediment loading with muddy substrate.
292. Increased siltation from human activities and coastal development has been identified as the cause of seagrass losses in several coastal areas (Krikman and Walker, 1989), and is expected to be the primary cause of deterioration of SE Asian seagrass ecosystem (Fortes 1988, 1995). Increased sediment deposition can lead to seagrass loss due to burial effects (Duarte et al., 1997). The presence of E. acoroides and the absence of other seagrass species in the area is the result of excessive sedimentation. This finding is consistent with prediction based on seagrass architecture (Vermaat et.al. 1997), and with the observed ranking of resistance of these species to experiment burial (Duarte et al., 1997).
293. The importance of seagrass in the marine environment is well described by Orth and Hech (1980). Seagrass/seaweeds provide a physical structure that enhances species diversity, provides shelter from predators, and provide important ecosystem functions. However, due to their proximity to shore, the seagrass communities are vulnerable to changes to both land and sea uses (Orth et al., 2006). Anthropogenic activities like result from direct marine-based activities (e.g. dredging, coastal and marine development, fishing disturbance, mooring, anchoring, and aquaculture) as well as indirect land-based activities (e.g. nutrient and sediment loading from terrestrial urbanization, agriculture development, deforestation) causes seagrass and seaweeds loss (Short and Wyllie- Echeverria, 1996).
C. Mangrove Community Structure
1. Result
294. Table 8 showed the Global Positioning System (GPS) coordinates of mangrove sampling stations. Six (6) sampling stations were established in the proposed Nalil-Sikkiat bridge to represent the mangrove community in the area. Mangrove density is higher in Nalil side as compared with the Pakias side.
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Sikkiat Pakias Rhizophora apiculata R. apiculata Rhizophora stylosa S. alba Ceriops tagal Sonneratia alba Bruguiera gymnorrhiza Total 5 Total 2
Table 61. Appendix 1-8 Global positioning System (GPS) coordinates of mangrove sampling stations in the proposed Nalil-Sikkiat bridge
Stations Coordinates Sikkiat Station 1 N5 02.101 E119 45.415 Station 2 N5 02.100 E119 45.423 Station 3 N5 02.084 E119 45.414 Station 4 N5 02.086 E119 45.421 Station 5 N5 02.077 E119 45.414 Station 6 N5 02.070 E119 45.416 Pakias Station 1 N5 02.213 E119 45.383 Station 2 N5 02.216 E119 45.393 Station 3 N5 02.213 E119 45.400 Station4 N5 02.214 E119 45.379 Station 5 N5 02.217 E119 45.374 Station 6 N5 02.219 E119 45.366
295. There were five (5) species of mangroves recorded in Sikkiat side and three (3) species found in Pakias side (Table 9). The mangrove species in Sikkiat are Rhizophora apiculata, Rhizophora stylosa, Sonneratia alba, Ceriops tagal, and Bruguiera gymnorrhiza while the mangrove species found in Pakias side are Rhizophora apiculata and Sonneratia. R. apiculata and had been recorded the most abundant and dominant mangrove species in the proposed bridge.
Table 62. Appendix 1-9 Mangrove species in the proposed Nalil-Sikkiat Bridge
296. Higher sapling and seedling counts were recorded in Pakias side as compare in Sikkiat side. The total seedling in Pakias is
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27 while 13 seedlings found in Sikkiat side. There are fifty-three (53) saplings recorded in Sikkiat side while three (3) saplings found in Pakkias side (Table 10). S. alba recorded the highest count of seedling (18) while R. apiculate recorded the highest count of sapling.
Table 63. Appendix 1-10 Seedlings and saplings recorded in the proposed Nalil- Sikkiat bridge Sikkiat Pakias Species seedling sapling seedling sapling R. apiculata 5 27 9 C. tagal 10 2 R. stylosa 4 S. alba 6 11 18 B. gymnorrhiza 2 1
297. In Sikkiat side, Rhizophora apiculata recorded the most dominant (516.67/ha) mangrove species in the area followed by Sonneratia alba (83.33/ha), C. tagal (50/ha), R. stylosa and B. gymnorrhiza (16.7), respectively (Figure 4). R. apiculata recorded 733.33 stand per hectare and 150.0 stand/hectare for S. alba found in Pakias side (Figure 5).
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Figure 20. Appendix 1-4 Average mangrove stands per hectare in Sikkiat side
700 600 516.67 500 400 300 200 83.33 100 50 16.67 16.67
no. of manghrove/ha 0 R. apiculata C. tagal R. stylosa S. alba B. gymnorrhiza Species
Figure 21. Appendix 1-5 Average mangrove stand per hectare in Pakias side
700 600 533.33 500 400 300 200 150
no. of mangroves/ha 100 0 S. alba R. apiculata Species
298. In Sikkiat side, Sonneratia alba was the tallest of all mangrove species with an average height of 5.9 meters, followed by B. bruguiera (4.2 m), R. apiculata (3.9 m), C. tagal (3 m), and R. stylosa (2.4m) (Figure 6). In Pakias side, S. alba was the tallest mangrove with an average height of 4.8 meters while R. apiculata was 2.6 meters (Figure 7).
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Figure 22. Appendix 1-6 Average height (meters) of mangrove in Sikkiat side
8 7 5.9 6 5 3.9 4.2 4 3 meters 3 2.4 2 1 0 R. apiculata C. tagal R. stylosa S. alba B. gymnorrhiza Species
Figure 23. Appendix 1-7 Average height (meters) of mangroves in Pakias sided
9 8 7 6 4.8 5 meters 4 3 2.6 2 1 Species 0 S. alba R. apiculata
2. Discussion
299. There are five mangrove species recorded in the area. This indicates that the area is suitable for mangrove development. Rhizophora apiculata appearing in both sides, recorded the highest number of mangrove stand, saplings, seedlings, and the most dominant mangrove species in the area. The species
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diversity and population density of mangroves increased through the introduction of management and reforestation activities.
300. The types of mangroves used for reforestation are: Rhizophora species because the propagules (planting material) of these species are easy to collect, plant and monitor. For this reason, most reforestation programs exclusively use these species for their large-scale coastal reforestation activities. However, there are several technical issues involved in such replanting activities that can lead to heavy mortalities: (i) propagules are planted in open waters (instead of upper intertidal areas, behind Sonneratia and Avicennia species) and are easily toppled by wave action or floating debris; (ii) mono-specific plantations can be attacked easily by diseases and pests; (iii) propagules are planted directly on seagrass beds or the wrong substrates lead to mortalities. Observed the zonation pattern of mangroves before planting and when using mangrove propagules (fruits), be sure that the propagules are mature enough to ensure higher survival rate. It is highly recommended that mangrove seedlings of other species are also planted to increase diversity and resilience of the mangrove stand.
