Feeding Association Between Harbour Porpoise (Phocoena phocoena) and Flyshoot Fishing

Abstract

Human fishing activities can provide easily acces-sible food resources for predators and scavengers such as fish, crustaceans, birds, and marine mam-mals. Feeding associations between cetaceans and fishing activities have been recorded for both passive (stationary nets or lines) and active (gears are moved, towed, or dragged to catch the fish) fishing methods (Northridge, 1984, 1991; Fertl & Leatherwood, 1997; Tixier et al., 2021; Bonizzoni et al., 2022). Cetaceans may, for example, eat fish out of gill and trammel nets, take fish from long-lines, or trail behind trawlers that discard unwanted catch or lose fish that slip through the cod-end mesh (Fertl & Leatherwood, 1997; Tixier et al., 2021; Bonizzoni et al., 2022). Such associa-tions provide easily accessible prey, though such interactions may also increase the risk of ceta-cean bycatch (Northridge, 1984, 1991; Waring et al., 1990; Lowry & Teilmann, 1994; Morizur et al., 1996; Fertl & Leatherwood, 1997; Read, 2008; Tixier et al., 2021; Bonizzoni et al., 2022). Dolphins, for example, have been recorded to swim into a trawl to catch fish and are occasion-ally bycaught while doing so (Jaiteh et al., 2013; Santana-Garcon et al., 2018). For some fisher-ies, it also poses a socioeconomic issue if fishery catches are reduced (Tixier et al., 2021).