BASELINE REPORT ON COASTAL RESOURCES for Linapacan Municipality
September 2006 Prepared for:
PALAWAN COUNCIL FOR SUSTAINABLE DEVELOPMENT Palawan Center for Sustainable Development Sta. Monica Heights, Puerto Princesa City, Palawan, Philippines 5300 Email: [email protected] Tel.: (63-48) 434-4235, Fax: 434-4234
Funded through a loan from :
JAPAN BANK FOR INTERNATIONAL COOPERATION
Prepared by:
PACIFIC CONSULTANTS INTERNATIONAL in association with ALMEC Corporation CERTEZA Information Systems, Inc. DARUMA Technologies Inc. Geo-Surveys & Mapping, Inc.
Photo Credits:
Photos by PCSDS and SEMP-NP ECAN Zoning Component Project Management Office
This report can be reproduced as long as the convenors are properly acknowledged as the source of information
Reproduction of this publication for sale or other commercial purposes is prohibited without the written consent of the publisher.
Printed by:
Futuristic Printing Press, Puerto Princesa City, Philippines
Suggested Citation:
PCSDS. 2006. Baseline Report on Coastal Resources for Linapacan Municipality, Palawan Council for Sustainable Development, Puerto Princesa City, Palawan
TABLE OF CONTENTS
List of Tables v List of Figures vi List of Plates ix
EXECUTIVE SUMMARY xi
CHAPTER I: CORAL REEFS 1
1.0 Introduction 1 2.0 Materials and Methods 1 3.0 Results 2 3.1 Live Coral Cover and Reef Condition 2 3.2 Live Hard Coral, Soft and Dead Coral Cover 8 3.3 Associated Macro-invertebrates and Seaweeds in Coral Reefs 8
4.0 Discussions 11 5.0 Summary of Findings 13 6.0 Recommendations 13
CHAPTER II: REEF FISHES 16
7.0 Introduction 16 8.0 Materials and Methods 16 9.0 Results 16 10.0 Discussions 28 11.0 Conclusions and Recommendations 28
CHAPTER III: SEAGRASS AND SEAWEEDS 30
12.0 Introduction 30 13.0 Materials and Methods 31 14.0 Results 34 14.1 Spatial Distribution and Use of Seagrass Habitat 34 14.2 Species Composition and Occurrence 39 14.3 Percentage Seagrass Cover 41 14.4 Associated Seaweeds and Macro-invertebrates 46
15.0 Discussions 51 16.0 Summary of Findings 54 17.0 Recommendations 55
______iii
CHAPTER IV: MARINE MAMMALS AND SEA TURTLES 57
18.0 Introduction 57 19.0 Methods 57 20.0 Results 57 20.1 Respondent’s Background 57 20.2 Dugong Status 60 20.3 Turtle Status 62 20.4 Cetacean Status 64 20.5 Threats 67 20.6 Conservation Awareness 68
21.0 Discussions 72 22.0 Conclusions and Recommendations 73
CHAPTER V: MANGROVE FOREST 75
23.0 Introduction 75 24.0 Objectives 75 25.0 Expected Outputs 75 26.0 Methodology 76 27.0 Results and Discussions 82 27.1 Biodiversity Assessment 82 27.2 Mangrove Vegetation Structural Analysis 86 27.3 Mangrove Pattern of Uses and Existing Land Use/Forest Condition 89
28.0 Recommendations 93
REFERENCES 97
______iv LIST OF TABLES
Table Title Page No. No.
1 Reef sites with live coral cover of 1-10%, Linapacan, Palawan, 2004 2 2 Reef sites with live coral cover of 11-30%, Linapacan, Palawan, 2004 5 3 Reef sites with live coral cover of 31-50%, Linapacan, Palawan, 2004 5 4 Reef sites with live coral cover of 51-75%, Linapacan, Palawan, 2004 6 5 Classification and distribution of coral reef sites surveyed based on 6 percentage live coral cover, Linapacan, Palawan, 2004 6 Average percentage covers of hard corals, soft corals, total live corals 7 (hard and soft corals combined) and dead corals observed in the reef sites surveyed, Linapacan, Palawan, 2004 7 Macro-invertebrates and seaweeds seen during the baseline survey in 9 coral reefs of Linapacan, Northern Palawan (May-June 2005), Linapacan, Palawan, 2004 8 Species Richness of Reef Fishes from 34 Sampling Station, 18 Linapacan, Palawan 2004 9 Occurrence of reef fishes from 34 sampling stations, Linapacan, 20 Palawan, May 2004, Fish categories are: 1-indicator species, M-major species, and T-target species 10 Number of Indicator, Major and Target Species from 34 Sampling 27 Station, Linapacan, Palawan 2004 11 Sampling stations data for the baseline survey of seagrass and 33 seaweeds in the municipality of Linapacan, Northern Palawan, 30 May – 03 June 2004. Legend: nplot=number of plots sampled; (*)=perpendicular distance from shore to seaward edge; S=Sandy; S- M=Sandy-Muddy; S-C=Sandy-Coralline; and S-R=Sandy-Rocky 12 Seagrass species composition and occurrence for the baseline survey 40 of seagrass and seaweeds in the municipality of Linapacan, Northern Palawan, 30 May-03 June 2004. Legend: nspecies=number of species; CYRO=Cymodocea rotundata, CYSE=Cymodocea serrulata, ENHA=Enhalus accoroides, HPIN=Halodule pinifolia, HOVA=Halophila ovalis, HUNI=Halodule uninervis, SYRI=Syringodium isoetifolium, THALI=Thalassia hemprichii, and TACIL=Thalassodendron ciliatum 13 Percentage bottom cover of the species of seagrasses for the baseline 43 survey in the municipality of Linapacan, Northern Palawan, 30 May- 03 June 2004. Legend: Legend: nplot=number of plots; CYRO=Cymodocea rotundata, CYSE=Cymodocea serrulata, ENHA=Enhalus accoroides, HPIN=Halodule pinifolia, HOVA=Halophila ovalis, HUNI=Halodule uninervis, SYRI=Syringodium isoetifolium, THALI=Thalassia hemprichii, 14 Seaweed species and their abundance observed at each of the seagrass 47 sampling stations in Linapacan, 30 May-03 June 2004
______v Table Title Page No. No.
15 Respondent’s Perception on Dugong Numbers, Linapacan, Palawan 62 2004 16 Respondents’ Perception on Turtle Numbers, Linapacan, Palawan 64 2004 17 Respondents’ Perception on Dophin Numbers, Linapacan, Palawan 67 2004 18 Respondents’ Perception on Whale Numbers, Linapacan, Palawan 67 2004 19 Reasons for releasing accidentally caught animals 69 20 Reasons on Actions Indicated When a Dead Animals is Accidentally 70 Captured 21 Awareness and Implementation on Conservation Laws 71 22 Perceptions on the Necessity for Animal Protection 72 23 Location and position of belt transects surveyed by the Mangrove 77 Team in Linapacan, Palawan, 2004 24 List of True and Associate Mangrove Species Identified and Recorded 82 Linapacan, Palawan, 2004 25 Distribution and Abundance of Top Ten Mangrove Species in 83 Different Sampling Sites of Linapacan, Palawan 2004 26 The Diveristy Indices of Mangrove Forest Calculated using Different 84 Diversity Formula, Linapacan, Palawan 2004 27 Relative Values of Shannon Diversity Index and Evenness of 85 Mangroves Species Distribution Linapacan, Palawan 2004 28 RF, RDen, RDom, and IV of Top 15 Mangrove Species, Linapacan, 87 Palawan 2004 29 Average Stocking (N/ha) of Timber and Pole Size Trees/Transect 87 Linapacan, Palawan, 2004 30 Stand Volume (m/ha) of Timber and Pole by Transect in Linapacan, 88 Palawan 2004 31 Mangrove Index of Degradation and Ecological Condition Indices 91 based on Forest Structure and Ecological Diversity Parameters, Linapacan, Palawan 2004 32 Factors Considered in Choosing Appropriate Management Strategies 94 for Mangrove Areas, Linapacan, Palawan 2004
______vi LIST OF FIGURES
Figure Title Page No. No.
1 The study area showing the coral reef sites surveyed (manta tow 3 tracts), 30 May – 03 June 2004 2 The sites surveyed showing percentage live coral cover scores and 4 condition, 30 May – 03 June 2004 3 Potential coral core zones, Linapacan, Northern Palawan, 30 May-03 14 June 2004 4 Baseline fish survey sampling stations, Linapacan, Palawan, May 17 2004 5 Potential reef fish core zones, Linapacan, Palawan, May 2004 29 6 Coastline surveyed and sampling stations established for the seagrass 32 and seaweed study in Linapacan, Palawan, 30 May – 03 June 2004 7 Coastline surveyed having seagrass beds in Linapacan, 30 May – 03 35 June 2004 8 Locations of fish corals, fish cages, pearl culture farms, seaweed 37 farms and pebble mining seen during the survey in Linapacan, 30 May-03 June 2004 9 Percentage Cover of Seagrass by Species Linapacan, 30 May-03 June 44 2004 10 Percentage Cover of Seagrasses by Sampling Station Linapacan, 30 44 May-03 June 2004 11 Percentage Seagrass Cover and Seagrass Beds Condition, Linapacan, 45 30 May-03 June 2004 12 Map Survey Areas, Linapacan, Palawan 2004 58 13 Fisher’s Classification 58 14 Years Fishing in Area 58 15 Fishing Frequency 58 16 Fishing Gears Used 58 17 Age Group 59 18 Ethnic Origin 59 19 Educational Attainment 59 20 Established Residency (Yrs) 59 21 Dugong Distribution, Linapacan, Palawan 2004 60 22 Dugong Sightings, Linapacan, Palawan 2004 61 23 Turtle Distribution and Nesting Sites, Linapacan, Palawan 2004 63 24 Turtle Sightings, Linapacan, Palawan 2004 63 25 Cetacean Distribution, Linapacan, Palawan, 2004 65 26 Dophin Sightings, Linapacan, Palawan 2004 66 27 Whale Sightings, Linapacan, Palawan 2004 66 28 Perceived Threats, Linapacan, Palawan, 2004 68 29 Action When a Live Animal is Accidentally Captured 69
______vii Figure Title Page No. No.
30 Action When a Dead Animal is Accidentally Captured 69 31 Satellite Map Showing the Municipality of Linapacan, Palawan 2003 76 32 Picture showing the lay-outing of transects, Linapacan, Palawan, 2004 79 33 Picture showing Rhizophora apiculata 83
______viii LIST OF PLATES
Plate Title Page No. No.
1 Seagrass beds at low tide in Station 11-San Miguel Poblacion 34 2 Seagrass beds at low tide near pier in San Miguel Poblacion showing 34 “sand volcanoes”, a common feature of sandy bottoms in Linapacan. No one has yet succeeded in digging out the inhabitants of these volcanoes. A likely candidate, however, is a ghost shrimp 3 Pearl culture farms along the sheltered cove in Northwest Bay (Sitio 36 Tabkangan, Maroyogroyog) 4 Pebble mining along the beach of Sitio Manlilic, Maroyogroyog 38 5 Feeding scar (graze mark) probably from dugong at Station 51-Lilo, 38 Maroyogroyog 6 Sand bottom, which covered with growth of Halophila ovalis 39 7 Sand bottom, which covered with growth of Halodule pinifolia 39 (Station 12-Sitio Pula, San Miguel) 8 Mixed species of Cymodocea rotundata, Cymodocea serrulata- 41 Halodule pinifolia (left) and a monospecific colony of Thalassodendron ciliatum (right) Station 9-Diringuan 3, San Miguel) 9 Sand bottom which is covered with growth of Enhalus acoroides, at 41 the center is a growth of the seagrass Halophila ovalis (Station 17- New Colaylayan Poblacion) 10 Mixed species of Enhalus acoroides and Syringodium isoetifolium 42 (Calunlauan Island) 11 Growth of the seagrass Cymodocea serrulata with “sand volcanoes” 42 (Cabunlauan Island) 12 Mixed sand and rock bottom in the subtidal shallows. The sand 42 supports a growth of the seagrass Cymodocea rotundata (Station 6- Babahalid Channel, Maroyogroyog) 13 End of seagrass bed along the transect with growth of Cymodocea 49 serrulata (foreground) together with a dense stand of brown seaweed Sargassum sp. background) 14 Padina sp. a folios brown alga whose fronds are prettily marked with 49 concentric dark rings of reproductive structures (Station 10-Ditinglan, San Miguel) 15 Sand bottom, which is covered with growth of calcareous green algae 50 Halimela (foreground) and seagrass Enhalus acoroides (background) 16 Mixed sand and rock beach at low tide in Station 6-Babahalid 51 Channel, Babahalid Island is in the background Maroyogroyog) 17 Old (left) and new (right) “kaingin” along Northwest Bay. Most of 53 the trees along the inner section of the mangrove forest shown in this picture have already been destroyed due to illegal cutting for local construction materials and charcoal making (Maroyogroyog 30 May- 03 June 2004)
______ix Plate Title Page No. No.
18 A close-up view of the new “kaingin” along Northwest Bay 53 (Maroyogroyog, 30 May – 03 June 2004 19 Another new “kaingin” along Northwest Bay (Maroyogroyog 30 May 54 – 03 Jun 2004
______x EXECUTIVE SUMMARY
This report presents the results of the baseline survey work on coral reef , reef fishes, seagrass-seaweed, marine mammal and sea turtles, and mangrove forest accomplished for the municipality of Linapacan, as one of the 11 survey sites for ECAN Zoning Project. Project survey results will recommend strategic core areas to function as protected zones to help sustain biodiversity. The actual survey was carried out on 30 May – 03 June 2004 in Linapacan Island including small islands and islets surrounding the island.
Survey data showed that the coral reefs of Linapacan are in very disturbed (poor) condition (average of only 29.6% live coral cover). Of the 37 reef sites surveyed, only 1 (2.7%) is in good condition (73% coral cover), 16 (43.2%) are in fair condition (range of 32-50% cover), 12 (32.4%) are considered poor (12-30% cover) and 8 sites (21.6%) are in very poor condition (10% cover each).
Hard corals in all reef sites are predominantly poor (average of 26.6% cover). Soft corals, represented mainly by Sarcophyton, are present in 16 out of the 37 sites surveyed, but did not contribute significantly to the bottom cover (average of only 3%). A very high bottom cover of dead corals (broken coral colonies, rubbles, traces of blast craters and old dead coral substrates) characterized most of the reef sites surveyed which range from 27% to 75%, with an average of 58.5% cover. It is highly likely that the reef corals in the Linapacan area have been badly damaged. Destructive fishing methods (primarily dynamite, cyanide, “muro–ami”, “kayakas”), Crown-of-Thorns starfish Acanthaster planci infestations, and siltation are the apparent causes of widespread coral reef destruction in the area.
From the 37 reef sites surveyed, at least 5 sites, geographically isolated from each other, were identified as potential core zones: Nanga Island N (73% live coral cover), followed by San Miguel Reef, North Bay Cove 3 Reef, South Bay Reef and Bangambangan Island SE Reef (50% cover each).
There are a total 16 species/groups from 8 phyla/classes of reef macroinverterbrates recorded. The fan sponge Phyllospongia papyracea, the long-spined urchin Diadema setosum and the blue starfish Linckia laevigata are the most prominent non-coral organism observed in most reefs surveyed. The Crown-of-Thorns starfish Acanthaster planci (a natural predator of hard corals) is also present within the study area. Likewise, very few giant clams were noticed during the survey, mostly on coral reef areas inside the North, Northwest and Colaylayan Bays of Linapacan mainland, and in far distant Iloc and Cabunlauan Islands. The sea cucumbers (holothuroids) are practically absent at all reef sites. Macrolagal cover encountered on most of the reef sites is dominated by luxuriant growth of the brown seaweed Sargassum. Another brown alga, Padina, is found to grow in relatively few reef sites.
Within this study area, 5 reef sites are recommended as core zones as they have the highest live hard coral cover recorded such as (a) Nangalao Island N Reef - in far distant western group Cabunlauan Group of Islands; (b) Bangambangan Island SE Reef - in far distant southern Iloc
______EXECUTIVE SUMMARY xi Group of Islands; (c) San Miguel Reef - in western section of Linapacan mainland (near Ile Island); (d) North Bay Cove 3 Reef - in northern section of Linapacan mainland (North Bay) and (e) South Bay Reef- in southern section of Linapacan mainland (South Bay)
The reef fishes survey of Linapacan resulted in relatively poor condition of the municipality’s reef fisheries condition. From the 34 sampling stations surveyed, on the basis of species richness, at least three (3) were identified as potential core zones: Stations 15 – Malubutlubut, Station 31 – Nangalao Island, and Station 4 – Bulawi had some of the highest species richness at 68, 57 and 49 species per 250m2. These stations are geographically isolated from each other, Station 15 at the northwestern group of islands, Station 4 at the western section of the mainland, and Stations 31 in the far eastern group of islands. It is recommended that a detailed assessment of these sites be conducted to generate more information on the status and condition of the fish communities and their habitat
Meanwhile, seagrass and seaweeds assessment revealed that there is still a widespread and an abundant coverage of seagrasses in the area, but mainly along numerous sheltered coasts of the Linapacan mainland, in association with the presence of mangroves and coral reefs. Almost half (47%) of seagrass areas surveyed are in fair condition. Good condition is shared at 35%. Excellent condition is shared at 9% in Cabunlauan Island seagrass sites. Colaylayan and Binalabag Island are in poor condition (shared at 9%).
The present survey recorded nine (9) species of seagrasses and 19 species of seaweeds recorded (nine (9) greens, six (6) browns and four (4) reds), and 13 species of macroinvertebrates. Site 9- Diringuan 3 had the most diverse seagrass bed, having 8 identified species, followed by Site 10- Ditinglan, Site 11- San Miguel Poblacion and Site 12- Sitio Pula having 7 identified species each. The least diverse was observed in Site 14- San Nicolas Poblacion, Site 15- Octon Island W and Site 18- Colaylayan having pure stands of Enhalus acoroides. .
Based on the results of this survey, the following are recommended sites based on 1. High Percentage Seagrass Cover: i) Site 11 (San Miguel Poblacion, San Miguel, NE Linapacan mainland) ; ii) Site 12 (Sitio Pula, Pula Bay, San Miguel, W Linapacan mainland); iii) Site 14 (San Nicolas Poblacion, South Bay, San Nicolas, S Linapacan mainland); iv) Site 15 (Octon Island West, South Bay, San Nicolas, S Linapacan mainland); v) Site 16 (South Bay Cove, South Bay, San Nicolas, S Linapacan mainland) ; vi) Site 3 (Tabkangan, Northwest Bay, Maroyogroyog, NW Linapacan mainland); vii) Site 4 (Bayotbot, Northwest Bay, Maroyogroyog, NW Linapacan mainland); viii) Site 5 (Lilo, Northwest Bay, Maroyogroyog, NW Linapacan mainland); ix ) Site 21 (Cabunlauan Island NW, Cabunlauan Group of Islands); x) Site 22 (Cabunlauan Island Poblacion, Cabunlauan Group of Islands); 2. High Species Richness: i) Site 9 (Diringuan 3, North Bay, San Miguel, N Linapacan mainland); ii) Site 10 (Ditinglan, San Miguel, NE Linapacan mainland); iii) Site 11 (San Miguel Poblacion, San Miguel, NE Linapacan mainland); iv) Site 12 (Sitio Pula, Pula Bay, San Miguel, W Linapacan mainland); 3. Presence of Grazing Area of Dugong: i) Site 5 (Lilo, Northwest Bay, Maroyogroyog, NW Linapacan mainland)
______EXECUTIVE SUMMARY xii Informant’s survey on marine mammal showed that the range of movements by dugongs to and from feeding sites within the municipality was more favorable during the summer months as compared to other municipalities given the geographical location of Linapacan. Feeding sites were reported in Calibangbangan, Maroyogroyog, and Binalabag island. Juvenile turtles found in nearshore waters of the areas surveyed may suggest coastal feeding sites in the area. However, whether these juveniles were the hatchlings belonging to the nesting sites reported in Magranting Island, and Calibangbangan or from elsewhere in the region are unknown.
______EXECUTIVE SUMMARY xiii CHAPTER I CORAL REEFS
1.0 INTRODUCTION
Coral reefs are important in protecting coastal areas, supplying sand for beaches, fish, invertebrates and seaweeds for harvest, sites for mariculture and other sources of benefit to people who live in coastal areas (McManus, 2002; cited in Morales et al., 2005). Coral reefs are widespread throughout the Philippines with an estimated area of 27,000 km2 (ERTL, 1995). Much of these reefs are in and around the island of Palawan (Philreefs, 2003; cited in Morales et al., 2005), with some 60% (White, 1987), which occur along more exposed coasts or around small islands (Jacobs, 1991). Earlier surveys conducted in 1981-1983 by BFAR show that more than half of the areas (54.54%) in northeastern Palawan were poor in coral cover, 36.36% were fair and 9.09% good. On the other hand, 67% of the total number of shoals covered in the eastern border of the Kalayaan Island Group was fair while about one-third (33%) was poor, and those shoals investigated in Bacuit Bay had fair coral cover (BFAR Annual Report, 1983). Both natural and human-induced disturbances/stresses play a major role in the degradation of most, if not all reefs in Palawan. The loss or degradation of the reefs results in lost habitats or niches for the various organisms eventually translating into decreased productivity.
This report presents the results of the baseline survey of coral reefs for the municipality of Linapacan for ECAN Zoning Project. The purpose of this activity is to determine the condition of the coral reef in terms of percentage coral cover and to identify potential core zones to function as protected areas.
2.0 MATERIALS AND METHODS
Baseline coral survey was made in selected reef sites (Figure 1) to determine the percentage cover of living hard and soft corals, dead coral and other benthic components such as algae and macroinvertebrates associated with the reef. Study sites were selected based on topographic maps, reconnaissance and information given by locally hired boat operator and guide familiar with the area as well as local fisherfolks encountered during the survey.
Surveys were conducted on the coral reefs around Linapacan mainland. The other reef areas were in small/distant islands and islets surrounding Linapacan mainland to the west down to the south and in the far distant Cabunlauan Group of Islands to the east (see Figure 1). Unfortunately, none of the small islands/islets on the northern side of Linapacan mainland was surveyed because of time constraint. In addition, inclement weather and sea conditions in the more open (offshore) waters frequently encountered during the survey period also contributed to this limitation.
The manta tow reconnaissance technique (English et al., 1994, 1997) was employed in this baseline survey. However, a slight modification was employed. Instead of the snorkeller being towed behind the boat, the observer uses the manta board that was secured to the outrigger. This permits the snorkeller to relay the observations directly to the person
______CHAPTER I: CORAL REEFS 1 on board who notes the interval time (every two minutes) of the observation points and records the GPS position of tow. The snorkeller records percentages of dead, living hard and soft coral covers. Other significant observations of lifeforms (e.g., macroalgae, Diadema sp., Acanthaster planci) as well as other outstanding reef features (e.g., anchor damage, dynamite/cyanide damage, Acanthaster infestation, coral bleaching) were also recorded. During the observation tow, the team encountered low to very poor visibility in some reef sites due to their proximity to the mangrove swamps.
The scoring categories to estimate coral cover outlined in the Coastal/Marine Survey Manual of the ECAN Zoning Project are those of English et al. (1994, 1997) and modified in Montebon (1997) as follows: 0= no cover, 1= 1-10%, 2=11-30%, 3= 31-50%, 4= 51-75%, and 5= 76-100%. Each category is qualitatively classified as being in very poor, poor, fair, good and excellent condition, respectively. The classification very poor is added here for the Category 1 (1-10%).
3.0 RESULTS
3.1 Live Coral Cover and Reef Condition
Fringing coral reefs were found along the coastline in most of the reef sites surveyed. Thirty-seven (37) sites (see Figure 1) were sampled for reef condition (i.e. 15 in Linapacan mainland and 22 in small islands and islets). Tables 1, 2, 3 and 4 list the reef sites surveyed with live coral cover scores of 1 (1-10% = very poor), 2 (11-30% = poor), 3 (31-50% = fair) and 4 (51-75% = good), respectively. These are all depicted in Figure 2.
