Greetings all, on behalf of my colleagues, we are happy to share this new open access publication as part of a special issue on Marine Vertebrate Bycatch in Endangered Species Research: https://www.int-res.com/journals/esr/specials/marine-vertebrate-bycatch-problems-and-solutions/

Getting to the bottom of bycatch: a GIS-based toolbox

to assess the risk of marine mammal bycatch

Ellen Hines, Louisa S. Ponnampalam, Chalatip Junchompoo, Cindy Peter,

Long Vu, Thien Huynh, Marjolaine Caillat, Andrew F. Johnson, Gianna Minton,

Rebecca L. Lewison, Gregory M. Verutes

ABSTRACT: Marine mammal bycatch poses a particular challenge in developing countries,

where data to document bycatch and its effects are often lacking. Using the Bycatch Risk Assessment

(ByRA) toolkit, based on InVEST open-source models, we chose 4 field sites in Southeast

Asia with varying amounts of data on marine mammals and fishing occurrence: Trat province in

the eastern Gulf of Thailand, the Sibu-Tinggi Islands and Kuching Bay, Malaysia, and Kien Giang

Biosphere Reserve in southwestern Vietnam. These field sites have similar species of coastal marine

mammals, small-scale and commercial fisheries, and support for research from universities

and/or management. In Thailand and Kuching, results showed changing patterns of fishing and

Irrawaddy dolphin Orcaella brevirostris habitat use across seasons, showing how bycatch risk

could change throughout the year. Risk maps for dugongs Dugong dugon in peninsular Malaysia

highlighted patterns of bycatch risk concentrated around a mainland fishing pier, and revealed

high risk in a northern subregion. In Vietnam, first maps of bycatch risk for the Irrawaddy dolphin

showed the highest risk driven by intensive use of gillnets and trawling gear. ByRA pinpointed

areas of spatial and seasonal bycatch exposure, and estimated the consequence of bycatch on

local species, providing managers with critical information on where to focus bycatch mitigation

and meet new global standards for US Marine Mammal Protection Act and other international

regulation (e.g. Official Journal of the European Union 2019; Regulation 2019/1241) compliance.

The toolbox, a transferable open-source tool, can be used to guide fisheries management, marine

mammal conservation, spatial planning, and further research.

Thanks to funding from the IWC Bycatch Mitigation Initiative, we have manuals for the toolbox in both English and Spanish (Kuit et al 2020).

Please email me and I’m glad to send.

Be well and be safe, Ellen

Ellen Hines, PhD

Associate Director and Professor of Geography & Environment

Estuary and Ocean Science Center

San Francisco State University

3150 Paradise Dr. Tiburon, CA 94920