Based on the survey, between 10-20 mangrove stands will be affected by this coastal development (bridge project) and this will not significantly affect the population density of mangroves in the area. Some of these mangrove trees have already been cut and the Sonneratia species are not primary growth but rather secondary or tertiary growth after these were cut several times. There will be no direct significant impact on the mangrove resources as there are many mangroves remaining in the area where the proposed coastal development will be done. The mangroves are previously cut by the people to make way for the construction of houses. If there are mangrove trees that will be affected by any coastal development, this must be replaced with more reforestation activities. Usually, ten thousand seedlings will be planted in one hectare but it can be more if the purpose is for protection. Mangrove reforestation does need any permit. However, the LGUs must be informed before planting activities are conducted. The more mangroves areas are restored, the more ecological benefits will be expected in the future.
D. Plankton Community
1. Result
301. The GPS coordinates of plankton sampling stations in the Sikkiat-Pakias side is the same with the sampling stations of coral reefs. Two (2) stations with three (3) replicates were established for the collection of water sample for plankton identification. The first station was located in the Sukkiat side, second station was located in the Pakias side.
302. There were 1,257cell density of phytoplankton recorded in the area while zooplankton recorded 84cell density as shown in Table 11. Sikkiat side recorded 603 cell density and 654
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recorded in Pakias side. There are 22 genera of phytoplankton recorded in the area and the most dominant is Skeletonema followed by Coscinodiscus, Ceratium, Lauderia and Thalassionema. Zooplankton is higher in Pakias side with 654 cell density while 603 cell density in Sikkiat side.
Table 64. Appendix 1-11 Cell density of plankton in the proposed Nalill-Sikkiat Bridge Sampling Stations Genus Sikkiat Pakias Composition Cell density Cell density Asterolampra 17 22 Asteromphalus 3 10 Basteriastrum 27 23 Ceratium 60 49 Chaetoceros 30 25 Coscinodiscus 60 62 Cylindrotheca 18 14 Eucampia 20 10 Gambierdiscus 12 15 Goniodoma 14 18 Gonyaulax 13 28 Guinardia 15 42 Lauderia 40 37 Pleurosigma 30 51 Prorocentrum 19 25 Protoperidinium 20 33 Pyrophacus 5 8 Rhyzosolenia 34 30 Skeletonema 65 76 Thalasiosira 16 20 Thalassionema 55 27 Tintinnopsis 30 29 Total 603 654 Zooplankton 60 24
2. Discussion
303. The biological importance of plankton is not considered in the area due to the minimal population of demersal and pelagic fish populations. Planktons free floating microscopic animals and serve as food for fish, which in turn eaten by other sea creatures such as seabirds, sharks, and seals, and ultimately eaten by larger predators. Zooplanktons are the initial prey item for almost all fish larvae as they switch from their yolk sacs for external feeding. The biological importance of plankton in the food wed is well studied and documented. They represent few levels of a food chain that supports commercially important fisheries, plankton ecosystems play a big role in the biogeochemical cycles of many important chemical elements, including the ocean's carbon cycle (Falkowski 1994). Natural factors (e.g., current variations) and man-made factors (coastal developments) strongly affect plankton population, which in turn strongly limit the larval survival, and therefore breeding success. This finding
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attests the statement of Zeitzschel (1978) that the production of plankton in the sea is mainly dependent on light and nutrients.
304. The phytoplankton and zooplankton abundance in the area is low due to the physical and chemical characteristics of the area. However, based on the result of the study, the living organisms like fishes are in poor category, so, the abiotic factors considered as the causes of plankton population variation. This conforms to the findings of Ayad (2002) and Dejen et.al., (2004) that salinity, and turbidity, has been identified as critical factors in the development of zooplankton. The main deleterious effect of suspended sediment to the population of zooplankton appear to reduce intake of nutritious particles due to the proportionately higher ingestion of abiogenic seston (Tester and Turner, 1989) or phytoplankton food uptake limitation (Gasparini et al., 1999). The zooplankton is mainly dependent to phytoplankton for their food. The abundance of phytoplankton is not directly related to the population of zooplankton in the area. The effect of abiotic factors and the introduction of waste water and other anthropogenic activities might affect the population of zooplankton. However, further study must be undertaken to validate the findings.
E. Benthos Community
1. Result
305. Sampling stations for the benthic community is the same as the sampling stations of seagrass/seaweeds community structure. Survey results revealed that there are three (3) infauna groups (buried in the sediment) recorded in the proposed bridge. The infauna groups are Polychaetes, Annelids and Nematods while seven (7) epifauna species (live on the surface of the sediment) are Coenobita, Echinoderms, Asteroids, Ascidians, Mollusks and Holothurians and Poriferans.
2. Discussion
306. Benthos is the community of aquatic organism that lives in above or near the bottom of lake, sea, river streams or any other aquatic environment. Benthos plays a big role in the ecosystem like decomposition, nutrition, remineralization, food source and increased oxygen in the bottom. They constitute a vital link in the food chain and energy flow, serve as food for other higher organisms such as fish and play a vital role in the circulation of nutrients (Oben et al., 2003).
307. Benthos population is very minimal due to the physical and chemical characteristics of the water, substrate structure, siltation, pollution and human disturbance. The substrate characteristics directly affect the benthic populations in the Nalil- Sikkiat bridge. Sedimentation and water turbidity limit the adaptability, settlement, recruitment, growth and development of benthos organisms. Berry et al. (2003) stated that suspended sediment directly affects invertebrates include, direct impacts
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due to abrasion, interference with respiration and ingestion by clogging of filtration mechanisms, and in extreme cases mortality from smothering and burial. The distribution of infauna and epibenthic species is impacted indirectly through light attenuation affecting feeding efficiency, behavior (avoidance and drift), and habitat alteration occurring from changes in the composition of substrate (Donahue and Irvine 2003; Waters 1995; Zweig and Rabeni 2001; Berry et al. 2003). Increases in suspended sediments resulted in increased drift and significantly altering the distribution of benthic invertebrates in streams (Herbert and Merkens 1961; Berry et al. 2003).
308. Birtwell (2000) also stated that invertebrate’s populations (secondary production) depend upon primary production, and the elevated levels of sediment adversely affect the growth and development of invertebrates. Certain benthic invertebrates are grazers and depend on periphyton for food, while others may be filter feeders, which could have their feeding structures clogged by sediment thereby reducing feeding efficiency and reducing growth rates. Some direct effects of sediment on aquatic invertebrates include: (a) physical habitat change due to the scouring of stream-beds and the dislodgment of individuals, (b) smothering of benthic communities, (c) clogging of the interstices between substrate components which affects microhabitat, and (d) abrasion of respiratory surfaces and interference of food uptake for filter feeders.
