How quota cuts, recreational fishing, and predator conservation can shape coastal commercial fishery efforts

Commercial fishing effort often collides with other uses and interests. Fisheries resources might be co-used by recreational fishers (anglers), support populations of nonhuman top-predators, and fishing space might be preserved for conservation purposes. This can affect how commercial fisheries operate. We studied how the spatial distribution of commercial fishing effort among fishing districts is related to quotas, the use of resources by anglers, and the re-emergence of natural predators (the grey seal (Halichoerus grypus) and the great cormorant (Phalacrocorax carbo sinensis)). Our study area is the small-scale commercial fishery of Mecklenburg-Vorpommern in Germany. We use seemingly unrelated regressions with vessel-level time series of commercial targeting behavior. Spatial shifts in effort shares were related to larger quotas. Further, effort would shift away from areas with high seal densities, but no clear changes with respect to cormorants were found. The relationship between commercial effort share and angling activity was mixed and depended on the type of angler. We found a negative relationship between commercial fishing activity and angling in fishing areas where fishing for trophy pike (Esox lucius) and other predator species was popular.