by Callum Roberts
Imagine an alien invasion of Earth not unlike the Vogan onslaught in Douglas Adam’s Hitchhikers Guide to the Galaxy. However, in this case the vast fleets of alien motherships cruised far above the Earth's surface, and slowly dragged massive, kilometer-wide steel nets across the surface of the earth, scouring everything in their path. Trees, houses, buildings, people and animals, cars, everything on the surface being swept into giant metal nets and hauled up to the motherships for processing.
Then imagine thousands of motherships crisscrossing the surface of the earth over and over and over again tearing up everything from the surface and hauling it away. Much of what was scraped up and brought to the motherships was considered worthless, and it would come raining down from the sky, smashed, destroyed and dead, when the aliens were done sifting through it.
Now imagine after decades of this that much of the surface of the earth was nearly barren mud, debris and dust, but the ships continued to cruise above and scrape away, trying to get anything that was left. The few remaining people and animals scurrying in the shadows, hiding in cracks and crevices.
While this may sound like science fiction, it is unfortunately scientific fact for the seafloor and everything that lives in the oceans. In his new book, “The Unnatural History of the Sea” (Island Press), Callum Roberts describes in great detail the human onslaught directed against all living creatures in the oceans, an exploitation that began in earnest almost 1000 years ago, and continues with renewed effort to this day.
In part 1 of his book, Professor Roberts uses a mix of narrative and historical records to describe the early accounts of fishing in Europe and details the sea life observed by early sailors and near-shore fishermen. The bounty of the pristine rivers, lakes and the oceans off the coasts of Europe was unimaginable by today’s standards. But with increasing technological advances in fishing, and increased fishing effort in early Europe, overexploitation of a critical natural resource spread across the continent. The pattern of human overexploitation of the fish populations of rivers and oceans is repeated again and again. First rivers are dammed and strung with nets until the runs of various fish species dwindles to a minute fraction of pre-exploitation levels. As fish runs in rivers are choked off and decimated, fishers turn to the local seas to catch near-shore fish which moved along the coasts in massive shoals. As near-shore species are fished out, fishermen moved further and further out to sea to maintain their catches.
By the time early sailors arrived at the New World, fish stocks in Europe had already been long since depleted. The visitors to the New World were astounded by the bounty of the rivers and oceans they encountered, with one early visitor declaring that they found fish schools so thick inshore that an axe handle shoved down into the swarming mass would stand upright. As the Western Hemisphere was colonized, the same pattern of over-exploitation of fish populations in rivers played out in the New World.
In part 2 Professor Roberts details the modernization of the fishery industry, and it’s move away from depleted inshore seas to the open ocean. With the advent of the steam trawler in the late 1800s, fishing power, capacity and ability to fish at greater distances from shore signaled the beginning of the great exploitation of the worlds oceans. First would come the whalers and those seeking fur seals and other sea mammals. As each species gave way to excessive, unmanaged slaughter, ship’s crews would turn to the next most desirable species, and begin the over-exploitation again in one deadly cycle after another.
After the hunting of sea mammals became less lucrative due to diminishing populations, ships would either move further afield in an attempt to find un-spoiled herds, or instead turned to fishing. Early trawler fishing in the North Atlantic proved very lucrative, and the catches were phenomenal. Cod schools were enormous, and proved easy to exploit. The ability to pack fish in ice greatly expanded ship’s reach into the open oceans and their capacity to bring back larger hauls. Steam powered engines and winches made trawling the method of choice for clearing the high seas of fish.
Eventually, as the Americas were populated with Europeans, the same pattern of unmanaged exploitation of the rivers and lakes that had occurred centuries earlier in Europe played out once again. Rivers were dammed and crossed with nets until the runs of fish dwindled to a fraction of their pre-exploitation levels. Fantastically productive ecosystems such as the Chesapeake Bay were stripped of their fish, oysters and crabs until fights broke out over what little remained. The so-called “oyster wars” took place between oyster pirates and the Navy in the Chesapeake Bay in the 1800’s as oyster stocks became severely depleted by dredgers.
Unfortunately for many marine fish and mammal species, as their numbers dwindled, the price that they could fetch on the market skyrocketed. Such supply and demand considerations took a great toll on animals ranging from whales, to sea otters to abalone. The extremely lucrative nature of hunting these animals ensured their near extinction.
As modern open ocean trawling and long-line fishing depleted cod, tuna, herring and other fish stocks, massive trawler-factory ships equipped with fish processing plants made their way into deeper and deeper waters looking for new fish shoals around sea mounts. One such discovery included the massive schools of slimehead fish found around sea mounts in the Pacific. These were quickly renamed “orange roughys” to make them sound more palatable, and they became a popular type of frozen fish. But after a few decades of unmanaged exploitation, orange roughy populations declined sharply, which baffled fishermen. The problem was identified when scientists carbon dated the inner ear bones of fully grown orange roughys and found that they could live to be nearly 150 years old. Indeed, these deep sea fish did not reach sexual maturity until they were decades old, ensuring sharp declines in their numbers as the slowly reproducing fish were removed wholesale from sea mount after sea mount in the Pacific.
Professor Roberts pinpoints the major sources of fisheries mismanagement as a combination of shifting expectations in conjunction with improved technologies and increased fishing effort. At fish stocks are depleted, the newly depleted oceans are accepted as the norm. As the catches are reduced, fishing effort increases in an attempt to make up the difference. In conjunction with improved trawling technologies, the detrimental effects on the oceans have been devastating. Shortsighted politicians consistently watered down the already over optimistic projections provided by scientists, with the inevitable result that virtually no limits were placed on how many fish could be taken from the seas.
In part 3, the reader is given hope that the situation can be turned around with vastly improved fishery management, including reduced fishing effort, moratoriums and a great expansion of marine refuges. An unexpected result of the closing of certain small areas of the ocean to all forms of fishing for research purposes was that fish stocks not only rebounded in the protected areas, but also in nearby waters that were still open to fishing. Unfortunately for some previously plentiful fish stocks such as cod in the North Atlantic, fishing moratoriums have had little effect on bringing back the species from population collapse. However, other species have responded to fishing moratoriums and sanctuaries far better.
Professor Roberts outlines the steps that will be required to bring back the previously prolific oceans of the past. His seven steps include 1) reduced fishing capacity in terms of the size of fishing fleets, 2) getting politicians out of the decision-making process of fisheries management, 3) eliminate catch quotas and replace them with controls on the levels of fishing effort, 4) require fishermen to keep all fish that they catch and stop discarding less valuable species (bycatch), 5) mandate the use of gear that reduces “bycatch” 6) ban the most destructive fishing methods, and 7) establish a large network of marine sanctuaries which are off limits to all fishing.
Professor Roberts dedicates the entire last chapter to issue number seven; establishing a network of permanent marine sanctuaries in every ocean around the world. Scientists have estimated that if between 20% and 30% of the world’s oceans, especially those that act as critical breeding grounds for important species, are made permanently off-limits to fishing, that these will act as nurseries or incubators which can repopulate the world's oceans with a virtually inexhaustible source of fish, if managed properly. Fishing effort could be greatly reduced while the size of the catches would greatly increase. But as long as the decisions on how to manage the worlds oceans are handled by fishermen and politicians, the relentless over exploitation of the world's oceans will continue unabated.
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