Principal Investigator: Todd Jones (PIFSC)
Co-Principal Investigators: John Wang, Summer Martin (PIFSC)
Key Collaborators: Bagus Oktori Sutrisno (Indonesia Ministry of Marine Affairs and Fisheries Directorate of Fishing Vessel and Fishing Gear), Professor Ronny Wahyu (Bogor Agricultural University, Department of Fisheries and Marine Science), Iman Musthofa (WWF - Indonesia, Marine and Fisheries Program), Dwi Ariyoga Gautama (WWF - Indonesia, Fisheries and Bycatch Program), Joel M. Palma (WWF – Philippines)


Project title

Quantifying marine turtle bycatch in small scale coastal fisheries of the Western Pacific

Background

Significant overlap of small-scale coastal fishery activity and sea turtle foraging habitat and nesting beaches in the Western Pacific and Coral Triangle region increase chances of bycatch for several highly endangered sea turtle populations including: leatherback (Dermochelys coriacea], green (Chelonia mydas) – Central Western Pacific and Central South Pacific distinct population segments (DPSs), hawksbill (Eretmochelys imbricata), olive ridley (Lepidochelys olivacea), and loggerhead (Caretta caretta). There is also very limited monitoring in the region to assess the impacts of extensive coastal fishing efforts on sea turtle populations. Assessing bycatch rate and associated mortality is critical to population assessments for sea turtles, as it informs the management of these species.

Research Objectives

In this proposal, we aim to quantify fisheries interaction rates with the 5 turtle species found in Indonesian and Filipino waters using a 2-pronged approach for data collection. Our approach includes (1) rapid assessments of fishing ports to obtain initial information on local fishing practices and turtle interactions; and followed by (2a) onboard fisheries observers to collect data on interaction and mortality rates from individual fishing vessels and (2b) a novel use of electronic monitoring systems to augment onboard observers and help expand the overall observer coverage. We will then examine these data to produce a Bayesian model of bycatch rates that we can use to identify variables associated with high bycatch (Martin et al., 2015).

Project significance, impacts, and applications

This study will improve our understanding of marine turtle bycatch in Indonesia and in the Philippines, where coastal fishery interactions are believed to be high for several turtle species. Of particular interest are interaction rates with the recently uplisted Central Western Pacific and Central South Pacific green sea turtles and for Pacific leatherback turtle, which interact with Hawaii longline fisheries. In addition, the established observer programs will provide the foundation for future bycatch mitigation gear trials in the fisheries. Our ultimate goal is to not only characterize the bycatch of marine turtles in these fisheries, but to also test bycatch mitigation tools (e.g. circle hooks for longline fisheries, net illumination for gillnet fisheries (Wang et al., 2013), and TEDs for trawl fisheries). Lastly, by developing these in water capabilities, we will be able to have platforms in which to help future projects aimed at post mortality studies, telemetry studies of juvenile/sub adults, resource use (Jones et al., 2012), etc.

These data directly fulfill two aspects of the SAIP Research Theme D – collect and analyze fisheries bycatch data. Specifically, this project will 1) identify and estimate the temporal and spatial distribution of bycatch within foraging and mating areas and along migration routes, and 2) advance development of novel EM tools for improved estimation of fisheries bycatch on sea turtle populations, particularly in data-poor regions.