In recent years, there has been growing support for using aquaculture – or fish farming – to bridge the gap between the finite supply of fish and our seemingly infinite appetite for it. Proponents of aquaculture often cite the sector’s recent impressive growth rates as evidence of its potential to provide a source of fish to match our increasing demand. There are, however, several important caveats that are often ignored in the case for fish farming.
First, modern aquaculture practices are highly unsustainable, as they consume natural resources at a very high rate. In fact, it is estimated that by 2050 the majority of the world’s fisheries will have collapsed. Industrial fishing is unsustainable largely because many of the fisheries are common, open-access sites and not constrained by ecological considerations or strong legislation. Common pool fisheries suffer from the tragedy of the commons – in that multiple parties squeeze as much profit as possible out of them and no one party is responsible for preventing overuse. Open-access fisheries are increasing in number as heavy government subsidies lead to the consolidation of small-scale fishing vessels into larger ones. The problem of unsustainable fishing is further compounded by the use of destructive methods – such as blast and cyanide fishing – and practices like bottom trawling (dragging a net along the sea floor) that wreck havoc on the seabed.
Current fish farming methods both induce and are vulnerable to pollution and disease outbreaks. Many aquacultures – such as shrimp farming – operate as “slash-and-burn” enterprises, leaving ravaged coastal habitats and human communities in their wake. In Lake Victoria – one of the African great lakes – for instance, the introduction of the Nile perch (to feed European seafood demand) provoked widespread hunger after the Nile perch – an invasive predator that sits at the top of its food chain – quickly decimated the weaker native fish stocks that the inhabitants of coastal regions depended on for their protein needs.
Furthermore, the industrialized fishing affects coastal communities by competing directly with small-scale, artisanal fisheries. Such local fisheries are vital – and almost irreplaceable – sources of income for millions of people. Threatening their viability as businesses could threaten the lifestyle of those local communities.
Another cause for concern is that there has been a gradual removal of large, long-living fishes from the ecosystems of the world’s oceans. Because many of the commercially valuable fishes are slow to mature, have limited geographic range and breed in sporadic and unpredictable patterns, it is feared that excessive farming will not give their populations sufficient time to recover. Their depletion from ecosystems could make the systems less diversified and cause overpopulation problems with non-targeted prey species that have been released from predation pressures. Indeed, ecological extinctions of entire trophic levels – or links – of oceanic food chains will make ecosystems in general more vulnerable to other natural disturbances such as nutrient loading and etrophication, hypoxia, disease and storms surges.
In order to prevent a complete collapse of the world’s fisheries, reform measures such as the establishment of marine protection reserves and a reduction of government subsidies to the fishing industry are necessary. Fortunately, some positive steps have already been taken to establish a series of marine reserve networks that are strategically placed to maximize their potential in the replenishment of surrounding seas. Expanding those efforts would go a long way in protecting representative portions of all marine habitats and ecosystems through the creation of blue oases of sustainability worldwide. On the part of the consumer, efforts such as instituting a personal moratorium of sorts on highly threatened species – such as sharks, Chilean sea bass and blue-fin tuna – and replacing them with less endangered alternatives like yellowtail or snapper, would send a signal to the fishing industry.
The conservation of the oceans’ endangered species will ultimately depend on a combination of political will, financial capital and the transmission of scientific knowledge to the skeptical public. There must be a concerted effort to correct the erroneous belief that the ocean – the last wild and unexplored frontier of nature – could potentially provide our growing protein needs infinitely and indefinitely. It would be a failure on the part of this generation if our descendants are faced with the bleak reality of a barren oceanic wasteland.
ichael Ang is a junior in the School of Foreign Service. “
