Halichoerus grypus is casing problems to the fishermen when taking

their catch and causing damages to the fishing gears. The problem is

most widespread in the middle and northern parts of the Baltic Sea where

the H. grypus is most abundant. In recent years the population has

recovered from a large decline due to hunting and diseases caused by

pollutants. The recovery has resulted in an increase of the seal inflicted

damages for the fisheries. The aim of this project was to investigate if H.

grypus uses above water stimuli to locate baited buoys, representing

fishing gears. The experiment was conducted in two areas along the

Swedish east coast. Four different types of buoys were used, and it was

hypothesised that the number of encounters would increase with buoy

size. With this kind of knowledge it might be possible to develop new

fishing methods in order to decrease the catch and gear damages and also

decrease the number of seals drowned in fishing gears. Thirty-three

percent of the buoys were equipped with a camera to verify that it

actually was H. grypus that took the bait. The buoys were deployed in

suitable areas where seals were commonly seen. They buoys were

checked once a day and they were moved if the bait had been taken. The

result showed that the buoy size matters and larger buoys are more easily

discovered by seals.