Part I – The Problem
Bill sat at the kitchen table, adding up last month’s expenses from running his fishing boat. With his trawler he fishes for bottom fish from his home base in Terrebone Bay, Louisiana—snapper and grouper mostly. But for the last few summers he has had to boat further and further out from the Louisiana shore to get to decent fishing grounds. The additional fuel costs were killing him. He rubbed his tired eyes and tried running the numbers through his calculator again.
“Hi Dad,” said his daughter Sue, walking into the kitchen. “How does it look this month?”
“Not so good,” said Bill, tossing his pencil onto the table. “The fuel bills were higher than ever this summer. It’s going to be tight for our finances. I wish I knew why the fish disappear near shore in the summer.”
He privately worried about how he was going to be able to afford Sue’s college tuition this fall. Maybe it was time to get out of the fishing business, except fishing was all he knew. Plus, all his money was tied up in his fishing boat and gear. Who would buy it now that fishing in the Gulf was so problematic?
Sue sat down at the table and toyed with the pencil. She knew about her dad’s worries. “You know, Dad,” she said, “I’ve been thinking. Let me talk with some of my professors at the university. Maybe I can get some information from them about what causes the fish to disappear, and whether anyone is working on a solution. Someone at school ought to know something.”
Bill smiled at his daughter, even though he wasn’t hopeful. “Good idea, kiddo,” he said. “Maybe more people are working on this than we know. See what the professors can tell you.”
Sue hurried across campus. She had an appointment with Professor Gracia in the biology department, and she was late. She rushed up the stairs of the biology building and knocked at his door.
“Come in,” Professor Gracia called out. “You must be Sue. I’m glad you could make it before I had to leave. You are right in thinking that a number of scientists must be working on the problem you described,” he said as he handed her a map of the United States.
“Look here,” he said, pointing to a region of the Gulf of Mexico just below Louisiana and eastern Texas. “See that shaded area? We call that the Dead Zone. During the summer there is very little in the way of marine macro-organisms there.”
“Wow, I had no idea it was so big!” said Sue. “Do the fish actually die there?”
Professor Gracia started gathering up materials for his next class. “Some fish may die. Most of the fish and crustaceans that can leave the Dead Zone do so. It’s called the Dead Zone because the dissolved oxygen levels in the water get so depleted the water can’t support life.”
Sue could see that the far edge of the Dead Zone corresponded with the distance her dad had to boat to get to good fishing grounds. “Is anyone working on why the Dead Zone forms?” she asked.
“A lot of people are very concerned and are actively collecting data to help get to the bottom of the cause,” said Professor Gracia. “I’ve got to get to class right now, but let’s meet again. I have more information and data to share with you.”
“That’s sounds great,” said Sue. “I’ll talk to you soon.”
Figure 1a. Map of the U.S. showing area of the Dead Zone in the Gulf coastal waters of Louisiana and Texas (Goolsby et al., 2000).
Figure 1b. Detail of the Dead Zone (shaded) in the Gulf of Mexico. (Rabalais et al., 2002. Copyright, American Institute of Biological Sciences. Used with permission.)
Figure References
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Goolsby, D.A., and W.A. Battaglin. 2000. Nitrogen in the Mississippi Basin—Estimating sources and predicting flux to the Gulf of Mexico. USGS Fact Sheet 135-00. http://ks.water.usgs.gov/pubs/fact-sheets/fs.135-00.html Last accessed: May 22, 2009.
Rabalais, N.N., R.E. Turner, and D. Scavia. 2002. Beyond science into policy: Gulf of Mexico hypoxia and the Mississippi River. BioScience 52: 129–142.
Date Posted: May 27, 2009.
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