Banda & Ceram Seas Marine Mammal Survey, east Indonesia: 5-15 November 2016
- Benjamin Kahn
- Rili Djohani
Goal: A Rapid Ecological Assessment (REA) for Marine Mammals in the Banda and Ceram Seas, Maluku Province, Indonesia.
A successful Rapid Ecological Assessment (REA) for Marine Mammals in the Banda and Ceram Seas was conducted on a bluewater sailboat from 5-15 November 2016, covering 1022 kilometers of trackline (552 nautical miles) during 108 daylight survey hours. The project was led by APEX Environmental and The Coral Triangle Center, with funding from the USAID-Sustainable Ecosystem Assessment program.
The Banda-Ceram Seas Marine Mammal REA was specifically designed to address the data-deficiency of this important species group in one of the most remote regions of eastern Indonesia with exceptional oceanic features such as clusters of seamounts, isolated oceanic islands, canyons, ecological corridors and vast, deep yet sheltered bays - all strongly influenced by the Indonesian Throughflow current.
The REA route included the following islands and surrounding waters:
Ambon - Haruku - Saparua - Nusa Laut - central S Ceram - the Banda Neira island group - W Ceram and Piru Bay - Manipa Island and Manipa Strait (the main channel between the islands of Ceram and Buru).
The marine mammal biodiversity recorded during the REA was exceptional. A total of 16 marine mammal species - 15 species of whales and dolphins and the dugong - were identified during the visual and acoustic assessment (this survey included hydrophone listening stations). A total of 49 separate sightings were recorded, resulting in a minimal animal count of 1771 individuals. A suite of other data were also noted for each sighting such as environmental parameters, group size and group composition and various behaviours.
Species positively identified included:
Blue whales, Bryde's whales, beaked whales, sperm whales, dwarf sperm whales, pilot whales, false killer whales, melon-headed-whales, pygmy killer whales, Risso’s dolphins, Fraser's dolphins, spinner and spotted dolphins, common and Indo-Pacific bottlenose dolphins, as well as the dugong.
Blue whales were the most frequently sighted large cetacean. This REA build on previous work done in the same waters (Kahn 2005, 2014 and unpublished data), confirming the Banda-Ceram seas important ecological role as a migratory end-point or "destination" for this endangered species – the Banda Blues. The REA included approx. 10 hours of intensive ecological tracking of blue whales, logging locations, durations and blow rates for long, uninterrupted series of surfacings. Sightings of mother-calf blue whale pairs, combined with habitat use observations of typical and frequent foraging behaviour of the mothers (as opposed to migratory behaviour) further confirms the Banda-Ceram Seas as critical blue whale habitat for both calving and nursing
In addition to the exceptional marine (mammal) bio-diversity, distribution, relative abundance and habitat use for priority species; the REA also recorded seabird diversity, marine IBAs (Important Bird Areas), the occurence of other large marine life (“non-cetaceans” such as billfish, oceanic sharks, turtles, mola mola) as sighted from deck. No in-water activities were planned for this REA. An important component of the REA was an initial treat assessment for marine mammals in these waters. The main and immediate threat are the numerous plastic trash fields recorded and categorized along all survey routes. In total we recorded
Fisheries interactions (i.e. net entanglements, propeller cuts from speedboats, accidental and possible targeted takes), shipping (international sealanes run through this area, as well as high local shipping densities and fast ferries) and oil and gas activities are other threats by ocean industries that need to be considered in marine mammal management plans.
This boat-based project in a remote and data-deficient region of the Coral Triangle also doubled-up as a Training-of-Trainers (ToT) project for the field team, which included marine monitoring and surveillance staff from the Coral Triangle Center and the Ministry of Fisheries and Marine Affairs.
Upon completion of the REA, a post-survey meeting was arranged at Pattimura University's Ecosystem Approach to Fisheries Management Learning Center. This half day seminar was attended by many local stakeholders, who had the first opportunity to provide feedback on the initial REA outcomes as presented (Kahn et al., 2016). One of the recommendations from local stakeholders was that the Banda-Ceram Seas Marine Mammal REA:
• has already provided important new knowledge on both species diversity, critical and preferred habitat use and initial threats.
• has created opportunities to collaborate with local stakeholders on marine mammal monitoring and conservation.
• will further assist with marine conservation planning for Maluku Province, including the development of a new provincial network of Marine Protected Areas.
A comprehensive Technical Report will be released by early 2017, including all the REA’s results, discussion and initial management recommendations. Additional marine mammal conservation projects in the Banda - Ceram Seas region will be conducted in 2017 and 2018.