Interactions with Fisheries

The oceans cover 70% of the earth’s surface and provide man with an annual harvest of around 60 million tonnes of fish (1 tonne = 1000 kg). The worldwide harvest has increased over the years as more and more fish species become commercially worth exploiting and fishing techniques develop. However, many fish stocks have been heavily exploited and yields from some of these have fallen. In some cases these declines can be attributed to overfishing, in others to climatic fluctuations, but declining commercial catches have sometimes led to suggestions from fishermen that natural predators such as seals and seabirds should be culled in order to reduce their impact on stocks. Where it is believed that this competition may result in serious and avoidable financial loss to fishermen, an assessment of economic impact of seabirds and seals is a prerequisite to sensible management.