IRRAWADDY DOLPHINS IN THE BAY OF

Saifullah A. JAAMAN1*, Nurul Hidayah ABDUL RAHIM1, Azzakirat ABDUL RAMAN1, Bohari ABDULLAH2 ,Nurlisa AZIZUL1, James BALI3, Farah Dayana HAJI ISMAIL1, Toloy KERIPIN MUNSANG3, Anisul Islam MAHMUD4, Mohd Vol MOMIN2 Azmi Marzuki MUDA1, Hairul Masrini MUHAMAD5, Felicita SCAPINI4 & Xuelei ZHANG6 1Institute of Oceanography & Environment (INOS), Universiti Terengganu (UMT), 21030 Kuala Nerus, Terengganu, Malaysia. 2 Sakam Enterprise, Unit 17C, 2nd Floor, Bgn. Ben Kassim & Hjh Zaliha, Spg 440, Kg. Sungai Tilong, Jalan Muara BC3315, Brunei Darussalam. 3SARAWAK FORESTRY Corporation Sdn. Bhd., Lot 218, KCLD, Jalan Tapang, Kota Sentosa, 93250 Kuching, Malaysia. 4Le Département de Biologie des Organismes (DBO), Université Libre de Bruxelles, (ULB), Franklin Roosevelt laan 50, 1050 Brussels, Belgium. 5Key Laboratory of Underwater Acoustics & Marine Information Technology, Department of Applied Marine Physics & Engineering, College of Ocean and Earth, Xiamen University, China. 6Marine Ecology Research Center, First Institute of Oceanography (FIO), State Oceanic Administration (SOA), Qingdao 266061, China. *Corresponding author: [email protected] Introduction • Irrawaddy dolphin is the most common inshore cetacean species sighted in large estuaries and bays of East Malaysia and (Jaaman, 2008; 2010; Minton et al., 2011; Jamal-Hisne et al., 2013) • Its habitat overlap with areas of intensive use by human activities, e.g. fishing, water traffic • Its population and habitat threaten - • By-catch in fisheries – gillnetting, trawling • Coastal development – habitat loss and degradation • Declining fishery resources • Increasing water traffic – accident, noise • Population and behavioural knowledge – vital aspect of the dolphin ecology and an indispensable component in the management of MES populations

Irrawaddy dolphins sighted in the Bay of Brunei. • A deep bay and sheltered from the conditions. • A natural sea port for the maritime and petroleum industries. • Extensive artisanal fishing and commercial trawling operate throughout the year. Why is the Bay of Brunei IMPORTANT?

• Since 2004, research and monitoring of the marine mammals and sea turtles (Marine Endangered Species – MES) and their habitats were conducted in the Malaysian side. • Collaborators: UMT, UMS, Forestry Corporation (SFC), Marine Parks & Bruneian friends (SAKAM Conservation Program). • A unique and special marine ecosystem – forests, seagrass beds, coral reefs, large estuaries, and continental slope…..esp. in Lawas, Sarawak.

• High diversity of fauna and flora. • Important nursery, feeding and transient ground for dugongs, turtles, dolphins, commercial fishes/shrimps, and seabirds. Why choose BAY OF BRUNEI??

 Consist of unique marine Large estuaries of Kuala ecosystems Lawas and Kg. Awat- • Mangrove forest Awat • Large estuaries • Seagrass beds • Mudflats

Seagrass at Bukit Sari, Kuala Lawas Kuala Lawas  BB is less exploited  BB & MES face multiple stressors:  climate change  pollution, land reclaimation, ship navigation, fishing  High diversity of fauna and flora.  Important nursery, feeding and transient ground for dugongs, turtles, dolphins, commercial fishes/shrimps, and seabirds. High fisheries productivity

Mangrove-rich ecosystem • A natural sea port for the maritime and petroleum industries. Labuan Island

Ferry and speed boat services at Menumbok,

PETRONAS petroleum refinery 9 center METHODOLOGY

Brunei Bay

Semi enclosed shared by: • Sabah • Sarawak • Malaysian Federal Territory of Labuan Study site – Bay of Brunei (N5 05.517, E115 19.300) • Brunei Darussalam Boat Survey Effort • Started from April 2013 (HICOE UMT) • Extended in Jan 2015 (FIO-UMT) and continues till Oct 2018 Brunei Bay • Cover all coastal waters • During Northeast (Jan), Pre- Southwest (Apr), Southwest (July) and Pre-Northeast (Oct) monsoon seasons

