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 Successful calculation of human and natural influence on cloud formation
04.11.2016 | Goethe-Universität Frankfurt am Main

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

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: Novel silicon etching technique crafts 3-D gradient refractive index micro-optics

A multi-institutional research collaboration has created a novel approach for fabricating three-dimensional micro-optics through the shape-defined formation of porous silicon (PSi), with broad impacts in integrated optoelectronics, imaging, and photovoltaics.

Working with colleagues at Stanford and The Dow Chemical Company, researchers at the University of Illinois at Urbana-Champaign fabricated 3-D birefringent...

Im Focus: Quantum Particles Form Droplets

In experiments with magnetic atoms conducted at extremely low temperatures, scientists have demonstrated a unique phase of matter: The atoms form a new type of quantum liquid or quantum droplet state. These so called quantum droplets may preserve their form in absence of external confinement because of quantum effects. The joint team of experimental physicists from Innsbruck and theoretical physicists from Hannover report on their findings in the journal Physical Review X.

“Our Quantum droplets are in the gas phase but they still drop like a rock,” explains experimental physicist Francesca Ferlaino when talking about the...

Im Focus: MADMAX: Max Planck Institute for Physics takes up axion research

The Max Planck Institute for Physics (MPP) is opening up a new research field. A workshop from November 21 - 22, 2016 will mark the start of activities for an innovative axion experiment. Axions are still only purely hypothetical particles. Their detection could solve two fundamental problems in particle physics: What dark matter consists of and why it has not yet been possible to directly observe a CP violation for the strong interaction.

The “MADMAX” project is the MPP’s commitment to axion research. Axions are so far only a theoretical prediction and are difficult to detect: on the one hand,...

Im Focus: Molecules change shape when wet

Broadband rotational spectroscopy unravels structural reshaping of isolated molecules in the gas phase to accommodate water

In two recent publications in the Journal of Chemical Physics and in the Journal of Physical Chemistry Letters, researchers around Melanie Schnell from the Max...

Im Focus: Fraunhofer ISE Develops Highly Compact, High Frequency DC/DC Converter for Aviation

The efficiency of power electronic systems is not solely dependent on electrical efficiency but also on weight, for example, in mobile systems. When the weight of relevant components and devices in airplanes, for instance, is reduced, fuel savings can be achieved and correspondingly greenhouse gas emissions decreased. New materials and components based on gallium nitride (GaN) can help to reduce weight and increase the efficiency. With these new materials, power electronic switches can be operated at higher switching frequency, resulting in higher power density and lower material costs.

Researchers at the Fraunhofer Institute for Solar Energy Systems ISE together with partners have investigated how these materials can be used to make power...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

ICTM Conference 2017: Production technology for turbomachine manufacturing of the future

16.11.2016 | Event News

Innovation Day Laser Technology – Laser Additive Manufacturing

01.11.2016 | Event News

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

14.10.2016 | Event News

 
Latest News

UTSA study describes new minimally invasive device to treat cancer and other illnesses

02.12.2016 | Medical Engineering

Plasma-zapping process could yield trans fat-free soybean oil product

02.12.2016 | Agricultural and Forestry Science

What do Netflix, Google and planetary systems have in common?

02.12.2016 | Physics and Astronomy

VideoLinks
B2B-VideoLinks
More VideoLinks >>>