科学美国人60秒 SSS Gulf Dead Zone Makes for Shrimpier Shrimp
时间：2019-02-14 作者：英语课 分类：2017年Scientific American(二)月
Every spring, the Mississippi River dumps tens of thousands of tons of nutrient 1 runoff into the Gulf 2 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."
That dead zone hits the Gulf's famed—and financially important—brown shrimp 3 fisheries. And it does two things: first, the low oxygen slows down the shrimps’ growth.
"The other thing that occurs is what I like to call the burning building effect." Martin Smith, an environmental economist 4 at Duke University. "The shrimp try to avoid the low oxygen so they swim out of these areas of depleted 5 oxygen. As a result they end up kind of aggregating 6 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."
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?
Smith and his team studied that link—between the dead zone and a spike 7 in large shrimp prices—using 20 years of shrimp pricing data. Their analysis is in the Proceedings 8 of the National Academy of Sciences. [Martin D. Smith, Seafood 9 prices reveal impacts of a major ecological 10 disturbance]
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 11?" In other words—whether there might be some net economic benefit to keeping the water environmentally protected.
—Christopher Intagliata
- Magnesium is the nutrient element in plant growth.镁是植物生长的营养要素。
- The roots transmit moisture and nutrient to the trunk and branches.根将水分和养料输送到干和枝。
- The gulf between the two leaders cannot be bridged.两位领导人之间的鸿沟难以跨越。
- There is a gulf between the two cities.这两座城市间有个海湾。
- When the shrimp farm is built it will block the stream.一旦养虾场建起来，将会截断这条河流。
- When it comes to seafood,I like shrimp the best.说到海鲜，我最喜欢虾。
- He cast a professional economist's eyes on the problem.他以经济学行家的眼光审视这个问题。
- He's an economist who thinks he knows all the answers.他是个经济学家，自以为什么都懂。
- The thesis first promotes based Object Oriented Modeling method-Aggregating & Deriving Mothod. 本文首先提出了基于面向对象思想的建模方法——聚合派生法。
- Multidimensional data cubes are composed of base cube and other cubes aggregating on base cube. 多维立方体由基本立方体和基本立方体的聚集产生的立方体组成。
- The spike pierced the receipts and held them in order.那个钉子穿过那些收据并使之按顺序排列。
- They'll do anything to spike the guns of the opposition.他们会使出各种手段来挫败对手。
- He was released on bail pending committal proceedings. 他交保获释正在候审。
- to initiate legal proceedings against sb 对某人提起诉讼
- There's an excellent seafood restaurant near here.离这儿不远有家非常不错的海鲜馆。
- Shrimps are a popular type of seafood.小虾是比较普遍的一种海味。
- The region has been declared an ecological disaster zone.这个地区已经宣布为生态灾难区。
- Each animal has its ecological niche.每种动物都有自己的生态位.