309. Accumulation of particles into the bottom changes the physical nature of substratum for benthic organisms. Hard substrates coated with fine particles are generally not as attractive to benthic organisms as clean surfaces and changes in community structure occurred. Accumulation of organic and in organic particles into the bottom makes the substrate not suitable for benthic organisms. The biodegradation of the organic particles exerts an oxygen demand in the sediment reducing available oxygen to infauna populations and changing some chemical processes within the substrate. In extreme cases, the deposition of organic and inorganic particles resulted in the eradication of the benthic fauna (UK Marine Science Areas of Conservation, Non-toxic substance profile -Turbidity). Human disturbance together with the rampant passage of boats have led to the changes of biota as loss of some benthic species as well as reduction in the abundance of other species. Habitat alteration caused by human disturbance is the major causes in the decreasing of benthic populations and other marine species.
F. Water Parameters
1. Result
310. The sampling stations for the water quality is the same with the sampling stations of coral reefs. Two sampling stations with ten replicates were established in the two areas. Table 9 presents the water parameters in the Sikkiat side of the bridge. The readings of water parameters between the surface and middle of
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the water are similar (Table 12). The average surface water temperature is 31.8 oC while 31.50 oC in the middle, the pH at the surface water and middle water column were both 8.8, water salinity at the surface water and middle water column were both 34.1 ppt, dissolve oxygen is 8.0 in the surface and 7.0 in the middle, total dissolved solid (TDS) (g/L) at the surface water and middle water column were 36,400 and 38,900, respectively. The water transparency is from 3.55 m in Sikkiat side and 4.25 m in Pakias side with an average of 3.9 meters.
Table 65. Appendix 1-12 Average water parameters in the Sikkiat side
Parameters Surface Middle Temperature (oC) 31.8 31.5 pH 8.8 8.8 Salinity (ppt) 34.1 34.1 DO 8.0 7.0 Total Dissolved Solid (mg/L) 36,400 38,900
311. Table 13 showed the average water parameters in Pakias side. The surface water and middle water column has an average temperature of 32.1 °C and 31.3°C, the pH values at the surface water and middle is 8.8; water salinity reading at the surface is 32.0 ppt and 33.1 ppt in the mid water column, dissolve oxygen measurement is 8.0 mg/l in the surface and 7.5mg/l in the mid water column and total dissolve solid measurement is 39,800 mg/l in the surface and 39,800 mg/L in mid water column.
Table 66. Appendix 1-13 Average water parameters in Pakias side
Parameters Surface Middle Temperature (oC) 32.1 31.3 pH 8.8 8.8 Salinity (ppt) 32.0 33.1 DO (mg/L) 8.0 7.5 Total Dissolved Solid (mg/L) 39,800 39,800
312. The ranges of water parameters for marine organisms in the tropics are presented in Table 14. Marine organisms have different ranges of water parameters since they have the ability to adopt changes in their environment. Sudden changes on the level of water parameters affect the reproductive mechanism, feeding habit, growth and development of fish and other invertebrates.
Table 67. Appendix 1-14 Range of water parameters for marine organisms in the tropics Parameters Temperature (oC) 24-32
148 Appendix 1 Marine Ecological Assessment Tawi-Tawi Bridge No. 1: Nalil-Sikkiat pH 7.5-8.5 Salinity (ppt) 33-37 DO (mg/L) 5-20 Total Dissolved Solid (mg/L) 30,000-40,000
2. Discussion
Temperature
313. The water quality parameters recorded in the proposed Nalil- Sikkiat bridge are within the tolerable and optimum limit for marine organisms. Water temperature ranges from 31.5 to 32.1oC were recorded and the normal range of surface temperature varies between 24°C and 32°C (75°F to 89°F). The water temperature is favorable for marine organisms for their growth and development. It is noted that changes in water temperature affect the environments where fish, shellfish, and other marine species live. As climate change causes the oceans to become warmer year-round, populations of some species may adapt by shifting toward cooler areas. Each species has a specific range of temperature at which it can live, the warmer the water gets the faster the reactions and the cooler the water the slower the reactions. Some marine organisms are cold blooded (or poikilothermic) or warm blooded (homeothermic) depending on their ability to control their internal body temperature and any species moved out of its temperature tolerance range it may die in a short period of time (Anderson 2003).
Salinity
314. The salinity of the water recorded ranges from 32.0 to 34.1 parts per thousand. The normal range of ocean salinity ranges from 33 to 37 parts per thousand (NWS, Jetstream/Seawater), with an average of 35 parts per thousand. The salinity level of the water in the proposed Sikkiat-Pakias bridge is lower than the normal ranges of salinity in the open ocean. This is because of the influx of fresh water from the community. However, some marine organisms tolerate lower salinity and most aquatic species can adopt different salinity levels like some reef-building corals require very saline water ranging from 32 to 42 ppt.
pH or hydrogen ion concentration
315. Hydrogen ion concentration of pH and measurement of acidity in seawater. The average pH level recorded in the proposed Sikkiat-Pakias bridge was 8.8. This data is within the optimum pH level of seawater. The normal ph level of seawater is from 7.5 to 8.5 for marine organisms (Table 11). Majority of aquatic creatures prefer a pH range of 6.5-9.0, though some species live in water with pH levels outside of this range. As pH levels move up or down from this range, it reduced survival rates of hatchings. Higher pH outside of the optimum pH range value is, the higher the mortality rates. In addition to biological effects, extreme pH levels usually increase the solubility of elements and compounds,
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making toxic chemicals more mobile and increasing the risk of absorption by aquatic life (Fondriest Environmental, Inc. 2013).
Dissolve Oxygen
316. The dissolve oxygen content of the water in the proposed bridge recorded ranges from 7 mg/l to 8.0 mg/l. The dissolve oxygen content of the water is within the normal ranges of dissolve oxygen in other areas. The dissolve oxygen needed by the marine organisms living in the bottom or substrate is ranges from 1-6 mg/l while 4-15 mg/l dissolve oxygen level needed by marine organisms living in the shallow portion of the sea. If the dissolved oxygen levels of seawater drop below 5.0 mg/l, aquatic life is under stress. The lower the concentration of dissolve oxygen, the greater the stress and if dissolve oxygen levels drop to 1-2 mg/l for a few hours, it resulted to large fish kills (Lenntech BV).
Total dissolve solid (TDS)
317. The total dissolve solid recorded in the proposed Nalil-Sikkiat bridge is within the optimum level of concentration from 36,400 mg/l to 39,800 mg/l. The normal total dissolve solid of marine water is more than 35,000 mg/l. According to the Texas Water Development Board, the high concentration of total dissolve solid is due to soil erosion resulting to sedimentation, siltation, debris of solid particles from commercial and residential areas, waste- water system and rotting animals and plants.
