The low-oxygen waters of the dead zone in the Gulf of Mexico result in smaller shrimp, and a spike in large shrimp prices. Christopher Intagliata reports.

墨西哥湾死水区的低氧水导致虾变得更小，进而导致大虾的价格大幅上涨。克里斯托弗·因塔利亚塔报道。

撰文/播音：克里斯托弗·因塔利亚塔（Christopher Intagliata）

翻译：郭鑫鹏

审校：杨枭

Every spring, the Mississippi River dumps tens of thousands of tons of nutrient runoff into the Gulf of Mexico. Add temperature, current and wind to that pollution, and you have the Western Hemisphere’s largest stretch of oxygen-poor waters-a so-called “dead zone.”

每年春天，密西西比河将成千上万吨营养物质倾注入墨西哥湾。再加上温度、洋流和风的影响，这片污染区成为了北半球最大的贫氧水域，即所谓的“死水区”。

That dead zone hits the Gulf’s famed-and financially important-brown shrimp fisheries. And it does two things: first, the low oxygen slows down the shrimps’ growth.

这片死水区重创了这个海湾著名且有着重要经济价值的褐虾渔业。原因有两方面：第一，低氧导致虾的成长变缓。

“The other thing that occurs is what I like to call the burning building effect.” Martin Smith, an environmental economist at Duke University. “The shrimp try to avoid the low oxygen so they swim out of these areas of depleted oxygen. As a result they end up kind of aggregating on the edges. They kind of line up outside the deoxygenated waters. And that’s why I call it the burning building effect. If you’re in a burning building you’re running to get out of the fire, you don’t keep running when you get outside, you stop and you take a breath.”

“另一方面我喜欢把它称作燃烧建筑效应。“杜克大学环境经济学家马丁·史密斯（Martin Smith）说。”虾为了避免低氧而逃离贫氧区域。结果它们聚集在了边界上，它们在低氧水域外排成一排。这就是为什么我把它称作燃烧建筑效应。如果你在一栋燃烧的建筑物中，当你逃离火海时，你并不会继续跑下去，而是会停下来喘口气。“

Fishermen flock to where those shrimp “take a breath.” And shrimp get caught earlier in the season. So combine these two effects-slower growth and earlier catches-and the result is a haul of more small shrimp, and fewer large and jumbo shrimp. Meaning the price on big shrimp temporarily goes up. Supply and demand, right?

渔民们聚集在这些虾“喘口气“的地方，因而虾在这个季节被过早地捕获。所以结合这两种效应——低成长速率和过早捕获——结果就是有过多的小虾却鲜有大虾。因此大虾的价格会暂时性升高。这就是供求关系，不是吗？

Smith and his team studied that link-between the dead zone and a spike in large shrimp prices-using 20 years of shrimp pricing data. Their analysis is in the Proceedings of the National Academy of sciences. [Martin D. Smith, Seafood prices reveal impacts of a major ecological disturbance]

史密斯和他的团队通过使用20年的虾价格数据，研究了死水区和大虾价格上升之间的联系。他们的分析发表在《美国国家科学院院刊》上。

The brown shrimp fishery in the Gulf was once the most valuable in the U.S. Now, Smith says, we can measure the true cost of that nutrient runoff. “We can start to ask questions like, how much does the shrimp industry lose as a result of this problem, and how does that compare to what it would cost to control nutrient flows coming from food prediction upstream in the Mississippi watershed?” In other words-whether there might be some net economic benefit to keeping the water environmentally protected.

墨西哥湾的褐虾渔业曾是美国最有价值的产业。现在，史密斯说，我们可以评估这个养分径流真正的代价。“我们可以这样提出问题，这个污染问题导致虾产业损失了多少，这与控制密西西比河上游食品预测产生的养分流需要的花费相比又如何？“换句话说——是否可能有一些纯经济收益来保护水域环境。

-Christopher Intagliata