Planned routes for Brunei Bay boat survey

Survey route planning RESULTS The Bay of Brunei Malaysia and Brunei Darussalam Map of survey tracks and sighting of Irrawaddy dolphin in the Bay of Brunei (January 2013 – October 2018)

• Total number of Irrawaddy dolphin sightings = 145

• Total distance = 4,395.0 km • • Total hours = 308.97 hours

• Total survey effort = 50,059.57 kmh

Legend

Boat track line

Irrawaddy dolphin OVERALL EFFORT BY REGION (Brunei and Malaysia)

Sighting Day Time Survey Effort No of Region Distance (km) rate (100 Surveyed (hour) (kmh) Sighting km.hrs)

Labuan 15 965.20 69.81 5,156.05 8 0.16

Weston 40 2,639.60 207.13 13,611.25 16 0.12

Lawas 61 3,441.60 245.39 15,447.42 57 0.37

Brunei 44 2,998.80 228.46 15,844.86 64 0.40

TOTAL 160 10,045.20 750.79 50,059.57 145 0.29

Table 1.1 Overall boat survey effort and sighting rate of Irrawaddy dolphins in the Bay of Brunei between April 2013 and October 2018 by region. 18000 0.45 16000 0.40 14000 0.35 12000 64 0.30 10000 16 0.25 8000 57 0.20 6000 0.15 4000 0.10 Survey Effort (kmh) Effort Survey 8

2000 0.05 (100km.hrs.) Rate Sighting 0 0.00 Labuan Weston Lawas Brunei Region Survey Effort(kmh) Sighting rate (100 km.hrs)

Figure 1.1 : Survey effort and sighting rate of Irrawaddy dolphins observed at different region of the Bay of Brunei.

Occurrence by region: (휒2 = 27.64, df = 3, p < 0.01) Highly significant difference; p= 4.32x10-06 Num. of sighting between region. OVERALL EFFORT BY MONSOON SEASON (Brunei and Malaysia)

Survey Sighting Day Distance Time No of Season Effort rate (100 Surveyed (km) (hour) Sighting (kmh) km.hrs)

JAN (NE) 43 2,606.50 209.38 13,461.09 31 0.23 APRIL (Pre-SW) 38 2,326.20 160.65 10,802.06 40 0.37 JULY (SW) 42 2,648.80 195.41 13,100.54 42 0.32 OCT (Pre-NE) 37 2,463.70 185.35 12,695.88 32 0.25 TOTAL 160 10,045.20 750.79 50,059.57 145 0.29

Table 1.2 Overall boat survey effort and sighting rate of Irrawaddy dolphins in the Bay of Brunei between April 2013 and October 2018 by monsoon seasons. 18000 0.45 16000 0.40 14000 0.35 12000 0.30 10000 0.25 8000 0.20 6000 42 32 0.15 4000 31 40 0.10

Survey Effort (kmh) Effort Survey 2000 0.05 0 0.00

JAN (NE) APRIL (Pre-SW) JULY (SW) OCT (Pre-NE) (100 km.hrs.) Rate Sighting Monsoon season

Survey Effort (kmh) Sighting rate (100 km.hrs)

Figure 1.2 Survey effort and sighting rate of Irrawaddy dolphins observed during monsoons in the Bay of Brunei

Occurrence by season: (휒2= 5.12 , df = 3, p > 0.05) No significant difference; p= 0.16351 Num. of sighting between season OVERALL GROUP SIZE BY REGION (Brunei and Malaysia) Num. of groups with Num. of Sighting Rate calf REGION Group size sighting (% of (per 100 (% of total number of total) km.hrs) sighting) Mean SD Median Range LABUAN 8(6%) 0.16 3(2%) 5.00 5.83 3.50 1 to 19 WESTON 16(11%) 0.12 4 (3%) 8.46 7.02 7.00 1 to 21 LAWAS 57(39%) 0.37 31 (21%) 8.77 7.26 7.00 1 to 35 BRUNEI 64(44%) 0.40 14 (10%) 4.13 3.26 3.00 1 to 15 TOTAL 145 0.29 52 (36%) 6.36 6.02 4.00 1 to 35 Table 1.3 Overall group size of Irrawaddy dolphins in the Bay of Brunei between April 2013 and October 2018 by regions. significantly difference; Kruskal-Walis: H= 16.604, df = 3, p=0.001 group size between region