318. According to Lehigh Environmental Initiatives EnviroSci Inquiry (2000-2011), some dissolved solids come from organic sources such as leaves, silt, plankton, and industrial waste and sewage. Other sources come from runoff from urban areas, road salts used on street during the winter, and fertilizers and pesticides used on lawns and farms. Some dissolved solids come also from inorganic materials such as rocks and air that may contain calcium bicarbonate, nitrogen, iron phosphorous, sulfur, and other minerals. Changes in the amounts of dissolved solids can be harmful because the density of total dissolved solids determines the flow of water in and out of an organism’s cells. Many of these dissolved solids contain chemicals, such as nitrogen, phosphorous, and sulfur, which are the building blocks of molecules for life. Concentration of total dissolved solids that are too high or too low may limit the growth and may lead to the death of many aquatic organisms. High concentrations of total dissolved solids also reduce water clarity, which contributes to a decrease in photosynthesis and lead to an increase in water temperature.
G. Water Current
319. Water current was measured in forty (40) points around the proposed bridges (Table 15). The average velocity of the water current during the sampling period is 0.15 m/sec. Typical maximum current speeds in tidal inlets are approx. 1 m/s, whereas tidal current speeds in straits and estuaries can reach speeds as
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high as approx. 3 m/s. The current in the area is primarily wind generated. Wind-generated currents are caused by the direct action of the wind shear stress on the surface of the water. It is normally located in the upper layer of the water body and are therefore not very important from a morphological point of view. In very shallow coastal waters and lagoons, the wind-generated current can, however, be of some importance. It brings nutrients and oxygen needed by some marine organisms. The water currents primarily influenced by the occurrence of tides and it is expected to increase during windy and rainy season. The water current is driven primarily by gravity, wind, rise and fall of tide. The flow of water varies spatially as well as temporally within the area, dependent upon the volume of water, tides. stream gradient and channel geometry. Further study and monitoring on the velocity of the water current in the area must be done in daily, monthly or seasonal basis. Weather condition directly influence the water velocity in the area.
Table 68. Appendix 1-15 Sampling points of water current in the proposed Nalil- Sikkiat Bridge
Replicate Rate (m/s) starting point end point
1 0.09 N5 02.131 E119 45.402 54⁰ NE 2 0.10 N5 02.130 E119 45.401 2⁰ N 3 0.05 N5 02.135 E119 45.398 44⁰ NE 4 0.07 N5 02.140 E119 45.395 99⁰ E 5 0.09 N5 02.147 E119 45.400 42⁰NE 6 0.06 N5 02.142 E119 45.404 93⁰ E 7 0.08 N5 02.149 E119 45.407 81⁰ E 8 0.08 N5 02.152 E119 45.416 336⁰ NW 9 0.10 N5 02.151 E119 45.419 49⁰ NE 10 0.10 N5 02.143 E119 45.423 58⁰ NE 11 0.10 N5 02.143 E119 45.422 65⁰ E 12 0.14 N5 02.138 E119 45.421 65⁰ NE 13 0.08 N5 02.131 E119 45.415 8⁰ N 14 0.11 N5 02.113 E119 45.412 358⁰ N 15 0.07 N5 02.110 E119 45.403 46⁰ NE 16 0.02 N5 02.110 E119 45.401 223⁰ SW 17 0.09 N5 02.104 E119 45.392 69⁰ NE 18 0.04 N5 02.103 E119 45.388 122⁰ SE 19 0.10 N5 02.113 E119 45.377 190⁰ S 20 0.04 N5 02.118 E119 45.376 203⁰ SW 21 0.08 N5 02.132 E119 45.375 189⁰ S
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Replicate Rate (m/s) starting point end point
22 0.05 N5 02.138 E119 45.376 216⁰ SW 23 0.06 N5 02.153 E119 45.384 164⁰ SE 24 0.06 N5 02.158 E119 45.384 167⁰ SE 25 0.05 N5 02.160 E119 45.385 143⁰ SE 26 0.09 N5 02.169 E119 45.387 150⁰ SE 27 0.07 N5 02.175 E119 45.384 131⁰ SE 28 0.04 N5 02.180 E119 45.388 169⁰ S 29 0.08 N5 02.201 E119 45.407 26⁰ N 30 0.13 N5 02.202 E119 45.410 18⁰ N 31 0.11 N5 02.199 E119 45.412 51⁰ NE 32 0.07 N5 02.197 E119 45.411 84⁰ E 33 0.10 N5 02.193 E119 45.410 56⁰ NE 34 0.09 N5 02.191 E119 45.408 86⁰ E 35 0.06 N5 02.184 E119 45.411 39⁰ NE 36 0.04 N5 02.187 E119 45.412 60⁰ NE 37 0.08 N5 02.189 E119 45.411 47⁰ NE 38 0.10 N5 02.184 E119 45.404 60⁰ NE 39 0.08 N5 02.182 E119 45.401 60⁰ NE 40 0.03 N5 02.181 E119 45.401 3⁰ N
H. Water Circulation
320. The proposed Nalil-Sikkiat bridge is located in a channel that connects the Sulu Sea and Celebes Sea also known as Sulawesi Sea. Water circulation in the area is controlled by physical forcing at the open boundaries, namely the river inflow, the groundwater inflow, the wind, and the oceanic forcing like tides, fluctuations of the mean sea level like storm surges, the waves, and the net oceanic currents. Hydrologic cycle or water cycle in the channels is responsible for transport of food, nutrients, and pollution downstream.
CONCLUSION
321. The present state of coral reef in the proposed bridge is in good condition while the other biological resources is in imperiled status. The marine biological component except coral reefs is characterized by low species diversity due to human activities. The coral reefs are located mostly in the middle of the channel which characterized by good water movement. Frequent water circulation brings nutrients and minimized sedimentation which is favorable for the growth and development of coral reefs.
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322. Sedimentation, alteration of habitat and deposition of waste materials are among the end result of human activities in the area. The result of these anthropogenic activities and the deposition of organic and inorganic substances greatly affect the recruitment, growth and development of some marine biological resources. Negative impact on sedimentation includes: loss of important or sensitive aquatic habitats, decrease in fishery resources, loss of recreation attributes, loss of coral reef and reef fish communities, changes in fish migration, increases in erosion, circulation changes, increases in turbidity, prevent marine organism recruitment, settlement and development, loss of submerged vegetation, and coastline alteration. Sedimentation and siltation are detrimental to bottom-dwelling organisms through burial effect. The minimal population of benthic organisms like fishes, marine plants, benthos and plankton is mainly attributed by the deposition of suspended sediments resulting to the alteration of habitat and low light penetration. Marine organisms like seagrass/seaweeds and benthos need good substrates, good water quality, sufficient light and pollution free environment for their growth and development.