Table 1. Reef sites with live coral cover of 1-10%, Linapacan, Palawan, 2004
Location N Latitude E Longitude Live Coral cover
Northwest Bay Cove 2 (Maroyogroyog) 11.27299 119.46399 1-10% North Bay Cove 1 (Maroyogroyog) 11.28304 119.47201 1-10% North Bay Cove 1 (Maroyogroyog) 11.28340 119.47183 1-10% Condut Island 11.28047 119.39384 1-10% Calibangbangan Island SE 11.23034 119.39296 1-10% Calibangbangan Island SW 11.24248 119.38359 1-10% Cacayatan Island E 11.28333 119.39332 1-10% Barongonan Island W 11.20359 119.41362 1-10% Barongonan Island W 11.20400 119.41317 1-10% Bagambangan Island NW 11.15037 119.41538 1-10% Bagambangan Island NW 11.14579 119.41542 1-10%
______CHAPTER I: CORAL REEFS 2 Legend:
1. Patoyo Island N 19. Condut Island 2. San Miguel Reef (near Ile Island) 20. Calibangbangan Island N 3. Pula Bay 21. Calibangbangan Island SW 4. North Bay Cove 3 22. Calibangbangan Island SE 5. North Bay Cove 2 23. Barongonan Island W 6. North Bay Cove 1 24. Barongonan Island S 7. Northwest Bay Cove 2 25. Iloc Island N 8. Northwest Bay Cove 1 26. Iloc Island (Muñoz Bay) 9. Sidsid Point 27. Iloc Island W 10. South Bay Inner Cove 28. Iloc Island E 11. South Bay Reef 29. Iloc Island E (near Pinamalayan Island) 12. Bubulauan Point 30. Iloc Island SE 13. Bina Reef 31. Bagambangan Island NW 14. Colaylayan Reef 32. Bagambangan Island SE 15. Colaylayan Bay 33. Cabunlauan Island NW 1 16. San Pedro 34. Cabunlauan Island NE 17. Malubutglubut Island SW 35. Cabunlauan Island W 18. Cacayatan Island NE 36. Nanga Island N 17 6 37. Nangalao Island NE 18 5 2 19 37 16 15 7 4
8 20 14 11 3 10 13 36 21 22 12 33 9 34
35
23
25 24 26
28 27 29 30
31
32
Figure 1 The study area showing the coral reef sites surveyed (manta tow tracts), 30 May – 03 June 2004 2004. ______CHAPTER I: CORAL REEFS 3 LEGEND: Live coral cover 1-10 % (Very poor) 11-30 % (Poor) 31-50 % (Fair) 51-75 % (Good) 76-100 % (Excellent)
Figure 2 The reef sites surveyed showing percentage live coral cover scores and reef condition, 30 May – 03 June 2004. ______CHAPTER I: CORAL REEFS 4
Table 2. Reef sites with live coral cover of 11-30%. Linapacan, Palawan, 2004
Location N Latitude E Longitude Live Coral cover
South Bay Inner Cove 11.25008 119.49019 11-30% Sidsid Point 11.23038 119.49548 11-30% Sidsid Point 11.23185 119.49535 11-30% Pula Bay 11.25568 119.31161 11-30% Northwest Bay Cove 1(Maroyogroyog) 11.26295 119.45574 11-30% Northwest Bay Cove 1(Maroyogroyog) 11.26294 119.45562 11-30% North Bay Cove 2 (San Miguel) 11.28059 119.49221 11-30% Calibangbangan Island N 11.25041 119.39153 11-30% Iloc Island W 11.17191 119.39187 11-30% Iloc Island W 11.17106 119.39208 11-30% Barongonan Island S 11.20101 119.41537 11-30% Iloc Island N 11.19433 119.41027 11-30% Iloc Island (Muños Bay) 11.19152 119.40385 11-30% Cabunlauan Island NE 11.23207 120.06127 11-30% Nangalao Island NE 11.27379 120.11204 11-30% Nangalao Island NE 11.27443 120.11168 11-30%
Table 3. Reef sites with live coral cover of 31-50%. Linapacan, Palawan, 2004
Location N Latitude E Longitude Live Coral cover
Patoyo Island N 11.30280 119.53326 31-50% Patoyo Island N 11.30276 119.53239 31-50% San Miguel (near Ile Island) 11.28293 119.52038 31-50% San Miguel (near Ile Island) 11.28356 119.52045 31-50% North Bay Cove 3 (San Miguel) 11.27444 119.49525 31-50% San Pedro Reef 11.27494 119.42393 31-50% Colaylayan Bay 11.27605 119.43289 31-50% Colaylayan Reef 11.25581 119.43327 31-50% Bina Reef 11.25017 119.44588 31-50% Bubulauan Point 11.23431 119.46226 31-50% Malubutglubut Island SW 11.29238 119.40404 31-50% Malubutglubut Island SW 11.29209 119.40429 31-50% Iloc Island SE 11.16071 119.40471 31-50% Iloc Island SE 11.16119 119.40499 31-50% Iloc Island E 11.17111 119.41001 31-50% Iloc Island E 11.17172 119.41059 31-50% Iloc Island E (near Pinamalayan Island) 11.17534 119.41279 31-50% Bagambangan Island SE 11.14017 119.42044 31-50% Bagambangan Island SE 11.14074 119.42095 31-50% Cabunlauan Island W 11.22362 120.05005 31-50% Cabunlauan Island NW 11.23367 120.04531 31-50% South Bay Reef 11.25112 119.47348 31-50%
______CHAPTER I: CORAL REEFS 5 Table 4. Reef sites with live coral cover of 51-75%, Linapacan, Palawan, 2004
Location N Latitude E Longitude Live Coral cover
Nangalao Island N 11.24483 120.08183 51-75%
Among the reefs surveyed, only 1 (about 2.7%, Table 5) which is located in Nangalao Island N (an islet in Cabunlauan Group of Islands) was in good condition (73% live coral cover, Table 6 and Figure 2).
Sixteen sites (43.2%, see Table 5) of the surveyed reefs were in fair condition. These are located in Patoyo Island N (40%), San Miguel Reef (near Ile Island, 50%), North Bay Cove 3 (San Miguel, 50%), South Bay Reef (50%), Bubulauan Point (35%), Bina Reef (40%), Colaylayan Reef (40%), Colaylayan Bay (40%), San Pedro (40%), Malubutlubut Island SW (40%), Iloc Island E (40%), Iloc Island E (near Pinamalayan Island, 32%), Iloc Island SE (32%), Bagambangan Island SE (50%), Cabunlauan Island NW (35%) and Cabunlauan Island W (35%) (see Table 6 and Figure 2).
Twelve sites (32.4%, see Table 5) with poor condition include Pula Bay (20%), North Bay Cove 2 (San Miguel, 30%), Northwest Bay Cove 1 (Maroyogroyog, 30%), Sidsid Point (30%), South Bay Inner Cove (30%), Calibangbangan lsland N (30%), Barongonan Island S (30%), Iloc Island N (20%), Iloc Island (Muños Bay, 20%), Iloc Island W (12%), Cabunlauan Island NE (25%) and Nangalao Island NE (15%) (see Table 6 and Figure 2).
The eight remaining sites (21.6%, see Table 5), which were sampled in North Bay Cove 1 (Maroyogroyog), Northwest Bay Cove 2 (Maroyogroyog), Cacayatan Island E, Condut Island, Calibangbangan Island SW, Calibangbangan Island SE, Barongonan Island W and Bagambangan Island NW have reefs with very poor coral cover (10% each, see Table 6 and Figure 2).
In general, the condition for all coral reef sites surveyed was poor with an overall average live coral cover of only 29.6% (see Tables 5 and 6).
Table 5. Classification and distribution of coral reef sites surveyed based on percentage live coral cover. Linapacan, Palawan, 2004
Category Limits Number of Classification Share (% Live Coral Cover) Reef Sites (%) 1-10 8 Very Poor 21.6 11-30 12 Poor 32.4 31-50 16 Fair 43.2 51-75 1 Good 2.7 76-100 - Excellent - Total 37 100.0 Overall Average = 29.6 Poor
______CHAPTER I: CORAL REEFS 6 Table 6. Average percentage covers of hard corals, soft corals, total live corals (hard and soft corals combined) and dead corals, observed in the reef sites surveyed. Linapacan, Palawan, 2004
Hard Soft % Total Reef Dead Reef Site Coral Coral Live Coral Condition Coral (HC) (SC) Cover (DC) (%) (%) (LCC) (%) 1. Patoyo Island N 30 10 40 Fair 50 2. San Miguel Reef (near Ile Island) 50 0 50 Fair 30 3. Pula Bay 20 0 20 Poor 50 4. North Bay Cove 3 (San Miguel) 50 0 50 Fair 30 5. North Bay Cove 2 (San Miguel) 30 0 30 Poor 50 6. North Bay Cove 1 (Maroyogroyog) 10 0 10 Very Poor 75 7. Northwest Bay Cove 2 (Maroyogroyog) 10 0 10 Very Poor 75 8. Northwest Bay Cove 1 (Maroyogroyog) 30 0 30 Poor 50 9. Sidsid Point 30 0 30 Poor 50 10. South Bay Inner Cove 30 0 30 Poor 50 11. South Bay Reef 50 0 50 Fair 50 12. Bubulauan Point 30 5 35 Fair 50 13. Bina Reef 30 10 40 Fair 50 14. Colaylayan Reef 30 10 40 Fair 50 15. Colaylayan Bay 30 10 40 Fair 50 16. San Pedro 30 10 40 Fair 50 17. Malubutlubut Island SW 30 10 40 Fair 50 18. Cacayatan Island E 10 0 10 Very Poor 75 19. Condut Island 10 0 10 Very Poor 75 20. Calibangbangan Island N 30 0 30 Poor 75 21. Calibangbangan Island SW 10 0 10 Very Poor 75 22. Calibangbangan Island SE 10 0 10 Very Poor 75 23. Barongonan Island W 10 0 10 Very Poor 75 24. Barongonan Island S 20 10 30 Poor 75 25. Iloc Island N 20 0 20 Poor 75 26. Iloc Island (Muños Bay) 20 0 20 Poor 75 27. Iloc Island W 10 2 12 Poor 75 28. Iloc Island E 40 0 40 Fair 50 29. Iloc Island E (near Pinamalayan Island) 30 2 32 Fair 50 30. Iloc Island SE 30 2 32 Fair 63 31. Bagambangan Island NW 10 0 10 Very Poor 75 32. Bagambangan Island SE 50 0 50 Fair 50 33. Cabunlauan Island NW 30 5 35 Fair 63 34. Cabunlauan Island NE 20 5 25 Poor 63 35. Cabunlauan Island W 30 5 35 Fair 63 36. Nangalao Island N 63 10 73 Good 27 37. Nangalao Island NE 10 5 15 Poor 50 Average 26.6 3.0 29.6 Poor 58.5
______CHAPTER I: CORAL REEFS 7 3.2 Live Hard Coral, Soft Coral and Dead Coral Cover
For all reef sites surveyed, live hard corals ranged from 10% to 63%, with an average of 26.6% (Table 7). The highest live hard coral cover was noted in Nanga Island N (Cabunlauan Group of Islands, 63%), followed by San Miguel Reef (near Ile Island), North Bay Cove 3 (San Miguel), South Bay Reef (San Nicolas) and Bangambangan Island SE with 50% each.
The common soft coral communities present on the coral reefs of Linapacan were the Sarcophyton. They were sighted in 16 out of 37 reef sites surveyed (see Table 7). They did not contribute significantly to the bottom cover, which ranged from 0 to 10% with an average of only 3%. The highest soft coral cover (10%) was observed in 8 reef sites, Patoyo Island N, west coast of Linapacan mainland (Bina Reef, Colaylayan Reef, Colaylayan Bay, San Pedro), and in small islands/islets (Malubutglubut Island SW, Barongonan Island S, Nanga Island). Next highest (5%) was noted at three reef sites in Cabunlauan Island (Cabunlauan Island NW, Cabunlauan Island NE, Cabunlauan Island W) and 1 reef site in Nangalao Island NE. The 3 reef sites surveyed around Iloc Island (Iloc Island W; Iloc Island E, near Pinamalayan Island; Iloc Island SE) were also observed to have soft coral communities, but its cover was very low (2%).
A notable feature of the reef sites surveyed was a very high bottom cover of dead corals, which ranged from 27% to 75%, with an average of 58.5% (see Table 7). Of the 37 reef sites surveyed, 13 sites (35.1%) had the highest dead coral cover of 75%, 4 sites (10.8%) had the second highest with 63% cover and 17 sites or nearly half (45.9%) had the third highest dead coral cover of 50%.
3.3 Associated Macroinvertebrates and Seaweeds in Coral Reefs
Macroinvertebrates and benthic algae found in each reef site surveyed are shown in Table 7. Eight phyla/classes of macroinvertebrates were represented. Only giant clams Tridacna and oyster Lopha cristagalli were found among the mollusks. The fan sponge Phyllospongia papyracea was the most prominent non-coral organism observed in many coral reefs of Linapacan (sighted in 26 out of 37 reef sites surveyed), followed by the long- spined black sea urchin Diadema setosum, the blue starfish Linckia laevigata, the gorgonians or seafans, the giant clams Tridacna, the seawhip Juncella juncella and the barrel sponge Xestospongia testudinaria at 19, 18, 10, 8, 7 and 6 reef sites, respectively. Occurrence of high densities of Diadema setosum was observed in San Pedro and Barongonan Island W.
The Crown-of-Thorns starfish Acanthaster planci (a natural predator of hard corals) was also present but only in 3 reef sites surveyed, Northwest Bay Cove 1, Bagambangan Island NW and Nanga Island N.
Other species/groups of macroinvertebrates found in some reefs surveyed were: sea urchin Echinometra, brittle stars, featherstars, sea squirts, hydroids, sea anemones and polychaete Christmas tree worms.
______CHAPTER I: CORAL REEFS 8 Table 7. Macroinvertebrates and seaweeds seen during the baseline survey in coral reefs of Linapacan, northern Palawan (May/June 2005), Linapacan, Palawan, 2004
MACROINVERTEBRATES MACROALGAE
REEF SITE
ECHINODERMS BIVALVE ASCIDIANS HYDROZOANS OCTOCORALS SPONGES ACTINIARIA POLYCHAETE BROWN SEAWEEDS MOLLUSCS
Diadema Echinometra Brittlestars Feather Linckia Giant Oyster Sea Squirts Hydroids Gorgonian Seawhip Barrel Fan sponge Sea Christmas setosum sp. Stars laevigata Clams Lopha Seafans Junceella sponge Phyllospongia Anemone Tree Sargassum Padina Tridacna Xestospongia Worm Sabellidae Acanthaster Planci
1. Patoyo Island x x X x x x x N 2. San Miguel Reef x x x x x x x (near Ile Island) 3. Pula Bay x x x 4. North Bay Cove 3 x x x x (San Miguel) 5. North Bay Cove 2 x x x x x x (San Miguel) 6. North Bay Cove 1 x X x x x x x x x x x
(Maroyogroyo g) 7. Northwest Bay Cove 2 x x x x x x
(Maroyogroy og) 8. Northwest Bay Cove 1 x x x x
(Maroyogroy og) 9. Sidsid Point x x x x 10. South Bay Inner x x x x x x Cover 11. South Bay x x x Reef 12. Bubulauan x x x x x x x Point 13. Bina Reef x x x x 14. Colaylayan x x x x x x Reef 15. Colaylayan x x x x
______CHAPTER I: CORAL REEFS 9 Bay 16. San Pedro x x x X x x 17. Malubutlubut x x x x Island SW 18. Cacayatan x x x Island E 19. Condut x x x x x x Island 20. Calibangba x x x x ngan Island N 21. Calibangba x x ngan Island SW 22. Calibangba X x ngan Island SE 23. Barongonan Island W x x X X 24. Barongonan Island S x x x 25. Iloc Island x x N 26. Iloc Island (Muños Bay) 27. Iloc Island x x x W 28. Iloc Island E x x x 29. Iloc Island (near x x x Pinamalayan Island) 30. Iloc Island x x x x SE 31. Bagamban x x x x x gan Island NW 32. Bagamban x x gan Island SE 33. Cabunlauan Island NW x 34. Cabunlauan Island NE x 35. Cabunlauan Island W x x x 36. Nanga Island N x x x 37. Nangalao Island NE x x
______CHAPTER I: CORAL REEFS 10 Macroinvertebrate species accounts for 9 out of 16 species recorded, (see Table 7). All the other sites have only 1 to 6 species recorded.
The most common macrobenthic alga sighted on most reefs (19) surveyed was the brown seaweed Sargassum (see Table 7). The macroalgal cover was quite dense. The brown alga Padina was also present but only on a few stations (8 out of 37) surveyed.
4.0 DISCUSSIONS
Most of the reef corals surveyed in the Linapacan area have been badly damaged. They were found to be poor in live coral cover (hard and soft corals combined, with an average of only 29.6%). In fact, of the 37 reef sites surveyed, only 1 was good, 16 were fair, 12 were poor and 8 very poor (see Tables 5 and 6). On the hard coral cover, the surveyed coral reefs had an average of 26.6%; while soft corals growing over dead corals or colonizing the rocky substrates did not contribute significantly to the picture (average of only 3%). On the contrary, over 90% (34 out of 37 sites) of the reefs surveyed consisted of dead coral substrates (average of 58.5%; see Table 6) characterized as large tracts of broken coral colonies, rubbles, traces of blast craters and old dead corals. The depauperate nature of the reefs may be related to the physical damage caused by after effects of dynamite fishing, cyanide and “muro–ami” or “kayakas”. Another cause could be Acanthaster planci infestations of reefs, and also siltation (sediment smothering) particularly those emanating from the continuous practice of upland deforestation (“kaingin”) and cutting of the mangroves as was observed particularly in sheltered coves (e.g. at the vicinity of Site 7- Northwest Bay Cove 2, Sitio Pinagkalangan, Maroyogroyog).
Considering live coral cover as the criterion at least 5 reef sites were identified as potential core zones: Site 36 – Nangalao Island N had 73% cover, then followed by Site 2 - San Miguel Reef, Site 4 - North Bay Cove 3, Site 11 - South Bay Reef and Site 32 - Bangambangan Island SE with 50% each (see Table 6). These 5 sites are geographically isolated from each other. Sites 2, 4 and 11 at western (near Ile Island), northern (innermost cove of North Bay) and southern (inner cove of South Bay) sections of Linapacan mainland, respectively; while Site 32 is in the far distant southern Iloc Group of Islands and Site 36 in the far distant western Cabunlauan Group of Islands (Figure 3).
There were 16 groups/species of reef macroinvertebrates recorded in this survey. North Bay Cove 1 (Maroyogroyog) supported the largest macroinvertebrate species numbers (9 species) while all the other reef sites supported from 1 to 6 species (see Table 7). It might be that the low macroinvertebrate species numbers observed are likely due to obstruction by dense macroalgal cover. Spatial disruption by macroalgal blooms may play a very important role in nearshore reefs. The macroinvertebrate sightings recorded for each reef may be also underestimated since many of the reef associated organisms are nocturnal.
The poisonous starfish Acanthaster planci observed during this survey in some few reefs were seen actively grazing on the branching coral Seriatopora and table coral Acropora. It is assumed that most reefs surveyed appear to have been host to previous Acanthaster outbreaks on coral reefs. In 1983, for instance, Cabunlauan Island and Linapacan Strait were among the 16 shoal reef areas surveyed in the northeast waters of Palawan by BFAR. The results obtained from this survey (BFAR Annual Report, 1983) show that the shoals surveyed were predominantly poor. In the same report, it was stated that
______CHAPTER I: CORAL REEFS 11 coral degradation in these areas studied may most probably be due to natural stress- i.e., strong currents and Acanthaster planci predation. Another cause could be dynamite fishing, which was rampant particularly in the northeast area.
Very few giant clams were noticed during the survey. Specimens of the endangered giant clam Tridacna were found only in some reef areas (8 out of 37 sites surveyed), particularly on coral reef areas in North, Northwest and Colaylayan Bays of Linapacan Island, and in far distant Iloc and Cabunlauan Islands (see Table 7). The clam probably appears to be a remnant of a once thriving population of giant clams in the area. Sea cucumbers, on the other hand, were practically absent at all reef sites. It is assumed that these have been completely fished out, suggesting that these organisms are among the most extensively exploited invertebrates.
It is of interest to note that a single specimen of the endangered green sea turtle (Chelonia mydas) was observed on the surveyed reef at Site 10- South Bay Cove (San Nicolas). This species, which as an adult is mainly vegetarian, and lives mostly on seagrass. Hence, the relatively shallow waters adjacent to this reef site were found to harbor sizable tracts of monospecific seagrass beds of Enhalus acoroides and fringing mangrove forests.
At Site 1- Patoyo Island, a “paaling” (drive-in-net) actual fishing operation with about 20 fishers/divers used exclusively on coral reefs to harvest reef fish fishes was also observed. The “paaling” is the modified version of the “muro-ami” or “kayakas”. Instead of swimmers, the method employs divers with a “kapandra” (or compressor) and its perforated rubber hose, scaring the fish out of hiding and driving them into the nets by air bubbles. On the other hand, “muro-ami” and “kayakas” fishing techniques use swimmers to chase fish into a net. The swimmers bang the bottom surface with poles and large rocks to break up and overturn coral colonies to drive the fish into the net by creating noise and forcing fish from hiding places (Carpenter and Alcala, 1977). The consequence is many broken corals in a disturbed bottom habitat (White, 1990).
Most of the reef areas surveyed were colonized by macroalgae, and was primarily Sargassum and Padina. Sargassum species are known to thrive in relatively harsh environments. The forces controlling the periodic blooms of macroalgae are unclear (Coles, 1988), but growth can be extensive. In some instances, reef corals become overgrown (normally the corals survive). It has been suggested that the defenses of these corals may be compromised due to competition for space (McCain et al., 1984) and even killed by algal shading (Crossland, 1981; Johannes et al., 1983). The extent of any sublethal reduction in coral growth and calcification due to algal competition is unknown and will only be determined by controlled experimentation (Coles, 1988). With large portions of living tissue being covered by the algal canopy for weeks to months, however, some negative influence on the viability of affected corals may be assumed (Coles, 1988). In the present survey, however, neither impacts nor stress was seen on any of the corals that can be associated to dense macroalgal cover of Sargassum.
______CHAPTER I: CORAL REEFS 12 5.0 SUMMARY OF FINDINGS
The major findings to be drawn from this study are:
1. The coral reefs of Linapacan are in very disturbed (poor) condition. Of the 37 reef sites surveyed, only 1 is in good condition, 16 are in fair condition, 12 are considered poor and 8 sites are in very poor condition. 2. At least 5 reef sites were identified as potential core zones: Nanga Island N (73% coral cover), followed by San Miguel Reef, North Bay Cove 3 Reef, South Bay Reef and Bangambangan Island SE Reef (50% cover each). These reefs are geographically isolated from each other. 3. Blast fishing, cyanide, “muro–ami” or “kayakas”, siltation, and Crown-of-Thorns starfish Acanthaster planci infestations are the apparent causes of widespread coral reef destruction in the area. 4. Broken coral colonies, rubbles, traces of blast craters and old dead corals predominate reef bottoms of the sites surveyed while the soft corals are not well developed. 5. There are about 8 phyla/classes of reef macroinvertebrates represented. The fan sponge Phyllospongia papyracea is the most prominent non-coral organism observed in most reefs surveyed, followed by sea urchin Diadema setosum, blue starfish Linckia laevigata, seafans, giant clam Tridacna, seawhip Juncella juncella and barrel sponge Xestospongia testudinaria. Other species/groups of macroinvertebrates observed are: sea urchin Echinometra, brittle stars, featherstars, sea squirts, hydroids, sea anemones and polychaete Christmas tree worms. Likewise, the Crown-of-Thorns starfish Acanthaster planci is also present within the study area. 6. Macroalgal cover on most reefs is dominated by the brown seaweed Sargassum while another brown seaweed, Padina, occurred at few reefs.
6.0 RECOMMENDATIONS
Based on the results of this survey, the following are recommended:
1. Within this study area, 5 reef sites (see Figure 3) are recommended as core zones as they have the highest live hard coral cover recorded. a. Nangalao Island N Reef - in far distant western Cabunlauan Group of Islands b. Bangambangan Island SE Reef - in far distant southern Iloc Group of Islands c. San Miguel Reef - in western section of Linapacan mainland (near Ile Island) d. North Bay Cove 3 Reef - in northern section of Linapacan mainland (North Bay) e. South Bay Reef- in southern section of Linapacan mainland (South Bay)
2. These 5 sites are recommended for more detailed study to generate more information on the status and condition of the corals reef communities and community structure, and the main organisms inhabiting them.
______CHAPTER I: CORAL REEFS 13
Site Site 4
Site
Site
Site
Figure 3 Potential coral core zones, Linapacan, northern Palawan, 30 May – 03 June 2004.
______CHAPTER I: CORAL REEFS 14 3. “Kaingin” and illegal cutting of mangrove trees should be stopped, due to threats to the nearby coral reefs and associated seagrass beds as well as its dependent organisms.
4. Strict implementation of laws regarding the protection, management and conservation of the fisheries and marine resources.
______CHAPTER I: CORAL REEFS 15 CHAPTER II REEF FISHES
7.0 INTRODUCTION
A survey of the coral reefs and reef-associated fishes from selected sites in Linapacan, Palawan was conducted for the Marine and Coastal Resources Survey and Research Component of the SEMP-ECAN Zoning Project. Data on the fish communities of the Municipality of Linapacan are an important contribution in the assessment of the resources of the coral reefs in the area.
A baseline survey of reef fishes was conducted in Linapacan. This survey is rapid and qualitative in nature. It will help construct and contribute to the listing of fish species that occur in specific reef sites in Linapacan and its surrounding islands. It also aims to identify sites with the highest species richness as potential core zones.
