Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Loss of oyster reefs a global problem, but one with solutions

04.02.2011
Those familiar with Chesapeake Bay know that its once-vast oyster population stands at a tiny fraction of its historical abundance. A new study by an international team including professor Mark Luckenbach of the Virginia Institute of Marine Science shows that the decline of oyster reefs is not just a local problem.

The team's global comparison of oyster reefs past and present shows that oyster reefs are at less than 10% of their prior abundance in 70% of the 144 bays studied, ranging from China to England to Australia to Brazil. Overall, they estimate that 85% of Earth's oyster reefs have been lost, typically due to overharvesting, habitat degradation, and disease.

The researchers note that the scope of oyster loss exceeds that for any other shallow-water marine habitats that have been similarly studied. "The most striking thing about our analysis," says Luckenbach, "is that it shows that oyster reefs are the most threatened of all shallow-water, structured habitats—more so than coral reefs, mangroves, or wetlands."

VIMS professor Mark Luckenbach.
Luckenbach and his co-authors—who hail from California, China, Florida, Italy, New Jersey, Rhode Island, Tasmania, Uruguay, and Washington, D.C.—hope the results of their study will help overcome what they see as one of the most pervasive obstacles to successful management of oyster reefs: "the perception among managers and stakeholders that no major problems exist."
Solutions
In addition to quantifying oyster-reef loss, the study also shows that recovery is possible, and suggests several management approaches that can aid restoration of oyster populations and the economic and ecological services they provide. Oysters filter water; offer food and habitat to fish, crabs, and birds; stabilize the shoreline; and have traditionally supported commercial fisheries.

The authors note that many of the countries in which oyster reefs remain most abundant have comparatively strong marine management policies. They suggest this link offers "a real, albeit unrealized, opportunity for reef recovery and conservation."

They further note that the few oyster reefs that have been protected, such as the "sanctuary reefs" in Chesapeake Bay, are showing signs of success. "These examples," write the authors, "indicate that protected areas are useful tools for oyster reef conservation and should be expanded."

Their other suggestions for improved oyster management include:

The prohibition of harvests where oyster populations constitute less than 10% of their prior abundances, unless it can be shown that dredging and other harvest methods do not substantially limit reef recovery.
New thinking and approaches to ensure that oyster reefs are managed not only for fisheries production but also as fundamental ecological components of bays and coasts that provide invaluable ecosystem services.

Steps to ensure that harvests, particularly those carried out by dredging, do not damage the remaining reefs.

Regular monitoring of reef conditions.
The researchers say their results also provide a useful yardstick for identifying reasonable goals for restoration and recovery, thus enhancing the chances for successful conservation and management.

They suggest, for instance, that restoration and recovery goals should require raising reef abundance and health to at least 10% of historical levels. That would equal a shift from "poor" to "fair" in the researcher's ranking scheme, which categorized the health of oyster reefs as "good" (less than 50% lost), "fair" (50% to 89% lost), "poor" (90% to 99% lost), and "functionally extinct" (more than 99% lost). They calculated the "percentage lost" by comparing current and historical oyster populations, with the historic records gathered anywhere from 20 to 130 years ago.

Chesapeake Bay's oyster fishery removed significant amounts of shell and reef framework. The researchers placed Chesapeake Bay in the "poor" category, with harvests continuing at approximately 1% of their peak levels (an annual harvest of 25,000 metric tons in the Virginian "ecoregion" today compared to harvests of 800,000 metric tons per year around 1890.)

They also call for more widespread mapping of reefs, noting that in many places the distribution of oyster habitat was better documented 100 years ago than it is today. They say the availability and relatively low cost of side-scan sonar, LIDAR, and other modern mapping techniques would facilitate this effort.

Funding & Return on Investment
The research team notes that current funding for oyster restoration is directed mainly toward enhancing oyster fisheries (and regaining fishery production following hurricanes), with the "return on investment" measured mostly by near-term harvest values.

A better approach, they say, would be to measure the long-term value of the reef's ecosystem services, which can easily exceed the value of the harvested oysters. "The desired investment outcomes," they write, "should include rebuilding the natural capital of reefs for long-term sustainable harvests and greater resilience to storms."

"We have to recognize oysters for the reef habitat they provide," says Luckenbach. "We need to work with regulators and resource managers to ensure that oyster conservation and restoration efforts are designed not just to sustain a fishery, but to provide a vibrant reef and the ecosystem services if offers."

