Culprits of Falling Fish Stocks

Fish stocks have been dramatically reduced, and species are being squeezed out of their habitats. The effects of our behaviour on the marine ecosystem can be clearly seen across a whole range of industries.

One example, in the health and beauty sector, is the plastic debris from face and body scrubs that is washed into the ocean. Too small to be caught by drain filters, the 1mm microbeads attract pesticides and pollutants which are then consumed—together with the plastic—by fish and other marine life.

In general terms, fish numbers are most pressured in legal and illegal fishing operations. The result has been a rapid depletion of fish populations in nearly every ocean. In fact, some experts have said that 2048 will mark the extinction of the majority of the species that we rely on for food.

In Nature—a prominent interdisciplinary scientific journal—Professor Michael Burrows, head of ecology at the Scottish Association for Marine Science, examines the increase in water temperatures over the past 50 years. Burrows explores how we can predict both the movement and impact of further increases. This impact will no doubt be a negative one.

Still, taking into account the impact of pollution and its twin, climate change, the real culprit of falling fish stocks is overfishing.

Overfishing results from exceeding safe-catch limits, which are scientifically determined to limit the number of fish caught and landed by a fishery. Often the influence of politics and short-term economic incentives override these limits. This is to the detriment of the fish population and, ultimately, our own futures.

Worldwide, over 120mn people—many of whom are in the developing world—pursue fishing to earn their living. Catch limits need to be managed, and controls put in place on bycatch—fish, crustaceans and other oceanic life that are unintentionally caught, and then killed and disposed of, while catching certain target species or sizes of fish.

As Burrows touches on in his article, the key parts of ecosystems need full protection from destructive fisheries. Areas that need to be conserved include the spawning and nursing grounds of fish, the delicate sea floor environment, unique unexplored habitats, and corals.

Finally, a monitoring system is needed to ensure fishermen do not land more catch than they are allowed to or fish in closed areas. This system would also protect against those who tried to cheat the system. Strong monetary enforcement is needed to make it uneconomic to cheat.

In combination with the banning of the lavish hidden subsidies to commercially nonviable fisheries, we need to make sure management systems based on these rules are implemented everywhere.