8.0 MATERIALS AND METHODS
A baseline survey was conducted to observe the reef fish assemblages at specific coral reef sites in Linapacan. Using snorkeling equipment, an observer swam along the reef for about 10 to 20 minutes (depending on factors such as water visibility, number of observable fish species, etc.). Fish were observed within a 50m by 5m survey corridor covering a total area of approximately 250m2 for each station. All fish observed were identified to the lowest possible taxon and recorded on an underwater slate. Fishes were identified based on visual appearance and comparing these with photographic references (Allen, 1991; Randall et al., 1997; FishBase, 2000; and Lieske and Myers, 2001). Fish were later categorized as target, indicator or major fish species based on the “importance” data compiled in FishBase 2000 (Froese and Pauly, 2000).
The survey method limited the observations and subsequent species listing to numerically dominant and visually obvious species of fish. Cryptic and small species of reef fishes were difficult to detect and identify using this technique. Furthermore, abundances and biomass of fish were not determined. Geo-references of the fish survey stations were determined and recorded with a Garmin Summit GPS.
9.0 RESULTS
A total of 34 sampling stations were surveyed in Linapacan (Figure 4). Stations were mainly situated at or near the reef crest where most of the fish occur. However, the observer commonly traversed the reef flat and reef slope areas thereby covering a wider range of reef zones . Furthermore, benthic cover and the dominant substrate also varied across stations including dominant stands of coral, Sargassum beds, sandy areas and rocky reefs . This also ensured that a variety of habitats were sampled throughout the survey.
______CHAPTER II: REEF FISHES 16 N
Figure 4. Baseline fish survey sampling stations, Linapacan, Palawan, May 2004
A total of 198 species of fish distributed among 36 families were recorded from the sampling stations (Table 8) . At least 11 fishes from 10 families were not identified to species level. A complete listing of the species observed and their occurrences is summarized in Table 9. Of the total species listed, 21 were indicator species, 94 were major species and 83 were target species . Indicator species are highly associated with their environment and their presence or absence may indicate the present condition of their habitat. Target species are fish commonly exploited in fisheries and are of commercial value. Major species are fish with no commercial value in fisheries but they occupy specialized niches in the marine environment and function as important trophic links.
The 21 indicator species were members of 4 fish families (Table 9). The majority of these were coral feeding butterflyfishes (Chaetodontidae, a few were wrasses (Labridae) and a single damselfish (Pomacentridae) was included. Other indicator species were associates of certain coral lifeforms (i.e. Chromis ternatensis is associated with branching Acropora), while others are common in silty environments (i.e. Chelmon rostratus, Aeoliscus strigatus). The vast majority of the major fishes were comprised of damselfishes (Pomacentridae; n=44 species) and wrasses (Labridae; n=35 species) (Table 9). Chaetodontidae and the parrotfishes (Scaridae) were also among the most speciose with 17 and 14 species, respectively (Table 9). The rest of the 88 species belonged to the other 32 families (Table 9). Major fishes were the most speciose group among the three fish categories (Table 10). This group of fishes represented at least 6 feeding guilds, including: herbivores, omnivores, planktivores, benthic carnivores, detritivores and piscivores. The 83 species of target fish were representatives of 21 families (Table 9). Majority of the target fish recorded were minor targets such as parrotfishes and wrasses. The high value target species Plectropomus leopardus (Serranidae) was only recorded in 3 sampling stations (Table 9).
______CHAPTER II: REEF FISHES 17 Table 8. Species richness of reef fishes from 34 sampling stations, Linapacan, Palawan, May 2004.
Station Family Species North East Locality Remarks 1 12 41 11 27 44.7 119 42 44.4 San Pedro, SW Linapacan good fish richness and abundance; high A. polyacanathus and A. curcao 2 14 38 11 27 05.4 119 43 33.4 Sitio Culaylayan reef flat at bay mouth 3 9 30 11 25 54.3 119 43 44.5 S of Culaylayan just past the small cemetery 4 13 49 11 25 07.6 119 45 01.6 Bulawi bay mouth 5 13 43 11 23 48.0 119 46 30.5 Capitan (Campot) bay mouth 6 11 35 11 25 10.1 119 47 43.1 Inside Campot Bay pearl farm, reef flat, tornado 7 11 39 11 25 02.2 119 48 55.9 San Nicolas inner bay, near mangroves, patchy Enhalus, crest to slope, many big target fish 8 10 22 11 23 24.4 119 49 55.1 back of San Nicolas Sargassum area, start of rep 2 9 12 27 11 25 58.4 119 51 09.9 small bay with mangroves 10 12 40 11 28 41.7 119 52 06.6 Poblacion near Maapdit and Ile Islands 11 14 35 11 26 29.7 119 45 50.2 Maruyogruygog Bay inner bay, Sargassum bed near sand 12 12 28 11 27 30.8 119 46 34.8 Maruyogruygog Bay dynamite tracks, high DCA 13 10 21 11 28 32.8 119 47 14.0 sargassum reef, edge of SG bed 14 9 14 11 27 40.2 119 49 48.9 near SW farms 15 23 68 11 29 18.2 119 40 46.7 Malubutglubut crest to slope, high abundance of C. cyanopleura, A. sexfasciatus, A. polyacanthus, P. alexanderae; some large groupers 16 11 29 11 28 54.0 119 39 50.8 Nanga Island 17 8 16 11 28 04.7 119 39 38.4 Cacayaton Island small islet, Sargassum area 18 9 16 11 25 02.4 119 39 18.3 Calibangbangan Island NE bay, dynamited coral rubble, no damsels, no planktivores, low abundance 19 9 18 11 24 24.8 119 38 35.9 Calibangbangan Island (W) no damsels, low abundance 20 13 28 11 16 16.6 119 40 51.1 Iloc Island (E) S of Pinamalayan Island, high R, low abundance, no damsels and planktivores 21 9 16 11 17 21.4 119 41 09.5 Iloc Island (E) N of Pinamalayan Island, no damsels, low abundance, Sargassum area 22 7 16 11 18 08.2 119 41 31.0 Iloc Island (E) no fish, coral R area 23 5 18 11 20 10.7 119 42 04.3 Barangonan Island (S) no fish, dynamited area, 2 blasts 24 6 15 11 20 43.8 119 41 29.0 Barangonan Island (W) no fish, Sargassum area
______CHAPTER II: REEF FISHES 18 Table 8 continued . . . 25 7 18 11 19 34.7 119 40 54.6 Iloc Island (W) no fish, coral R area 26 14 29 11 19 05.3 119 40 32.5 Iloc Island (W, cove) no fish, coral R area, some big fish on bommies 27 7 19 11 17 04.8 119 39 22.9 Iloc Island (W, south) no fish, coral R area 28 13 34 11 14 50.6 119 41 53.1 Bagambongan Island no fish, low abundance 29 8 25 11 14 12.8 119 43 16.1 Bagambongan Island (E) 30 5 11 11 27 49.6 120 11 11.9 Nangalao (N side) no fish, island is DCA 31 15 57 11 24 50.2 120 08 22.2 Nanga Island (N side) high richness, low abundance, good corals 32 5 11 11 23 26.1 120 05 58.3 Cabunlawan Island (N side) low abundance, R area 33 10 43 11 23 36.2 120 05 00.5 Cabunlawan Island (N side) 34 11 30 11 30 24.1 119 53 23.9 Patoyo Island (N side) Total Families 36 Total Species 198 mean 29 stdev 13.4655
______CHAPTER II: REEF FISHES 19
Table 9. Occurrence of reef fishes from 34 sampling stations, Linapacan, Palawan, May 2004. Fish categories are: I - indicator species, M - major species, and T - target species.
Station 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 TOTAL Family Species Category Acanthurus Acanthuridae xanthopterus T * * 2 Acanthuridae Ctenochaetus binotatus T * * * 3 Acanthuridae Ctenochaetus striatus T * * * * * * * * * * * * 12 Acanthuridae Naso lituratus T * * 2 Acanthuridae Naso thynnoides T * 1 Acanthuridae Naso unicornis T * 1 Acanthuridae Zebrasoma scopas M * * 2 Acanthuridae Zebrasoma veliferum T * 1 Apogonidae Apogon bandanensis M * 1 Apogonidae Apogon sp. M * * 2 Apogonidae Archamia zosterophora M * 1 Cheilodipterus Apogonidae macrodon M * * 2 Cheilodipterus Apogonidae quinquelineatus M * * * * * * * * 8 Balistidae Balistapus undulatus T * 1 Balistidae Pseudobalistes fuscus T * 1 Balistidae Sufflamen chrysopterus T * 1 Blenniidae Atrosalarias fuscus M * * * * 4 Blenniidae Blenny sp. M * 1 Blenniidae Ecsenius bicolor M * * * 3 Blenniidae Meiacanthus grammistes M * 1 Blenniidae Salarias fasciatus M * 1 Caesionidae Caesio caerulaurea T * 1 Caesionidae Caesio teres T * 1 Carangidae Carangoides ferdau T * * 2 Carangidae Decapterus sp. T * 1
______CHAPTER II: REEF FISHES 20 Table 9 continued . . . Carangidae Gnathanodon speciosus T * 1 Centriscidae Aeoliscus strigatus I * * 2 Chaetodontidae Chaetodon adiergastos I * 1 Chaetodontidae Chaetodon auriga I * * * * * * 6 Chaetodontidae Chaetodon baronessa I * * * 3 Chaetodontidae Chaetodon kleinii I * 1 Chaetodontidae Chaetodon lunula I * * 2 Chaetodontidae Chaetodon melannotus I * 1 Chaetodontidae Chaetodon octofasciatus I * * * * * * * * 8 Chaetodontidae Chaetodon plebeius I * 1 Chaetodontidae Chaetodon rafflesii I * 1 Chaetodontidae Chaetodon trifascialis I * 1 Chaetodontidae Chaetodon trifasciatus I * * * 3 Chaetodontidae Chaetodon vagabundus I * 1 Chaetodontidae Chelmon rostratus I * * * 3 Chaetodontidae Coradion chrysozonus I * 1 Chaetodontidae Heniochus chrysostomus I * 1 Chaetodontidae Heniochus singularis I * * 2 Chaetodontidae Heniochus varius I * * 2 Dasyatidae Dasyatis kuhlii T * 1 Engraulidae Spratelloides sp. T * * * * * * * * * * * * * 13 Ephippidae Platax pinnatus T * 1 Fistulariidae Fistularia commersonii T * * 2 Gobiidae sp. (white goby) M * 1 Gobiidae Stenogobius sp. M * 1 Holocentridae Sargocentron rubrum T * * 2 Kyphosidae Kyphosus cinerascens T * 1 Anampses Labridae caeruleopunctatus M * 1 Labridae Anampses geographicus M * * 2 Labridae Bodianus mesothorax M * * 2
______CHAPTER II: REEF FISHES 21 Table 9 continued . . . Labridae Cheilinus chlorourus T * * * * * * * * 8 Labridae Cheilinus fasciatus T * 1 Labridae Cheilinus trilobatus T * * * * * * * * * * * * * * * * * * 18 Labridae Cheilio inermis T * * 2 Labridae Choerodon anchorago T * * * * * * * * * * * * 12 Cirrhilabrus Labridae cyanopleura M * * * * * * * * * 9 Labridae Coris batuensis M * * * * 4 Labridae Coris gaimard T * 1 Diproctacanthus Labridae xanthurus I * * * * * * * * * * * 11 Labridae Epibulus insidiator T * ** * * * * 7 Labridae Gomphosus caeruleus M * * * 3 Halichoeres Labridae chloropterus M * * * * * * * * * * * * 12 Labridae Halichoeres hortulanus M * * * 3 Labridae Halichoeres leucurus M * * 2 Labridae Halichoeres marginatus M * 1 Labridae Halichoeres melanochir M * * * 3 Labridae Halichoeres melanurus M * * * * * * * * * * * * * 13 Labridae Halichoeres nebulosus M * * * * * * 6 Labridae Halichoeres sp. M * * * 3 Labridae Hemigymnus fasciatus T * ** * * 5 Labridae Hemigymnus melapterus T * * * * * * * * * * * * * * * * * 17 Labridae Hologymnosus doliatus M * 1 Labridae Labrichthys unilineatus I * 1 Labridae Labroides dimidiatus M * * * * * * * * * * * * * * * * * * * 19 Macropharyngodon Labridae meleagris M * * 2 Labridae Oxycheilinus digrammus T * ** * * * * 7 Oxycheilinus Labridae unifasciatus T * * * * 4 Labridae Stethojulis bandanensis M * 1 Labridae Stethojulis strigiventer M * ** * * 5 Labridae Stethojulis trilineata T * 1 Labridae Thalassoma hardwicke M * * * * * * * * * 9
______CHAPTER II: REEF FISHES 22 Table 9 continued . . . Labridae Thalassoma lunare M * * * * * * * * * * * * * * * * * * * * * * * * * * 26 Lethrinidae Lethrinus erythropterus T * * * * * * * * * 9 Lethrinidae Lethrinus harak T * 1 Lutjanidae Lutjanus carpanotatus T * * * * * * * * * 9 Lutjanidae Lutjanus decussatus T * * * * * * * * * * * * * * * * * * * * 20 Lutjanidae Lutjanus monostigma T * * * * 4 Monacanthidae Amanses scopas M * * * * * * 6 Pervagor Monacanthidae melanocephalus M * 1 Mulloidichthys Mullidae flavolineatus T * * 2 Parupeneus Mullidae barberinoides T * * 2 Mullidae Parupeneus barberinus T * * * * * 5 Mullidae Parupeneus bifasciatus T * 1 Mullidae Parupeneus cyclostomus T * * 2 Mullidae Parupeneus indicus T * 1 Parupeneus Mullidae multifasciatus T * * * * * * * * * * * * * 13 Muraenidae sp. (red eel) T * 1 Nemipteridae Pentapodus caninus T * * * * * * * * * * * 11 Nemipteridae Pentapodus emeryii T ** * * 4 Nemipteridae Pentapodus trivitattus T * 1 Nemipteridae Scolopsis bilineata T * * * * * * * * * * * * 12 Nemipteridae Scolopsis ciliatus T * 1 Nemipteridae Scolopsis lineatus T * 1 Nemipteridae Scolopsis margaritifer T * * * * * * * * 8 Nemipteridae Scolopsis sp. T * 1 Ostraciidae Ostracion meleagris M * 1 Pempheridae Pempheris oualensis M 2 2 Pinguipedidae Parapercis hexophtalma M * * * 3 Plotosidae Plotosus lineatus M * * 2 Pomacanthidae Centropyge vrolikii M * * 2 Chaetodontoplus Pomacanthidae mesoleucus M * * * * * * * * * * * * * * 14 Pomacanthus Pomacanthidae semicirculatus M * 1 Pomacanthidae Pomacanthus sexstriatus M ** * * 4
______CHAPTER II: REEF FISHES 23 Table 9 continued . . . Pomacentridae Abudefduf lorenzi M * 1 Pomacentridae Abudefduf sexfasciatus M * * * * * * * 7 Pomacentridae Abudefduf vaigiensis M * * * 3 Acanthochromis Pomacentridae polyacanthus M * * * * * * * * * * * * * * * * * * * * * * * * * 25 Amblyglyphidodon Pomacentridae curacao M * * * * * * * * * * * * * * * * 16 Amblyglyphidodon Pomacentridae leucogaster M * * 2 Amblyglyphidodon Pomacentridae ternatensis M * * ** * * 6 Pomacentridae Amphiprion clarkii M * * * 3 Pomacentridae Amphiprion frenatus M * * 2 Amphiprion Pomacentridae sandaracinos M * 1 Pomacentridae Chromis amboinensis M * 1 Pomacentridae Chromis margaritifer M * 1 Pomacentridae Chromis ternatensis I * 1 Pomacentridae Chromis viridis M * * * * * 5 Pomacentridae Chromis weberi M * * 2 Pomacentridae Chrysiptera parasema M * * * * 4 Pomacentridae Chrysiptera rex M * * * * * * 6 Pomacentridae Chrysiptera talboti M * * 2 Pomacentridae Chrysiptera unimaculata M * * * * * 5 Pomacentridae Dascyllus aruanus M * * * 3 Pomacentridae Dascyllus reticulatus M * * * * 4 Pomacentridae Dascyllus trimaculatus M * * 2 Pomacentridae Dischistodus melanotus M * * * * * * * * 8 Dischistodus Pomacentridae perspicillatus M * * * 3 Dischistodus Pomacentridae prosopotaenia M * * * 3 Pomacentridae Neoglyphidodon melas M * * * * * * * * * * * * * 13 Neoglyphidodon Pomacentridae nigroris M * * * * * * * * * * * * * * * * * * * * * * 22 Neoglyphidodon Pomacentridae oxyodon M * 1 Plectroglyphidodon Pomacentridae lacrymatus M * * * * * * * * * * * * * * * * * * * * * * 22 Pomacentrus Pomacentridae alexanderae M * * * * * * * * * 9
______CHAPTER II: REEF FISHES 24 Table 9 continued . . . Pomacentrus Pomacentridae amboinensis M * * * * * * * * * * * * * * 14 Pomacentridae Pomacentrus brachialis M * 1 Pomacentridae Pomacentrus burroughi M * * * * * * 6 Pomacentridae Pomacentrus caeruleus M * 1 Pomacentridae Pomacentrus chrysurus M * * * * * * * 7 Pomacentridae Pomacentrus coelestis M * * * * * * * * * * * * * 13 Pomacentrus Pomacentridae lepidogenys M * * * * * * * * * * * * * * * * 16 Pomacentrus Pomacentridae moluccensis M * * * * * * * * * * * * * * * * * * * 19 Pomacentridae Pomacentrus philippinus M * * * * * * * * * * * 11 Pomacentridae Pomacentrus simsiang M * * 2 Pomacentridae Pomacentrus stigma M * * * * 4 Pomacentridae Premnas biaculeatus M * 1 Pomacentridae Stegastes sp. M * * * 3 Labracinus Pseudochromidae cyclophthalmus M * * * * * * * * 8 Labracinus Pseudochromidae melanotaenia M * * * * * * * * 8 Labracinus Pseudochromidae melocephalus M * 1 Scaridae Cetoscarus bicolor T * 1 Scaridae Chlorurus bleekeri T * * * * * * * * 8 Scaridae Hipposcarus longiceps T * * * * * * * * * * * * * * * * * * 18 Scaridae Scarus chameleon T * * 2 Scaridae Scarus dimidiatus T * * * * * * * * * * * 11 Scaridae Scarus forsteni T * * * * * * * * * * * * * * 14 Scaridae Scarus ghobban T * * * * * * * * * * 10 Scaridae Scarus hypselopterus T * * * 3 Scaridae Scarus niger T * * * * * * * * * * * * * * * * * * * * 20 Scaridae Scarus quoyi T * * ** ** * * * 9 Scaridae Scarus schlegeli T * * * * * * * * * * * * * * * * * 17 Scaridae Scarus sordidus T * * * * * * * * * * * * 12 Scaridae Scarus sp. T * * 2 Scaridae Scarus spinus T * * * * 4 Serranidae Cephalopholis boenak T * * 2
______CHAPTER II: REEF FISHES 25 Table 9 continued . . . Cephalopholis Serranidae cyanostigma T * * * * * 5 Cephalopholis Serranidae microprion T * * * 3 Serranidae Diploprion bifasciatum M * * * * * * 6 Serranidae Epinephelus fasciatus T * 1 Epinephelus Serranidae fuscoguttatus T * 1 Serranidae Plectropomus leopardus T * * * 3 Serranidae Pseudanthias huchtii M * * 2 Siganidae Siganus corallinus T * 1 Siganidae Siganus fuscescens T * 1 Siganidae Siganus stellatus T * * 2 Siganidae Siganus unimaculatus T * 1 Siganidae Siganus virgatus T * * * * * * * * * * * 11 Siganidae Siganus vulpinus T * * * * * * * * * * 10 Sphyraenidae Sphyraena barracuda T * 1 Sphyraenidae Sphyraena flavicauda T * * * 3 Synodontidae Synodus variegatus T * * 2 Tetraodontidae Arothron nigropunctatus M * * * 3 Zanclidae Zanclus cornutus M * * * * * 5
4 3 3 4 4 3 3 2 2 TOTAL 1 8 0 9 3 5 9 2 7 40 35 28 21 14 68 29 16 16 18 28 16 16 18 15 18 29 19 34 25 11 57 11 43 30 979
______CHAPTER II: REEF FISHES 26 Table 10. Number of Indicator, Major, and Target Species from 34 Sampling Stations, Linapacan, Palawan, May 2004
Station indicator major target Total Rank 15 4 38 26 68 1 31 3 34 20 57 2 4 3 30 16 49 3 5 3 20 20 43 4 33 1 24 18 43 4 1 1 25 15 41 5 10 1 23 16 40 6 7 2 17 20 39 7 2 3 23 12 38 8 6 4 15 16 35 9 11 6 11 18 35 9 28 2 19 13 34 10 3 2 13 15 30 11 34 2 18 10 30 11 16 17 12 29 12 26 1 13 15 29 12 12 2 13 13 28 13 20 1 14 13 28 13 9 2 15 10 27 14 29 13 12 25 15 8 1 12 9 22 16 13 1 8 12 21 17 27 13 6 19 18 19 1 6 11 18 19 23 9 9 18 19 25 9 9 18 19 17 7 9 16 20 18 2 8 6 16 20 21 1 8 7 16 20 22 7 9 16 20 24 5 10 15 21 14 2 6 6 14 22 30 2 5 4 11 23 32 7 4 11 23 Total Indicators 21 Total Majors 94 Total Targets 83
______CHAPTER II: REEF FISHES 27 Species richness among the 34 stations ranged from 11 to 68 species 250 per m2 with a mean of 29 (±13) species 250 per m2. Species richness varied between stations but the degree of differences was not great. Stations 30 – Nangalao and 32 – Cabunlawan Island in the far eastern group of islands of Linapacan had the lowest species richness with only 11 species 250 per m2 each ( Figure 4). These sites were characterized with dominant covers of dead corals and rubbles. In contrast, Station 15 – Malubutlubut in the northwest regions of the municipality had the highest species richness of 68 species 250 per m2 (Figure 4). The fish assemblage at this station was dominated by damselfishes such as Abudefduf sexfasciatus, Acanthochromis polyacanthus, Pomacentrus alexanderae, and the wrasse Cirrilabrus cyanopleura (Table 9). Several large individuals of the grouper Cephalopholis cyanostigma were also observed at this stations (Table 9).
10.0 DISCUSSIONS
The low species richness observed in most of the sampling stations around Linapacan suggested that the fish communities in the area might be in relatively poor condition. The fish communities were well represented in terms of the trophic guilds but not in terms of species variety. Target fishes were relatively small, few and of low commercial value such as parrotfishes (Table 9). It is highly likely that the reef fish communities in the area are under high fishing pressure in many sites in Linapacan. The status of the reef fishes in the area should set the bases for the implementation of some forms of protective management of the fishes and their habitats in order to allow the resource to recover in the area.
Considering species richness as the criterion, at least 3 sites were identified as potential core zones for reef fishes. Stations 15 – Malubutglubut at the northwestern group of islands, Station 31 – Nangalao Island in the far eastern group of islands, and Station 4 – Bulawi at the western section of the mainland had some of the highest species richness at 68, 57 and 49 species 250 per m2, respectively. These three sites are geographically isolated from each other (Figure 5). As such, impacts and benefits that protective management may have on the resource may not be appreciated immediately. It is therefore recommended that several sites be protected to form a “network” of marine reserves (Ballantine, 1994, 1995 and 1998).
11.0 CONCLUSIONS AND RECOMMENDATIONS
The reef fishes of Linapacan are in relatively poor condition. From the 34 sampling stations surveyed, at least three (3) were identified as potential core zones. These stations are geographically isolated from each other. Hence, the prospect of establishing several protected areas that may constitute a “network” of marine reserves is forwarded. Such a “network” may prove to be an effective strategy that will enhance the status of fish species richness, abundance and standing stock biomass in Linapacan.
It is recommended that a detailed assessment of these three (3) sites be conducted to generate more information on the status and condition of the fish communities and their habitat.
______CHAPTER II: REEF FISHES 28 It is also suggested that the same detailed assessment be conducted in other areas of special interest (i.e. high live hard coral cover) in order to find other potential core zone candidates. These detailed assessments of other sites of special interest may become the bases for the establishment of additional core zones to form the “network” of protected areas.
N
Figure 5. Potential reef fish core zones, Linapacan, Palawan, May 2004.
______CHAPTER II: REEF FISHES 29 CHAPTER III SEAGRASSES AND SEAWEEDS
12.0 INTRODUCTION
Seagrasses (locally called ‘lusay’ or ‘baryaw-baryaw’) are marine angiosperms that posses true roots, stems and leaves (Fortes, 1981), and produce flowers, fruits and seeds during certain seasons (Fortes, 1990). Adaptability to estuarine or marine environments enables seagrasses to colonize large intertidal and subtidal zones of coastal areas. They usually flourish in areas between mangrove forests and coral reefs (Meñes et al., 1983). Most of the time they are found near mangrove areas where nutrient is very much available. Sixteen species of seagrasses have been reported to occur in the Philippines (Fortes, 1990).
Seaweeds, on the other hand, are macroscopic marine algae found throughout the photic zone. Algae attach themselves via holdfasts to boulders, cobbles, fine sand, clay, mud, or even to corals and larger seaweed species (Fortes, 1981). Algae can thrive in seagrass meadows (Fortes, 1990) or they can be found in highly disturbed reef fringes (Trono and Biña, 1987).
