"The world has passed "peak fish" and fishermen's nets will be hauling in ever diminishing loads"
Because we are land-living, our exploitation of the land has gone a lot further than the exploitation of oceans, but oceans are now rapidly exploited. Still, we use only eight percent of the biological production of the oceans, notwithstanding numerous fisheries have collapsed. On the temperate continental shelves, we use approximately 35 percent of the production. Our fisheries are targeting a few species, normally in the top of the food chain (cod, tuna, salmon). Global predatory fish biomass today is only about 10% of pre-industrial levels. At a first glance one might believe that it is quite safe to take the fish on the top of the chain, but that can also lead to major ecological changes. In addition, some fisheries have vast by-catches of other species, sometimes up to a third of the catch. The fishermen have to go deeper and deeper to get the fish and the fishing methods themselves destroy fish habitat, in particular bottom trawling. In the UK, landings per unit of fishing power reduced by 94%—17-fold—over the past 118 years. This implies an extraordinary decline in the availability of bottom-living fish and a profound reorganization of seabed ecosystems since the nineteenth century industrialization of fishing. (Vitousek and others 1997, Thurstan and others 2010, Economist 2009b).
Figure 1 The average depth of fishing 1950 to 2001
Source: MEA 2005
The combination of increasing population, subsidies for oversized fishing fleets, too generous fishing quota, profit-seeking and new technologies has lead to massive overfishing. Most indications points to that we have already passed “peak-fish”, i.e. that global catches of fish are bound to decline (Zeller and others 2009). Between 1950 and 2005, commercial fish and shellfish landings in the United States increased by almost 90%, which could point to that there should be no worries. But since 1990, Alaskan waters have accounted for the bulk of U.S. commercial landings and Alaska is the only region where landings have increased since 1978. Landings have decreased between 1978 and 2005 in the West Coast and Hawaii, the Gulf of Mexico, and the North, Mid-, and South Atlantic (the H. John Heinz III Center 2008). Within the EU 88 percent of the fish stock is subject to over-fishing and 93 percent of the cod is caught before it is sexually mature, and will therefore never reproduce (Thurstan and others 2010, Economist 2009b). The world trade in fish has increased more than ten times in thirty years from 1976 to 2007 from US$8 billion dollars worth to over 90 billion (Ababouch 2009). Ironically, the fisheries are also subsidized to a large extent. In 2005, the total value added by global fisheries was estimated by the United Nations Environment Program (UNEP) to US$17 billion while subsidies amounted to US$27 billion (UNEP 2011).