Combining electronic tag data and fish harvesters’ knowledge to identify ocean management concerns

Abstract

Understanding the distribution and reproductive behavior of marine species can inform ocean spatial management to address conservation needs and reduce risks of conflicts among various marine and coastal industries. Combining spatial data on species behavior with fish harvesters’ knowledge can be particularly effective for identifying spatiotemporal overlaps between human activities and critical events at various life stages of marine species. In the present study, the migratory behavior of Atlantic halibut (Hippoglossus hippoglossus), a flatfish of great economic importance in the Gulf of St. Lawrence, was characterized using electronic tags, and potential ocean industry impacts to the halibut population were identified using fish harvesters’ knowledge reported at public meetings and during semi-structured interviews. Results from electronic tagging analyses, including potential seasonal migration paths and presumed spawning locations, were presented to halibut harvesters who responded by identifying industries that could impact the halibut population. Harvesters identified the potential for halibut bycatch in the developing redfish trawl fishery as the main risk to the current high halibut abundance levels, which they attributed to the reduction of Gulf trawling and halibut bycatch since the 1990s. Other potential impacts to halibut identified by harvesters included offshore oil and gas drilling, and effluent discharge from a paper mill transformation project. The present study demonstrates that utilizing complementary data from both fish tracking devices and fish harvesters’ knowledge can help identify and anticipate potential conflicts between fisheries and other ocean industries, and ultimately inform the ecosystem-based marine spatial management of large marine ecosystems.