Oysters at risk as one percent of reefs remain

A new, wide-ranging survey that compares the past and present condition of oyster reefs around the globe finds that more than 90 per cent of former reefs have been lost in most of the "bays" and eco-regions 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 one percent of former reefs persisting.

The declines are in most cases a result of disease and over-harvesting of wild populations, often exacerbated by the introduction of non-native species. Oysters have fueled coastal economies for centuries, and were once astoundingly abundant in favoured 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. Dr Beck's team examined oyster reefs across 144 bays and 44 eco-regions. 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. Read more...

This blog is written by Martin Little The Aquaculturists, published and supported by the International Aquafeed Magazine from Perendale Publishers.