Post-hoc analysis (Mann-Whitney test): U=1044.000, p-val=0.000; there is a difference around Lawas and Brunei OVERALL GROUP SIZE BY REGION (Brunei and Malaysia)

50.00 10 45.00 9 • Group size ranges between 1 to 35 40.00 8 individuals. • Out of 145 sightings of Irrawaddy 35.00 7 dolphins, 30.00 6 • 52 (36%) occurrences of calves in 25.00 5 the group ranges between 1 to 4 20.00 4 individual 15.00 3

10.00 2 • Highest mean of total individuals Num. of sighting total) of (% ofsighting Num. 5.00 1 per group was found in Lawas 0.00 0 (8.77, SD=7.26) Labuan Weston Lawas Brunei Region • The biggest group size of Irrawaddy dolphins (35 individuals) was also Num. of sighting (% of total) discovered in the area. Figure 1.3 Percentage of number of sighting of Irrawaddy dolphins in four different regions. OVERALL GROUP SIZE BY MONSOON SEASON (Brunei and Malaysia)

Num. of Group size Sighting Num. of groups with calf sighting Species Rate (per (% of total number of (% of 100 km.hrs) sighting) Mean SD Median Range total) JAN (NE) 31(21%) 0.23 17(12%) 8.52 7.67 7.00 1 to 35 APRIL (Pre-SW) 40(28%) 0.37 15(10%) 6.20 5.00 4.50 1 to 18 JULY (SW) 42(29%) 0.32 12(8%) 5.38 5.36 3.50 1 to 25 OCT (Pre-NE) 32(22%) 0.25 8(6%) 5.72 5.99 3.00 1 to 25 TOTAL 145 0.29 52(36%) 6.36 6.02 4.00 1 to 35 Table 1.4 Overall group size of Irrawaddy dolphins in the Bay of Brunei between April 2013 and October 2018 by monsoon seasons. Kruskal-Wallis: H = 5.6740, df = 3, p=0.129 No significant difference; group size between monsoon season OVERALL GROUP SIZE BY MONSOON SEASON (Brunei and Malaysia)

35 9 8 30 7 • Highest mean of total 25 6 individuals per group was 20 5 found during Northeast 15 4 3 monsoon (8.52, SD=7.67) 10 2 Number of sighting Numberofsighting total)(%of 5 1 • The biggest group size of 0 0 JAN (NE) APRIL (Pre-SW) JULY (SW) OCT (Pre-NE) Irrawaddy dolphins (35 individuals) was also Season Num. of sighting discovered during Northeast Num. of groups with calf (% of total number of sighting) monsoon. Mean

Figure 1.6 Percentage of number of sighting of Irrawaddy dolphins between monsoon in Brunei Darussalam and Lawas, Malaysia. GROUP SIZE (Brunei Darussalam) GROUP SIZE (Lawas, Malaysia)

35 8 35 12 30 7 30 10 25 6 25 5 8 20 20 4 6 15 15 3 4 10 2 10

5 1 5 2 Num. sighting Num.sighting oftotal) (% 0 0 0 0 JAN APRIL JULY OCTOBER JAN APRIL JULY OCTOBER Season

Num. of Sighting of (% total) ofSighting Num. Season Num. of sighting (% of total) Num. of sighting (% of total)

Num. of groups with calf (% of total number of Num. of groups with calf (% of total number of sighting) sighting) Figure 1.4 Percentage of number of sighting of Irrawaddy Figure 1.5 Percentage of number of sighting of Irrawaddy dolphins between monsoon in Brunei Darussalam. dolphins between monsoons in Lawas, Malaysia.

Kruskal-Wallis: H=9.667, df = 3 p=0.022 Kruskal-Wallis: H= 1.388, df = 3; p=0.708

Significantly difference; group size between monsoon No significant difference; season group size between monsoon season IRRAWADDY DOLPHIN’S ACTIVITIES (Brunei and Malaysia)

Feeding at the fishing area Group travelling Water spitting Surfacing many times

Fluking IRRAWADDY DOLPHIN PHOTO IDENTIFICATION (Malaysia’s side)

Using dorsal fin photo match software DARWIN

41 individuals of Irrawaddy dolphins were identified

The super-population size was 47 (95 % CI = 42 - 62) using mark-recapture open- population POPAN parameterization in Program MARK; the mean school size was 6 (SE = 0.66, range 1-18)

