With new research and findings, it is routinely becoming more and more difficult to make environmentally conscious decisions, especially when it comes to shopping for fish. Those worried about the overfishing crisis who buy farmed fish may be in for a surprise, as fish farming is proving to be detrimental to the surrounding environment. Aquaculture may never have been the safe alternative many were led to believe.
Wild Fisheries vs. Farm (Cage) Fisheries
Wild fisheries (sometimes referred to as capture fisheries) are designated areas in which certain types of fish are expected to be found and harvested for commercial purposes. As the name would imply, wild fisheries do not control the fish populations as do farms. Consequently, marine capture fisheries have come under fire from regulators and environmentalists for the disappearance of populations and decimated ocean floors.
Many wild fisheries utilize the bottom trawler method of hauling in their catch, a method that has been blamed for 95 percent of the damage to seamount ecosystems. Due to the criticism of trawlers, gill nets, and bycatch, these fisheries have come under regulatory scrutiny. Most of the fisheries in the world are wild fisheries.
Farm fisheries (or aquaculture) aim to more closely regulate their stock. A farm fishery is exactly what it sounds like - a fish farm. There are several kinds of marine fish farms, but one of the most prevalent methods in oceanic farming is the cage system. This method stocks fish in many cages in designated marine areas, and those fish are raised and harvested according to commercial demand.
Though cage systems are gaining in popularity, there are still concerns about escape, disease, and poaching. In spite of these concerns, cage farming seems to be the safe, responsible alternative to bottom trawlers - on the surface, anyway.
Farm Fisheries Pollute Surrounding Environment
Recent studies have shown major problems arising from aquaculture. Professor Neil Frazer of the Department of Geology and Geophysics at the University of Hawaii at Manoa came forward recently to explain how local wild fish populations surrounding cage farms quickly decline.
“Farm fish share water with wild fish, which enables transmission of parasites, such as sea lice, from wild to farm and farm to wild fishes,” Frazer explains. The central argument in his essay, "Sea-Cage Aquaculture, Sea Lice, and Declines of Wild Fish," is that the higher density of fish lends to a breeding ground of infection, negatively affecting all the fish, wild and caged.
This is basic physics. If there are more fish than the environment can support, infection spreads. The unexpected problem then arises in the wild fish populations; while the caged fish have protection from predators, the wild fish do not. When the latter become susceptible to these imposed sicknesses, they fall weak and are easily captured by predators they might usually outswim.
Preventing Infection in Caged and Wild Fish
There are steps that can be taken to reduce the decline of the wild fish populations. Professor Frazer suggests that farm fisheries keep their stocking density down and implement medication to ward-off infection. Cages should be moved farther away from wild populations, mitigating the spread of potential infection; either the caged and wild fish need to be kept apart, or farm fisheries must more closely regulate the growth and health of their stock.
Because of the recent studies on the negative effects of farm fisheries on wild fish, there are sure to be regulations put into effect in the near future to manage and improve the health of wild and caged fish. Until then, farm fisheries will continue to systematically weaken the wild fish that surround them.
 |
