Potential for managing life history diversity in a commercially exploited intermediate predator, the goldsinny wrasse (Ctenolabrus rupestris)
Abstract Small-bodied wrasse species are important for structuring coastal marine ecosystems but are also increasingly harvested as parasite cleaners on farmed salmon. Identifying management regulations that will support long-term sustainability of wrasse fisheries is challenging, because there is still limited knowledge about the impacts of fisheries on the demography of these intermediate predators in their natural environments. To this end, we studied individual growth histories of goldsinny wrasse (Ctenolabrus rupestris) at a fine spatial scale across replicated marine protected areas (MPAs) and areas open to commercial harvesting on the Norwegian coast. The MPAs were established 1–7 ye…
Movement patterns of temperate wrasses (Labridae) within a small marine protected area
The movement patterns of three commercially important wrasse (Labridae) species inside a small marine protected area (~ 0.15 km2 ) on the west coast of Norway were analysed over a period of 21 months. The mean distance between capture and recapture locations varied between 10 and 187 m, and was species and season specific. The extent of movement was not related to body size or sex. These results imply that a network of small strategically located marine protected areas can be used as management tools to protect wrasses from size- and sex-selective fishing mortality.
Impact of harvesting cleaner fish for salmonid aquaculture assessed from replicated coastal marine protected areas
Wrasse (Labridae) fisheries have increased markedly in Norway since 2010. Wrasse are being used as cleaner fish in salmonid aquaculture to control sea-lice infestations. However, fundamental knowledge on the demography and abundance of the targeted wrasse populations in Norwegian waters is lacking, and the consequences of harvesting at the current intensity have not been assessed. Here, we compared catch per unit effort (CPUE), size, age and sex ratio of goldsinny wrasse (Ctenolabrus rupestris) and corkwing wrasse (Symphodus melops) between marine protected areas (MPAs) and control areas open for fishing at four localities on the Skagerrak coast in Southern Norway. The CPUE of goldsinny lar…
Mind the depth: The vertical dimension of a small-scale coastal fishery shapes selection on species, size, and sex in wrasses
Small‐scale fisheries (SSFs) tend to target shallow waters, but the depth distributions of coastal fish can vary depending on species, size, and sex. This creates a scope for a form of fishing selectivity that has received limited attention but can have considerable implications for monitoring and management of these fisheries. We conducted a case study on the Norwegian wrasse fishery, a developing SSF in which multiple species are caught in shallow waters (mean depth = 4.5 m) to be used as cleaner fish in aquaculture. Several of these wrasses have life histories and behaviors that are sensitive to selective fishing mortality, such as sexual size dimorphism, paternal care, and sex change. A…