# Recent photo ID results = Figure 1.7 All 41 individuals of Irrawaddy dolphins with identified different 70 individuals dorsal fins in the Brunei Bay, Malaysia (2013-2015) (Mahmud, 2016). Figure 1.8 All 41 individuals of Irrawaddy dolphins with identified dorsal fin outlines in the Brunei Bay, Malaysia (2013-2015) that were imported from DARWIN 2.22 for iOS 2011 dorsal fin ID software (Mahmud, 2016). ON – GOING PROJECTS

How to Study MES? Bay of Brunei (Malaysia) Many ways to study them!! The MES PROGRAM is a collaborative research between UMT, FIO (China), UM and UMS in studying the population ecology and behaviour of cetaceans, dugong, and sea turtles, and human-animal interactions in Malaysia, particularly in the Bay of Brunei and Matang, Perak

Presentation by: Assoc. Prof. Dr. Saifullah A. Jaaman INOS-UMT Another ADVANCE method used to study marine endangered species (MES)?

Molecular/isotope analysis with autopsy and biopsy samples genetic analysis --->subpopulations, relationships within/between population/species analysis of lipids or stable isotopes--->feeding habits / age hormone levels ---> reproductive status

paxarms dart & rifle Genetic and Health Studies of Marine Mammals and Sea Turtles Another ADVANCE method used to study marine endangered species (MES)?

Bioacoustics: ultrasonic, sonic •Whistles/call/chirp: 0.2-24 kHz Emotion and Communication (most variable and complex) •Echolocation/click: 100-200 kHz Sensing surrounded environment •Burst pulse: loud & low freq. Stunning preys BIOACOUSTIC SURVEY Another ADVANCE method used to study marine endangered species (MES)?

Satellite/radio telemetry (+/- data loggers):  fors: long period, continuous monitoring of the habitats, migration paths  pros: relys on animal capture, the satellite(s) used matter accuracy Drones (UAV & USV) Intergrated Study of MES

Population dynamics spotting, photo ID UAV genetics Habitat and migration spotting, photo ID UAV bioacoustics satellite/SMS telemetry Biology and behaviors Molecular/isotope analysis spotting UAV bioacoustics satellite/SMS telemetry The significance of protecting dolphins, dugongs, sea turtles and their habitats:

 High diversity of MES.  Little information, particularly in Brunei waters.  Threatened by 1) incidental catches in fisheries, 2) loss or degradation of aquatic habitats, 3) water pollution, 4) declining food resources, 5) rapid coastal development, 6) destructive fishing methods, and 7) increasing water traffics (vessel collision).  Potentially a very important resource for tourism. THE WAY FORWARD... 1. To increase public awareness and strengthen legislative protection on MES (marine mammals and sea turtles) in the Bay of Brunei

2. To assess and explain the temporal and spatial patterns of occurrence, distribution and abundance of MES in the Bay of Brunei.

3. To identify and monitor influential chemical, physical and biological components of the environment that affect the MES distribution, abundance and behavioural patterns.

4. To identify the MES diversity and “hot-spot” habitats and develop a strategy for management and conservation of these areas (e.g. MPA).

5. To assess the feasibility of a small scale and sustainable MES-related tourism in the area. Program NICHE

MES Science (Marine Mammal & SeaTurtle) Awareness Restoration Conservation (MPA, Sanctuary) Critical Marine Habitats (Seagrass & ) Sunday, 10th Jan 2016 In the Bay of Brunei, Brunei Darussalam side

Mother & Calf Sunday, 10th Jan 2016 In the Bay of Brunei, Brunei Darussalam side Wednesday, 13th April 2016 At the Brunei Bay, Brunei Darussalam – Malaysian border Wednesday, 13th April 2016 In the Bay of Brunei, Brunei Darussalam side

Getting very close with the fishing boats Friday, 15th April 2016 In the Bay of Brunei Brunei Darussalam side