Seagrasses and seaweeds are important habitat components of Linapacan’s coastline. However, seaweeds are not as dominant as seagrassses as they cover only a small portion of the seagrass beds in the area.
Seagrasses are nursery grounds and permanent habitats for certain fishes and economically important invertebrates, e.g., siganids, shrimps, sea cucumbers, sea urchins and shellfishes. Like mangroves, seagrasses hold sediment, which prevents siltation to corals. Nutrients, specifically carbon and nitrogen, are produced by seagrasses for the consumption of nearby coral reef communities. Seagrass is an important habitat and virtually the only food of the dugong (Dugon dugon), preferring the carbohydrate-rich underground storage roots (rhizomes) of the smaller seagrass species (Bateman, 1984 as cited in ERTL, 1995). It is also the principal food of the green turtle (Chelonia mydas). Both animals are still breeding abundantly in northern Palawan. On a worldwide scale, seagrasses influence global budget of carbon. Smith (1981) estimated that marine macrophytes (seagrasses and seaweeds) impact the global C budget by sequestering as much as 109 tons of carbon per year.
Thus, this study is an important step in making a comprehensive inventory (mapping and identification) of the seagrass communities in Linapacan to catalogue the extent and location of the resource, and identify areas in need for protection before this very important resource will be lost.
This report summarizes the results of the baseline survey of seagrass-seaweed resources in the municipal waters of Linapacan. Their species composition, percent cover and spatial distribution are presented.
______CHAPTER III: SEAGRASS AND SEAWEEDS 30 13.0 MATERIALS AND METHODS
Reconnaissance survey was conducted on the coastline around Linapacan mainland and at three (3) distant small islands to the north and 1 far distant small island to the east. Prior to this survey, interviews were also conducted to gather information from barangay officials/local residents in consultation with the locally hired boat operator/guide familiar with the area as to the locations of seagrass beds. Unfortunately, none of the small islands/islets on the western and southern side off Linapacan mainland were surveyed because of time constraint. The inclement weather and sea conditions frequently encountered during the entire duration of the survey also contributed to this limitation.
Figure 6 shows the coastline surveyed and the locations of the specific sampling sites. All the 23 stations sampled during the survey are listed in Table 11, which also indicates their locations and coordinates, number of plots sampled, bed width, and types of substrate and coastal vegetation. A GPS was used to record actual positions of seagrass beds observed and sampling stations established.
The transect-quadrat sampling method (perpendicular to the shore on a 10 m2 plot) for baseline assessment of study sites for ECAN priority areas was applied in this survey. However, a modification was employed, instead of placing the 10 m2 plot along the imaginary transect for every 10 meters interval, observations were made at interval of 50 meters. The 10 meters interval was found time consuming, hence, the whole study area could not be surveyed within the given time frame taking into consideration the distance between islands, the number of islands involved, the length of the coastline, and the inclement weather and sea conditions prevailing in the area.
The first designated plot was assigned to the shallowest area where seagrass was found, while the next plot (second plot) was designated after swimming with 50-fin stroke (approximated as 50 meters). At each plot, the percentage bottom cover of seagrasses (from the categories in SeagrassNet, Short et al., 2002) and species composition were determined. Seaweeds, since they were observed to occur only in a small portion of the seagrass bed were qualitatively described as to rare, occasional, common and abundant. Likewise, seaweeds had a very patchy distribution. The other parameters obtained from each plot/imaginary transect location and along the vicinity of the sampling site to describe the seagrass habitat were: substrate type, feeding craters of dugongs, presence of conspicuous macroinvertebrates and types of coastal vegetations. Anthropogenic-related activities or disturbances prevailing in the area (“kaingin”, mangrove cutting, fishing/mariculture practices) were also noted. Site features were photo documented whenever possible.
______CHAPTER III: SEAGRASS AND SEAWEEDS 31
Figure 6. Coastline surveyed and sampling stations established for the seagrass-seaweed study in Linapacan, Palawan 30 May-03 June 2004.
______CHAPTER III: SEAGRASS AND SEAWEEDS 32
Table 11. Sampling stations data for the baseline survey of seagrass-seaweeds in the municipality of Linapacan, northern Palawan, 30 May- 03 June 2004. Legend: nplot= number of plots sampled; ( * ) = perpendicular distance from shore to seaward edge; S = Sandy; S-M = Sandy-Muddy; S-C = Sandy- Coralline; S-R= Sandy-Rocky.
Location Position Approx. Substrate Coastal Area/Bay Barangay/Island (Station Name) Station Lat. N Long. E nplot Bed Width* Type Vegetation (m) Northwest Bay Maroyogroyog Malatobtob 1 11o28’10.8 119o46’25.0 2 60 S-M/S-C Mangroves Pinagkalangan 2 11o27’32.2 119o46’31.5 2 60 S-M Mangroves Tabkangan 3 11o26’57.2 119o45’55.9 3 100 S-M Mangroves Bayotbot 4 11o26’39.7 119o45’36.1 4 40 S-M Mangroves Lilo 5 11o28’20.1 119o46’00.3 1 300 S-R Old ‘kaingin’ planted with cashew/mango trees North Bay Maroyogroyog Babahalid Channel 6 11o28’21.0 119o47’32.5 7 230 S-R Beach shrubs/mangroves (Babahalid Island) San Miguel Diringuan 1 7 11o28’00.6 119o49’14.3 5 200 S-R Beach shrubs Diringuan 2 8 11o27’48.7 119o49’26.1 5 200 S-R Beach shrubs/mangroves Diringuan 3 9 11o27’56.1 119o49’46.7 4 150 S Beach shrubs/mangroves Northeast Side San Miguel Ditinglan 10 11o30’35.0 119o51’17.6 5 200 S Mangroves/beach shrubs San Miguel Poblacion 11 11o29’45.4 119o52’14.9 5 200 S/S-M Breakwater West Side San Miguel Sitio Pula 12 11o26’07.4 119o51’04.3 5 200 S-M Mangroves South Bay San Nicolas Tondaje Island SE 13 11o23’17.8 119o48’24.8 2 50 S-M Mangroves San Nicolas Poblacion 14 11o23’42.0 119o48’39.9 2 50 S-M Mangroves Octon Island W 15 11o24’14.6 119o48’36.4 2 50 S-M Mangroves South Bay Cove 16 11o25’02.0 119o48’18.5 2 50 S-M Mangroves Southwest Side New Colaylayan New Colaylayan Poblacion 17 11o25’14.9 119o45’31.7 4 150 S Beach shrubs/mangroves West Side Colaylayan Colaylayan 18 11o26’36.8 119o43’54.7 2 50 S-M Mangroves San Pedro Balanben 19 11o27’34.5 119o43’13.2 2 50 S Mangroves Northeast Side San Miguel Lalanan 20 11o30’28.2 119o51’48.2 6 250 S/S-C Beach shrubs Cabunlauan Cabunlauan Island Cabunlauan Island NW 21 11o23’28.9 120o04’58.5 4 150 S Beach shrubs Islands Cabunlauan Island Poblacion 22 11o23’20.7 120o05’35.0 3 100 S Beach shrubs Linapacan Strait Binalabag Island Binalabag Island W 23 11o34’58.8 119o55’30.2 4 150 S/S-M Beach shrubs
______CHAPTER III: SEAGRASS AND SEAWEEDS 33 14.0 RESULTS
14.1 Spatial Distribution and Use of Seagrass Habitat
Figure 7 shows the coastline surveyed having seagrass beds based from the plotted GPS readings taken during the reconnaissance survey.
The seagrass beds were found in association with the presence of mangroves (15 out of 23 stations surveyed, see Table 11) and coral reefs. Their distribution is mainly along the numerous coves of the Linapacan mainland: 1. San Miguel – West coast in Diringuan (mixed species) and a small cove in front of Binipitan Island (pure stands of Enhalus acoroides); northeast coast in Ditingilan, Lalanan and San Miguel Poblacion (breakwater and pier, Plates 1 and 2); and east coast in Pula Bay (mixed species)
Plate 1. Seagrass beds at low tide in Station 11- San Miguel Poblacion
Plate 2 Seagrass beds at low tide near pier in San Miguel Poblacion showing “sand volcanoes”, a common feature of sandy bottoms in Linapacan. No one has yet succeeded in digging out the inhabitants of these volcanoes. A likely candidate, however, is a ghost shrimp .
______CHAPTER III: SEAGRASS AND SEAWEEDS 34
Figure 7. Coastline surveyed having seagrass beds in Linapacan, Palawan, 30 May-03 June, 2004
______CHAPTER III: SEAGRASS AND SEAWEEDS 35 2. Maroyogroyog- Northwest coast in Babahalid and Lilo (mixed species), Malatobtob, Pinagkalangan, Tabkangan, Bayotbot (dominated by Enhalus acoroides), and Balanben (mixed species)
3. Colaylayan – Southwest coast in Colaylayan Bay (pure stands of Enhalus acoroides) and New Colaylayan Poblacion (mixed species)
4. San Nicolas- South coast, virtually the entire coast along South Bay is dominated in particular by Enhalus acoroides or pure stands.
In addition, seagrass beds were found at two specific locations along the western and southern coasts of Binalabag Island (mixed species), and along the entire northern coast of Cabunlauan Island (mixed species) (see Figure 7).
The ocular survey around the coast of Dimancal and Arigara Islands located north of Linapacan mainland showed the total absence of seagrass beds. The substrate was composed of rocks/boulders, long dead corals, rubbles and sand colonized by tall stands of brown alga Sargassum.
Along some of these seagrass beds, the dominant type of fishing gear being employed is fish corral or “baklad”. Grouper fattening using fish cage was also noted. Fish corrals exist in Barangay San Nicolas while a number of fish cages are present in New Colaylayan Poblacion. Small-scale seaweed Eucheuma/Kappaphycus farming is also present on coral reefs adjacent to seagrass beds. Pearl culture (Hikari) farms are found in the sheltered coves of San Miguel and Maroyogroyog (Plate 3).
Plate 3. Pearl culture farms along the sheltered cove in Northwest Bay (Sitio Tabkangan, Maroyogroyog).
There are also some pebble mining activities along the coastal beaches of Diringuan (San Miguel) and Manlilic (Maroyogroyog, Plate 4) (Figure 8). However, mangroves, seagrass beds and coral reefs are entirely absent from the shore in front of the pebble mining area in Manlilic, only dense stands of the brown alga Sargassum are found.
______CHAPTER III: SEAGRASS AND SEAWEEDS 36
Figure 8 Locations of fish corrals, fish cages, pearl culture farms, seaweed farms and pebble mining seen during the survey in Linapacan, 30 May-03 June 2004.
______CHAPTER III: SEAGRASS AND SEAWEEDS 37
ab
c d Plate 4. Pebble mining along the beach of Sitio Manlilic, Maroyogroyog
Dugong graze marks (Plate 5) were found at Station 5- Lilo (Maroyogroyog), indicating that this site is a feeding area of such endangered mammal.
Plate 5. Feeding scar (graze mark) probably from dugong at Station 51-Lilo, Maroyogroyog
______CHAPTER III: SEAGRASS AND SEAWEEDS 38 14.2 Species Composition and Occurrence
The species composition and occurrence of seagrasses observed on each sampling station are presented in Table 12. Nine species of seagrasses have so far been identified from the 23 study sites.
Among the 9 seagrasses species observed, Enhalus acoroides was the most frequently encountered species (21 out of 23 sites), followed by Cymodocea serrulata (18 sites), Cymodocea rotundata (16 sites), Thalassia hemprichii (14 sites), Halophila ovalis (Plate 6, 12 sites), Halodule pinifolia (Plate 7, 11 sites), and Halodule uninervis (10 sites). The least frequently encountered species were Syringodium isoetifolium (5 sites) and Thalassodendron ciliatum (only I site). Thalassodendron ciliatum, a rare species was however observed outside of the imaginary transect location surveyed (Station 9 – Diringuan 3, Plate 8), thus, data on percent cover were not collected. Likewise, only one colony of the same species was found despite great effort to look for other colonies near the vicinity.
Plate 6. Sand bottom, which is covered with growth of Halophila ovalis.
Plate 7. Sand bottom, which is covered with growth of Halodule pinifolia (Station 12- Sitio Pula, San Miguel).
______CHAPTER III: SEAGRASS AND SEAWEEDS 39
Table 12. Seagrass species composition and occurrence for the baseline survey of seagrass-seaweeds in the municipality of Linapacan, northern Palawan, 30 May- 03 June 2004. Legend: nspecies= number of species; CYRO= Cymodocea rotundata, CYSE= Cymodocea serrulata, ENHA= Enhalus acoroides, HPIN= Halodule pinifolia, HOVA= Halophila ovalis, HUNI= Halodule uninervis, SYRI= Syringodium isoetifolium, THALI= Thalassia hemprichii, TACIL= Thalassodendron ciliatum.
Location Area/Bay Barangay/Island (Station Name) Station nspecies CYRO CYSE ENHA HPIN HOVA HUNI SYRI THALI
Northwest Bay Maroyogroyog Malatobtob 1 4 X X X X Pinagkalangan 2 3 X X X Tabkangan 3 4 X X X X Bayotbot 4 3 X X X Lilo 5 6 X X X X X X North Bay Maroyogroyog Babahalid Channel 6 8 X X X X X X X X San Miguel Diringuan 1 7 6 X X X X X X Diringuan 2 8 6 X X X X X X Diringuan 3 9 8 X X X X X X X X Northeast Side San Miguel Ditinglan 10 7 X X X X X X X San Miguel Poblacion 11 7 X X X X X X X West Side San Miguel Sitio Pula 12 7 X X X X X X X South Bay San Nicolas Tondaje Island SE 13 5 X X X X X San Nicolas Poblacion 14 1 X Octon Island W 15 1 X South Bay Cove 16 4 X X X X Southwest Side New Colaylayan New Colaylayan Poblacion 17 5 X X X X X West Side Colaylayan Colaylayan 18 1 X San Pedro Balanben 19 4 X X X X Northeast Side San Miguel Lalanan 20 4 X X X X Cabunlauan Cabunlauan Island Cabunlauan Island NW 21 4 X X X X Islands Cabunlauan Island Poblacion 22 6 X X X X X X Linapacan Strait Binalabag Island Binalabag Island W 23 4 X X X X
______CHAPTER III: SEAGRASS AND SEAWEEDS 40
Plate 8. Mixed species of Cymodocea rotundata- Cymodocea serrulata-Halodule pinifolia (left) and a monospecific colony of Thalassodendron ciliatum (right) (Station 9- Diringuan 3, San Miguel)
Of the 23 study sites, Diringuan three (3) had the most diverse seagrass bed, having eight (8) identified species, followed by Ditinglan, San Miguel Poblacion and Sitio Pula having seven (7) identified species each. The least diverse was observed in San Nicolas Poblacion, Octon Island W and Colaylayan having pure stands of Enhalus acoroides. These areas were characterized by sandy-muddy substrate and very close to the mangroves. Similarly, Pinagkalangan and Bayotbot recorded a total of only three (3) species each (mixed stands of Enhalus acoroides-Thalassia hemprichii-Halophila ovalis species and Enhalus acoroides-Thalassia hemprichii-Cymodocea serrulata species, respectively).
14.3 Percentage Seagrass Cover
In terms of percent substrate cover, on the average, Enhalus acoroides (Plates 9 and 10) coverage was found to be the most dominant on the seagrass beds with 47% (Table 13 and Figure 9), followed by Cymodocea serrulata (Plate 11), Thalassia hemprichii and Cymodocea rotundata (Plate 12) with 37%, 34% and 30%, respectively.
Plate 9. Sand bottom, which is covered with growth of Enhalus acoroides. At the center is a growth of the seagrass Halophila ovalis (Station 17- New Colaylayan Poblacion).
______CHAPTER III: SEAGRASS AND SEAWEEDS 41
Plate 10. Mixed species of Enhalus acoroides and Syringodium isoetifolium (Cabunlauan Island).
Plate 11. Growth of the seagrass Cymodocea serrulata with “sand volcanoes” Cabunlauan Island).
Plate 12. Mixed sand and rock bottom in the subtidal shallows. The sand supports a growth of the seagrass Cymodocea rotundata (Station 6- Babahalid Channel,Maroyogroyog).
______CHAPTER III: SEAGRASS AND SEAWEEDS 42 Table 13. Percentage bottom cover of the species of seagrasses for the baseline survey in the municipality of Linapacan, northern Palawan, 30 May – 03 June 2004. Legend: n-plot = number of plots; CYRO= Cymodocea rotundata, CYSE= Cymodocea serrulata, ENHA= Enhalus acoroides, HPIN= Halodule pinifolia, HOVA= Halophila ovalis, HUNI= Halodule uninervis, SYRI= Syringodium isoetifolium, THALI= Thalassia hemprichii.
Location Area/Bay Barangay/Island (Station Name) Station CYRO CYSE ENHA HPIN HOVA HUNI SYRI THALI
Northwest Bay Maroyogroyog Malatobtob 1 40 85 20 10 Pinagkalangan 2 83 9 35 Tabkangan 3 42 10 8 60 Bayotbot 4 40 83 50 Lilo 5 20 46 46 9 36 32 North Bay Maroyogroyog Babahalid Channel 6 36 40 7 7 16 16 29 10 San Miguel Diringuan 1 7 60 50 20 30 10 30 Diringuan 2 8 20 20 65 5 5 10 Diringuan 3 9 32 38 13 20 20 5 23 Northeast Side San Miguel Ditinglan 10 70 28 33 50 5 50 40 San Miguel Poblacion 11 18 5 58 12 5 20 10 West Side San Miguel Sitio Pula 12 10 53 25 40 5 23 10 South Bay San Nicolas Tondaje Island SE 13 20 40 15 5 20 San Nicolas Poblacion 14 100 Octon Island W 15 100 South Bay Cove 16 10 20 60 10 Southwest Side New Colaylayan New Colaylayan Poblacion 17 78 70 15 5 25 West Side Colaylayan Colaylayan 18 100 San Pedro Balanben 19 20 60 10 10 Northeast Side San Miguel Lalanan 20 24 64 10 40 Cabunlauan Islands Cabunlauan Island Cabunlauan Island NW 21 25 33 15 30 Cabunlauan Island Poblacion 22 20 40 10 5 10 53 Linapacan Strait Binalabag Island Binalabag Island W 23 23 23 13 90 Total 486 670 980 204 112 192 128 480 Mean Bottom Cover (%) 30.38 37.22 46.66 18.54 9.33 19.20 25.60 34.28 Mean Relative Cover (%) 14.94 20.60 30.14 6.27 3.44 5.90 3.94 14.76
______CHAPTER III: SEAGRASS AND SEAWEEDS 43 50 45 40 35 30 25 20
Percentage 15 10 5 0 CYRO CYSE ENHA HPIN HOVA HUNI SYRI THALI
Species
Cover (%) Relative Cover (%) Figure 9. Percentage cover of seagrass species in Linapacan, 30 May - 03 June 2004.
The seagrass beds surveyed at Cabunlauan Island Poblacion (Stn 22) and Cabunlauan Island NW (Stn 21) showed the highest substrate cover at 80% and 75%, respectively (see Figure 10, Plates 10 and 11)) under the excellent category (Figure 11). The next highest was observed in San Miguel Poblacion at 70% (see Plate 1), then followed by Lilo (65%, see Plate 5), Bayotbot (64%), Sitio Pula (63%), San Nicolas Poblacion (60%), Octon Island W (60%), South Bay Cove (60%) and Tabkangan (52%) under the good category.
The lowest seagrass cover was observed in Colaylayan and Binalabag Island W at 20% and 17%, respectively under the poor category. All the remaining 11 seagrass stations have cover ranging from 31% to 48% under the fair category (see Figures 10 and 11).
100 90 80 70 60 50
Percentage 40
30 20 10 0 1 2 3 4 5 6 7 8 9 1011121314151617181920212223 Stations
Figure 10. Percentage Cover of Seagrasses at Each Sampling Station Linapacan, 30 May - 03 June 2004.
______CHAPTER III: SEAGRASS AND SEAWEEDS 44
Figure 11. Percentage Seagrass Cover and Seagrass Beds Condition, Linapacan, 30 May – 03 June 2005
______5. . CHAPTER III: SEAGRASS AND SEAWEEDS 45 14.4 Associated Seaweeds and Macroinvertebrates
The species composition, occurrence and abundance of seaweeds at each of the seagrass sampling stations are presented in Table 14. Abundance has been noted qualitatively as rare, occasional, common and abundant. Seaweeds were seen interspersed with seagrass in most of the study sites. Nineteen seaweed species were found in the whole study area and represented by 9 species from the Chlorophyta (the greens such as Caulerpa taxifolia, Caulerpa serrulata, Caulerpa racemosa, Halimeda macroloba, Halimeda opuntia, Colpomenia sinuosa, Udotea orientalis, Codium sp., and Avrainvillea erecta), 6 species from Phaeophyta (the browns such as Padina australis, Padina japonica, Sargassum oligocystum, Sargassum sp., Dictyota sp., and Hydroclathrus clathratus) and 4 from Rhodophyta (the reds represented by Halymenia sp., Laurencia papillosa, Laurencia sp., and Galaxaura sp.).
In most of the seagrass beds surveyed, the brown pigmented alga Sargassum was the most common seaweeds encountered in 14 out of 23 surveyed sites, usually as common (Sargassum sp.) and abundant (Sargassum oligocystum) (see Table 14), most occurring at the seaward edge of the seagrass bed (end of the transect, Plate 13) near the reef. They were found attached to rocks, rubbles and dead coral substrate. Likewise, thick stands of Sargassum were also observed on the shallower sections of the intertidal reef flats, which included dead reef surfaces and living coral colonies. The brown alga Padina (Plate 14) was the next most common seaweeds found in the seagrass areas surveyed. In one instance, net like appearance brown alga Hydroclathrus clathratus, an indicator of abnormal nutrient loading was found at Station 12- Sitio Pula.
The green seaweeds of the genera Caulerpa and Halimeda (Plate 15) were also the frequently encountered algal species within the seagrass bed, as a common constituent. Codium sp. was also found but only at Station 19- Balanben, as an occasional constituent while Udotea orientalis was rarely found. The green alga Avrainvillea erectaas an occasional constituent was present at 3 sites.
Red pigmented seaweeds such as Halymenia sp., Galaxaura sp., and Laurencia papillosa were found as a rare constituent at Station 3- Tabkangan, Station Station 5- Lilo and Station 10- Ditinglan, respectively.
In terms of species richness, Station 2- Pinagkalangan recorded the highest seaweed species numbers (10 species), dominated by the greens (2 Caulerpa species, 2 Halimeda species, 1 Colpomenia species, 1 Avrainvillea species) and browns (2 Sargassum species, 2 Padina species). This was followed by Station 5- Lilo, Station 3- Tabkangan, and Station 1- Malatobtob and Station 10- Ditinglan at 9, 8, and 6 species, respectively. Station 18- Colaylayan, Station 21- Cabunlauan Island NW and Station 22- Cabunlauan Island Poblacion had the lowest species richness at 2 species each. Similarly, Stations 13, 14, 15 and 16, all within the South Bay (San Nicolas), had only 3 species each, represented by the green algae Halimeda and Caulerpa and the brown alga Padina. No Sargassum was observed in these seagrass beds.
______CHAPTER III: SEAGRASS AND SEAWEEDS 46 Table 14 Seaweed species and their abundance observed at each of the seagrass sampling stations in Linapacan, 30 May- 03 June 2004.
Area/Bay Barangay/Island Seagrass Site Species of Macroalgae Abundance No. of Remarks Species Encountered
Northwest Bay Maroyogroyog 1. Malatobtob Avrainvillea erecta Occasional 6 No sign of holothurians, commonly Colpomenia sinuosa Common known as the black sea cucumber. Halimeda macroloba Common The long-spined black sea urchin, Halimeda opuntia Common Diadema setosum was abundant. Padina japonica Common Sargassum Abundant oligocystum
2. Pinagkalangan Avrainvillea erecta Occasional 10 No sign of holothuroid sea Caulerpa racemosa Abundant cucumber. The horned sea star, Caulerpa serrulata Common Protoreaster nodosus was abundant Colpomenia sinuosa Common together with Diadema setosum, Halimeda macroloba Common Diadema savignyi, Echinothrix Halimeda opuntia Common calamaris and Tripnuestes gratilla. Padina australis Common The giant clam, Tridacna crocea Padina japonica Common was likewise present. Sargassum sp. Common Sargassum Abundant oligocystum
3. Tabkangan Avrainvillea erecta Occasional 8 No sign of holothuroid sea Caulerpa racemosa Common cucumber. Sea urchins Echinothrix Colpomenia sinuosa Common calamaris and Echinometra mathaei Halimeda macroloba Common were present. Eucheuma seaweed Halimeda opuntia Common farming was noted. Halymenia sp. Rare Padina australis Common Sargassum oligocystum Abundant
______CHAPTER III: SEAGRASS AND SEAWEEDS 47 Table 14 continued . . .
4. Bayotbot Caulerpa racemosa Common 4 No sign of holothuroid sea Caulerpa serrulata Common cucumber. Seashell Strombus Halimeda macroloba Common abundant, while sea anemone was Padina japonica Common common.
