Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:


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

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."
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:

More articles from Ecology, The Environment and Conservation:

nachricht Invasive Insects Cost the World Billions Per Year
04.10.2016 | University of Adelaide

nachricht Malaysia's unique freshwater mussels in danger
27.09.2016 | The University of Nottingham Malaysia Campus

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: Etching Microstructures with Lasers

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...

Im Focus: Light-driven atomic rotations excite magnetic waves

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...

Im Focus: New 3-D wiring technique brings scalable quantum computers closer to reality

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...

Im Focus: Scientists develop a semiconductor nanocomposite material that moves in response to light

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...

Im Focus: Diamonds aren't forever: Sandia, Harvard team create first quantum computer bridge

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...

All Focus news of the innovation-report >>>



Event News

#IC2S2: When Social Science meets Computer Science - GESIS will host the IC2S2 conference 2017

14.10.2016 | Event News

Agricultural Trade Developments and Potentials in Central Asia and the South Caucasus

14.10.2016 | Event News

World Health Summit – Day Three: A Call to Action

12.10.2016 | Event News

Latest News

Greater Range and Longer Lifetime

26.10.2016 | Power and Electrical Engineering

VDI presents International Bionic Award of the Schauenburg Foundation

26.10.2016 | Awards Funding

3-D-printed magnets

26.10.2016 | Power and Electrical Engineering

More VideoLinks >>>