Mother & Calf

Mother & Calf Summary High productivity and healthy bay – existence of MES (e.g. dolphins, dugong, The Bay of Brunei turtles, shorebirds), fishery resources, and important habitat for Irrawaddy seagrass, mangrove, coral reef habitats dolphins and sea turtles in the SEA – and large mudflats/estuaries. feeding and nursery ground. The bay offers safe and well-preserved area A long-term monitoring and research for marine mammals and sea turtles program needed to aid the management sustaining natural ecological cycle. and conservation of MES and their habitats in the Bay of Brunei (Sabah, Sarawak, Labuan – Malaysia and BRUNEI DARUSSALAM). Acknowledgments: 1. MINISTRY OF PRIMARY RESOURCES & TOURISM (MPRT), BRUNEI DARUSSALAM 2. Department of Fisheries, Brunei Darussalam 3. SAKAM Conservation Program, Brunei Darussalam 4. Universiti Malaysia Terengganu (UMT) 5. Universiti Malaysia Sabah (UMS) 6. Universiti Malaya (UM) 7. First Institute of Oceanography (FIO), China 8. Xiamen University China Terima kasih (Thank You) REFERENCES 1. Jaaman, S. A. (2010). Marine mammals in East Malaysia: Distribution and Interactions with Fisheries. Saarbrucken, Germany: VDM Verlag Dr. Muller Aktiengesellschaft & Co. KG. 284 pp. 2. Jaaman, S. A., Abdullah, B., Abdul Rahim, N. H., Azizul, N., Haji Ismail, F. D., Mahmud, A. I., Momin, M. V., Muda, A. M., Muhamad, H. M. and X. Zhang. In press. Influences on the Daytime Behaviours of Irrawaddy Dolphins Orcaella brevirostris (Owen in Gray, 1866) in the Bay of Brunei. in The South China Sea: Oceanography Studies in Malaysian Waters (Suratman, S., ed.), Universiti Malaysia Terengganu, Kuala Terengganu. 3. Joseph, J., Nishizawa, H., Othman, R., Syed Kadir, S. A., Bali, J., Jalimin, S. N., Jolis, G., Jaaman, S. A. and X. Zhang. In press. Brunei Bay: A Major Foraging Ground for Green Turtle (Chelonia mydas) in South China Sea. in The South China Sea: Oceanography Studies in Malaysian Waters (Suratman, S., ed.), Universiti Malaysia Terengganu, Kuala Terengganu. 4. Jaaman, S. A., Muda, A. M., Abdul Raman, A., Bali, J., Keripin Munsang, T. and H. M. Muhamad. 2016. Survey of Marine Mammals in the Bay of Brunei, Malaysia. Pages 151-174, in Scientific Expedition to Brunei Bay (Suratman, S., ed.), Universiti Malaysia Terengganu, Kuala Terengganu. 5. Muhamad, H. M., Xu, X., Zhang, X., Jaaman, S. A., Muda, A. M., Haji Ismail, F. D. and N. Azizul. 2020. Echolocation Clicks of Irrawaddy Dolphins (Orcaella brevirostris) During Foraging in the Bay of Brunei, Malaysia. Acoust. Aust. https://doi.org/10.1007/s40857-020-00183-5. 6. Jiang, Y., Liu, Z., Yang, C., Lu, L., Yu, X., Huang, L., Zhang, X., Yang, Z., Yang, G., Sun, L., Jaaman, S. A. and A. M. Muda. 2020. High-frequency whistles of Irrawaddy dolphins (Orcaella brevirostris) recorded in Brunei Bay. Mar Mam Sci. 2020; 1–12. https://doi.org/10.1111/mms.12681. 7. Jiang, Y., Zhang, X., Yang, Z., Jaaman, S. A., Xu, Q., Muda, A. M. and H. M. Muhamad. 2019. Preliminary Analysis of Echolocation Signals Produced by Fleeing Irrawaddy dolphins (Orcaella brevirostris). Acta Oceanologica Sinica, 38(1): 85–89, doi: 10.1007/s13131-019-1373-y. 8. Mahmud, A. I., Jaaman, S. A., Muda, A. M., Muhamad, H. M., Zhang, X. and F. Scapini. 2018. Population Estimation, Distribution, and Habitat Preference of Orcaella brevirostris (Owen in Gray, 1866) in the Brunei Bay, Malaysian Waters. Wildlife Biology 2018: wlb.00383, doi: 10.2981/wlb.00383. 9. Mahmud, A. I., Jaaman, S. A., Muda, A. M., Muhamad, H. M., Zhang, X. and F. Scapini. 2018. Factors Influencing the Behaviour of Irrawaddy Dolphins Orcaella brevirostris (Owen in Gary, 1866) in Brunei Bay, Malaysia. Journal of Ethology (https://doi.org/10.1007/s10164-018-0549- 9) 10. Muhamad, H. M., Xu, X., Zhang, X., Jaaman, S. A. and A. M. Muda. 2018. Whistle Description of Irrawaddy Dolphins (Orcaella brevirostris) in Bay of Brunei, Sarawak, Malaysia. Journal of Acoustical Society of America 143 (5): 2708–2714. (https://doi.org/10.1121/1.5036926).