Heaps of abalone shells in Santa Barbara, Calif., from a 1920 postcard. (Census of Marine Life)
By ANDREW C. REVKIN
I’ve written off and on about research revealing that ocean resources today are a pale shadow of the extraordinary abundance of just a few generations ago, and I touch on this theme again in a Science Times feature this week on new maps of human impacts on the sea.
Societies tend to have “ocean amnesia,” in the words of some scientists and campaigners who’ve highlighted the recent, and largely unnoticed, vanishing of marine life. Daniel Pauly of the University of British Columbia coined the phrase “shifting baselines” to describe how our definition of “normal” changes over time.Several studies of the Gulf of California have vividly illustrated the phenomenon. A 2005 paper charted changing impressions of fish abundance through three generations of Mexican fishers, finding that “old fishers named five times as many species and four times as many fishing sites as once being abundant/productive.”For a 2006 paper in the journal Fish and Fisheries, the same team estimated marine abundance in the same region by combing diaries and other written records from the 16th to the 19th century.“The diaries written by conquerors, pirates, missionaries and naturalists described a place in which whales were ‘innumerable,’ turtles were ‘covering the sea’ and large fish were so abundant that they could be taken by hand,” the scientists said.When I went fishing off Long Island with the marine biologist and author Carl Safina in 2006 (video here, article here), we had no problem reeling in fluke and bluefish in the right spots. But a century earlier, the right spot could have been just about anywhere.The right spots for Pacific abalone along the West Coast are now few and far between. In 1920, as you can see on the postcard above (provided by scientists working on the Census of Marine Life), they were abundant.A growing body of research shows that significant increases in fish populations could come with the expansion of marine reserves, more careful oversight of shared ocean resources like bluefin tuna, and education of fishing communities around coral reefs.But the pressures on marine fisheries appear to be mounting faster than the push for new practices to shift to more sustainable harvests.As the human species heads toward 9 billion in the next few decades, with a tendency to eat up the food chain as prosperity rises, is there any prospect of sustaining yields of seafood, whether wild-caught or farmed?Jesse Ausubel of Rockefeller University told me he was worried, for example, about the “democratization of sushi” as a growing source of pressure on tuna and other coveted species.Views diverge sharply on how to keep oceans productive and at least somewhat wild.Many environmental groups strongly oppose expanded marine aquaculture and, at the same time, are pushing for a vast expansion of protected areas, both to shield ecosystems and to provide nurseries for commercial fish.Scientists seem divided, with some supporting the idea of concentrated husbandry of high-value species (tuna, salmon) and others warning of indirect harm from the equivalent of factory farming of the sea.Sylvia Earle, the oceanographer and explorer, sees no future for wild harvests, given rising human populations and their growing appetite for protein.“One way or another, commercial fishing as a way of life does not have a future, any more than market hunting of terrestrial birds and furry creatures,” she said in an e-mail message on Monday, just after returning from the Galápagos. “Our long-ago ancestors lived by hunting and gathering wild things, a recipe for success that worked when our numbers were small and the wild world was relatively intact. Six billion people cannot be sustained on bush meat from the land — or from the sea.” If you’re a seafood lover, where do you expect your yellowtail or fried clams will come from a couple of decades from now?
I’ve written off and on about research revealing that ocean resources today are a pale shadow of the extraordinary abundance of just a few generations ago, and I touch on this theme again in a Science Times feature this week on new maps of human impacts on the sea.
Societies tend to have “ocean amnesia,” in the words of some scientists and campaigners who’ve highlighted the recent, and largely unnoticed, vanishing of marine life. Daniel Pauly of the University of British Columbia coined the phrase “shifting baselines” to describe how our definition of “normal” changes over time.Several studies of the Gulf of California have vividly illustrated the phenomenon. A 2005 paper charted changing impressions of fish abundance through three generations of Mexican fishers, finding that “old fishers named five times as many species and four times as many fishing sites as once being abundant/productive.”For a 2006 paper in the journal Fish and Fisheries, the same team estimated marine abundance in the same region by combing diaries and other written records from the 16th to the 19th century.“The diaries written by conquerors, pirates, missionaries and naturalists described a place in which whales were ‘innumerable,’ turtles were ‘covering the sea’ and large fish were so abundant that they could be taken by hand,” the scientists said.When I went fishing off Long Island with the marine biologist and author Carl Safina in 2006 (video here, article here), we had no problem reeling in fluke and bluefish in the right spots. But a century earlier, the right spot could have been just about anywhere.The right spots for Pacific abalone along the West Coast are now few and far between. In 1920, as you can see on the postcard above (provided by scientists working on the Census of Marine Life), they were abundant.A growing body of research shows that significant increases in fish populations could come with the expansion of marine reserves, more careful oversight of shared ocean resources like bluefin tuna, and education of fishing communities around coral reefs.But the pressures on marine fisheries appear to be mounting faster than the push for new practices to shift to more sustainable harvests.As the human species heads toward 9 billion in the next few decades, with a tendency to eat up the food chain as prosperity rises, is there any prospect of sustaining yields of seafood, whether wild-caught or farmed?Jesse Ausubel of Rockefeller University told me he was worried, for example, about the “democratization of sushi” as a growing source of pressure on tuna and other coveted species.Views diverge sharply on how to keep oceans productive and at least somewhat wild.Many environmental groups strongly oppose expanded marine aquaculture and, at the same time, are pushing for a vast expansion of protected areas, both to shield ecosystems and to provide nurseries for commercial fish.Scientists seem divided, with some supporting the idea of concentrated husbandry of high-value species (tuna, salmon) and others warning of indirect harm from the equivalent of factory farming of the sea.Sylvia Earle, the oceanographer and explorer, sees no future for wild harvests, given rising human populations and their growing appetite for protein.“One way or another, commercial fishing as a way of life does not have a future, any more than market hunting of terrestrial birds and furry creatures,” she said in an e-mail message on Monday, just after returning from the Galápagos. “Our long-ago ancestors lived by hunting and gathering wild things, a recipe for success that worked when our numbers were small and the wild world was relatively intact. Six billion people cannot be sustained on bush meat from the land — or from the sea.” If you’re a seafood lover, where do you expect your yellowtail or fried clams will come from a couple of decades from now?
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