The team's study, Oyster Reefs at Risk and Recommendations for Conservation, Restoration, and Management, appears in the February 2011 issue of BioScience.

Team members are Michael Beck (University of California, Santa Cruz), Robert Brumbaugh (The Nature Conservancy), Laura Airoldi (Università di Bologna), Alvar Carranza and Omar Defeo (Montevideo, Uruguay), Loren Coen (Sanibel-Captiva Conservation Foundation Marine Laboratory) Christine Crawford and Graham Edgar (University of Tasmania), Boze Hancock (University of Rhode Island), Matthew Kay and Hunter Lenihan (University of California, Santa Barbara), Caitlyn Toropova (International Union for the Conservation of Nature), Guofan Zhang (Chinese Academy of Sciences), and Ximing Guo (Rutgers University).

David Malmquist | EurekAlert!
Further information:
http://www.vims.edu

More articles from Ecology, The Environment and Conservation:

nachricht Joint research project on wastewater for reuse examines pond system in Namibia
19.12.2016 | Technische Universität Darmstadt

nachricht Scientists produce a new roadmap for guiding development & conservation in the Amazon
09.12.2016 | Wildlife Conservation Society

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: Designing Architecture with Solar Building Envelopes

Among the general public, solar thermal energy is currently associated with dark blue, rectangular collectors on building roofs. Technologies are needed for aesthetically high quality architecture which offer the architect more room for manoeuvre when it comes to low- and plus-energy buildings. With the “ArKol” project, researchers at Fraunhofer ISE together with partners are currently developing two façade collectors for solar thermal energy generation, which permit a high degree of design flexibility: a strip collector for opaque façade sections and a solar thermal blind for transparent sections. The current state of the two developments will be presented at the BAU 2017 trade fair.

As part of the “ArKol – development of architecturally highly integrated façade collectors with heat pipes” project, Fraunhofer ISE together with its partners...

Im Focus: How to inflate a hardened concrete shell with a weight of 80 t

At TU Wien, an alternative for resource intensive formwork for the construction of concrete domes was developed. It is now used in a test dome for the Austrian Federal Railways Infrastructure (ÖBB Infrastruktur).

Concrete shells are efficient structures, but not very resource efficient. The formwork for the construction of concrete domes alone requires a high amount of...

Im Focus: Bacterial Pac Man molecule snaps at sugar

Many pathogens use certain sugar compounds from their host to help conceal themselves against the immune system. Scientists at the University of Bonn have now, in cooperation with researchers at the University of York in the United Kingdom, analyzed the dynamics of a bacterial molecule that is involved in this process. They demonstrate that the protein grabs onto the sugar molecule with a Pac Man-like chewing motion and holds it until it can be used. Their results could help design therapeutics that could make the protein poorer at grabbing and holding and hence compromise the pathogen in the host. The study has now been published in “Biophysical Journal”.

The cells of the mouth, nose and intestinal mucosa produce large quantities of a chemical called sialic acid. Many bacteria possess a special transport system...

Im Focus: Newly proposed reference datasets improve weather satellite data quality

UMD, NOAA collaboration demonstrates suitability of in-orbit datasets for weather satellite calibration

"Traffic and weather, together on the hour!" blasts your local radio station, while your smartphone knows the weather halfway across the world. A network of...

Im Focus: Repairing defects in fiber-reinforced plastics more efficiently

Fiber-reinforced plastics (FRP) are frequently used in the aeronautic and automobile industry. However, the repair of workpieces made of these composite materials is often less profitable than exchanging the part. In order to increase the lifetime of FRP parts and to make them more eco-efficient, the Laser Zentrum Hannover e.V. (LZH) and the Apodius GmbH want to combine a new measuring device for fiber layer orientation with an innovative laser-based repair process.

Defects in FRP pieces may be production or operation-related. Whether or not repair is cost-effective depends on the geometry of the defective area, the tools...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

12V, 48V, high-voltage – trends in E/E automotive architecture

10.01.2017 | Event News

2nd Conference on Non-Textual Information on 10 and 11 May 2017 in Hannover

09.01.2017 | Event News

Nothing will happen without batteries making it happen!

05.01.2017 | Event News

 
Latest News

Multiregional brain on a chip

16.01.2017 | Power and Electrical Engineering

New technology enables 5-D imaging in live animals, humans

16.01.2017 | Information Technology

Researchers develop environmentally friendly soy air filter

16.01.2017 | Power and Electrical Engineering

VideoLinks
B2B-VideoLinks
More VideoLinks >>>