5. Lilo Caulerpa taxifolia Common 8 No sign of holothuroid sea Colpomenia sinuosa Common cucumber. Synapta maculata was Galaxaura sp. Rare common. Protoreaster nodosus was Halimeda macroloba Common also common. Common Laurencia sp. Common Padina japonica Rare Udotea orientalis Abundant Sargassum oligocystum
North Bay Maroyogroyog 6. Babahalid Channel Halimeda opuntia Common 4 No sign of holothuroid sea (Babahalid Island) Abundant cucumber. Protoreaster nodosus, Caulerpa racemosa Common Tripneustes gratilla, Echinothrix Padina japonica Common calamaris and Echinometra mathaei Sargassum oligocystum common. Bivalve mollusk Lopha cristagalli and starfish Linckia laevigata were noted. Eucheuma farming was also noted.
San Miguel 7. Diringuan 1 Caulerpa racemosa Common 5 No sign of holothuroid sea Halimeda macroloba Common cucumber. Among the Common invertebrates, only the blue starfish Padina japonica Abundant Linckia laevigata was noted. Sargassum sp. Abundant Sargassum oligocystum
8. Diringuan 2 Halimeda opuntia Common 4 No sign of holothuroid sea Halimeda macroloba Common cucumber. Bivalve mollusk Lopha Caulerpa racemosa Common cristagalli was common. Fishing Sargassum oligocystum Abundant with the used of gill net was noted.
______CHAPTER III: SEAGRASS AND SEAWEEDS 48
Plate 13. End of seagrass bed along the transect with growth of Cymodocea serrulata (foreground) together with a dense stand of brown seaweed Sargassum sp. (background).
Plate 14. Padina sp., a foliose brown alga whose fronds are prettily marked with concentric dark rings of reproductive structures (Station 10- Ditinglan, San Miguel).
______CHAPTER III: SEAGRASS AND SEAWEEDS 49
Plate 15. Sand bottom, which is covered with growth of calcareous green algae Halimeda (foreground) and seagrass Enhalus acoroides (background)
Macroinvertebrates, on the other hand, were found only from few localities. Thirteen species of macroinvertebrates were observed during this survey. The most common macroinvertebrate recorded (in 4 to 7 out of 23 sites, see Table 14) was the blue sea star Linckia laevigata along with the horned sea star Protoreaster nodosus, long-spined black urchin Diadema setosum, the urchin Echinothrix calamaris, the rock-boring urchin Echinometra mathaei, and the urchin Tripneustes gratilla. The highest density of Diadema setosum was noted at Station 11- San Miguel Poblacion.
A gastropod mollusk Strombus sp. (“sikad-sikad”) was observed as abundant in only one location at Station 4- Bayotbot. Sea anemone was also noted as a common constituent on this seagrass bed. Giant clam Tridacna crocea was likewise noted (but not common) from only one site at Station 2- Pinagkalangan. Lopha cristagalli, a bivalve mollusk was found in seagrass beds where the substrate is sandy-rocky (Station 6- Babahalid Channel and Station 8- Diringuan 2) and sandy-muddy (Station 15- Octon Island W and Station 23- Binalabag Island W).
No sea cucumbers (Holothuridae) were encountered in all the seagrass areas surveyed except for the sticky snake sea cucumber Synapta maculata (Synaptidae). This animal was found in only two sites, Station 5- Lilo in which it was common and Station 17- New Colaylayan Poblacion in which it was abundant.
In terms of species richness, Station 2- Pinagkalangan and Station 6- Babahalid Channel (Plate 16), located along the sheltered Northwest Bay (Maroyogroyog), recorded the highest macroinvertebrate species numbers (6 species each). In contrast, macroinvertebrates were found absent at Station 13- Tondaje Island SE, Station 14- San Nicolas Poblacion and Station 16- South Bay, located all along the coastline of San Nicolas (South Bay) in the southern portion of Linapacan mainland.
______CHAPTER III: SEAGRASS AND SEAWEEDS 50
Plate 16. Mixed sand and rock beach at low tide in Station 6- Babahalid Channel. Babahalid Island is in the backgroud (Maroyogroyog).
15.0 DISCUSSIONS
Almost half (47%) of seagrass areas surveyed are in fair condition. Good condition is shared at 35%. On the other hand, excellent condition is shared at only 9% and is spotted at 2 sites in Cabunlauan Island, where seagrass beds are composed of mixed species. Only 2 seagrass areas, Colaylayan and Binalabag Island, are in poor condition (shared at 9%). A pure stands of Enhalus acoroides is found in Colaylayan on sandy-muddy substrate, while Thalassia hemprichii-Cymodocea serrulata-Cymodocea rotundata- Halodule uninervis association thrive in Binalabag Island on sandy/sandy-muddy substrates.
The present survey recorded 9 species of seagrasses belonging to 7 genera. These are Cymodocea serrulata, Cymodocea rotundata, Enhalus acoroides, Thalassia hemprichii, Halophila ovalis, Halodule pinifolia, Halodule uninervis, Syringodium isoetifolium and Thalassodendron ciliatum. The surveyed seagrass beds are usually associated with the mangroves and coral reefs. Thus, these seagrass species found were basically mangroves-corals associates, predominated by Enhalus acoroides or in pure stands mostly found next to a mangrove where the substrate is generally sandy-muddy, or in mixed association with Cymodocea serrulata, Cymodocea rotundata, Halophila ovalis, Syringodium isoetifolium and Halodule uninervis where the substrate is sandy-corraline/sandy-rocky. However, in areas where there are no mangroves (only beach shrubs, for example, in Lalanan, Cabunlauan and Binalabag Islands, see Table 11), Enhalus acoroides is in occasional patches growing together with Cymodocea rotundata, Cymodocea serrulata and Thalassia hemprichii. All species present in Linapacan are also found in other coastal areas in Palawan. However, in this survey, the presence of rare species Thalassodendron ciliatum (see Plate 8) in the area was established in which the plant occurred in sheltered locality at Station 3 – Diringuan 3 (Maroyogroyog). The collected specimen is deposited in the herbarium of PCSD.
______CHAPTER III: SEAGRASS AND SEAWEEDS 51
As to seaweeds, 19 species are found on the seagrass beds surveyed. Survey results indicate substantial growth of brown seaweed Sargassum particularly at the seaward edge of the seagrass bed near the reef. The high occurrence, along with high cover (tall stands) indicates that the seaweed Sargassum may be important to the productivity of the areas surveyed. They may have a substantial role in reducing water energy and regulating flows and may also serve as a habitat together with the seagrasses. Sargassum is already known to provide an important protective habitat (shelter) of juvenile stages of penaeid shrimp from predators (Al Attar, 1981) and probably a food source as well (Vousden, 1988). Sargassum species are known to thrive in relatively harsh environments. Turbulent water conditions favor the growth of Sargassum. They are equipped with discoid holdfasts that allow them to attach to solid substrates preventing them from being dislodged by strong waves. Furthermore, Sargassum species have air bladders that allow them to float and avoid smothering by silt. Sargassum species are commercially important as sources of raw material for the production of alginates, phycocolloids used primarily for food and industrial applications.
The present survey found 13 species of macroinvertebrates. The echinoderms (the blue sea star Linckia laevigata, the horned sea star Protoreaster nodosus, long-spined black urchin Diadema setosum, the urchin Echinothrix calamaris, the rock-boring urchin Echinometra mathaei, the urchin Tripneustes gratilla) are the most important animals in all the seagrass beds. Most of these animals showed preference on the sandy substrate and appear to feed on algae and dead corals (with its contained organisms). The presence of algae on the surface of rocks, rubbles and dead corals and organic detritus on the surfaces of the sand, enables these animals to graze and live abundantly. There are a number of fisheries based on echinoderms, principally sea urchins. When ripe, the gonads of some sea urchins are highly valued as food items in the Orient (Colin and Arneson, 1995). In the Philippines, the sea urchins preferrence is Tripneustes gratilla, although Diadema setosum and Echinothrix diadema are also used if Tripneustes gratilla is not available (Trinidad-Roa, 1989).
The absence of the holothuroids, commonly known as sea cucumbers or beche-de-mer (called “trepang” locally) in this survey, is very unusual since the animals are supposed to be very common in seagrass beds. Sea cucumbers are sedentary marine creatures that belong to the same group as starfish and sea urchins. They are considered as the “earthworms of the sea”. They feed on detritus and turn over to the sea floor as much as the earthworms do on land. Most of the holothuroids feed on the rich organic film that covers sandy surfaces (Allen and Steene, 1998). Sea cucumbers are harvested from wild populations. These are dried and exported to Manila. An unregulated collection of these animals has been observed in Linapacan since even small sea cucumbers (dried) are being sold in the market. The unregulated collection of sea cucumbers greatlty affects the ecosystem and therefore will affect the ecological balance prevailing in the seagrass bed.
______CHAPTER III: SEAGRASS AND SEAWEEDS 52 It was observed in this survey that in some coastline of Linapacan mainland, in particular along sheltered coves in Northwest Bay (Barangay Maroyogroyog, Plates 17, 18, 19), “kaingin” or slash-and burn agriculture and illegal cutting of mangroves (i.e., for charcoal and lumber), are still being practiced which threaten not only the survival of mangroves, but also the associated seagrass beds, coral reefs and fisheries resources.
Plate 17. Old (left) and new (right) “kaingin” along Northwest Bay. Most of the trees along the inner section of the mangrove forest shown in this picture have already been destroyed due to illegal cutting for local construction materials and charcoal making (Maroyogroyog, 30 May 2004).
Plate 18. A close-up view of the new “kaingin” along Northwest Bay (Maroyogroyog, 30 May 2004).
______CHAPTER III: SEAGRASS AND SEAWEEDS 53
Plate 19. Another new “kaingin” along Northwest Bay (Maroyogroyog, 30 May 2004).
16.0 SUMMARY OF FINDINGS
The major findings to be drawn from this study are:
1. There is still a widespread coverage of seagrasses, mainly along numerous sheltered areas of the Linapacan mainland, in association with the presence of mangroves and coral reefs.
2. Seagrass resources in Linapacan are still abundant. Almost half (47%) of seagrass areas surveyed are in fair condition. Good condition is shared at 35%. Excellent condition is shared at 9% in Cabunlauan Island. Only 2 sites, Colaylayan and Binalabag Island, are in poor condition (shared at 9%).
3. The present survey recorded 9 species of seagrasses. These are Cymodocea serrulata, Cymodocea rotundata, Enhalus acoroides, Thalassia hemprichii, Halophila ovalis, Halodule pinifolia, Halodule uninervis, Syringodium isoetifolium and a rare species Thalassodendron ciliatum. Enhalus acoroides is the frequently encountered species, followed by Cymodocea serrulata, Cymodocea rotundata Thalassia hemprichii. In terms of percent cover, on the average, Enhalus acoroides is the most dominant, followed by Cymodocea serrulata, Thalassia hemprichii and Cymodocea rotundata.
4. Of the 23 study sites, Diringuan 3 had the most diverse seagrass bed, having 8 identified species, followed by Ditinglan, San Miguel Poblacion and Sitio Pula having 7 identified species each. The least diverse was observed in San Nicolas Poblacion, Octon Island W and Colaylayan having pure stands of Enhalus acoroides.
______CHAPTER III: SEAGRASS AND SEAWEEDS 54 5. Nineteen (19) species of seaweeds were recorded (9 greens, 6 browns and 4 reds). The brown pigmented alga Sargassum is the most common, most occurring at the seaward edge of the seagrass bed near the reef. This is followed by another brown alga, Padina spp.
6. The present survey found 13 species of macroinvertebrates. The echinoderms (the blue sea star Linckia laevigata, the horned sea star Protoreaster nodosus, long-spined black urchin Diadema setosum, the urchin Echinothrix calamaris, the rock-boring urchin Echinometra mathaei, the urchin Tripneustes gratilla) are the most important animals in all the seagrass beds. The black sea cucumbers (holothuroids) were not found in this survey, suggesting that these organisms are among the most extensively exploited invertebrates in the area.
7 There are a number of issues that threaten the seagrass ecosystem in the area. These issues are largely man-made activities such as:
• Continuous practice of slash-and-burn farming (“kaingin”), which contribute to soil erosion (deposition of silt);
• Siltation, which is further aggravated by the continuous illegal cutting of the mangroves; and
• Overexploitation of the associated fisheries resources such as sea cucumbers and giant clams, etc.
17.0 RECOMMENDATIONS
Based on the results of this survey, the following are recommended:
1. Recommended sites for core zones
a) Based on the High Percentage Seagrass Cover
i) Site 11 (San Miguel Poblacion, San Miguel, NE Linapacan mainland)
ii) Site 12 (Sitio Pula, Pula Bay, San Miguel, W Linapacan mainland)
iii) Site 14 (San Nicolas Poblacion, South Bay, San Nicolas, S Linapacan mainland)
iv) Site 15 (Octon Island West, South Bay, San Nicolas, S Linapacan mainland)
v) Site 16 (South Bay Cove, South Bay, San Nicolas, S Linapacan mainland)
vi) Site 3 (Tabkangan, Northwest Bay, Maroyogroyog, NW Linapacan mainland)
vii) Site 4 (Bayotbot, Northwest Bay, Maroyogroyog, NW Linapacan mainland)
______CHAPTER III: SEAGRASS AND SEAWEEDS 55 viii) Site 5 (Lilo, Northwest Bay, Maroyogroyog, NW Linapacan mainland)
ix ) Site 21 (Cabunlauan Island NW, Cabunlauan Group of Islands)
x) Site 22 (Cabunlauan Island Poblacion, Cabunlauan Group of Islands)
b) Based on High Species Richness
i) Site 9 (Diringuan 3, North Bay, San Miguel, N Linapacan mainland)
ii) Site 10 (Ditinglan, San Miguel, NE Linapacan mainland)
iii) Site 11 (San Miguel Poblacion, San Miguel, NE Linapacan mainland)
iv) Site 12 (Sitio Pula, Pula Bay, San Miguel, W Linapacan mainland)
c) Based on the Presence of Grazing Areas of Dugong
i) Site 5 (Lilo, Northwest Bay, Maroyogroyog, NW Linapacan mainland)
1. These 15 sites are recommended for more detailed study to generate more information on the status and condition of the seagrass communities and community structure, and the main organisms inhabiting them.
2. “Kaingin” and illegal cutting of mangrove trees should be stopped, due to threats to the nearby seagrass beds and associated coral reefs as well as its dependent organisms and fisheries.
3. Collection or gathering of seagrass-associated invertebrates for commercial purposes must be regulated.
4. Formulation of Coastal Resource Management Plan (CRMP) for immediate protection of the coastal/marine resources.
______CHAPTER III: SEAGRASS AND SEAWEEDS 56 CHAPTER IV MARINE MAMMALS AND SEA TURTLES
18.0 INTRODUCTION
To address the absence of data on the distribution and status of dugongs, turtles, and cetaceans in Linapacan, this baseline survey was conducted as part of a series of surveys on the status of the marine and coastal environment in Northern Palawan.
The primary objective of the survey was to obtain local knowledge about the habitat, status, and conservation awareness of marine wildlife in Linapacan. What came through as a result of this survey are some of the commonly held perceptions about dugongs, turtles and cetaceans in Northern Palawan including the Calamianes, as well as threats.
Results of this survey are primary information that can provide indications for further research on marine wildlife with focus on conservation issues.
19.0 METHODS
The key informant interview (KII) method was used in this survey. Using a standardized form, the survey team did a random house to house survey of fisherfolks in coastal and island barangays of Linapacan during the last week of May till the first week of June, 2004 (Plate 20). Base maps and animal photographs were also used to obtain data.
The results of the interviews were compiled in a database and processed into tabular form, while animal sightings were translated into coordinates. Given the Plate 20. Survey team with respondents in Linapacan. (Photo by: J. Garcia) method used to conduct this survey, results are limited to highly qualitative information and as such, are subject to further research and monitoring using quantitative methods.
20.0 RESULTS
20.1 Respondent’s Background
A total of one hundred eighty three (183) fisherfolks were interviewed in five (5) coastal and island barangays in the municipality of Linapacan (Figure 12). Majority (91.80%) was full- time fishermen who frequented their waters once daily (73.22%) to fish using hook and line (57.37%) and long lines (28.95%). The number of years spent fishing was varied, 19.67% has spent 5-10 years fishing in the area, while 18.04% have been fishing for 21-30 years. Figures 13 to 16 show a detailed fishing profile of the respondents.
______CHAPTER IV: MARINE MAMMALS AND SEA TURTLES 57
Figure 12. Map Survey Areas, Linapacan, Palawan, 2004
5.46% 1.10% 8.20% 4.37% 16.39% Full Time 9.84% Part-time 19.67% 18.04%
10.38% 14.75%
91.80% 1-4 5-10 11-15 16-20 21-30 31-40 41-50 51-60 no answer
Figure 13. Fisher’s Classification Figure 14. Years Fishing In Area
28.95% Hook & Line Once daily 9.84% 0.53% Multiple Hook & Line 6.56% Irregular 3.67% Long Line Twice weekly 3.83% 4.21% Spear Twice daily 3.28% Fish Net Thrice weekly 0.53% 1.64% Compressor 6x weekly 0.53% 0.54% Fish Corral 3-6x weekly 0.53% Bubo 0.54% 3x monthly 73.22% 57.37% 3.68% Ketang 0.55% Seasonal
Figure 15. Fishing Frequency Figure 16. Fishing Gears Used
______CHAPTER IV: MARINE MAMMALS AND SEA TURTLES 58 Age groups among the respondents varied; with majority (36.56%) belonging to the 20-29 age bracket. Ethnicity was primarily Palaweños (67.21%), mostly (37.40%) from the municipality of Cuyo. Established residency in Linapacan was again varied; majority (27.32%) of whom had lived in the area for 21-30 years. Educational attainment generally was in the primary level with 37.16%, while 30.60% were elementary graduates. Figures 17 to 20 illustrate the respondent profile in detail.
6.01% 5.91% 4.30% 15-19 10.75% 20-29 26.78% 30-39 36.56% 40-49
50-59 22.04% 67.21% 60 & older
Palawan Visayas Masbate 20.44%
Figure 17. Age Group Figure 18. Ethnic Origin
0.55% 2.19% 3.83% 4.37% 7.65% 17.49% Elementary level 0.54% Elementary graduate 9.84% 8.74% Secondary level 8.74% 37.16% 10.93% High school graduate13.11% 5.46% College level Vocational 11.48% 27.32% No schooling No answer 30.60% 1-4 5-10 11-15 16-20 21-30 31-40 41-50 51-60 >60
Figure 19. Educational Attainment Figure 20. Established Residency
______CHAPTER IV: MARINE MAMMALS AND SEA TURTLES 59 20.2 Dugong Status
Animal Identification
A little more than fifty five percent (55.19%) of respondents have reportedly seen dugongs in their areas and most of them gave correct descriptions. However, 17.82% of those who saw dugongs erroneously described the animal as a cetacean.
Behavior
Swimming was the common behavior seen by most of the respondents. In Calibangbangan, Maroyogroyog, and Binalabag Island, feeding was observed in the area.
Distribution
Dugongs when sighted were mostly found in coves, and in-between islands around the municipality. Figure 21 illustrates animal distribution.
Binalabag Island
Maglubotlubot Island
Maruyogruyog
San Miguel Calibangbangan
Calibangbangan Turtle Nest Barangonan Turtle Nest
Barangonan
Figure 21. Dugong distribution, Linapacan, Palawan, 2004
______CHAPTER IV: MARINE MAMMALS AND SEA TURTLES 60 Frequency of Sightings
Results from the interviews revealed that dugongs were rarely seen in their areas based on 55.42% of the respondents knowledgeable on the animal, while the remaining 44.58% reported having seen dugongs within the period starting Dec 2003 to May 2004 (Figure 22). Animals, when seen, were usually during the early mornings in most areas except in San Miguel where respondents reported sightings in the late afternoons.
14 12 10 No. of 8 Sightings 6 4 2 0 Dec 03 Jan 04 Feb 04 Mar 04 Apr 04 May 04 Period
Maroyogroyog Calibangbangan San Miguel Nangalao Barangonan
Figure 22. Dugong Sightings,Linapacan, Palawan, 2004
Group Size
Solitary individuals were most commonly seen. However, mother and calf pairs were also common in most areas, particularly in San Miguel. Groups of three were reported in Calibangbangan, San Miguel, and Barangonan Island.
Trends in Animal Numbers
Respondents claimed that dugong numbers were increasing (56.05%) mainly because they gives birth. Those who believe that the numbers were decreasing (17.58%) reported that the reduction may be due to the fact that the animal is rarely seen. The rest (26.37%), were unsure of any trends. Table 15 details respondents’ answers.
______CHAPTER IV: MARINE MAMMALS AND SEA TURTLES 61 Table 15. Respondents’ Perception on Dugong Numbers, Linapacan, Palawan, 2004
% Gives Lays Not Don’t Always Animal birth eggs hunted know seen not disturbed Increasing 56.05 % 52.94 1.96 3.93 21.57 11.76 7.84 100 Rarely Direct Die Don’t Few in seen catch natural know numbers death Decreasing 17.58 % 31.25 12.50 6.25 25 25 100
Unsure 26.37 100
20.3 Turtle Status
Animal Identification
The hawksbill (Eretmochelys imbricata) and green (Chelonia mydas) turtle were the commonly occurring species in the municipality as identified by respondents. Various carapace width and length descriptions correspond to juvenile and adult turtles present in their waters. Several respondents from Calibangbang and Nangalao reported animals weighing from 20 to 60 kilos.
Behavior
Swimming, breathing, floating, and mating were common behaviors observed in all areas. Feeding on seagrasses was reported in Nangalao. No nesting behaviors were reported.
Distribution
Turtles were distributed in nearshore waters of coastal and island barangays in the municipality. Nesting sites were reported in Magranting Island south of Nangalao, and Calibangbangan. Figure 23 illustrates sightings and nests.
______CHAPTER IV: MARINE MAMMALS AND SEA TURTLES 62
Figure 23. Turtle Distriction and Nesting Sites, Linapacan, Palawan, 2004
Frequency of Sightings
While respondents in general (82.08%) reported that turtles were present all year round in their waters mostly in the early mornings (42.19%), results revealed that sightings commonly occur during the month of May (90.70%) (Figure 24) with occasional sightings during March, April, and June.
60 50 No. of 40 30 Sightings20 10 0 Jan 04Feb 04Mar 04Apr 04May 04June 04 Period
Maroyog2 Calibangbang Sn Miguel Nangalao Barangonan
Figure 24. Turtle Sightings,Linapacan,Palawan, 2004
______CHAPTER IV: MARINE MAMMALS AND SEA TURTLES 63 Solitary individuals up to groups of three were reported in all areas surveyed. However, groups of four to ten individuals were reported in Calibangbangan, San Miguel, and Nangalao.
Trends in Animal Numbers
Majority (89.50%) believed that turtle numbers were increasing in their areas, but do not know (43.21%) why they think so. 6.63% were unsure whether numbers were increasing or decreasing, 2.76% believe turtle numbers were decreasing, while 1.11% stated that there were no changes. Table 16 lists the details on turtle numbers.
Table 16. Respondents’ Perception on Turtle Numbers, Linapacan, Palawan,2004
% Gives Lays Not Don’t Always Animal birth eggs hunted know seen not disturbed Increasing 89.50 % 11.73 32.10 8.02 43.21 4.32 .62 100 Rarely Direct Die Don’t Few in seen catch natural know numbers death Decreasing 2.76 % 0 0 0 80 20 100
Unsure 6.63 Die Don’t natural know death No Change 1.11 % 50 50 100 100
20.4 Cetacean Status
Animal Identification
Respondents seem to be very familiar with the morphological characteristics of dolphins and whales. Eighty four percent (84%) of the respondents have seen dolphin and can distinguish it from sharks, while 40.56% of the respondents who have seen whales can distinguish it from the whale shark. Common dolphin species reported were Spinner dolphins (Stenella longirostris), Risso’s dolphins (Grampus griseus), and Killer Whales (Orcinus orca). Whale species reportedly occurring were the Sperm whale (Physeter macrocephalus), and the Short-finned Pilot whale (Globicephala macrorhynchus).
______CHAPTER IV: MARINE MAMMALS AND SEA TURTLES 64 Behavior
Swimming and porpoising were the common behaviors reported for dolphins in all areas surveyed. In Nangalao, several respondents reported feeding on small fishes. Swimming and breathing were behaviors for whales, while logging was reported in all areas except in San Miguel and Barangonan. Feeding on sergistid shrimps, locally known as ‘alamang’, was reported in Nangalao.
Distribution
Whale sightings were found in the North Sulu Sea as well as facing the South China Sea. Dolphins were commonly distributed in offshore waters surrounding the municipality. Figure 25 illustrates cetacean distribution.
Legend: Whale Dolphin
San Miguel
Nangalao
Calibangbangan
Barangonan
Figure 25. Cetacean Distribution, Linapacan,Palawan, 2004
Frequency of Sightings
Dolphin sightings varied from once per week (35.10%) to everyday sightings (33.11%), while whales were usually sighted from once a month (40.26%) to once per year (23.40%). Most sightings for cetaceans occurred in the early mornings (Do=43.45%, W=46.05%), although they were also reportedly seen in the late afternoons (Do=22.6%, W=29%). Sightings were common during the month of May as shown in Figures 26 and 27.
