DECLINE IN WRASSE FISHING EFFORT

Decline in Wrasse fishing effort in Devon. Onboard surveys in Devon have found there has been a decline in fishing effort for wrasse destined to be ‘cleaner fish’ on salmon farms

A fishery for the live capture of wrasse for use as cleaner fish in Scottish salmon farms developed in the Devon and Severn Inshore Fisheries and Conservation Authorities’ (D&S IFCA) District in 2015. In 2017 management was introduced via the D&S IFCA potting permit byelaw. These management measures were largely based on best practice identified in the literature and included minimum and maximum conservation references sizes, a closed season, a fully documented fishery and a cap on effort.

Four commercial vessels operate within the Devon & Seven IFCA district targeting ballan, goldsinny, corkwing and rock cook. Devon & Severn IFCA officers have been undertaking on-board observer surveys to capture temporal and spatial trends in catch per unit effort (CPUE).

There was a reduction in overall effort in 2018 compared to 2017 with a 68% reduction in the number of days vessels targeting wrasse. The reduction is thought to have been caused by a combination of mechanical issues with vessels, individual fisher’s circumstances, fishers targeting Cornish waters within the Plymouth Sound during the Devon closed season and vessels remaining in Cornwall once Devon waters reopened.

Cleaner wrasse are the best-known of the cleaner fish. They live with larger, often predatory, fish, grooming them and benefiting by consuming what they remove. Wrasse are employed as cleaner fish to combat sea-lice infestations in salmon farms. Commercial fish farming of cleaner wrasse for sea-lice pest control in commercial salmon farming has developed in Scotland, with apparent commercial benefit.