Background
Ecosystems In and Out of Balance
An ecosystem is a collection of tightly interconnected organisms that live in dynamic balance. Each member depends on the other members to create that balance. Some species have familiar connections, like that between direct competitors, or between predators and prey. Others have indirect, but no less important connections, like that between a species and the predator of its predator, or that between a species and the predator of its competitor.
It is a grand play of checks and balances, each interconnection binding the ecosystem together like the paired bases of DNA. In essence, the ecosystem acts as a single organism. Damage to one part of this organism trickles through the maze of interconnections, affecting every other part of the system in some way, or multiple ways. The balance changes entirely.
The fallout from such damage is complex, and is often unexpected. Take, for one example, a possible connection between Antarctic toothfish and scallops. The toothfish is the largest predatory fish in the Ross Sea (see Threats), and the Ross Sea scallop population is prolific. Toothfish do not eat scallops. But the toothfish eats the fish that eat scallop larvae. Thus, if fishing depletes the toothfish population, the fish that eat larval scallops could be left unchecked. Scallops would suffer the consequence. Similar scenarios have played out before in many parts of the World Ocean when other top predators, like sharks, have been depleted.
But the fallout would not stop there. The impact of the fishing would continue to work its way through the ecosystem – along this pathway, and numerous other pathways, most of which are still undiscovered. It is almost impossible for a deeply damaged system to ever recover and return to its original state, even if the outside pressure, the fishing, stops. There are too many pathways, too many compounded changes. The chain of events also weakens the system’s defenses against invasive species and makes it more susceptible to the forces of climate change. The effects of this weakened “immune system” have been shown again and again in ecosystems where top predators have been removed. Once the balance is destroyed, it is gone forever.
State of the Oceans
In its 1998 report “Ocean Ecology: Understanding and Vision for Research,” The National Science Foundation stated “Little, if any of the ocean remains unaffected by fisheries, agricultural runoff, sewage, aquaculture and industry.” The recently released Millennium Ecosystem Assessment, which amassed information from 1,300 researchers in 95 countries, reports that 25% of all the world’s fisheries are in severe decline. The Food and Agriculture Organization has estimated that in the Southern Ocean, over 60% of fisheries are “fully exploited,” “overexploited” or “depleted.”
The result: overall global fish-landings have been in decline since the 1980s, despite our best efforts to develop new fisheries and more efficient management practices. Estimates are that we’ve eaten our way through 90% of the top predatory fish in the ocean since 1950. We have pushed ocean ecosystems to the brink of collapse worldwide.
But these statements only reflect the absolute worst cases, and then only from the perspective of how many fish we can hook or net. They don’t reflect an even more disturbing observation: the natural balance is gone from every open ocean ecosystem in the world, except for one. The situation is almost unfathomable. It seems impossible that we could have so severely damaged something as large as the ocean. But the evidence is clear.
Importance of the Ross Sea
The dire state of the world’s oceans is not only a threat to fish, seabirds, or scallops. We depend on ocean resources. We are, inseparably, part of the same ecosystem. Our rampant disregard for these problems has already started to catch up with us. Numerous fisheries have gone belly up, leaving entire regions out of work. Fish prices have skyrocketed – the best fish is now only available to the wealthy. A single blue fin tuna can fetch up to $170,000. But the worst is yet to come unless we change our pattern of over-consuming, leaving broken ecosystems in our wake.
Much of the problem, as well as the key to a possible solution, is contained in a simple observation: we don’t yet know how a healthy marine ecosystem works. A functional knowledge of a healthy ecosystem would greatly improve our abilities to predict the fallout from a fishery. While such knowledge would not solve the entire problem, it is requisite to any improvement in the situation.
But the pathways that connect the different members of an ecosystem are extremely difficult to deduce. Further, if we only study ecosystems that have already been damaged, deduction, at least of the interconnections of a healthy ecosystem, is impossible. If we want to develop a picture of a healthy open ocean ecosystem, we have only one option left: The Ross Sea, Antarctica.