Some fish learn to avoid fishing gear, others don't
In many cases, stock assessment is based on fishery-dependent data generated from fish markets or creel surveys. The assumption is: that the lower the catches in a certain unit of time, the smaller the stock of fish should be.
However German researchers have just shown that some fish species show enhanced gear-avoidance behaviour in regions with high angling intensity compared to fish exposed to low levels of exploitation near marine protected areas. The consequence is the impression that there are fewer fish in the sea, which does not necessarily agree with underwater reality.