Our Exhausted Oceans

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.
more from the NY Times