Otter (Lutra lutra)

Candidate marine SAC: Yell Sound Coast, Afon Teifi

Otters live on the coast as well as along inland water courses. In coastal environments they forage in intertidal and shallow rocky areas, feeding on fish and crustaceans, and therefore come into contact with certain types of fishing gear. They are known to be attracted to eels, fish, and crustaceans which are used as bait or caught in fyke nets and creels. There is documented evidence of otter mortality in fyke nets, creels (for lobsters, crabs and prawns), fish farm nets and wade nets19,48,49 as well as through entanglement in lost fishing net50. A survey of drowned otters in lobster creels off the Uists revealed that the majority drowned while foraging in depths of 2-5 m and that mortality increased with the incorporation of a parlour in the creels used in the area46. Crab creels did not appear to pose such a threat as the gear was usually set on sandy seabed in deeper water, further offshore, and therefore outside the favoured foraging area of otters47.

The majority of documented deaths of otters in these types of fishing gear are of adult females46,48. The areas of capture correspond to sites where the fisheries operate near otter populations but data suggest that eel fyke nets can also attract and kill otters living at very low densities51. A marked concentration of drownings in autumn and winter has been recorded and may be partly explained by the seasonality of fish and the fact that this is when their main food may not be as easily available, leading them to investigate prey in nets and pots51. Various types of otter guards have been tested and some form of guard is now mandatory for eel fyke nets. No suggestions have been put forward on how to reduce the threat from crustacean traps nor is there a clear indication of whether mortality from this cause is a conservation problem.

Summary of the potential effects of fishing on otters

Fishery

Methods

Potential effects

Eels

Fyke nets

  Inquisitive and foraging otters accidentally caught in these nets has led to mandatory use of otter guards.

Crustaceans

Pots and creels

  Inquisitive and foraging otters accidentally caught in these traps. Occurrence of accidental capture may be linked to season and availability of food.

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