RECOMMENDATIONS
323. It is strongly suggested that extra caution when doing some coastal development in the area due to the presence of good coral resources. Coastal development that causing sedimentation is minimized by putting sediment traps or fine nets before any development has been made. Timing of coastal development must be planned carefully to reduce the disturbance in the area by considering neap tides or low tides during the summer months.
324. A mangrove rehabilitation program shall complement the coastal development to replace the mangroves that will be affected. This will also help stabilize the bridge structures (e.g. abutments) and the roots are effectively reduced wave action and prevent soil erosion. However, replanting programs should use the right mangrove species to increase their survival and maintain biodiversity. The fast-growing Rhizophora apiculata, which obviously can be easily sourced in the area can be used in reforestation programs but can be mixed with other suitable mangrove species present in the area such as Avicennia, Sonneratia and Ceriops to maintain biodiversity and prevent insect pest infestation associated with monospecific mangrove plantations.
325. Mangrove seedlings must be used in mangrove reforestation in order to obtain higher survival rate. However, mangrove propagules will also be used in the absence of mangrove seedlings but lower survival rate. Training on mangrove nursery establishment will be done to produce the number of seedlings for mangrove enrichment or mangrove reforestation activities. A community-based training on solid waste management and
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environmental laws is recommended along with a stricter enforcement of ordinances as there are obvious infractions related to mangrove cutting and dumping of domestic garbage and wastes in the area. Utmost care must be observed so that possible harmful effluents/chemicals from the construction are handled safely and effectively and are not carried by wave action to these mangrove habitats. 326. Patches of seagrass will be affected during the construction of bridge in the area. It is strongly recommended that seagrass transplantation must be done after any coastal development in order to increase the density, thereby, increase the biological function such as stabilizing the sea bottom, trapping fine sediment, provide food for marine organisms, habitat and nursery areas for numerous vertebrate and invertebrates species. Considering the physical characteristics of the area, Enhalus acoroides is the best seagrass species to be transplanted and this shall be collected from the nearby seagrass bed areas and transplantation will be done in the nearest areas where the proposed bridge is located to hasten acclimatation.
327. The issue of impact and risk in biodiversity conservation is not problem in the establishment of the proposed Nalil-Sikkiat bridge if careful planning be done before any coastal development has been made. The occurrence of sedimentation and siltation during the construction stage is very critical to marine resources. Except for coral reefs, minimal number of marine resources affected and this will be complemented by several management activities as explained above.
328. The potential sources of water pollution associated with different construction activities include excavation and filling, bore piling and pier construction for bridge works, concrete mixing, refueling facilities, and equipment maintenance will be done in the land- based areas to avoid seawater contamination of other chemicals. Control of siltation during construction will be achieved through limiting the exposure of areas prone to erosion. Sediment- trapping materials will be installed during the construction stage to prevent the deposition of sediments into the water. Equipment service and maintenance yards will be provided with impermeable flooring and collection area. Avoid fuel or any impermeable liquid spills to the seawater, as this will affect the growth and survival of seaweeds and other marine organisms. Lastly, since the Channel is not classified as protected area or as critical high biodiversity areas, which support survival of critically endangered species, ecological impacts are not considered significant.
MATRIX OF COMPLIANCE Table 69. Appendix 1-16 Matrix of compliance of the baseline survey Baseline Marine Observation/Results Recommendations environmental survey Coral reefs Two sampling stations Reduce established in the area. anthropogenic 37% coral reefs cover activities of
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observe in the area. Good fisherfolks in the water movement surrounding favorable for coral growth communities whose and development of main activities are corals. Sedimentation is fishing by providing minimized by the frequent additional source of tidal flushing. income and reduce dependency on fishing. This may take the form of employment as either skilled or unskilled labor or providing alternative livelihood to augment their income during construction. If fishing activities is reduced, destruction and or disturbance on the marine environment is also reduced and will be favorable for the growth and development of the marine resources like corals. Contractor shall also ensure the minimization of sediment loading in the water during the bored piling and associated activities. Reef fishes Two sampling stations Reduce established in the area. anthropogenic The status of reef fishes is activities and under poor category. minimize sediment Sedimentation, turbidity, loading in the water. water movement greatly affects the recruitment, growth and development of reef fishes Seagrass/ Six sampling stations Management seaweeds established in the area. strategies must be Two species of seagrass applied to increase and seven species of seagrass and seaweeds present. seaweeds species Sedimentation greatly diversity affects the occurrence of other seagrass and seaweeds species
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Mangroves Twelve sampling stations Management established in the area. strategies must be Five species of done to increase mangroves recorded in mangrove density. the area and cutting of Mangrove mangroves appears to be reforestation and main cause of mangrove enrichment using degradation. mangrove seedlings must be applied. In planting mangroves, the distance of seedlings must be 1 x 1 meter or ten thousand seedlings in one hectare Plankton Two sampling stations Reduce the with ten replicates anthropogenic established in the area. activities that cause Plankton population is low sedimentation and especially the siltation. zooplankton. Sedimentation resulting to turbidity affects the population of plankton Benthos Six sampling stations Reduce sediment established in the area. loading in the Minimal number of substrate. Further benthos species found in study must be the area. Substrates undertaken to affects the recruitment, determine the factors growth and development affecting benthos of benthos population. Water Quality Two sampling stations Management with ten replicates measures will be established in the area. applied to reduce Water parameters are sedimentation. within the tolerable ranges for marine organisms Water current Forty sampling points Further observations established in the area. and monitoring on Water velocity is 0.15 the water current will m/sec. The water velocity be done on daily, is influenced by tides. monthly and seasonal basis by the Contractor. The MSU Tawi-Tawi Campus may be willing to do the monitoring activities if commissioned by the Contractor. Water circulation 15% below the maximum Construction current in tidal inlets. activities related to Water circulation is the bridge
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controlled by physical construction will be forcing at the open done during boundaries, namely the summer time and river inflow, the avoid activities groundwater inflow, the during the rainy wind, and the oceanic season.. forcing like tides, fluctuations of the mean sea level like storm surges, the waves, and the net oceanic currents.
REFERENCES
A. Coral Reefs
English S., Wilkinson C. and Baker, V. (eds). 1997. Survey manual for tropical marine resources – Second edition. Australian Institute of Marine Science, ASEAN-Australia Marine Science Project, 390 pp. Gomez, E.D., Alcala, A.C., San Diego, A.C., 1981. Status of Philippine coral reefs, Proceedings of the Fourth International Coral Reef Symposium, Manila, pp. 275-282. Goreau, T.F., N.I. Goreau and T.J. Goreau. 1979. Corals and coral reefs. Sci. A. 241(2): 124-136. Licuanan, A.M., Reyes, M.Z., Luzon, K.S., Chan, M.A.A., Licuanan, W.Y., 2017. Initial Findings of the Nationwide Assessment of Philippine Coral Reefs. Philippine Journal of Science 146, 177-185. Nybakken, J.W. 1982. Marine biology: an ecological approach. Harper and Row, Publishers, New York.
