Worldwide, there are now over a thousand coastal areas where fish can’t breathe. The nitrogen that makes crops grow is also destroying offshore ecosystems.
| “Let us not, however, flatter ourselves overmuch on account of our human victories over nature. For each such victory nature takes its revenge on us. Each victory, it is true, in the first place brings about the results we expected, but in the second and third places it has quite different, unforeseen effects which only too often cancel the first.” —Frederick Engels |
Talk about bad timing. This year’s Shelfwide Hypoxia Cruise, the annual scientific expedition that measures oxygen-depleted waters off the Louisiana coast, started on July 25, just after Hurricane Hanna raged through the area. High winds and waves continued through the cruise, thoroughly mixing the water column: high-oxygen surface waters were forced deep, and low-oxygen bottom waters were pushed off the continental shelf.
As a result, the official area of year’s dead zone is 5,048 square kilometers, the third-smallest since surveys began in 1985. Future charts and graphs will require a footnote, explaining that weather conditions produced a misleading result.
Northern Gulf of Mexico Dead Zone after Hurricane Hanna, July 2020.[1]
If the survey had been done a week earlier, or a couple of weeks later, the low-oxygen area would likely have been three or four times as large, because the conditions that deplete oxygen on the continental shelf haven’t changed.
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In the summer of 1972, an environmental assessment study for a proposed oil facility off the coast of Louisiana found something unexpected — an area below the surface, where the water contained little or no oxygen. In waters that had long supported a large and profitable fishing industry, there were areas where fish couldn’t breathe.
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