85% of World's Oyster Reefs Already Gone, Many Functionally Extinct

oyster reef photo

photo: The Nature Conservancy

The first-ever comprehensive review of the state of the world's shellfish has just been released by The Nature Conservancy and the prognosis (as you may expect) really isn't good. In fact, when oysters are concerned it's downright awful.Globally, about 85% of the world's oyster reefs have vanished and in many areas oyster reefs are functionally extinct:The report says that the main factors in the decline of oyster reefs are: Destructive fishing practices, coastal over-development, the effects of upstream activities such as altered river flows, dams, poorly managed agriculture, and poor water quality.

Oysters Much More Important Than Simply Food
If oysters weren't just a currently and historically important human food source this would all be bad enough, but oyster reefs also provided several valuable ecosystem services. They act as natural water filters and improve water quality, proved food and habitat for fish, crabs and birds. And perhaps of increasing importance is the fact that they also as natural coastal buffers, helping to protect shorelines and keep coastal wetlands intact, thereby protecting coastal communities against storm surges and sea-level rise.

So, what can we do to protect what oyster reefs we have left?

Awareness About Oyster's Ecosystem Function Needs to Increase
The first thing to tackle, the report says, is the fact that there is so little awareness of all the good that oyster reefs do, besides providing food for people.

The second is that we need to erase the commonly-held perception that if native shellfish decline, non-native species can be an ecologically suitable replacement. Though over long periods of time, the ecosystem may be able to adapt to non-native species, in previous cases where non-native oysters and shellfish have been introduced, the effect has been negative on the surrounding environment.

Plus, Conservation Measures Need to Be Enacted...
From there, several more concrete recommendations are made. For the full list, check out the Nature Conservancy's page on the subject, and download the original report: Shellfish Reefs at Risk Report
Oceans, Shellfish
Increasingly Acidified Waters Could Prompt Mass Shellfish Dissolution
A Primer on Global Warming-Caused Marine Dead Zones
Oysters are Restored to Waters in Need
Solar Powered Reef Keeping Oysters in East Coast Waters

Related Content on Treehugger.com