Empty Nets Jun. 2014 | Página 2

The Issue of Overfishing

By Josie Lucier

World Health Organization reports that more than 1 billion people around the world depend on fish as their main source of protein. But our world’s ocean populations are decreasing to shocking numbers due to non-sustainable use of Earth’s marine ecosystems, specifically through overfishing. Overfishing is when fish and other marine species are caught faster than they can reproduce. 75% of the world’s fish stocks are being harvested in this way.

The earliest documentation of overfishing occurred in the early 1800s when people obliterated the whale population, seeking whale blubber for lamp oil. In the mid-1900s, fish that we eat like Atlantic cod and California’s sardines were also harvested almost to the point of extinction. However, by the late 1900s overfishing went from a few isolated cases to becoming a disastrous global issue.

This began because the international effort to make high-protein foods more abundant and affordable led to government push to increase fishing through loans, policies, and subsidies. Industrial fishing soon replaced local fisherman as the main seafood source. The large and profit pursuing industrial fleets were very aggressive with their methods. In 2003, a scientific report stated that the number of large ocean fish has reduced to only 10% of their populations prior to commercial fishing.

By 1989 the fishing industry hit its record high of 90 million tons of catch taken from the ocean and yields have declined ever since. Fisheries for highly desired fish like orange roughy, Chilean sea bass, and bluefin tuna has collapsed.

Because of this, commercial fleets are now going deeper in the ocean and farther down the food chain for acceptable catches. This is known as “fishing down” and it is highly disruptive to the food chain. As predatory fish are being removed from the ocean, they must rely on species below them in the food chain (on a lower trophic level). The abundance of these smaller and fast-reproducing species has great fluctuations throughout the year and the remaining larger fish are left with greater variability in their food supply. When commercial fisheries target these crucial species at the bottom of the food chain, they

disrupt the already delicately balanced structure and they push the entire ecosystem to the brink of collapse.

A 2006 study of catch data estimated that if fishing rates continue as they are now, all of the world’s fisheries will be collapsed by 2048. But fish farming is currently the fastest growing agricultural industry in the world. In order to continue depending on our oceans as a food source, practices must be changed immediately. Many scientists agree that most ocean populations can be restored with aggressive management, better law enforcement, and increased use of aquacultures instead of wild catch.