______CHAPTER IV: MARINE MAMMALS AND SEA TURTLES 65 25 20 15 No. of Sightings 10 5 0 Dec 03 Jan 04 Feb 04 Mar 04 Apr 04 May 04 June 04 Period
Maruyogruyog Calibangbangan San Miguel Nangalao Barangonan
Figure 26. Dolphin Sightings,Lina pacan,Palawan,2004
10 8 No. of 6 Sightings4 2 0 Dec 03Jan 04Feb 04Mar 04Apr 04May 04 Period
MaruyogruyogCalibangbangan San MiguelNangalao Barangonan
Figure 27. Whale Sightings, Linapacan, Palawan, 2004
Group Size
Reported group sizes for dolphins ranged from units to groups in most areas, while aggregations were reported in San Miguel. Whales ranged from solitary individuals to units as reported in Nangalao.
______CHAPTER IV: MARINE MAMMALS AND SEA TURTLES 66
Trends in Animal Numbers
Respondents believed that dolphin numbers were increasing (89.19%). However, most don’t know (43.18%) the reason why. Whale numbers on the other hand, were also believed to be increasing (71.08%) due to offsprings. Tables 17 and 18 list the details in trends.
Table 17. Respondents’ Perception on Dolphin Numbers,Linapacan, Palawan,2004
% Gives No direct Hunting Don’t Many Animal No one birth captures prohibited know when not eating seen disturbed Increasing 89.19 % 20.46 8.33 6.06 43.18 14.39 3.03 4.55 100 By-catch in Don’t ‘pangulong’ know Decreasing 4.73 % 57.14 42.86 100
Unsure 6.08
100
Table 18. Respondents’ Perception on Whale Numbers, Linapacan, Palawan,2004
% Gives Animal Hunting Don’t Many Animal Animal not birth difficult prohibited know when not slaughtered to catch seen disturbed Increasing 71.08 % 35.59 10.17 8.48 18.64 6.78 16.95 3.39 100 Rarely Die Don’t seen natural know death Decreasing 7.23 % 67 17 16 100
Unsure 21.69
100
20.5 Threats
As with other municipalities in Northern Palawan, dynamite (28.45%) and cyanide (28.03%) fishing were the commonly perceived threats resulting in deaths of marine wildlife. Figure 28 represents other identified threats in the barangays surveyed.
______CHAPTER IV: MARINE MAMMALS AND SEA TURTLES 67
30 Number of Respondents 25 Maruyogruyog 20 Calibangbangan 15 San Miguel Nangalao 10 Barangonan 5
0 MeatCommercial Buyer CyanideDegradedSeagrassDon’t KnoDynamitew Fish NetHook &IllegalFishingNo ExistingPollutionSpeaFishingr SuperTaiwanese LightPoachers Animal FishingVessels Beds Line Threat s
Identified Threats
Figure 28. Perceived Threats, Linapacan, Palawan, 2004
By-catch and Direct Captures
Incidents of by-catch (26.78%) and direct captures (7.10%) for dugongs and sea turtles were common in Linapacan, with turtles having the greatest impact. Fish nets (67.34%) account for most catches, particularly for turtles, followed by hook and line (30.61%) and fish corrals (2.05%). In Barangonan, dynamite fishing reportedly affected dugongs eventually leading to its death. Around thirty three percent (32.65%) of the respondents involved in by-catch reportedly slaughtered the animal, 26.53% released the animal, 38.77% gave no answers on what they did with the animal, and 2.05% reportedly kept turtles as house pets.
Direct takes of turtles using fish nets, hands, and spears were reported in all areas surveyed . In Calibangbangan, nesters as well as their eggs were taken for food consumption .
Strandings
Although animal strandings were generally uncommon in the areas surveyed, occasional strandings were reported in the areas of Calibangbangan: dugongs and dolphins; San Miguel: dugongs and whales; and Nangalao: dugongs, dolphins, and whales. Turtle strandings were absent. Mass stranding reportedly occurred in Nangalao in 2003 involving 11 dolphin individuals, details of which were unknown.
20.6 Conservation Awareness
Fisherfolk Attitude on Accidental Captures
Majority (93.15%) of the respondents will release the animal when it is accidentally caught (Figure 29). Corresponding reasons are listed in Table 19. If the animal is dead, 44.88% shall leave
______CHAPTER IV: MARINE MAMMALS AND SEA TURTLES 68 the animal, while 19.32% shall bury and throw the animal respectively (Figure 30). Table 19 lists the various reasons on actions when a dead animal is accidentally caught.
Slaughter, Report to 4.57% Barangay No answer, No answer, Capt., 0.57% Taken as house 1.71% 3.41% pet, 0.57% Will sell, 2.27% Leave alone, Throw away, 44.88% 19.32%
Slaughter, 10.23%
Release, Bury, 19.32% 93.15 %
Figure 29. Action When A Live Animal Figure 30. Action When A Dead Animal Is Is Accidentally Captured Accidentally Captured
Table 19. Reasons for Releasing Accidentally caught Animals Reason % Captures prohibited by law 53.98 No economic value / can’t 14.20 sell Not eating animal meat 9.66 Pitiful 7.39 No reason given 3.98 So that their numbers shall 2.84 increase Kind animals 1.70 Helps people 1.70 Animal can’t fit in boat 1.70 Bad luck when taken 1.14 May die when taken captive .57 Indicator for presence of fish .57 Contains toxins from cyanide .57 100
______CHAPTER IV: MARINE MAMMALS AND SEA TURTLES 69 Table 20. Reasons on Actions Indicated When a Dead Animal is Accidentally Captured
% No Captures Not Will No Can’t fit Contains I have economic prohibited eating stink reason in boat toxins from nothing value / by law animal given cyanide to do can’t sell meat with it Leave 44.88 alone % 44.30 13.93 11.39 11.39 3.80 7.59 1.27 6.33 100 No Captures Not Will No It’s So as not So that economic prohibited eating stink reason dead to people value / by law animal given already influence won’t can’t sell meat other get animals to sick sympathize Bury 19.32 % 11.76 2.94 2.94 55.88 17.66 2.94 2.94 2.94 100 No Captures Not Will No Bad economic prohibited eating stink reason luck value / by law animal given when can’t sell meat taken Throw away 19.32 % 36.36 6.07 30.30 15.15 9.09 3.03 100 Slaughter 10.23 Will sell 2.27 Report to .57 Brngy. Capt. No 3.41 answer 100
Awareness of Laws
Respondents in general (73.68%) have heard of laws regarding animal protection through the radio (22.28%), and community leaders (19.80%). However, 66.67% of the respondents were unsure whether such laws are being implemented in their areas. Details are shown in Table 21 .
______CHAPTER IV: MARINE MAMMALS AND SEA TURTLES 70
Table 21. Awareness & Implementation on Conservation Laws A. Awareness on existence of laws on animal protection Yes No Unsure (%) (%) (%) 26.32 73.68 0 Source: Meetings / Seminars 1.97 Community Leaders 19.80 DENR 1.48 BFAR / Fisheries 9.90 Extension Workers 5.45 Fellow Fishermen 19.30 Radio 22.28 Newspaper 4.95 Posters 2.48 El Nido PA Staff .99 Bantay Dagat .50 Coastguard .50 Coron leaders .50 No answer given 9.90 B. Implementation of laws in area Yes No Unsure (%) (%) (%) 23.98 9.35 66.67
Animal protection
Most respondents (95.03%) believe that marine wildlife should be protected primarily because they help people when in distress at sea (44.32), 3.87% said otherwise, while 1.10% were unsure. Table 22 lists the details.
______CHAPTER IV: MARINE MAMMALS AND SEA TURTLES 71 Table 22. Perceptions on the Necessity for Animal Protection
Perception Yes No Unsure (%) (%) (%) 95.03 3.87 1.10 Why protection is needed: Helps people when 44.32 distressed at sea The law says so 9.75 For food consumption 3.78 Kind animals 9.19 To increase their 18.38 numbers Aesthetic value at sea 3.78 No reason given 1.08 Rarely seen already 1.62 For future generation .54 For animal to live longer 3.78 Animals have right to life .54 For tourist attractions 2.16 They protect the seas 1.08
21.0 DISCUSSIONS
Results from this survey suggest range of movements by dugongs between seagrass areas in coastal waters within the municipality and most probably to and from the Northern Mainland Palawan and the Calamianes. This is based on the most common behavior observed, which was swimming; and that sightings were mostly in coves and in-between islands in the western sector of the municipality. Marsh (2002) in her report stated that dugongs are known to move large distances between one seagrass area and another.
Compared to sighting frequencies in Taytay and San Vicente during a similar six-month period (Digdigan 2005), results for Linapacan also suggest correlation between seasonality and movement. Animal sightings occurred most during April – generally the season for calm waters thus favoring large scale distance movements. Results also suggest, based on feeding behaviors in Calibangbangan, Maroyogroyog, and Binalabag island, that dugong movement include ‘feeding pit stops’ in its’ range. Assumptions made however, need verification through seagrass surveys, and further research and monitoring over a period of time.
A conflict was also noted in the results on sighting frequency and trends in numbers. While most respondents believe that dugongs were rarely seen in the municipality, they also believe that animal numbers were increasing since according to their knowledge, dugongs produce offsprings much like fishes - an indication of unawareness on the animals’ life history owing to the absence of information and education campaigns in the area.
______CHAPTER IV: MARINE MAMMALS AND SEA TURTLES 72 Juvenile turtles, as per respondents’ animal descriptions, in the nearshore waters of the areas surveyed may suggest coastal feeding sites. Studies (Spotila 2004, Gulko and Eckert 2003, Houghton et al 2003) on the feeding ecology of juvenile turtles revealed that after completion of their pelagic hatchling phase, they recruit to coastal feeding areas until they reach sexual maturity. Whether these juveniles were the hatchlings belonging to the nesting sites identified in Linapacan or from elsewhere in the region are unknown.
Results on turtles also indicate high sightings during the month of May with as many as ten turtles seen together. While mating had been identified as one of the behaviors observed in the area, results suggest that May could be the mating season for turtles in the municipality. It is usually the male turtles that arrive first in the mating grounds and eagerly wait for the females to appear. Females are receptive to mating only during the month before the nesting season and the 12 hours after they lay each clutch of eggs (Spotila 2004). We can assume therefore, that nesting season occurs in Linapacan by June, which coincides with the peak nesting season for Green and Hawksbill turtles in Malaysia (Ibrahim 1994).
Of all surveys done in Northern Palawan, it is in Linapacan that respondents can distinguish cetaceans from sharks. Cetacean species identified by respondents are mostly offshore/oceanic species thus explaining the offshore distribution in the municipality. While it is not surprising that May exhibited highest animal sightings, Calibangbangan exhibited regular cetacean sightings for a six-month period. Data on sightings and observed behaviors in dolphins and whales as reported by respondents from the area, may suggest the area to be a regular route from the South China Sea to the North Sulu Sea or vice-versa. Monitoring and research conducted on a regular basis, however, should be done to support the assumption. Likewise, the same should be conducted in Nangalao to determine whether the area is a feeding habitat for cetaceans in the municipality.
It is not surprising that a myriad of threats occur in Linapacan. The area is well-known for illegal fishers (ELAC, pers. comm.) and its relative isolation and difficult access favor such. Dugongs and turtles are mostly affected given their nearshore occurrence leading to direct captures. Law implementation is a gray area in the municipality, and the lack of knowledge on the value of dugongs, turtles, and cetaceans to the marine environment are indications that arresting the threats in the area is way far-off. While it is true that establishment of core zones in confirmed dugong feeding areas and turtle nesting sites protect the habitat, species protection in Linapacan is another matter. Dugong and turtle meat are cheap, if not, “free” sources of protein and given the social and economic status of most residents in the municipality, animal captures, at an unknown rate, shall be a bane as to the reason why core zones are established in the first place.
22.0 CONCLUSIONS AND RECOMMENDATIONS
Range of movements by dugongs to and from feeding sites within the municipality was more favorable during the summer months as compared to other municipalities given the geographical location of Linapacan. Feeding sites were reported in Calibangbangan, Maroyogroyog, and Binalabag island. Verification of such sites however, is needed through seagrass survey and monitoring.
______CHAPTER IV: MARINE MAMMALS AND SEA TURTLES 73 Juvenile turtles found in nearshore waters of the areas surveyed may suggest coastal feeding sites. Whether these juveniles were the hatchlings belonging to the nesting sites reported in Magranting Island, and Calibangbangan or from elsewhere in the region are unknown.
Mating season for turtles most probably occur during the month of May prior to nesting season.
The waters surrounding Calibangbangan may be a regular route for cetaceans from the South China Sea to the North Sulu Sea or vice-versa.
A myriad of threats is an expected result given the social status of the municipality. Law implementation is a gray area, and the lack of knowledge on the value of dugongs, turtles, and cetaceans to the marine environment among coastal and island communities are impediments to arrest threats. While the radio can be a tool to address the unawareness on the life history and value of marine wildlife, a behavioral change on the social acceptability of the lack or most probably, absence of law implementation in Linapacan remains a big challenge.
Given the highly qualitative nature of this report, and it is strongly recommended that data resulting from this survey be subject to research and monitoring over a period of time. As with the rest of Northern Palawan, the future of marine wildlife in Linapacan is uncertain unless efforts to study their behavioral ecology, as well as community dynamics affecting such animals are carried out in order to develop conservation measures.
______CHAPTER IV: MARINE MAMMALS AND SEA TURTLES 74 CHAPTER V MANGROVE FOREST
23.0 INTRODUCTION
The estimated mangrove area of Palawan is 26,086 hectares which represents about 35% of the total conservation or mangrove reservation of the country. As per Presidential Proclamation (P.P.) 2152, said whole mangrove area has been declared as mangrove swamp forest reserve. In mangrove forest reserves, small-scale sustainable utilization of forest resources is allowed but commercial and large-scale utilization and conversion to other land uses such as fishpond are strictly prohibited.
Recent surveys and studies however, showed that mangrove forest inside the reservation are continuously subjected to cutting and worst, cleared and developed into fishponds. The depletion of stock of old growth mangrove forests is primarily due to commercial large scale cutting for timber, fuelwood, charcoal and direct conversion into fishponds. Likewise, the stock depletion in second growth is largely due to continuous cutting for sustenance/subsistence use as poles and piles and fuelwood and some local industrial requirements such as bakery, construction materials, and fish trap poles and low- cost housing materials (Bennagen and Cabahug, 1991). The previously dense mangrove forests are now sparsely vegetated second growth and became reproductive-brush.
The mangrove forest in Linapacan had been subjected into commercial cutting during the 1970s to the early 1980s. The issuance of concession for mangrove cutting during this period primarily caused the clear cutting of mangrove forest. Most of the workers of the concessionaire settled in the area after the expiration of the concession. They continued with the cutting of mangrove for charcoal and for household uses. The influx of people to Linapacan due to in-migration and high population growth rate geometrically increased the demand for mangrove products for low cost housing construction materials, firewood, fish trap poles, fences, etc. which contributed to the rapid degradation of mangrove forest.
24.0 OBJECTIVES
The study aims to:
1. determine the forest structure, condition and ecological diversity of mangroves in Linapacan; 2. determine the pattern of uses and existing land uses of mangroves; and 3. determine the appropriate management zoning of mangroves.
25.0 EXPECTED OUTPUTS
• Characterization of the status of mangrove habitats in terms of forest conditions, structures and ecological diversity; and
______CHAPTER V: MANGROVE FORESTS 75 • Classification and zoning of mangroves for strict protection or preservation, conservation or community-based sustainable small-scale utilization, and for restoration or rehabilitation.
26.0 METHODOLOGY
Date and Place of Survey and Location of Transects
Resource and Ecological Assessment (REA) of mangrove in Linapacan, Palawan was conducted from June 15 to July 5, 2004. The distribution of mangrove areas in the municipality of Linapacan is shown in Figure 31 while the location of 37 transects is presented in Table 23.
Figure 31. Satellite Map Showing the Municipality of Linapacan, Palawan, 2003
______CHAPTER V: MANGROVE FORESTS 76 Table 23. Location and position of belt transects surveyed by the Mangrove Team in Linapacan, Palawan, 2004.
No. Location: Linapacan, Transect Area Dominant Co- Coordinates of Remarks Palawan No. (m²) Species Dominant Plot N 11° So. Pinagkalangan, 27.158 E 1 7 3480 Rm Ra W/ cuttings Brgy. Maroyogroyog 119° 46. 948 N 11° 26 So. Tabkangan, Brgy. 15.9 Charcoal 2 4 2000 Ra Rm Maroyog-royog E 119°45 making 48.9 N11° 26.409 Bgy Maroyog-royog 3 5 2500 Ra Rm W/ cuttings E119° 46.445 N11° 26' Sitio Canog, Brgy. 25.4" E Charcoal Malbarok Linapacan 4 4 1880 Ra Rm 119° 46' making Island 32.8" Brgy. Maruyog-Ruyog N11° 28' (Brgy. Proper) 14.2" E119° 5 6 2650 Ra Rm W/ cuttings Linapacan Island 45' 48.3" N11° 26.409' Sitio Bayotbot, E 119° 6 5 2500 Ra Rm W/ cuttings Maroyogroyog 43.609' 83" N11° 27' 45.1" E Brgy. Maroyog-royog 7 3 1500 Ra Rm, Bg W/ cuttings 119° 47' 37.4" N11° 27' 24.1" E Brgy. Maroyog-royog 8 4 1650 Ra Rm W/ cuttings 119° 48' 48.6" N11° 27' Brgy. Maroyog-royog 21.5" E 119° 9 2 1000 Rm Ra W/ cuttings Landward-River 49' 37.4" N11° 27' Brgy. Maroyog-royog 22.5" E 119° 9.a 4 2000 Ra Ct,Ea W/ cuttings Landward to River 49' 33.9" N11° 27.441' Sitio Duruguan, Brgy. E 119° 10 10 5000 Rm Ra W/ cuttings San Miguel 50.140' N11° 28.143' Sitio Ragara, Brgy. San E 119° 11 2 1000 Rm Ra W/ cuttings Miguel 50.115' N11° 28.143' Sitio Diwata, Brgy. San E 119° 12 1 500 Rm Ra, Hl W/ cuttings Miguel 50.115' Sitio Dimwabuangan, Ra, Ct, 13 4 2000Rm W/ cuttings Brgy. San Miguel Sal N 11° Sitio Maldungon, Brgy. 28.143" E 14 3 1500 Ra Rm W/ cuttings San Miguel 119° 50.115"
______CHAPTER V: MANGROVE FORESTS 77 Table 23 continued . . . N 11° Sitio Sigakgak, Brgy. 29.356" E 15 4 2000 Ra Rm W/ cuttings San Miguel 119° 50.723" N 11° Sitio Linayto, Brgy. San 29.688" E 16 2 1000 Ra Rm W/ cuttings Miguel Pal. 119° 50.525" N 11° Sitio Ditinglan, Brgy. 30.451" E 17 4 1900 Ra W/ cuttings San Miguel 119° 51.325" Sitio Langka, Brgy. San N 11° 28' Miguel ( Seaward - 51.1" E 119° 18 4 2000 Rm Ra W/ cuttings Landward ) 52.06.9" Sitio Iloc, Brgy. San N 11° 29' Miguel ( Landward - 02.1" E 119° 19 3 1500 Ra Rm, Sc W/ cuttings Seaward ) 51' 53.4" N 11° 26' Sitio Pula, Linapacan, 09.4" E 119° 20 5 2500 Rm Rs, Ra W/ cuttings Palawan 51' 12.9" N 11° 25.5' Sitio Libong, Brgy. San 5.1" E 119° 20.a 3 1500 Ra W/ cuttings Miguel 51.0' 34" Sitio Pula, Brgy. San Miguel Linapacan, 20.b 2 700 Ra Sal W/ cuttings Palawan Cabunlawan Island, N 11° 22' Linapacan, Palawan 47" E 120° 21 2 1000 W/ cuttings (lake) 05' 38.9" N 11° 22' Cabunlawan Island, 47" E 120° 22 1 120 Ra W/ cuttings Linapacan 05' 38.9" N 11° 24' Sitio Tara-tara, Brgy. 04.3" E 119° 23 3 1500 Ra Rm W/ cuttings San Nicolas 48' 43.0" N 11° 25' Sitio Alelik, Brgy. San 40.2" E 119° 24 2 1000 Ra Rm W/ cuttings Nicolas 49' 23.2" N 11° 25' Sitio Bisaya, Brgy. San Rm, Sal, 22.6" E 119° 25 2 1000 Ra W/ cuttings Nicolas Ct 47' 42.3" N 11° Sitio Campot, Brgy. San 24.969" E 26 3 1500 Ra Rm W/ cuttings Nicolas 119° 46.375" N 11° 24' Sitio Campot, Brgy. San 42.8" E 119° 27 2 1000 Ra W/ cuttings Nicolas 46' 32.5" N 11° Sitio Kakamain, Brgy. 25.395" E 28 2 800 Ra W/ cuttings New Calaylayan 119° 44.971" N 11° Brgy. New Calaylayan 26.735" E 29 6 2890 Ra Rm W/ cuttings 119° 44.252" N 11° 18' Iloc Island, Linapacan 33.3" E 119° 30 3 1500 Ra, Rs Bg,Bs W/ cuttings Palawan 40' 00.8"
______CHAPTER V: MANGROVE FORESTS 78 Table 23 continued . . . N 11° 18' 1 River Side Iloc Island, 20.3" E 119° 30.a 1 500 Bg, Ra Ct W/ cuttings Linapacan, Palawan 40' 36.5" N 11° 25' Calibangbangan Island, 50.8" E 119° 31 1 500 Rs Af W/ cuttings Linapacan Palawan 38' 28.8" N 11° Isla Decabaitot, 39.681 E 32 2 630 Rs Ra W/ cuttings Linapacan Palawan 119° 57.541 N 11° Isla Decabaitot, 39.014 E 33 1 500 Rs, Ra Sal W/ cuttings Linapacan Palawan 119° 57.852
Sampling Procedure
Transects were laid out in the base map taking into consideration the different land uses, forest conditions and extent of mangrove areas. Reconnaissance was conducted to validate the mangrove forest conditions and the result was considered in the final selection of the sampling sites. The belt transect of 10 meter width traversed the different mangrove forest conditions perpendicular to the shorelines and riverbanks.
Field Methods
The study areas were demarcated into transects running perpendicular to the seashore up to the inland using GPS to ascertain the direction and avoid overlapping or intersection of transects toward the landward area. Each transect was divided into 10m x 50m size plot. In each transect, trees inside the plot larger than 5cm in diameter were recorded per plot for (Figure 32) total Figure 32. Picture showing the lay-outing of height and/or merchantable height; transects,Linapacan, Palawan, 2004 and diameter at breast height (DBH)/diameter above bud-root (DAB)
A 2m x 50m subplot was laid out for the measurement of regeneration. Saplings, (with diameter smaller than 5cm and height more than 2m) were identified and the number of individuals by species was determined. Counts of seedlings of each species (height lower than 2m) were recorded as number of individuals.
Within each plot in the different transects, mangrove species were identified and classified into:
1. Timber size trees (> 15cm DBH/DAB) 2. Pole size trees (> 5cm up to 15cm in DBH/DAB) 3. Regeneration
______CHAPTER V: MANGROVE FORESTS 79 ¾ Saplings (5cm DBH/DAB and 2m in height)
¾ Seedlings (height below 2m)
For timber size trees (>15cm DBH/DAB), the following parameters were assessed:
1. Merchantable height (to the nearest 0.5m). The height from stump (0.3m above the budroot in Rhizophora spp. or ½m above the ground in non-Rhizophora spp up to the first major branch or 10 cm top diameter limit). 2. Total height (to the nearest 0.5m) 3. DAB/DBH (to the nearest 0.5cm)
For pole-size trees, only the total height and DBH/DAB were measured. Due to some difficulties in site conditions, which hindered the work, the height was measured directly using calibrated poles as guide for small to medium size trees. For large size trees (more than 10m high), height was estimated.
Initially, the diameter was measured accurately using a diameter tape, and as the work progressed, the diameter was already estimated directly. In all species, except for Rhizophora, diameter was recorded at 1.3m height from the ground level known as DBH. In Rhizophora spp., because of the presence of stilt roots, the diameter was recorded at height of 0.3m from the topmost stilt roots known as DAB.
In the case of regeneration saplings and seedlings, the density (number present in each plot) in the different transects were recorded by species.