B. Reef fish
Barrett, J.C., Grossman, G.D., & Rosenfeld, J. 1992. Turbidity induced changes in reactive distance of rainbow trout. Trans. Am. Fish. Soc. 121:437–443 Bell, J.D. & Galzin, R. 1984. Influence of live coral cover on coral reef fish communities. In Marine Ecology Progress Series 15(3):265-274 Bell, J.D. & Galzin, R. 1988. Distribution of coral and fish in the lagoon at Mataiva: potential for increase through mining. Proc. 6th Int. Coral reef Symp. 2:347-352. Carpenter, K.E, Miclat, R. I., Albaladejo, V.D., & Corpuz VT. 1981. The influence of substrate structure on the local abundance and diversity of Philippine fishes. Proc. 4th Int. Coral Reef Symp. 2:497-502.113:357–361 Castro, J., & F. Reckendorf. 1995. Effects of sediment on the aquatic environment: potential NRCS actions to improve aquatic habitat. Working Paper No. 6. Natural Resources Conservation Service, Oregon State University, pp 24 Connell J.H. 1978. Diversity in rain tropical rainforest and coral
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reefs. Science. 199:1302-1310 English S., Wilkinson C. and Baker, V. (eds). 1997. Survey manual for tropical marine resources – Second edition. Australian Institute of Marine Science, ASEAN-Australia Marine Science Project, 390 pp. Hazelton, P.D., & Grossman, G.D. 2009. Turbidity, velocity and inter- specific interactions affect foraging behavior of rosyside dace (Clinostomus funduloides) and yellowfin shiners (Notropis lutippinis). Ecol. Freshw. Fish. 18:427–436 Hilomen, V.V., Nañola Jr, C.L. and Dantis, A.L. 2000. Status of Philippine reef fish communities. Gomez (eds.). Philippine Coral Reefs, Reef Fishes, and Associated Fisheries: Status and Recommendations to Improve their Management. Global Coral Reef Monitoring Network (GCRMN). Luckhurst, B., & Luckhurst, K. 1978. Analysis of the influence of substrates variables on coral reefs communities. Mar. Biol. 49:317-323. Lloyd, D. S.; Koenings, J. P.; LaPerriere, J. D. 1987: Effects of turbidity in fresh waters of Alaska. North American journal of fisheries management 7: 18-33 McManus J.W. et al,. 1981. Coral and Fish Community Structure of Sombrero Isnad, Batangas, Philippines. In, Proceedings of the Fourth International Coral Reef Symposium, Manila 1981. Vol 2 Muck, J. 2010. Biological effects of sediment on bull trout and their habitat—guidance for evaluating effects. Fish and Wildlife Service, Lacey, p 57 Nañola CL Jr, Alcala AC, Aliño PM, Arceo HO, Campos WL,Gomez ED, Licuanan WY, Quibilan MCC, Uychiaco AJ, White AT (2006) Status report of the coral reefs in thePhilippines. Proc 10th Internat Coral Reef Symp 4- 1:1055–1061 Newcombe, C.P., & MacDonald, D.D. 1991. Effects of suspended sediment on aquatic ecosystems. N. Am. J. Fish. Manag. 11:72–82 Rabeni, C.F., Doisy, K.E., & Zweig, L.D. 2005. Stream invertebrate community functional responses to deposited sediment. Aquat. Sci. 67:395–402 Roberts, C. M., & Ormond, R.F. 1987. Habitat complexity and coral reef diversity and abundance on Red Sea fringing reefs. Mar. Ecol. Prog. Ser. 41:1-8. Sano, M., Shimizu, M., & Nose, Y. 1984. Changes in the structure of coral reef fish communities by destruction of hermatypic corals: observation and experimental views. Pac.Sci. 38 (1):51-79. Sano, M., Shmizu. M., & Nose, Y. 1987. Long-term effects of destruction of hermatypic corals by Acanthaster planci infestation on reef fish communities at Iriomote Island, Japan. Mar. Ecol.Prog. Ser. 37:191-199 Sutherland, A.B., & Meyer, J.L. 2007. Effects of increased suspended sediment on growth rate and gill condition of two southern Appalachian minnows. Environ. Biol. Fish. 80:389– 403 Sutherland, A.B, 2007. Effects of increased suspended sediment on the reproductive success of an upland crevice spawning
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minnow. Trans. Am. Fish. Soc. 136:416–422 Talbot, F, H., Russel, B.C., & Anderson, G.R. 1978. Coral reef fishes communities: unstable high-diversity systems” Eco. Monogr: 425-440. Uychiaoco, A. et al., 2000. Initiatives in Philippine Coastal Management: An Overview. January 2000 Coastal Management 28(1) Wood, P.J., Toone, J., Greenwood, M.T., Armitage, P.D. 2005. The response of four lotic macroinvertebrate taxa to burial by sediments. Arch. Hydrobiol. 163:145–162 Zamor, R.M., & Grossman, G.D. 2007. Turbidity affects foraging success of drift–feeding rosyside. Trans. Am. Fish. Soc. 136:167–176
C. Seagrass/seaweeds
Agawin N. S. R., M.D. Fortes, S. S. Bach and W.J. Kenworthy.1997. Response of a mixed Philippine seagrass meadow to experimental burial. Mar.Ecol.Prog.Ser., 147:285-294. Bach, S.S., Borum, J., Fortes, M.D., Duarte, C.M., 1998. Species composition and plant performance of mixed seagrass beds along a siltation gradient at Cape Bolinao, The Philippines. Marine Ecology-Progress Series 174, 247-256. Duarte, C. M., 1991. Seagrass depth limits. Aquatic Botany 40: 363–377. Duarte, C. M., J. Terrados, S. R. Agawin-Nona, M. D. Fortes, S. Bach & W. J. Kenworthy, 1997. Response of a mixed Philippine seagrass meadow to experimental burial. Marine Ecology Progress Series 147: 285–294. English S., Wilkinson C. and Baker, V. (eds). 1997. Survey manual for tropical marine resources – Second edition. Australian Institute of Marine Science, ASEAN-Australia Marine Science Project, 390 pp123- 161. Fortes, M.D. 1988. Mangrove and Seagrass Beds of East Asia: habitats under stress. Ambio 17, 207-213 Fortes, D. M. 1994. Philippine Seagrasses: Status and Perspectives. In, Proceedings, Third Asean Australia Symposium on Living Coastal Resources. Eds. Clive R. Wilkinson, S. Sudara and C. L. Ming. Vol. 1 Status Reviews. Fortes, M.D. 1995. Seagrasses of East Asia: Environmental and Management Perspectives. RCU/EAS Technical Report Series No. 6. United Nations Environment programme, Bangkok. Kirkman, H. and Walker D. I. 1989. Regional Studies-Western Australian Seagrasses. In Biology of seagrasses (Larkum, A. W. D., MacComb, A.J. & Sheperd S. A. eds). Elsevier. Amsterdam pp.157-181. Orth, R., Heck, K. 1980. Structural components of eelgrass (Zostera marina) meadows in the lower Chesapeake Bay— fishes. Estuaries 3 (4), 289–295. Orth, R., Carruthers, T., Dennison, W.C., Duarte, C.M., Fourqurean, J.W., Heck, K.L., Hughes, A.R., Kendrik, G.A., Kenworth, W.J., Olyarnik, S., Short, F.T., Waycott, M., & Williams, S.L., 2006. A global crisis for seagrass ecosystems. Bioscience 56 (12), 987–996.
