Oysters at risk: Gastronomes' delight disappearing globally

A new, wide-ranging survey that compares the past and present condition of oyster reefs around the globe finds that more than 90 percent of former reefs have been lost in most of the “bays” and ecoregions where the prized molluscs were formerly abundant.

In many places, such as the Wadden Sea in Europe and Narragansett Bay, oysters are rated “functionally extinct,” with fewer than 1 percent of former reefs persisting. The declines are in most cases a result of over-harvesting of wild populations and disease, often exacerbated by the introduction of non-native species.

Oysters have fueled coastal economies for centuries, and were once astoundingly abundant in favored areas. The new survey is published in the February issue of BioScience, the journal of the American Institute of Biological Sciences. It was conducted by an international team led by Michael W. Beck of The Nature Conservancy and the University of California, Santa Cruz. Beck's team examined oyster reefs across 144 bays and 44 ecoregions. It also studied historical records as well as national catch statistics. The survey suggests that about 85 percent of reefs worldwide have now been lost. The BioScience authors rate the condition of oysters as “poor” overall.

Most of the world's harvest of native oysters comes from just five ecoregions in North America, but even there, the condition of reefs is “poor” or worse, except in the Gulf of Mexico. Oyster fisheries there are “probably the last opportunity to achieve large-scale oyster reef conservation and sustainable fisheries,” Beck and his coauthors write. Oysters provide important ecosystem services, such as water filtration, as well as food for people. The survey team argues for improved mapping efforts and the removal of incentives to over-exploitation. It also recommends that harvesting and further reef destruction should not be allowed wherever oysters are at less than 10 percent of their former abundance, unless it can be shown that these activities do not substantially affect reef recovery.

After noon EST on 3 February and for the remainder of the month, the full text of the article will be available for free download through the copy of this Press Release available at http://www.aibs.org/bioscience-press-releases/

BioScience, published monthly, is the journal of the American Institute of Biological Sciences (AIBS). BioScience publishes commentary and peer-reviewed articles covering a wide range of biological fields, with a focus on “Organisms from Molecules to the Environment.” The journal has been published since 1964. AIBS is an umbrella organization for professional scientific societies and organizations that are involved with biology. It represents some 200 member societies and organizations with a combined membership of about 250,000.

The complete list of peer-reviewed articles in the February 2011 issue of BioScience is as follows:

Oyster Reefs at Risk and Recommendations for Conservation, Restoration, and Management. Michael W. Beck and colleagues.

Sustainability Challenges of Phosphorus and Food: Solutions From Closing the Human Phosphorus Cycle. Daniel L. Childers, Jessica Corman, Mark Edwards, and James L. Elser.

Is Wildlife Going to the Dogs? Impacts of Feral and Free-roaming Dogs on Wildlife Populations. Julie K. Young, Kirk A. Olson , Richard P. Reading, Sukh Amgalanbaatar, and Joel Berger.

Perceptions of Strengths and Deficiencies; Disconnects between Graduate Students and Prospective Employers. Marshall D. Sundberg and colleagues.

The Short- and Long-term Effects of Fire on Carbon in Dry, Temperate Forest Systems of the United States. Matthew D. Hurteau and Matthew L. Brooks.

Climate Change and Biosphere Response: Unlocking the Collections Vault. Kenneth G. Johnson and colleagues.