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Explore the ecology and status of dugongs in Johor through aerial surveys, habitat mapping, and feeding ecology investigations. Learn about dugong distribution, habitat use, and feeding preferences to inform conservation efforts. Collaborative research aims to protect critical habitats and address knowledge gaps to support dugong and seagrass conservation in Johor. Supported by a dedicated team and local collaborators. Join us in safeguarding marine biodiversity and promoting sustainable practices in the Mersing Archipelago. Pending gazette for the Johor Dugong Sanctuary. Thank you! (500 characters)
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Dugong and seagrass research results – Project MY4 Louisa Ponnampalam. Ng Jol Ern . Jillian Ooi . Heng Wei Khang . Gregory Verutes
“A Multi-Pronged Approach in Overcoming Knowledge Barriers on the Ecology and Status of Dugongs in Johor – Towards Critical Habitat Protection (MY4-2114)”
Research team and collaborators • Jillian Ooi, University Malaya • Heng Wei Khang, University Malaya • KeeAlfian, SEAlutionsSdnBhd • Affendi Yang Amri, University Malaya • Ng Jol Ern, MareCet • Louisa Ponnampalam, MareCet • Gregg Verutes, Universidade de Santiago de Compostela, Spain
Project site @ PulauSibu and Pulau Tinggi, Johor,Malaysia Bali
Dugong/seagrass conservation issues Problem • Lack of detailed information on dugong distribution • Some parts of core habitat fell outside protected area (Ponnampalam et al. 2015) • Lack of information on dugong density and habitat use • Lack of information and understanding on the overlaps with human activities • Seagrass meadows at PulauSibu extensive but never been mapped in detail • Lack of knowledge on main dugong feeding grounds • Lack of information on dugong feeding preferences Objectives • Determining dugong distribution and habitat use • MappingPulauSibu seagrass meadows • Investigating dugong feeding ecology around PulauSibu and Pulau Tinggi
Strategy, Methods, Tools • Aerial surveys to systematically collect data on dugong distribution across the years, and in differing variables (e.g. time of day, tidal state), and data on the occurrence and distribution of human activities • Bycatch Toolkit – Risk Assessment • Seagrass mapping of PulauSibu • Underwater surveys of the subtidal seagrass to identify core feeding grounds and sample feeding trails and seagrass • Laboratory analyses of seagrass samples and photo-quadrat data
RESULTS Aerial surveys
Dugong core areas 2.7 dugong sightings/100 km 4.5 dugong sightings/h (LOW encounter rates) 642 sightings 24.5% sightings with calves Group size range: 1 – 43 (Mean = 1.9 ± 3.6, Median = 1, Mode = 1) X Mother-calf pair sightings All sightings
ByRA (bycatch risk analysis) Trawls Nets
ByRA (bycatch risk analysis) Recreational fishing Traps
ByRA (bycatch risk analysis) FISHERIES BYCATCH RISK was calculated as: (1) exposure(the degree a species experiences stress due to gear-specific threat (spatial/temporal overlap, threat intensity, likelihood of interaction, catchability, and current status of management strategies)); (2) consequence(defined as the resilience of a species to a stressor (age of maturity, reproductive strategy, population connectivity, local status of species)); and (3) sensitivity(mortality and life stages affected by gear).
ByRA toolkit Verutes et al. in prep Hines et al. in prep
Results Co-investigators: Jillian Ooi, Heng Wei Khang (University of Malaya) Seagrass mapping Pic: Heng WK Pic: Nazirul Amin
Dugong feeding grounds Inter-monsoon, June 2016 Pre-monsoon, Oct 2016
Dugong feeding trails Feeding trail dimensions
Dugong feeding preferences Analysis by: Heng Wei Khang (University of Malaya) • Main species consumed – Halophilaovalisand Haloduleuninervis • HO shoot density was significantly higher in FT compared to NFT (Wilcoxon rank sum: Z = 2.16, n = 22, p = 0.03). • HO was significantly higher than HU in FT (Wilcoxon signed rank: Z = 4.93, n = 22, p = <0.001) Denser HO areas were preferred by dugongs. Shoot Density (m-2) Seagrass sp_Area type
Dugong feeding preferences Analysis by: Heng Wei Khang (University of Malaya) • HO biomass was significantly higher in FT areas compared to NFT areas. • HO biomass was significantly lower than HU only in NFT areas higher HO biomass areas were preferred Seagrass Biomass (g/ DW m2) Seagrass sp_Area type
Not just a research project….. Mersing Archipelago IUCN Important Marine Mammal Area – Sep 2018
Not just a research project….. Towards the Johor Dugong Sanctuary 150,000+ ha
Not just a research project….. MANAGEMENT • Enhance governance, encourage co-management • Towards financial sustainability Towards the Johor Dugong Sanctuary CONSERVATION • Increasing understanding • Minimizing threats • Sustaining dugongs, seagrass and fisheries OUTREACH • Improving awareness • Increasing recognition • Empowering communities DEVELOPMENT • Improving facilities and amenities • Introducing unique products • Creating new livelihoods • World class conservation and ecotourism area Pending Gazette by the Dept of Fisheries Malaysia
Lessons learned Aerial surveys Seagrass surveys ?? X 17
Replication potential ByRA toolkit