A Textbook for the Gulf

November 18, 1999

Judith Zwolak

Thomas Bianchi likens the newly published book he edited to "a textbook for the Gulf of Mexico coastal region." The book, Biogeochemistry of Gulf of Mexico Estuaries, is a compilation of basic-science research from scientists from all coastal regions of the Gulf-from the Yucatan Peninsula in Mexico to the Florida Keys.

"When you talk to other marine scientists in other regions of the country, they are usually ignorant of the Gulf of Mexico and its estuaries," says Bianchi, an associate professor of ecology, evolution and organismal biology. "I think some of that is because the Gulf hasn't been showcased in the proper manner. This book does exactly that."

Basic research on the Gulf of Mexico and particularly its estuaries-the coastal areas where seawater mixes with freshwater-is vital to understanding one of the country's most significant aquatic resources, Bianchi says.

"The Gulf of Mexico is one of the major fisheries in the country and the largest river in the country drains into this system," he says. "It's also a dynamic system, meaning that very dramatic things happen there, as opposed to the open ocean where things are just moving along at a very steady pace."

The 34 contributors to the book include Bianchi and Brent McKee, associate professor of geology at Tulane. Topics encompass the biological, chemical and geological characteristics of the estuaries, their nutrient dynamics and how organic matter and pollutants move through these systems.

Bianchi and his fellow editors, Jonathan Pennock from the University of Alabama's Dauphin Island Sea Laboratory, and Robert Twilley from the University of Southwestern Louisiana, also provide a summary of the research's implications for managing issues related to water quality and commercial activities in these areas.

The book primarily consists of basic-science research, which focuses on fundamental scientific questions and lays the groundwork for future inquiry.

"Basic science is really critical to understanding many of the applied questions in natural ecosystems," Bianchi says. To understand any of the problems related to the presence of toxic metals or nutrients, like nitrogen and phosphorous, for example, you need to know and understand the forces that affect them. "There's no way that you can go out there and just measure concentrations of pollutants without understanding the basic mechanisms of fate and transport, which requires basic-science questions."

The book also documents the varied characteristics of estuaries along the 17,000 miles of Gulf shoreline. The southern tip of Florida is a carbonate system of coral reefs with little freshwater input, while the Louisiana and Mississippi estuaries are dominated by rivers.

The Laguna Madre system that separates Padre Island from the Texas mainland is a unique system that has the highest salinity of any coastal body of water in the country, Bianchi says. Compared to more extensively studied estuaries in the Northeast and on the West Coast, the Gulf of Mexico systems have some markedly different characteristics.

"The systems up north tend to shut down in the winter months, but the Gulf is subtropical and is much more dynamic year-round," Bianchi says. "Also, the tides are not as important as wind in terms of the mixing process."
The paucity of research on the Gulf is largely due to its location, Bianchi says. "A lot of it has to do with where marine scientists have historically been employed," he says. "The external funding for such research is also dependent on the proximity of the region to ears of politicians-most of the classic work that's been done on estuaries in the United States has been on the Chesapeake Bay."

Because this is a particularly good fit with the university's Mississippi River Interdisciplinary Research program, Tulane can play a major part in future studies of the Gulf's estuaries, Bianchi says. "This book is the only resource of its kind for this region," he says. "It's a good link for us to continue to gain recognition in coastal and riverine studies."

Tulane University, New Orleans, LA 70118 504-865-5000