Writing in the Journal of Coastal Research, Gary P. Shaffer, Southeastern professor of biological sciences, notes that the Maurepas Swamp complex, the second largest coastal forest in Louisiana, has been radically reduced over the years due to excessive logging, development, changing water levels, nutrient deprivation and saltwater intrusion. The paper was co-authored with several other scientists from Southeastern and LSU.
“Much of the remaining swamp is in a severe state of deterioration,” Shaffer said.
He explained that the establishment of levees over the last century along the Mississippi River to eliminate natural flooding removed a once reliable source of fresh water, sediments and nutrients that swamps require for healthy growth.
“This has enabled salt water from the Gulf of Mexico to make further inland intrusions,” he said. “Combined with rising sea levels and the construction of massive canals, such as the Mississippi River Gulf Outlet (MRGO), the intensity and frequency of saltwater intrusions has only grown worse. Consequently, most of the Maurepas Swamp appears to be in transition to marsh and open water.”
The scientists’ findings are based on comparisons of selected groupings of sites in the southern wetlands of Lake Maurepas. The sites had three different levels of water quality: including stagnant and nearly permanently flooded areas, sites with severe saltwater intrusion, and sites that receive some freshwater runoff. Salinity levels appeared to be the major factor causing sites to rapidly deteriorate, with the most degraded areas located near Lake Pontchartrain or along the margin of Lake Maurepas.
“The Maurepas Swamp is in a steady state of rapid decline, and that’s evident by the loss of much of the baldcypress and water tupelo forests that were a mainstay of the swamp,” Shaffer said. “Over the past seven years, nearly 20 percent of the original 1,860 trees in our study plots have died.”
A Mississippi River diversion – under study for several years now by the Environmental Protection Agency and scientists at Southeastern and LSU – would decrease the salinity, increase the levels of nutrients, and provide much needed sediment necessary to rebuild the subsiding swamp, Shaffer explained.
“It is likely that the influences of freshening would be felt in wetlands as distant as Lake Pontchartrain,” he said. “Even the smallest proposed diversion would replace all of the water in Lake Maurepas twice each year and it can only exit to Lake Pontchartrain through Pass Manchac and North Pass.”
Mississippi River reintroductions have been considered at Violet, Bonnet Carre, La Branch and two in the Maurepas Swamp, Shaffer said
The study also evaluated the region following the 2005 hurricanes, with the scientists concluding that the extensive lateral root systems of baldcypress and water tupelo can hold an entire ecosystem together, while also serving as valuable natural storm buffers.
“If we want to reverse the decline of coastal Louisiana swamps, we have to find and use sources of fresh water that currently are being wasted, including water from the Mississippi River, as well as treated sewage effluent,” he said. “The proper freshening of the region should enable restoration of the swamps in the Lake Pontchartrain Basin.”
Co-authors of the study included Thais E. Perkins, William B. Wood and Jason Zoller of Southeastern; Susan S. Hoeppner of the LSU Department of Oceanography and Coastal Science; and Demetra Kandalepas of the LSU Department of Biological Sciences. Shaffer also credited the efforts of numerous undergraduate and graduate students who performed much of the field work.
Rene Abadie | Newswise Science News
Diagnoses: When Are Several Opinions Better Than One?
19.07.2016 | Max-Planck-Institut für Bildungsforschung
High in calories and low in nutrients when adolescents share pictures of food online
07.04.2016 | University of Gothenburg
Ultrafast lasers have introduced new possibilities in engraving ultrafine structures, and scientists are now also investigating how to use them to etch microstructures into thin glass. There are possible applications in analytics (lab on a chip) and especially in electronics and the consumer sector, where great interest has been shown.
This new method was born of a surprising phenomenon: irradiating glass in a particular way with an ultrafast laser has the effect of making the glass up to a...
Terahertz excitation of selected crystal vibrations leads to an effective magnetic field that drives coherent spin motion
Controlling functional properties by light is one of the grand goals in modern condensed matter physics and materials science. A new study now demonstrates how...
Researchers from the Institute for Quantum Computing (IQC) at the University of Waterloo led the development of a new extensible wiring technique capable of controlling superconducting quantum bits, representing a significant step towards to the realization of a scalable quantum computer.
"The quantum socket is a wiring method that uses three-dimensional wires based on spring-loaded pins to address individual qubits," said Jeremy Béjanin, a PhD...
In a paper in Scientific Reports, a research team at Worcester Polytechnic Institute describes a novel light-activated phenomenon that could become the basis for applications as diverse as microscopic robotic grippers and more efficient solar cells.
A research team at Worcester Polytechnic Institute (WPI) has developed a revolutionary, light-activated semiconductor nanocomposite material that can be used...
By forcefully embedding two silicon atoms in a diamond matrix, Sandia researchers have demonstrated for the first time on a single chip all the components needed to create a quantum bridge to link quantum computers together.
"People have already built small quantum computers," says Sandia researcher Ryan Camacho. "Maybe the first useful one won't be a single giant quantum computer...
14.10.2016 | Event News
14.10.2016 | Event News
12.10.2016 | Event News
25.10.2016 | Earth Sciences
25.10.2016 | Power and Electrical Engineering
25.10.2016 | Process Engineering