Non-target bycatch or incidental catch in fishing gear is a global problem that concerns marine conservation biologists and fishers alike. Large vertebrate entanglements impose substantial mortality often reflected at population levels. The most destructive fishing gear to non-target animals is the gillnet, the ubiquitous gear of choice by inshore commercial fishers owing to high catch rates. Each year, hundreds of thousands seabirds are drown in gillnets in the North Atlantic, and in Atlantic Canada extensive gillnet fishing in Newfoundland accounts for most seabird bycatch drowning thousands of seabirds [murres, puffins, gannets, shearwaters] on an ongoing annual basis with negative population effects.
As the northern cod gillnet fishery is re-opening after 25 years of closure, it is opportune time for collaborative research with commercial fishers to address unwanted by-catch problems. This development and the dominance of gillnet fishing throughout northern oceans make it imperative to
1) improve estimates of bycatch mortality,
2) minimize the gear's destructive aspects and
3) consider alternative fishing options.
The present application integrates fishery, biological, behavioral and risk/benefit investigations and analyses in experiments that measure and compare target catch and non-target bycatch to test hypotheses about the behavioral and ecological interactions of seabirds, fishes and fishers with different fishing gears. Research objectives are to fill critical bycatch information gaps with different gears [surface and deep-set gillnets, hand-lines], to modify gear with warning flags and lights and manipulate fishing activity [set and soak times] to minimize bycatch without impacting target catch, to compare bycatch, catch and catch quality among gear types, and to assess fishers' behavior, risk and concerns with different gear types. Research objectives will be achieved through five hypothesis-driven projects that fill critical information gaps about bycatch mortality and mitigation, including the unstudied herring gillnet fishery.
The integration of the basic and applied research projects proposed in this Discovery research program will enable a novel interdisciplinary “real world” program of scientific inquiry that will lead the way forward on bycatch mitigation, conservation and sustainable fishing practices. Comparative studies of fishing gear modifications, fishing activity, catch quality, fisher behavior, risk and attitudes, and outreach engagement will provide the next generation of environmental scientists with research and analytical expertise grounded in direct collaboration and onboard experiment with commercial fishers. This program assures successful achievement, evidence-based decision-making, conflict resolution, and future inquiry.