In addition to the above quantitative data, observations were made on the following:
1. Presence of ferns and other non-woody species; 2. Presence of crab mounds; and 3. Presence of avifauna and wildlife
Data Processing and Analysis
Individual tree volume of timber size trees were computed using the volume equations or using the volume tables for each species derived by Cabahug (1986a; 1986b) for timber-producing mangrove species. Based on the computed volume, a stand and stock table was constructed using the suggested format. Other tree parameter variables such as stand volume (SV), stand stock per hectare (N), diameter of the mean basal area of the tree (Dg), stand dominant height (Ho), mean diameter of dominant height (Dho), stand mean (H) and stand basal area (G) were computed using the formula/equations formulated by FAO, as follows:
Stand volume (SV) SV (m3/ha) = ΣV Plot area
Stand stock per hectare (N) N (tree/ha) = Total no. of live trees on the plot Plot area 2 Mean Diameter (Dg) Dg (cm) = Σd /No. of trees on the plot where: d = diameter of each tree
______CHAPTER V: MANGROVE FORESTS 80 Stand dominant height (Ho) Ho (m) = ΣDh/No. of dominant trees on the plot where: Dh = height of dominant trees
Mean diameter of dominant Dho (cm) = ΣDd/No. of dominant trees on the plot height (Dho) where: Dd = diameter of dominant trees
Stand mean height (H) H(m) = ΣTh/No. of trees on the plot where: Th = tree height
Stand basal area (G) G (m2/ha)) = ΣBa/Plot area where: Ba = 0.007854 (Dbh) 2
The dominant species for each site were determined based on the importance value (IV). The IV is the sum of the relative density, relative frequency, and relative coverage. These are computed using the following formula:
Density = Total number of individuals counted for a given species Total area sampled
Relative density Total number of individuals of a given species x 100 = Total number of individuals of all species
Coverage = Total area covered by a given species Total area sampled
Relative coverage = Total coverage of a species x 100 Total coverage of all species
Frequency = Number of plots where a given species occur Total number of plots in the site
Relative frequency = Frequency of a given species x 100 Total frequency of all species
Importance Value = Relative density + Relative coverage + Relative frequency
The diversity indices were computed using the following formula:
Species richness measures
Margalef’s index DMg = (S-1)/ln N Menhinick’s index DMn = S/√ N where: S = number of species N = total number of individuals for all species Shannon diversity index
H’ = -Σpi ln pi where pi, the proportional abundance of the ith species = (ni/N) and ln = natural logarithm function
______CHAPTER V: MANGROVE FORESTS 81 Evenness of the species can now be calculated using the formula:
E = H’ /ln S
Simpson’s index
(n1(n1- 1)) D = Σ ______(N(N-1)) where n1 = the number of individuals in the ith species N= the total number of individuals.
Berger-Parker diversity index
The Berger-Parker index is calculated from the equation: d = Nmax/N where N = total number of individuals and Nmax = number of individuals in the most abundant species. In order to ensure that the index increases with increasing diversity the reciprocal form of the measure is usually adopted.
Similarity measures
Sorenson measure using the qualitative data, the formula: CN = 2jN / (aN + bN)
Where aN = the number of individuals in site A, bN = the number of individuals in site B, and jN = the sum of the lower of the two abundances or species which occur in the two sites.
27.0 RESULTS AND DISCUSSIONS
27.1 Biodiversity Assessment
Species Composition and Distribution
There are 18 true and 20 associate mangrove species identified and recorded during the survey belonging to 14 families and 27 genera of vascular plants (Table 24).
Table 24. List of True and Associate Mangrove Species Identified and Recorded in Linapacan, Palawan, 2004.
Scientific Names Code Common Name Existing in Coron
TRUE MANGROVE Aegiceras floridum Af * Bruguiera gymnorrhiza Bg SiBusain i * Bruguiera sexangula Bs Pototan * Bruguiera cylindrical Bc Pototan lalaki * Bruguiera parviflora Bp Langarai * Ceriops tagal Ct Tangal * Ceriops decandra Cd Malatangal * Lumnitzera littorea Ll Tabau * Lumnitzera racemosa Lr Kulasi * Nypa fruticans Nf Nipa *
______CHAPTER V: MANGROVE FORESTS 82 Table 24 continued . . . Rhizophora apiculata Ra Bakauan lalaki * Rhizophora mucronata Rm Bakauan babae * Rhizophora stylosa Rs Bakauan bato * Sonneratia alba Sal Pagatpat * Sonneratia caseolaris Sc Pedada * Excoecaria agallocha Ea Buta-buta * Xylocarpus granatum Xg Tabigi * Xylocarpus moluccensis Xm Piagau * MANGROVE ASSOCIATE Acanthus ebracteatus Aeb Tigbau * Acacia farnesiana Afa Aroma * Acrostichum aureum Aau Lagolo * Barringtonia asiatica Ba Botong * Barringtonia racemosa Br Putat * Caesalpinia crista Cc Sapinit * Cynometra ramiflora Cr Balitbitan * Derris trifoliate Dt Mangasin * Hibiscus tiliaceus Ht Malubago * Instia bijuga Ib Ipil * Morinda citrifolia Mc Bangkoro * Osbornia octodonta Oo Tualis * Pandanus tectorius Pt Prickly pandan * Pongamia pinnata Pp Bani * Scyphiphora hydrophyllacea Sh Nilad * Terminalia catappa Tc Talisai * Thespesia populneoides Tp Malabanalo * Thespesia populnea Tpo Banalo * Cerbera manghas Cm Baraibai * Dolichandrone spathacea Dsp Tui *
The most abundant species recorded in 37 transects are Rhizophora apiculata (Ra), Rhizophora mucronata (Rm), Ceriops tagal (Ct), Rhizophora stylosa (Rs), Sonneratia caseolaris (Sc), Xylocarpus granatum (Xg), Excoecaria agallocha (Ea), Bruguiera cylindrica (Bc), Bruguiera gymnorrhiza (Bg) and Lumnitzera racemosa (Lr) with a total individual counts of 4,578 ; 1,950 ; 304 ;214 ;135 ;130;122; 101; 99 and 74 respectively. The most widely distributed species are Ra, Ct, Rm, Sc, Bc, Bg, Rs, Ea, and Lr respectively which are recorded in 35, 28, 27, 23, 19, 18, 17, 7, 7. and 3 transects (Table 25). Species diversity depends on species composition, and number of individual species in certain vegetation Figure 33. Picture showing community hence the most diverse species in Linapacan in terms of abundance and distribution was Rhizophora Rhizophora apiculata apiculata (Figure 33).
Table 25. Distribution and Abundance of Top (10) Mangrove Species in Different Sampling Sites of Linapacan, Palawan, 2004
Species No. Transects Individual Count (N)
Ra 35 4578 Rm 27 1950 Ct 28 304 Rs 7 214
______CHAPTER V: MANGROVE FORESTS 83 Table 25 continued . . . Sc 19 135 Xg 23 130 Ea 7 122 Bc 18 101 Bg 17 99 Lr 3 74
Diversity Indices
Table 26 shows the diversity indices of 37 sampling sites using the relative values of species richness, species abundance, dominance and species distribution. The most diverse sampling site in terms of species richness (S) and (Dmg), is Transect 9’A which has the highest relative value of Margaleft’s species richness. In terms N and E transect 10 has the highest number of individual counts and species are evenly distributed. Transect 12 has the highest Shannon’s value of species diversity index. However, in terms of Simpson’s index of species dominance (1/D) and Berger Parker species of diversity (N∞) transect 20 had the highest index of diversity. According to Maguran (1987) the greater the evenness of species distribution, the more diverse it becomes thus the top five (5) diverse sampling sites ( with top 5 index of Evenness) are T-10, T-1, T-20, T-29 and T-14 where distribution of species are equitably abundant, hence indicated a high diversity index. Considering combination of 1 indices such as S, Mmg, H ,1/D, N∞ and E, there is no single transect which had consistently indicated diverse indices. However, considering Margaleft’s species richness (Dmg), the top 5 sampling sites are T-9’A (2.80), T-11 (2.37), T-28 (2.30), T-12 (2.3) and T-23 (2.2). In terms of Shannon’s species abundance (H') the top 5 transects are T-12 (1.81), T-9’A (1.77), T-20 (1.73), T-21 (1.69) and T-28 (1.60). On the other hand the top five (5) diverse sampling sites in terms of Berger Parker’s species dominance are T-20 (3.09), T-30’A (2.85), T-33 (2.53), T-20’B (2.52), and T-24 (2.49). The higher diversity index means longer food chains and more cases of symbiosis hence increase in stability and stable environment (Odum,1971).
Table 26. The Diversity Indices of Mangrove Forest Calculated Using Different Diversity Formula, Linapacan, Palawan, 2004.
Species Berger- Shannon richness Individuals Margalef Shannon Simpson Parker evenness Transect (S) (N) (Dmg) (H') (1/D) (N∞ ) (E) 1 5 344 0.6849 0.74962 0.60085 1.32819 0.0832173 2 7 230 1.1033 1.17024 0.34878 2.16981 0.0518785 3 10 346 1.5394 0.80009 0.60377 1.32567 0.0583973 4 6 206 0.9385 0.92155 0.54052 1.40136 0.052023 5 13 431 1.9782 1.15656 0.44023 1.62642 0.0607568 6 13 271 2.142 1.374 0.42189 1.60355 0.0442394 7 11 179 1.9278 1.538 0.32892 1.86458 0.0350693 8 10 239 1.6434 0.92337 0.49334 1.59333 0.0450673 9 3 81 0.4551 0.73122 0.50123 1.6875 0.0418372 9A 16 212 2.8003 1.76706 0.25002 2.46512 0.0343282
______CHAPTER V: MANGROVE FORESTS 84 Table 26 continued . . . 10 11 968 1.4545 0.90746 0.46634 1.86873 0.1057369 11 13 160 2.3645 1.32156 0.36541 2.31884 0.0301673 12 12 120 2.2977 1.80495 0.23011 2.5 0.0250652 13 9 267 1.4318 1.29012 0.3691 1.82877 0.0511035 14 3 174 0.3877 0.57743 0.64527 1.28889 0.0749588 15 7 219 1.1134 0.99962 0.44594 1.752 0.0500766 16 6 128 1.0305 0.62144 0.7297 1.17431 0.0365114 17 5 147 0.8015 0.37051 0.84512 1.08889 0.0451243 18 9 448 1.3104 0.97159 0.44565 1.97357 0.0727511 19 8 260 1.2588 1.47366 0.29403 2.20339 0.0529915 20 10 303 1.5752 1.72499 0.20346 3.09184 0.0532904 20A 4 238 0.5482 0.27477 0.88005 1.06726 0.0746307 20B 6 58 1.2314 1.42699 0.26921 2.52174 0.0196999 21 6 107 1.07 1.68669 0.18727 4.28 0.0318391 22 1 51 0 0 1 1 0 23 13 243 2.1846 1.12474 0.50525 1.45509 0.0409409 24 11 209 1.8718 1.48063 0.31036 2.4881 0.0392836 25 8 194 1.3288 1.34648 0.32787 2.06383 0.0429042 26 4 274 0.5345 0.31577 0.8618 1.07874 0.0824907 27 9 168 1.5613 0.78865 0.6636 1.23529 0.0365174 28 11 77 2.3021 1.59055 0.33219 1.7907 0.0184217 29 5 334 0.6883 0.6855 0.57663 1.40928 0.0815522 30 8 200 1.3212 1.4288 0.27181 2.5 0.0438703 30A 5 77 0.9209 1.47442 0.24163 2.85185 0.0274464 31 5 66 0.9547 0.81922 0.52075 1.5 0.024304 32 6 53 1.2594 1.48255 0.26415 2.40909 0.01833 33 6 38 1.3745 1.54762 0.23613 2.53333 0.0140113
Based on Fernando Biodiversity Scale (1998), the relative value of Shannon’s diversity indices of 37 transects ranges from very low to low relative values of biodiversity indices. Likewise, in terms of evenness of distribution of species abundances, all transects have low relative biodiversity values (Table 27).
Table 27. Relative Values of Shannon Diversity Index and Evenness of Mangroves Species Distribution Linapacan, Palawan, 2004.
Shannon Evenness Transect Relative Values Relative Values Shannon (H') (E) 1 0.74962 Very Low 0.083217305 Very Low 2 1.17024 Very Low 0.051878507 Very Low 3 0.80009 Very Low 0.058397298 Very Low 4 0.92155 Very Low 0.052022997 Very Low 5 1.15656 Very Low 0.060756836 Very Low 6 1.374 Very Low 0.044239389 Very Low 7 1.538 Low 0.035069303 Very Low 8 0.92337 Very Low 0.045067339 Very Low
______CHAPTER V: MANGROVE FORESTS 85 Table 27 continued . . . 9 0.73122 Very Low 0.041837211 Very Low 9A 1.76706 Low 0.034328228 Very Low 10 0.90746 Very Low 0.105736921 Very Low 11 1.32156 Very Low 0.030167289 Very Low 12 1.80495 Low 0.025065181 Very Low 13 1.29012 Very Low 0.05110351 Very Low 14 0.57743 Very Low 0.074958788 Very Low 15 0.99962 Very Low 0.050076609 Very Low 16 0.62144 Very Low 0.036511368 Very Low 17 0.37051 Very Low 0.045124294 Very Low 18 0.97159 Very Low 0.072751145 Very Low 19 1.47366 Very Low 0.052991503 Very Low 20 1.72499 Low 0.053290438 Very Low 20A 0.27477 Very Low 0.074630678 Very Low 20B 1.42699 Very Low 0.01969988 Very Low 21 1.68669 Low 0.031839143 Very Low 22 0.1245 Very Low 0.023467 Very Low 23 1.12474 Very Low 0.040940938 Very Low 24 1.48063 Very Low 0.039283629 Very Low 25 1.34648 Very Low 0.042904192 Very Low 26 0.31577 Very Low 0.082490736 Very Low 27 0.78865 Very Low 0.03651743 Very Low 28 1.59055 Low 0.018421716 Very Low 29 0.6855 Very Low 0.081552157 Very Low 30 1.4288 Very Low 0.043870343 Very Low 30A 1.47442 Very Low 0.027446442 Very Low 31 0.81922 Very Low 0.024304023 Very Low 32 1.48255 Very Low 0.01833002 Very Low 33 1.54762 Low 0.014011255 Very Low
27.2 Mangrove Vegetation Structural Analysis
Relative Frequency (RF), Relative Density (RDen), Relative Dominance (RDom) and Importance Value (IV)
Rhizophora apiculata (Ra) is the most dominant and important mangrove species in Linapacan. It is also the most frequent and dense mangrove species recorded. It has consistently recorded the highest value of RF, RDen, RDom and IV of 23.52; 56.37; 42.09 and 121.98, respectively. Rhizophora mucronata followed second in ranking to R. apiculata with RF, RDen, RDOm, and IV of 16.97; 24.00 ; 18.80; and 59.77 respectively. The other top 15 important mangrove species in decreasing order are: Bruguiera gymnorhiza, Ceriops tagal (Ct), Sonneratia caseolaris, Xylocarpus granatum (Xg), Bruguiera cylindrical (Bc), Rhizophora stylosa (Rs) Bruguiera sexangula (Bs), Excoecaria agallocha (Ea), Sonneratia alba (Sal), Avicennia officinalis (Ao), Heritiera littoralis (Hl), Pinea pongata (Pngp), and Lumnitzera racemosa (Lr). (Table 28).
______CHAPTER V: MANGROVE FORESTS 86 Table 28. RF, RDen, RDom, and IV of top 15 Mangrove Species Linapacan, Palawan, 2004
Species RF Rden Rdom IV Ra 23.515 56.3692 42.0926 121.9768 Rm 16.9714 24 18.7987 59.7701 Bg 4.4979 1.2185 8.3376 14.054 Ct 7.771 3.7415 2.5201 14.0326 Sc 4.7025 1.6615 5.2154 11.5794 Xg 5.3162 1.6123 2.6181 9.5466 Bc 5.3162 1.2431 1.0086 7.5679 Rs 1.8411 2.6338 2.5199 6.9948 Bs 1.8411 0.6031 3.7216 6.1658 Ea 2.4548 1.5138 1.5858 5.5544 Sal 2.0457 0.8369 2.6103 5.4929 Ao 2.0457 0.2462 3.1073 5.3992 Hl 3.4751 0.64 1.2798 5.3949 Pngp 3.0685 0.3323 0.4459 3.8467 Lr 0.8183 0.9108 0.4211 2.1502
Average Stocking
Following the DENR stocking classification, all transects have an open/cleared stocking ranging from 38 to 968 trees/ha. On the average, mangrove of Linapacan has an open stocking of 291 trees/ha mostly in pole sizes (Table 29).
Table 29. Average Stocking (N/ha) ofTimber and Pole Size Trees/Transect Linapacan, Palawan, 2004
Transect Timber Pole Total DENR Stocking Class 1 23 321 344 Open/Cleared Stocking 2 28 202 230 Open/Cleared Stocking 3 7 339 346 Open/Cleared Stocking 4 21 185 206 Open/Cleared Stocking 5 90 341 431 Open/Cleared Stocking 6 20 251 271 Open/Cleared Stocking 7 39 140 179 Open/Cleared Stocking 8 33 206 239 Open/Cleared Stocking 9 16 65 81 Open/Cleared Stocking 9A 67 145 212 Open/Cleared Stocking 10 25 943 968 Inadequate Stocking 11 13 147 160 Open/Cleared Stocking 12 19 101 120 Open/Cleared Stocking 13 51 216 267 Open/Cleared Stocking 14 15 159 174 Open/Cleared Stocking 15 10 209 219 Open/Cleared Stocking 16 7 121 128 Open/Cleared Stocking
______CHAPTER V: MANGROVE FORESTS 87 Table 29 continued . . . 17 20 127 147 Open/Cleared Stocking 18 140 308 448 Open/Cleared Stocking 19 77 183 260 Open/Cleared Stocking 20 85 218 303 Open/Cleared Stocking 20A 61 177 238 Open/Cleared Stocking 20B 31 27 58 Open/Cleared Stocking 21 3 104 107 Open/Cleared Stocking 22 0 51 51 Open/Cleared Stocking 23 44 199 243 Open/Cleared Stocking 24 39 170 209 Open/Cleared Stocking 25 82 112 194 Open/Cleared Stocking 26 18 256 274 Open/Cleared Stocking 27 31 137 168 Open/Cleared Stocking 28 22 55 77 Open/Cleared Stocking 29 56 278 334 Open/Cleared Stocking 30 124 76 200 Open/Cleared Stocking 30A 21 56 77 Open/Cleared Stocking 31 34 32 66 Open/Cleared Stocking 32 7 46 53 Open/Cleared Stocking 33 6 32 38 Open/Cleared Stocking Ave 37.43 182.03 219 Open/Cleared Stocking
Stand Volume
Generally, mangrove forest of Linapacan has an average stand volume of 60.59 m3/ha, which is classified by DENR and FAO as low volume forest stand. Almost all mangrove stand sampled in Linapacan has low stand volume except transects 5 (101.16 cu m), T-7 (71.98 cu m), T-12 (77.95 cu m), T-18 (94.96 cu m), T-19 (77.55 cu m), T-20’B (131.27 cu m), T-23 (96.32 cu m), T-24 (132.47 cu m), T-25 (127.86 cu m), T-27 (199.35 cu m) and T- 30’A (141.25 cu m). The lowest volume stand is sampled in T-22 with 0.0025 cu m per ha (Table 30).
Table 30. Stand Volume (m3/ha) of Timber and Pole by Transect in Linapacan, Palawan, 2004
Stand Volume (SV) Transect Timber Pole Total SV Classes 1 3.222 10.661 13.883 Low Volume 2 22.927 17.342 40.269 Low Volume 3 4.433 13.311 17.744 Low Volume 4 8.86 16.738 25.598 Low Volume 5 79.365 21.796 101.161 Moderate 6 6.52 13.151 19.671 Low Volume 7 58.359 13.616 71.975 Moderate 8 22.1 20.742 42.842 Low Volume
______CHAPTER V: MANGROVE FORESTS 88 Table 30 continued . . . 9 10.681 7.638 18.319 Low Volume 9A 35.014 17.976 52.99 Low Volume 10 2.423 18.167 20.59 Low Volume 11 8.448 24.661 33.109 Low Volume 12 26.782 51.169 77.951 Moderate 13 15.965 15.83 31.795 Low Volume 14 5.114 15.378 20.492 Low Volume 15 2.431 15.166 17.597 Low Volume 16 4.594 16.021 20.615 Low Volume 17 17.951 10.659 28.61 Low Volume 18 62.082 32.873 94.955 Moderate 19 50.896 26.655 77.551 Moderate 20 41.399 11.047 52.446 Low Volume 0A 39.524 24.812 64.336 Low Volume 20B 128.204 3.068 131.272 Moderate 21 1.539 11.177 12.716 Low Volume 22 0 0.0025 0.0025 Low Volume 23 23.191 73.131 96.322 Moderate 24 106.019 26.446 132.465 Moderate 25 95.915 31.943 127.858 Moderate 26 6.883 27.381 34.264 Low Volume 27 172.318 26.932 199.25 Moderate 28 29.021 22.765 51.786 Low Volume 29 17.886 6.386 24.272 Low Volume 30 259.126 22.265 281.391 High Volume 30A 137.936 3.31 141.246 Moderate 31 40.274 8.815 49.089 Low Volume 32 1.424 5.713 7.137 Low Volume 33 7.025 1.075 8.1 Low Volume Ave 42.05 18.54 60.59 Low Volume
27.3 Mangrove Pattern of Uses and Existing Land Use/Forest Condition
Existing and Pattern of Land Uses
Mangrove in Linapacan had been subjected to commercial cutting from early 70’s to late 80’s and afterward it has been continuously utilized for domestic or local consumptions. There are mangroves areas converted into fishponds in the 80’s but are still not fully developed, not productive, idle and abandoned particularly in barangay Maroyogroyog, San Miguel and San Nicolas. Cuttings of mangrove for poles and fuelwood are rampant also in these barangays while cuttings for charcoal are rampant in Sitio Duruguan, Dayara and Diwata of barangay San Miguel; Sitio Cayat and Bisaya in Barangay San Nicolas. Mangroves along the landward zone are also cultivated/planted with coconut and cashew in Sitio Liyato, Ditingla, Maldungan, and Pula of barangay San Miguel.
______CHAPTER V: MANGROVE FORESTS 89 Mangrove Ecological State and Index of Degradation
Table 31 shows the values of different ecological indicators and index of degradation. In terms of stocking, T-10 had the highest number of trees/ha (968 trees/ha), median Stocking of 448 in transect 18 and lowest stocking of 38 in transect 33. Transects 30, 12 and 32 had the highest, median, and lowest basal areas of 41.69, 21.17, and 0.7532 m2/ha, respectively. In terms of stand volume, transects 27, 32 and 5 had the highest, median and lowest values with stand volume of 97.54, 50.58 and 1.2495 m3/ha. The highest, median and lowest mean diameter at breast height is recorded in transects 27, 11, and 22, respectively. Transects 41, 23, and 17 had the highest, median and lowest mean heights. In terms of 1 average diversity indices (Dmg, H , 1/D, and N∞) transect 9’A had the highest average diversity index of 1.82 while transects 8 and 22 had the median and lowest average values of composite diversity indices of 1.16 and .5, respectively. Transects 10, 3 and 32 had the highest, median, and lowest average indices of Evenness. The highest values of different indicators mean that the mangrove is still in good ecological condition and the lower their aggregate values indicate the worst ecological state of mangrove. In terms of stand volume, the top 5 transects with higher volumes are T-30, T-27, T-30’A, T-24, and T-20”A with 281.39; 199.25; 141.25; 132.47; and 131.27 m3/ha which are located in the Iloc Islet; Sitio Carapot, San Nicolas; Riverside Iloc Islet; Sitio Alelik, San Nicolas; and Sitio Pula, San Miguel. The mangrove stands in those areas have comparatively good ecological condition compared to the rest of the mangrove areas in Linapacan. Transects 22, 32, 33, 21 and 1 are the most degraded mangrove areas with the lower stand volumes of 0.0025, 7.137, 8.1, 12.717 and 13.88 m3/ha which represent the worst mangrove condition in Linapacan However, Linapacan mangrove forest is relatively in good growth condition compared to San Vicente, Culion and Coron. There are two endemic mangrove species that can be found only in the Philippines which are abundantly found all throughout Northern Palawan including Linapacan namely, Rhizhopora stylosa (Bakawan bato) and Campostenum philipinnensis (Gapas gapas) (Table 28).
______CHAPTER V: MANGROVE FORESTS 90 Table 31. Mangrove Index of Degradation and Ecological Condition Indices Based on Forest Structure and Ecological Diversity Parameters, Linapacan, Palawan, 2004.
