A few hundred years ago, fishing around North America was reported to be as easy as dropping a basket into the water and pulling it back out full of fish. In 1497, the explorer Giovanni Caboto even reported that there were so many fish that they almost blocked his boat. Today, the Atlantic fisheries are collapsing and many of the once abundant species, particularly Atlantic cod (Gadus morhua), are reduced to tiny fractions of their populations and are now classified as “Vulnerable” according to the International Union for the Conservation of Nature and Natural Resources (IUCN)'s “red list” and here in Canada, Atlantic cod has been considered between "Threatened" and “Endangered” by the Committee on the Status of Endangered Wildlife in Canada (COSEWIC). Wikipedia reports that the cod stocks have fallen to 5% of what they once were (i.e. a 95% decrease in stocks). Cod is a textbook example of the dire state of the oceans due to overfishing, but a study released on March 2nd 2009 by Oceana, a link has been shown between overfishing and starvation by predators at higher trophic levels. Such predators include sharks, dolphins and sea birds. Although it may seem like no big deal to some people, such predators are necessary to maintain proper balance and interaction between the species in the food webs of the ocean. Without them, the collapse of the oceans will become faster and unavoidable.

The study points to a decline in prey stocks such as herring, mackerel, squid, anchovies and, of course, Atlantic cod. This isn't the first time scientists have warned the world about the dire state of the oceans; in their 2006 paper Dr. Boris Worm of Dalhousie University and his co-authors showed that according to the data available at the time, if human activity maintained its trends, the oceans would collapse entirely in approximately 40 years. The media reported the findings for a few days, but it was soon forgotten by the public. Although these findings may seem exaggerated and even the authors themselves admitted that some of their sources may have been less reliable, the evidence is still staggering, especially if we take into consideration that some countries probably underestimated their activities in order to appear more ecologically friendly.

When considering the state of marine systems, it is particularly important to remember that food webs are not constrained to any one system. There is considerable overlap between the ocean food chains and terrestrial ones. The collapse of the oceans would most probably mean the collapse of coastal systems, which would in turn result in the collapse of other ecosystems through a domino effect.

The issue becomes more complicated when we consider the human implications of a collapsing ocean system. The fishing industry accounts the majority of the revenue of many coastal and island communities. Unfortunately for our oceans, these communities often feel that they have no choice, but to continue with their industry by simply changing the species they target. Instead of fishing large fish, the fishing industry has turned to fishing smaller and smaller ones, often resulting in the complete destruction of some areas of the ocean floor and ecosystem through trawling.