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Saito, Y. and S. Atobe 1970. Phytosociological study of intertidal marine algae. I, Usujiri Benten-Jima, Hokkaido, Bulletin of the Faculty of Fisheries, Hokkaido University, 21:37-69. Savella, R. S. 2014. Assessment of Seagrass communities in Dumanquillas Bay. Paper presented to Protected Area Management Board, Zamboanga del Sur. Unpublished. Short, F. T. & E. S. Wyllie, 1996. Natural and human- induced disturbance of seagrasses. Environmental Conservation 3: 17–27. Terrados, J., Duarte, C.M., Fortes, M.D., Borum, J., Agawin, N.S.R., Bach, S., Vermaat, J., 1998. Changes in community structure and biomass of seagrass communities along gradients of siltation in SE Asia. Estuar. Coast. Shelf Sci. 46 (5), 757–768. Vermaat J. E., N. S. R. Agawin, C. M. Duarte, M. D. Fortes, N. Marba, J. S. Uri and W. van Viersen. 1997. The capacity of seagrass to survive increased turbidity and siltation: the significance of growth from light use. Ambio. 26:499-504.
D. Plankton
Dejen, E., Vijverberg. J., Nagelkerke. L.A., & Sibbing, F.A. 2004. Temporal and spatial distribution of microcrustacean zooplankton in relation to turbidity and other environmental factors in a large tropical lake (L. Tana, Ethiopia), Hydrobiology, 513: 39–49. Falkowski, Paul G. 1994. The role of phytoplankton photosynthesis in global biogeochemical cycles. Minireview. Photosynthesis research 39: 235-258.1994. Gasparini, S., Castel, J. and Irigoien, X. 1999. Impact of suspended particulate matter on egg production of the estuarine copepod, Eurytemora affinis. J. Mar. Sys., 22, 195–205. Tester, P. A. and Turner, J. T. 1989. Zooplankton feeding ecology: feeding rates of the copepods Acartia tonsa, Centropages velificatus and Eucalanus pileatus in relation to the suspended sediments in the plume of the Mississippi River (Northern Gulf of Mexico continental shelf). Scient. Mar., 53, 231–237. Zeitzschel, B. 1974. Oceanographic factors influencing the distribution of plankton in space and time. Paper presented at the 3rd Planktonic conference. Kiel, West Germany. September 1974. Pp. 139-159.
E. Benthos
Berry W, Rubinstein, N., Melzian, B., & Hill, B. 2003. The biological effects of suspended and bedded sediment (SABS) in aquatic systems: a review. US Environment Protection Agency, National Health and Environmental Health Effects Laboratory, Rhode Island, USA, pp. 58 Birtwell, I.K. 2000. The effects of sediment on fish and their habitat. DFO Can. Pacific Science Advice and Review Committee Habitat Subcommittee Res. Doc. Canadian Donahue,I. and K. Irvine. 2003. Effects of sediment particle size composition on survivorship of benthic invertebra tes from
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Lake Tanganyika, Africa. Arch. Hydrobiol. 157. pp 131-144. Herbert, W. M. & Merkens, J. C. 1961. The effect of suspended mineral solids on the survival of trout. Int. J. Air. Wat. Poll. 5: 46 – 55. Oben, B.O; Oben, P.M; Ugwumba, A.O; Okorie, T.G. & Pleysier, J. 2003. Trace metal dynamics in Water, Sediments and Shellfish of a Constructed Freshwater Wetland-toxic substance profile -Turbidity. www.marinesac.org.uk Waters, T.F. 1995. Sediment in streams: sources, biological effects, and control. American Fisheries Society Monograph 7, Bethesda, p 251 UK Marine Science Areas of Conservation. Non Zweig, L.D. and C. F. Rabeni. 2001. Biomonitoring for deposited sediment using benthic invertebrates: A test on 4 Missouri streams. Journal of the North American Benthological Society. Vol. 20.