ECOLOGICAL CRITERIA Pole and Timber Basal Mean Mean Area DBH Height Mean Transect Stocking (G) Vol (Dg) (H) Reg IV Dmg H' E 1/D N Endemism 1 344 4.192805 6.9415 13.78158 6.561525 406.5 299 0.6849 0.74962 0.083217 0.60085 1.32819 1 2 230 8.13016 20.1345 16.39972 8.783085 273.5 299 1.1033 1.17024 0.051879 0.34878 2.16981 1 3 346 5.190695 8.872 16.53677 6.49368 343.5 300 1.5394 0.80009 0.058397 0.60377 1.32567 1 4 206 6.73577 12.799 15.98608 8.16419 173.5 299 0.9385 0.92155 0.052023 0.54052 1.40136 2 5 431 16.15864 50.5805 17.36019 8.71288 474.5 299 1.9782 1.15656 0.060757 0.44023 1.62642 2 6 271 5.024205 9.8355 15.31644 7.787075 442 300 2.142 1.374 0.044239 0.42189 1.60355 1 7 179 12.39987 35.987517.64293 8.945995 92.5 299 1.9278 1.538 0.0350690.32892 1.86458 1 8 239 10.21923 21.421 16.21187 8.462745 232 300 1.6434 0.92337 0.045067 0.49334 1.59333 2 9 81 4.84013 9.1595 14.9347 7.435795 115 300 0.4551 0.73122 0.041837 0.50123 1.6875 2 9a 212 9.74834 26.495 16.02302 9.99409 234.5 300 2.8003 1.76706 0.034328 0.25002 2.46512 2 10 968 6.355395 10.295 13.33967 6.668235 1347 300 1.4545 0.90746 0.105737 0.46634 1.86873 2 11 160 8.915015 16.5545 14.83783 7.78322 158.5 300 2.3645 1.32156 0.030167 0.36541 2.31884 2 12 120 21.17046 38.9755 17.27263 7.45737 55.5 300 2.2977 1.80495 0.025065 0.23011 2.5 1 13 267 8.107275 15.8975 14.06908 7.18749 393.5 300 1.4318 1.29012 0.051104 0.3691 1.82877 1 14 174 5.62974 10.246 13.77365 7.24648 392.5 299 0.3877 0.57743 0.074959 0.64527 1.28889 1 15 219 5.521305 8.7985 15.18145 6.3029 198.5 299 1.1134 0.99962 0.050077 0.44594 1.752 1 16 128 6.609095 10.3075 16.58418 5.96346 132 300 1.0305 0.62144 0.036511 0.7297 1.17431 2 17 147 7.134005 14.305 19.57387 6.830005 55.5 299 0.8015 0.37051 0.045124 0.84512 1.08889 2 18 448 19.65573 47.4775 15.51208 8.90383 325 300 1.3104 0.97159 0.072751 0.44565 1.97357 3 19 260 16.10894 38.7755 16.14497 9.011855 130.5 299 1.2588 1.47366 0.052992 0.29403 2.20339 3 20 303 12.15183 26.223 17.22326 7.598045 421.5 300 1.5752 1.72499 0.05329 0.20346 3.09184 1 20a 238 12.94194 32.168 15.67124 9.01052 239 300 0.5482 0.27477 0.074631 0.88005 1.06726 1
______CHAPTER V: MANGROVE FORESTS 91 Table 31 continued . . . 20b 58 20.74775 65.636 19.0687 7.3868 224 300 1.2314 1.42699 0.0197 0.26921 2.52174 3 21 107 4.10401 6.358 13.62741 6.80048 219.5 300 1.07 1.68669 0.031839 0.18727 4.28 2 22 51 21.51721 36.56555.543135 3.3 30.5 300 0 0 1 1 2 23 243 11.48765 24.8185 15.25982 8.421025 305.5 299 2.1846 1.12474 0.040941 0.50525 1.45509 2 24 209 24.57179 68.981 18.24059 8.489005 131.5 300 1.8718 1.48063 0.039284 0.31036 2.4881 1 25 194 24.0827 61.648 16.28903 9.49338 135.5 299 1.3288 1.34648 0.042904 0.32787 2.06383 1 26 274 9.62401 16.9075 14.72292 7.09475 108 300 0.5345 0.31577 0.082491 0.8618 1.07874 2 27 168 28.96791 97.5415 23.56492 9.56701 87 300 1.5613 0.78865 0.036517 0.6636 1.23529 1 28 77 9.303405 17.7035 17.01566 6.698735 90 300 2.3021 1.59055 0.018422 0.33219 1.7907 2 29 334 8.35007 20.0755 15.6005 9.49287 182 300 0.6883 0.6855 0.081552 0.57663 1.40928 1 30 200 41.68733 131.21820.07681 7.15969 41.5 299 1.3212 1.4288 0.043870.27181 2.5 1 30a 77 23.33777 73.3755 21.94367 9.05401 61.5 299 0.9209 1.47442 0.027446 0.24163 2.85185 2 31 66 14.87744 22.9935 15.26517 5.266085 286 300 0.9547 0.81922 0.024304 0.52075 1.5 1 32 53 0.7532 1.2495 19.79985 6.39596 20.5 299 1.2594 1.48255 0.01833 0.26415 2.40909 1 33 38 5.77419 8.93 16.44271 6.18854 35 300 1.3745 1.547620.014011 0.23613 2.53333 2
______CHAPTER V: MANGROVE FORESTS 92 Over all Stocking and Forest Condition
The continuous community based small scale cutting of mangrove depleted the secondary growth forest into reproduction stand with remnants of old growth trees left from cutting because of its twisted hardness of wood grains which were difficult to cut. The 30 years that lapsed from commercial large-scale cutting would have provided sufficient period for the mangrove to grow into densely timber size stand attaining growth of at least approximately similar to original mangrove forest. However, mangrove in the case of Linapacan and even in the entire Northern Palawan mangroves had been continuously used for pole, piles, fuelwood, fishtrap poles and low cost housing materials which primarily caused its current stage of growth condition. It is characterized as open-cleared stocking with correspondingly low stand volume due to low growth stature and loosely scattered-patches of vegetation. The continuous cutting for charcoal cleared more areas into open and devoid of vegetation, which can be difficult for natural regeneration to occur. But compareing the mangrove forest condition of Linapacan to other areas in Northern Palawan, Linapacan has relatively better forest condition than Culion , Coron and San Vicente.
28.0 RECOMMENDATIONS
Proposed Management Zoning
All mangrove areas in Palawan were declared as mangrove swamp forest reserve as per Presidential Proclamation 2152. The implementing rules and regulation of PP 2152 as embodied in the DENR Administrative Order No. 1521 series of 1986 allowed small-scale community based utilization in sustainable manner but conversion into other uses such as fishpond, settlement and agriculture are strictly prohibited. The PCSDS allowed issuance of CBFMA in mangrove areas under restriction of using the open, logged-over, inadequately stock areas for rehabilitation purposes only. Based on PCSDS guidelines mangrove under rehabilitation can be zoned as restricted multiple use zone. However, on the basis of the ECAN Management Framework and Guidelines, the entire mangrove areas of Palawan are classified as core zone but can be further categorized into restoration sub-zone if needing rehabilitation or restricted multiple use for mangrove areas covered by existing CBMFMAs can be zoned as multiple use zone. Nonetheless, PCSDS issued in 2003, SEP clearances for four (4) CBFMA projects with the objective of implementing mangrove restoration activities in the applied areas. Thus, this set the precedence for allowing CBFMA in mangrove areas of Palawan. Considering this development from PCSDS, the national mangrove policy as per PP 2152 and NIPAS law, mangrove areas in Palawan can now be therefore zoned into core zone, restoration zone and restricted multiple use zones.
It is therefore proposed that mangrove areas with open, logged over and inadequate stock with low stand volume be zoned into a restoration zone. On the other hand, mangrove forest with inadequate to adequately stock with moderate to high volume stand may be zoned into core zone while those mangrove areas identified with potential ecological tourist destination and those unproductive, abandoned fishpond and fishpond areas without FLA may be classified as restricted multiple use zone.
______CHAPTER V: MANGROVE FORESTS 93 Proposed Management Strategy
The management strategy recommended is presented in Table 32. Mangrove areas with similar forest structures and conditions with those of transect 5, 7, 12, 14, 18, 19, 20’B, 24, 25, 27 and 30’A shall be rehabilitated through assisted natural regeneration (ANR) that are intended for conservation purposes. The community based mangrove forest management agreement (CBMFMA) shall be an appropriate tenurial arrangement in rehabilitating mangrove areas either through ANR, reforestation or aqua silviculture. Mangrove with similar mangrove condition with transects 4 and 23 shall be appropriate for aqua-silviculture which is prescribed to rehabilitate areas with clearings and fishpond development either unproductive, abandoned and not covered with FLA. Immediate reforestation shall be applied to mangrove areas with similar state of forest structures and condition to transects 1, 2, 3, 6, 8, 9, 9’A, 10, 11, 13, 15, 16, 17, 20, 20’A, 21, 22, 26, 28, 29, 31, 32 and 33 (Table 32).
Table 32. Factors Considered in Choosing Apropriate Mnagement Srategies for Mangrove Areas Linapacan, Palawan, 2004
Average Forest Stand Biodi Threaten Transec Biodi Management Stocking Cover Volume Index Endemic t No. Hotspots Strategy Class Class Class Class Spp. Open/ Low Very Minimal CBMFM 1 Logged over Presence Cleared Volume Low Cuttings Forestation Open/ Low Very Minimal CBMFM 2 Logged over Presence Cleared Volume Low Cuttings Forestation Open/ Low Very Minimal CBMFM 3 Logged over Presence Cleared Volume Low Cuttings Forestation Open/ Newly Very CBMFM-Aqua 4 Cleared Logged over Low Presence Developed Low Silviculture Volume Fishpond Open/ Very W/ Coconut CBMFM 5 Logged over Presence Cleared Moderate Low Plantation ANR Open/ Low Very W/ Coconut CBMFM 6 Logged over Presence Cleared Volume Low Plantation Forestations Open/ Minimal CBMFM 7 Logged over Low Absence Cleared Moderate Cuttings ANR Open/ Low Very Minimal CBMFM 8 Logged over Absence Cleared Volume Low Cuttings Forestation Open/ Low Very W/ Cashew CBMFM 9 Logged over Absence Cleared Volume Low Plantation Forestation Open/ Low Charcoal CBMFM- 9A Logged over Low Absence Cleared Volume Making Forestation Inadequate Low Very Minimal CBMFM 10 Sparse Absence Volume Low Cutting Forestation
______CHAPTER V: MANGROVE FORESTS 94 Table 32 continued . . . Open/ Low Very Minimal CBMFM- 11 Logged over Absence Cleared Volume Low Cutting Forestation Open/ Minimal 12 Logged over Low Absence CBMFM-ANR Cleared Moderate Cutting Open/ Low Very Minimal CBMFM- 13 Logged over Presence Cleared Volume Low Cutting Forestation Open/ Moderate Very Minimal 14 Logged over Presence CBMFM-ANR Cleared Volume Low Cutting Open/ Low Very Minimal CBMFM- 15 Logged over Presence Cleared Volume Low Cutting Forestation Open/ Low Very Minimal CBMFM- 16 Logged over Presence Cleared Volume Low Cutting Forestation Open/ Low Very Minimal CBMFM- 17 Logged over Presence Cleared Volume Low Cutting Forestation Open/ Very W/ Coconut 18 Logged over Presence CBMFM-ANR Cleared Moderate Low Plantation Open/ Very Rampant 19 Logged over Presence CBMFM-ANR Cleared Moderate Low Cuttings Open/ Low Minimal CBMF- 20 Logged over Low Presence Cleared Volume Cutting Forestation Open/ Low Very Minimal CBMFM- 20A Logged over Presence Cleared Volume Low Cutting Forestation Open/ Very Minimal 20B Logged over Presence CBMFM-ANR Cleared Moderate Low Cutting Open/ Low Minimal CBMFM- 21 Logged over Low Presence Cleared Volume Cutting Forestation Open/ Low Very Minimal CBMFM- 22 Logged over Presence Cleared Volume Low Cutting Forestation Open/ CBMFM-ANR Very 23 Cleared Logged over Presence Clearings and Low Moderate Fishpond Aqua-silviculture Open/ Very Rampant 24 Logged over Presence CBMFM-ANR Cleared Moderate Low Cuttings Open/ Very Minimal 25 Logged over Presence CBMFM-ANR Cleared Moderate Low Cuttings Open/ Low Very CBMFM- 26 Logged over Presence Cleared Volume Low Clearings Forestation Open/ Very Minimal CBMFM 27 Logged over Presence Cleared Moderate Low Cuttings ANR Open/ Low Rampant CBMFM- 28 Logged over Low Presence Cleared Volume Cuttings Forestation
______CHAPTER V: MANGROVE FORESTS 95 Table 32 continued . . . Open/ Low Very CBMFM- 29 Logged over Absence Cleared Volume Low Clearings Forestation Open/ High Very Charcoal CBMFM- 30 Logged over Absence Cleared Volume Low Making Protection Open/ Very Minimal CBMFM 30A Logged over Absence Cleared Moderate Low Cutting ANR Open/ Low Very CBMFM- 31 Logged over Absence Cleared Volume Low Cutting Forestation Open/ Low Very CBMFM 32 Logged over Absence Cleared Volume Low Cutting Forestation Open/ Low CBMFM- 33 Logged over Low Absence Cleared Volume Clearings Forestation
______CHAPTER V: MANGROVE FORESTS 96 REFERENCES
Al Attar, M. 1981. Studies on the penaeid shrimps of Kuwait. PhD. Dissertation, University of Wales. 217 pp.
Allen, G.R. 1991. Damselfishes of the World. Mergus Publishers Han A. Baensch, Melle, Germany. 271 p.
Allen, G. R. and R. Steene, 1998. Coral Reef: Indo Pacific Field Guide. Tropical Reef Research, Singapore. 378 pp.
Ballantine, B. 1994. The practicality and benefits of a marine reserve network. In: Limiting Access to Marine Fisheries: Keeping the focus on conservation. K.L. Gimel (ed.), pp. 205 –223. Center for Marine Conservation and World Wildlife Fund US, Washington D.C., 1994. 316 pp.
Ballantine, B. 1995. Networks of “no-take” marine reserves are practical and necessary. In; Marine Protected Areas and Sustainable Fisheries, (13-20 pp) N.L. Shackell and J.H.M. Willison (eds.), Science and Management of Protected Areas Association, Wolfville, Nova Scotia, Canada. 300 pp.
Ballantine, B. 1998. Marine reserves: the time for a new approach. Presented at the Department of Conservation, Wellington, October, 1998. 10 pp.
Bennagen, E. C. and D. M. Cabahug, Jr. 1991. Natural Resources Accounting: Mangroves Technical Report No. 2. Paper presented at the Natural Resources Accounting Final Workshop, October 15, 1991, NIGS, UP Diliman, Quezon City, Philippines (unpublished).
BFAR Annual Report. 1983. Exploration, inventory and survey of shoal reefs in waters of Palawan. Bureau of Fisheries and Aquatic Resources. pp. 10-11.
Cabahug, D. M. Jr. 1986. Timber Producing Mangrove Species Volume Functions in Palawan for Mangrove Timber Inventory Uses, Bakawan II (1):7, NRMC, Quezon City, Philippines.
Carpenter, K.E. and A.C. Alcala. Philippine coral reef fisheries resources, Part II. muro-ami and kayakas reef fisheries, benefit or bane? Phil.J. Fish. 15 (2): 217-225.
Coles, S.L. 1988. Limitations on coral reef development in the Arabian Gulf: temperature or algal competition. Proc. 6th Int’l. Coral Reef Symp., Australia. 9:231-237.
______REFERENCES 97 Colin, P.L. and C. Arneson. 1995. Tropical Pacific Invertebrates. A Field Guide to the Marine Invertebrates Occurring on Tropical Pacific Coral Reefs, Seagrass Beds and Mangroves. The Coral Reef Research Foundation. Coral Reef Press. 1353 pp.
Crossland, C.J. 1981. Seasonal growth of Acropora cf. formosa and Pocillopora damicornis on a high latitude reef (Houtman Abrolhos, Western Australia). Proc. 4th Intern. Coral Reef Symp., v. 1, pp. 663-667.
Digdigan, M.F. 2005. Baseline Assessment on the Status of Marine Mammals in the Municipality of Taytay, Northern Palawan. PCSD SEMP-ECAN.
Digdigan, M.F. 2005. Baseline Assessment on the Status of Marine Mammals in the Municipality of San Vicente, Northern Palawan. PCSD SEMP-ECAN.
English, S.C. Wilkinson and V. Baker (eds.) 1994. Survey manual for tropical marine resources. Australian Institute of Marine Science, Townsville.
English, S.C. Wilkinson and V. Baker (eds.) 1997. Survey manual for tropical marine resources. Australian Institute of Marine Science, Townsville (revised).
ERTL (Environment and Resource Technology Ltd.). 1995. Environmental profile offshore Philippines. Prepared for Shell Internationale Petroleum Maatschappij B.V., The Haque, Exploration and Production.
Fortes, M.D. 1981. Methodology: inventory and assessment of seaweed stocks in their natural environment, pp. 27-40. In Report on the Training Course on Gracilaria Algae. Manila Philippines.
Fortes, M.D. 1990. Seagrasses: a resource unknown in the ASEAN region. ICLARM Education Series 5, 46 pp. International Center for Living Aquatic Resoures Management, Manila, Philippines.
Fortes, M.D. 1995. Seagrasses at East Asia: environmental and management perspective. Marine Science Institute, United nations Environmental Program. Bangkok.
Froese, R. and D. Pauly, Editors. 2000. FishBase 2000: concepts, design and data sources. ICLARM, Los Baños, Laguna, Philippines. 344 p.
Gulko D.A. and Eckert, K.L. 2003. Sea Turtles: An Ecological Guide. Mutual Publishing, Honolulu, Hawaii. 128 pp.
Houghton, J., Callows, M., and Hays, G. 2003. Habitat utilization of juvenile hawksbill turtles around a shallow water coral reef. Journal of Natural History. 37: 1269-1280.
______REFERENCES 98 Ibrahim, K. 1994. The Status of Marine Turtle Conservation in Peninsular Malaysia. In: Proceedings of the First Asean Symposium-Workshop on Marine Turtle Conservation. World Wildlife Fund. Pp. 87-101.
Ingles, J. 2000. Fisheries of the Calamianes Islands, Palawan Province, Philippines. In Werner, T.B and G. R. Allen (eds) A rapid marine biodiversity assessment of the Calamianes Islands, Palawan Province, Philippines, RAP Bulletin of Biological Assessment 17. Washington, D.C.: Conservation International.
Jacobs, R.P.W.M. 1991. Exploration activities offshore Palawan, the Philippines. Environmental impact report. Prepared for Shell Philippines Exploration B.V. 34 pp.
Johannes, R.E., W. J. Wiebe, C.J. Crossland, D.W. Rimmer, and S.V. Smith. 1983. Latitudinal limits on coral reef growth. Mar. Ecol. Prog. Ser., v. 11, pp. 105-111.
Lugo, A.E. and Snedaker, S.C. 1974. The ecology of mangroves. Ann Rev. Ecol. Sys. 5: 39-64.
Macintosh, D.J. 1984. Ecology and productivity of Malaysia mangrove crab populations. 345- 377. In: Proceedings of the Asian Symposium on mangrove Environment-Research and Management. Soepadmo, E. Rao. A.N. and Macintosh, D.J. (Edus.). University of Malaysia, Kuala Lumpur, Malaysia.
Marsh, H., Penrose, H., Eros, C., and Hugues, J. 2002. Dugong Status Report and Action Plans for Countries and Territories. United Nations Environment Programme (UNEP) Early Warning and Assessment Reports Series, UNEP/DEWA/RS.02-1.
Meñes, E., R.C. Philipps and H. Calumpong. 1983. Seagrassess from the Philippines. Smith. Contrib. Mar. Sci. No. 21.
McCain, J.C., A.B. Tarr, K.E. Carpenter, and S. Coles. 1984. Marine ecology of Saudi Arabia. A survey of coral reefs and reef fishes in the northern area, Arabian Gulf. Saudi Arabia. Fauna of Saudi Arabia, v. 6, pp. 102-106.
McManus, J.W. 2002. The global importance of Philippine coral rees. In Aliño P.M., Miclat, E.F.B, Nañola, C.L. Jr., Roa-Quiaoit, H.A., and Campos, R.T. (eds). Atlas of the Philippine Coral Reefs, Philreefs, Goodwill Trading Co., Quezon Coty, xvi + 264 pp.
Montebon, A.R.F. 1997. Status of coral reefs in Negros Oriental, Cental Philippines. Proc. 8th Int’l. Coral Reef Symp., Panama. 1:295-300.
Morales, C.M., J. Buaruang, B.L. Stockwell, U. Satapoomin, N.V. Nguyen, and V.P.U. Nguyen. 2005. Benthos characterization in southern Palawan. In A.C. Alcala and M.C.G. Rañola (eds) Exercise Luzon Sea Phase I (Palawan Expedition). Report of the status of the marine environment and the marine resources of southern Palawan, Philippines, Occasional Papers of the Silliman University-Angelo King Center for
______REFERENCES 99 Research and Envronmental Management (SUAKCREM), Vol. 1 (1), January 2005, pp. 49-56.
MERF.1994. Environmental baseline and sensitive resources study of northwestern Palawan area. Study commissioned by Shell Philippines Exploration (SPEX). 78 pp.
Morgan, J. and M.J. Valencia. 1983. Atlas for marine policy in Southeast Asian seas. Berkeley, USA: University of California Press.
Lieske, E and R. Myers. 2001. Coral Reef Fishes, Indo-Pacific and Caribbean. Princeton University Press, Princeton, New Jersey. 400 p.
Odum, W.E. and Heald, E.J. 1975. Mangrove forests and aquatic productivity. 129-136. In: Coupling of Land and Water System. Hasler, P.D. (Ed.). Springer-Verlag, Berlin.
Ong, J.E., Gong, W.K., Wong, C.H. and Dhanarajan, G. 1984. Contribution of aquatic productivity in managed mangrove ecosystem in Malaysia. 209-215. In: Proceedings of the Asian Symposium on Mangrove Environment-Research and Management. Soepadmo, E., Rao, A.N. and Macintosh, D.J. (Eds.). University of Malaysia.
Ong, T.L. and Sasekumar, A. 1984. The trophic relationship of fishes in the shallow waters adjoining a mangrove shore. 453-469. In: Proceeding of the Asian Symposium on Mangrove Environment-research and Management. Soepadmo, E., Rao, A.N. and Macintosh, D.J. (Eds.). University of Malaysia Kuala Lumpur, Malaysia.
Philippine Coast Pilot. 1968. Part II. Sailing directions for the coast of Palawan, Mindanao and Sulu Archipelago, 5th Edition. Department of National Defense- Bureau of Coast and Geodetic Survey (DND-BCGS). 126 pp.
Randall, J.E., G.R. Allen and R. Steene. 1997. The Complete Divers’ and Fishermen’s Guide to Fishes of the Great Barrier Reef and Coral Sea (revised and expanded edition). Crawford House Publishing Pty. Ltd.. 557 pp.
Short, F.T., Mckenzie, L.J., Coles, R.G. Gaeckle, J.L. 2004. Sea grassNet Manual for Scientific Monitoring of Seagrass Habitat-Western Pacific Edition. University of New Hampshire, USA; QDPI, Northern Fisheries Centre, Australia. 71 pp.
Smith, S.V. 1981. Marine macrophytes as a global carbon sink. Science, v. 211, pp. 838-840.
Snedaker, S.C. 1978. Mangroves: Their value and perpetuation. Nature and Resources 14: 6-13.
Snedaker, S.C. 1984. The mangroves of Asia and Oceanic: Status and research planning. 5-15. In: Proceedings of the Asian Symposium on Mangrove Environmental-Research and Management. Soepadmo, E., Rao, A.N. and Macintosh, D.J. (Eds.). University of Malaysia, Kula Lumpur, Malaysia.
______REFERENCES 100 Soegiarto, A. 1984. The mangrove ecosystem in Indonesia, its problems and mgt. 69-78. In: Physiology and Mgt. of Mangroves. Teas, H.J. (Ed.) Dr. W. Junk Publishers. The Hague.
Spotila, J. 2004. Sea turtles: a complete guide to their biology, behavior, and conservation. The Johns Hopkins University Press. 227 pp.
Thong, K.L. and Sasekumar, A. 1984. The trophic relationships of the fish community of the Angsa bank, Selangor, Malaysia. 385-399. In: Proceedings of the Asian Symposium on Mangrove Environment- Research and Mgt. Soepadmo E., Rao, A.N. and Macintosh, D.J. (Eds.) . University of Malaysia, Kuala Lumpur, Malaysia.
Trinidad-Roa, M.J. 1989. Mariculture potential of giant clams and sea in the Lingayen Gulf area. pp. 133-137. In G. Silvestre, E. Miclat, and T.-E. Chua (eds.) Towards sustainable development of the coastal resources of Linvayen Gulf, Philippines. ICLARM Conference Proceedings 17, 200 pp.
Trono, G.C. Jr. and R.T. Biña. 1987. Notes on the vertical distribution and species succession of macrobenthic algae in highly disturbed reef. Phil. Jour. Sci. 17:55-61.
Vousden, D.H. 1988. The Bahrain marine habitat survey: a study of the marine habitats in the waters of Bahrain and their relationship to physical, chemical, biological and anthropogenic influences. Vol. 1-The technical Report. State of Bahrain, 103 pp.
WCPI. 2000. Environmental monitoring of gas pipe laying activities, Linapacan Strait, September/October 2000. Terminal Report. Study commissioned by Shell Philippines Exploration (SPEX).
White, A. T. 1987. Philippine coral reefs: a natural history guide. New Day Publishers, Manila.
White, A.T. 1990. Coral reefs: valuable resources of Southeast Asia. ICLARM Education Series 1, 36 pp. International Center for Living Aquatic Resources Management, Manila, Philippines.
______REFERENCES 101