Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Troubled waters: Low Apalachicola River flow may hurt gulf fisheries

23.06.2009
Reductions in the flow of the Apalachicola River have far-reaching effects that could prove detrimental to grouper and other reef fish populations in the northeastern Gulf of Mexico, according to a new Florida State University study that may provide new ammunition for states engaged in a nearly two-decade water war.

The Florida State researchers found that in years with low river flow, the concentration of phytoplankton -- the microscopic plant-like organisms that feed into the food chain -- decreased over a large area of the continental shelf.

This is significant because scientists have hypothesized that year-to-year changes in the phytoplankton can alter the availability of food for the very young fish larvae, according to research scientist Steven Morey of the Center for Ocean-Atmospheric Prediction Studies (COAPS) at Florida State.

Though much of the scientific research examining the consequences of low-flow conditions, primarily caused by extended drought in recent years, has focused on the Apalachicola River and the estuary system of Apalachicola Bay, the Florida State researchers instead examined the effect of unusually low and high flows over the wide western Florida continental shelf. A number of important reef fish, such as grouper, spawn on the outer shelf edge and use the inner shelf areas as nursery habitat.

"This work shows that variations in the river flow can have implications on marine ecosystems over a much broader geographic region, namely much of the continental shelf extending out several hundred miles," Morey said. "This now suggests that there might be a link between the river flow variations and offshore fisheries."

Morey, Dmitry Dukhovskoy, also of COAPS, and Mark Bourassa, an associate professor of meteorology at FSU, examined the seasonal and year-to-year variability of the river flow caused by changes in precipitation over the watershed encompassing much of western Georgia and parts of eastern Alabama and the Florida Panhandle. The researchers used satellite ocean color data and computer models of ocean circulation to identify a region extending about 125 miles offshore of Apalachicola Bay in which the changes in ocean color, which is indicative of the abundance of phytoplankton and other organic material in the water, is linked to changes in the river flow.

The researchers outlined their findings in an article, "Connectivity of the Apalachicola River flow variability and the physical and bio-optical oceanic properties of the northern West Florida Shelf," published in the journal Continental Shelf Research.

The findings broaden the environmental considerations of managed flow reductions in the Apalachicola-Chattahoochee-Flint (ACF) river system. The Apalachicola River, the final leg of the river system, has been the focus of a nearly 20-year legal battle between Florida, Georgia and Alabama, known as the Tri-State Water War. At the heart of the dispute is Georgia's desire to divert water from the ACF river system to the burgeoning population of the Atlanta metropolitan area, and Florida and Alabama's contention that this flow reduction could have negative consequences for the downstream river environment.

The Apalachicola River is considered a "hot spot" of ecological biodiversity, and Apalachicola Bay supports extensive finfish and shellfish communities dependent on the regular flow of freshwater from the river. The river is a source of nutrients that can contribute to the abundance of phytoplankton, which are consumed by small zooplankton, thus feeding the marine food web in the region. The strongest connection between the river flow rate and the offshore water properties is seen during the late winter and early spring months, which coincide with the spawning period of several reef fish species.

"It is possible that if the natural flow of the river is reduced by water being diverted to reservoirs upstream, it could reduce the natural nutrient supply to the local food web," Morey said. "That could potentially result in a reduction of food available for larger plankton, like fish larvae."

The study sheds some light on potential effects of climate change scenarios altering precipitation patterns over the southeastern United States, Morey said, but further study is needed to determine if the proposed man-made flow reductions at the center of the water wars will have a significant impact on the offshore marine systems, especially during abnormally dry years.

Steven Morey | EurekAlert!
Further information:
http://www.fsu.edu

More articles from Ecology, The Environment and Conservation:

nachricht Waste in the water – New purification techniques for healthier aquatic ecosystems
24.07.2018 | Eberhard Karls Universität Tübingen

nachricht Plenty of habitat for bears in Europe
24.07.2018 | Deutsches Zentrum für integrative Biodiversitätsforschung (iDiv) Halle-Jena-Leipzig

All articles from Ecology, The Environment and Conservation >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: It’s All in the Mix: Jülich Researchers are Developing Fast-Charging Solid-State Batteries

There are currently great hopes for solid-state batteries. They contain no liquid parts that could leak or catch fire. For this reason, they do not require cooling and are considered to be much safer, more reliable, and longer lasting than traditional lithium-ion batteries. Jülich scientists have now introduced a new concept that allows currents up to ten times greater during charging and discharging than previously described in the literature. The improvement was achieved by a “clever” choice of materials with a focus on consistently good compatibility. All components were made from phosphate compounds, which are well matched both chemically and mechanically.

The low current is considered one of the biggest hurdles in the development of solid-state batteries. It is the reason why the batteries take a relatively long...

Im Focus: Color effects from transparent 3D-printed nanostructures

New design tool automatically creates nanostructure 3D-print templates for user-given colors
Scientists present work at prestigious SIGGRAPH conference

Most of the objects we see are colored by pigments, but using pigments has disadvantages: such colors can fade, industrial pigments are often toxic, and...

Im Focus: Unraveling the nature of 'whistlers' from space in the lab

A new study sheds light on how ultralow frequency radio waves and plasmas interact

Scientists at the University of California, Los Angeles present new research on a curious cosmic phenomenon known as "whistlers" -- very low frequency packets...

Im Focus: New interactive machine learning tool makes car designs more aerodynamic

Scientists develop first tool to use machine learning methods to compute flow around interactively designable 3D objects. Tool will be presented at this year’s prestigious SIGGRAPH conference.

When engineers or designers want to test the aerodynamic properties of the newly designed shape of a car, airplane, or other object, they would normally model...

Im Focus: Robots as 'pump attendants': TU Graz develops robot-controlled rapid charging system for e-vehicles

Researchers from TU Graz and their industry partners have unveiled a world first: the prototype of a robot-controlled, high-speed combined charging system (CCS) for electric vehicles that enables series charging of cars in various parking positions.

Global demand for electric vehicles is forecast to rise sharply: by 2025, the number of new vehicle registrations is expected to reach 25 million per year....

All Focus news of the innovation-report >>>

Anzeige

Anzeige

VideoLinks
Industry & Economy
Event News

LaserForum 2018 deals with 3D production of components

17.08.2018 | Event News

Within reach of the Universe

08.08.2018 | Event News

A journey through the history of microscopy – new exhibition opens at the MDC

27.07.2018 | Event News

 
Latest News

Quantum bugs, meet your new swatter

20.08.2018 | Information Technology

A novel synthetic antibody enables conditional “protein knockdown” in vertebrates

20.08.2018 | Life Sciences

Metamolds: Molding a mold

20.08.2018 | Information Technology

VideoLinks
Science & Research
Overview of more VideoLinks >>>