F. Water Parameters
Anderson. G. 2003. Seawater composition-Marine Bio.net. https:www.marinebio.net /marinescience/02ocean/swcoposition.html Eutrophication I Soil Science Society of America. Soil Sustain Life. https:www.soils.org /discover-soils-in-the- city/…/eutrophication Fondriest Environmental, Inc. (2013). “pH of Water.” Fundamentals of Environmental Measurements. 19 Nov. 2013. Fondriest Environmental Learning Center. Web. https://www.fondriest.com/environmental- measurements/parameters/water-quality/ph/ Fondriest Environmental, Inc. 2013.“Conductivity, Salinity and Total Dissolved Solids.” Fundamentals of Environmental Measurements. 3 Mar 2014. Web. PHOTO DOCUMENTATIONS 161 Appendix 1 Marine Ecological Assessment Tawi-Tawi Bridge No. 1: Nalil-Sikkiat 329. Plate 1. Transect line laid on top of Acropora branching in the proposed Nalil-Silkkiat bridge 330. Plate 2. Corals survived on the silted substrate in the proposed Nalil-Sikkiat bridge 162 Appendix 1 Marine Ecological Assessment Tawi-Tawi Bridge No. 1: Nalil-Sikkiat 331. Plate 3. Transect line stretched on the sandy muddy substrate in the proposed Nalil-Sikkiat bridge 332. Plate 4. Scuba diver conduct seagrass assessment in the proposed Nalil-Sikkiat bridge. Only Enhalus acoroides is visible in the quadrat. 163 Appendix 1 Marine Ecological Assessment Tawi-Tawi Bridge No. 1: Nalil-Sikkiat 333. Plate 5. The researcher conducted mangrove assessment in the proposed Nalil-Sikkiat bridge. 334. Plate 6. Houses was built inside the mangrove area in the proposed Nalil-Sikkiat bridge. This is one human activity that destroy the mangrove resources. 164 Appendix 1 Marine Ecological Assessment Tawi-Tawi Bridge No. 1: Nalil-Sikkiat A B 335. Plate 7. Sample image of plankton. (A) Asterolampra and (B) Diatoms in the proposed Nalil-Sikkiat bridge A B 336. Plate 8. Sample image of epifauna species in the proposed Nalil-Sikkiat bridge. (A) Diadema and (B) Ascidian 165 Appendix 2 Grievance Intake Form Tawi-Tawi Bridge No. 1: Nalil-Sikkiat Appendix 2. Grievance Intake Form 166 Appendix 2 Grievance Intake Form Tawi-Tawi Bridge No. 1: Nalil-Sikkiat 167 Appendix 3 Project Semi-Annual Environmental Monitoring Report Outline Tawi-Tawi Bridge No. 1: Nalil-Sikkiat Appendix 3. Project Semi-Annual Environmental Monitoring Report Outline 1. Outline of a Project Environmental Progress and Monitoring Report 1. The borrower/client is required to prepare periodic monitoring reports that describe progress with implementation of the project EMP and compliance issues and corrective actions. A sample outline which can be adapted as necessary is provided below. Not all sections will be relevant in all cases. Ranking systems for compliance, mitigation effectiveness, etc., are indicative examples only, and should be modified as appropriate. 1. Introduction 1.1. Report Purpose 1.2. Project Implementation Progress 2. Incorporation of Environmental Requirements into Project Contractual Arrangements Manner by which EMP requirements are incorporated into contractual arrangements, such as with contractors or other parties. 3. Summary of Environmental Mitigations and Compensation Measures Implemented Based on EMP; may include measures related to air quality, water quality, noise quality, pollution prevention, biodiversity and natural resources, health and safety, physical cultural resources, capacity building, and others. 4. Summary of Environmental Monitoring 4.1. Compliance Inspections (if relevant) 4.1.1. Summary of Inspection Activities 4.1.2. Mitigation Compliancea 4.1.3. Mitigation Effectivenessb 4.2. Emission Discharge (Source) Monitoring Program (if relevant) 4.2.1. Summary of Monitoring 4.2.2. Results a Overall compliance with mitigation implementation requirements could be described in qualitative terms or be evaluated based on a ranking system, such as the following: 1. Very Good (all required mitigations implemented) 2. Good (the majority of required mitigations implemented) 3. Fair (some mitigations implemented) 4. Poor (few mitigations implemented) 5. Very Poor (very few or no mitigations implemented) Additional explanatory comments should be provided as necessary. b Effectiveness of mitigation implementation could be described in qualitative terms or be evaluated based on a ranking system, such as the following: 1. Very Good (mitigations are fully effective) 2. Good (mitigations are generally effective) 168 Appendix 3 Project Semi-Annual Environmental Monitoring Report Outline Tawi-Tawi Bridge No. 1: Nalil-Sikkiat 3. Fair (mitigations are partially effective) 4. Poor (mitigations are generally ineffective) 5. Very Poor (mitigations are completely ineffective) Additional explanatory comments should be provided as necessary. 4.2.3. Assessmentc 4.3. Ambient Monitoring Program (if relevant) 4.3.1. Summary of Monitoring 4.3.2. Results 4.3.3. Assessmentd 5. Key Environmental Issues 5.1.1. Key Issues Identified 5.1.2. Action Taken 5.1.3. Additional Action Required 6. Conclusion 6.1. Overall Progress of Implementation of Environmental Management Measurese 6.2. Problems Identified and Actions Recommended Appendices 1. Site Inspection / Monitoring Reports 2. Ambient Monitoring Results 3. Photographs 4. Others c Discharge levels should be compared to the relevant discharge standards and/or performance indicators noted in the EMP. Any exceedances should be highlighted for attention and follow-up. In addition, discharge levels could be compared to baseline conditions (if baseline data is available) and described in qualitative terms or be evaluated based on a ranking system, such as the following: 1. Very Good (overall conditions are generally improved) 2. Good (conditions are maintained or slightly improved) 3. Fair (conditions are unchanged) 4. Poor (conditions are moderately degraded) 5. Very Poor (conditions are significantly degraded) Additional explanatory comments should be provided as necessary. d Ambient environmental conditions should be compared to the relevant ambient standards and/or performance indicators noted in the EMP. Any exceedances should be highlighted for attention and follow-up. In addition, ambient environmental conditions could be compared to the baseline conditions (if baseline data is available) and described in qualitative terms or be evaluated based on a ranking system, such as the following: 1. Very Good (overall conditions are generally improved) 2. Good (conditions are maintained or slightly improved) 3. Fair (conditions are unchanged) 4. Poor (conditions are moderately degraded) 5. Very Poor (conditions are significantly degraded) Additional explanatory comments should be provided as necessary. e Overall sector environmental management progress could be described in qualitative terms or be evaluated based on a ranking system, such as the following: 1. Very Good 2. Good 3. Fair 4. Poor 5. Very Poor Additional explanatory comments should be provided as necessary. 169 Appendix 3 Project Semi-Annual Environmental Monitoring Report Outline Tawi-Tawi Bridge No. 1: Nalil-Sikkiat Appendix 4. Approved/Signed REA and Environmental Categorization 170 Appendix 3 Project Semi-Annual Environmental Monitoring Report Outline Tawi-Tawi Bridge No. 1: Nalil-Sikkiat 171 Appendix 3 Project Semi-Annual Environmental Monitoring Report Outline Tawi-Tawi Bridge No. 1: Nalil-Sikkiat 172 Appendix 3 Project Semi-Annual Environmental Monitoring Report Outline Tawi-Tawi Bridge No. 1: Nalil-Sikkiat 173 Appendix 3 Project Semi-Annual Environmental Monitoring Report Outline Tawi-Tawi Bridge No. 1: Nalil-Sikkiat 174 Appendix 3 Project Semi-Annual Environmental Monitoring Report Outline Tawi-Tawi Bridge No. 1: Nalil-Sikkiat 175 Appendix 3 Project Semi-Annual Environmental Monitoring Report Outline Tawi-Tawi Bridge No. 1: Nalil-Sikkiat 176 Appendix 3 Project Semi-Annual Environmental Monitoring Report Outline Tawi-Tawi Bridge No. 1: Nalil-Sikkiat 177 Appendix 3 Project Semi-Annual Environmental Monitoring Report Outline Tawi-Tawi Bridge No. 1: Nalil-Sikkiat 178 Appendix 3 Project Semi-Annual Environmental Monitoring Report Outline Tawi-Tawi Bridge No. 1: Nalil-Sikkiat Appendix 5. Attendance Sheets 179 Appendix 3 Project Semi-Annual Environmental Monitoring Report Outline Tawi-Tawi Bridge No. 1: Nalil-Sikkiat 180