Fishery observers address arctic fishery discards

Abstract

Fishery observers are prevalent actors in the global effort to reduce discards in fisheries, but there remains considerable uncertainty about how effective they are. We analyzed high-resolution logbook records of individual hauls (n = 127 415) across five-and-a-half-years (2012–2018) for all of Greenland’s large-scale fisheries to determine if onboard fishery observers influence the mandatory reporting of discards. To do so, we used exact matching to compare reported discards for observed and unobserved hauls (each time a catch is recorded), thus controlling for systematic differences between monitored and unmonitored practices. After adjusting for variables that represent species caught, gear, vessel, owner, year, license, and location, we found that skippers systematically underreport discards when no observers are on board. Systematic underreporting was most pronounced in less valuable fisheries, in contrast to theoretical arguments in previous studies. The differences between reported discards from observed and unobserved fishing leads us to assume that onboard observers encourage more faithful logbook records. Thus, onboard observers play a vital role in improving information on the environmental impact of fishing and in turn, make a key contribution to sustainable fisheries management.