First-Ever Global Report on Shellfish Indicates 85 Percent of Oyster Reefs Have Vanished

“Shellfish Reefs at Risk” report shows habitat loss widely impacts ecosystems and economies, identifies solutions for bringing oyster reefs back from the brink

Mark Dumesnil

Conservancy staffer Mark Dumesnil blows oyster shells into Copano Bay in Texas

Shellfish Reef Map

North American shellfish distribution.

ARLINGTON, VA | May 21, 2009

The Nature Conservancy today released the first-ever comprehensive global report on the state of shellfish at the International Marine Conservation Congress in Washington, DC.The report, which finds that 85 percent of oyster reefs have been lost worldwide, concludes that oyster reefs are the most severely impacted marine habitat on the planet. While the report listed the condition of oyster reefs along most North American coasts as poor or functionally extinct, those along most of the Gulf of Mexico were listed as fair, indicating better hope for restoration.

“This report underscores the importance of the Conservancy’s efforts to restore the Gulf’s oyster reefs,” said Laura Huffman, the director of the Conservancy of Texas. “Oyster reefs filter and clean our water, provide habitat for fish and other wildlife that help fuel the state’s economy, and they protect communities from storm surges. And most of the nation’s total oyster landings come from the Gulf. Conserving and restoring oyster reefs is critically important to us all.”

Last year the Conservancy partnered with NOAA’s Community Restoration Program, the Mission-Aransas National Estuarine Research Reserve (NERR), Texas Parks and Wildlife Department and Texas A & M University in restoring a reef by depositing 200 cubic yards of oyster shell into the shallow waters at Texas’ Copano Bay near Corpus Christi.

“The Conservancy contracted with the Harte Research Institute for Gulf of Mexico Studies to monitor the reef’s growth and development at Copano Bay,” said Rafael Calderon, the director of the Conservancy’s Gulf of Mexico program. “Their research will help the Conservancy develop an estimate of how much additional restoration is required to achieve significant water quality improvements within the Bay. Ultimately, our goal is to conserve and restore oyster reefs at a scale large enough to re-establish their ecosystem functionality throughout the Gulf of Mexico.”

Mike Beck, senior marine scientist at The Nature Conservancy and lead author of the report agreed that goal is achievable.“If we take actionnow with sensible and proven solutions, all hope is not lost” he said. “Ensuring that oyster reefs and other shellfish habitats are managed as critical components of coastal ecosystems, and garnering commitments from policymakers and marine practitioners to restore and protect these critical habitats will help to ensure that they are around for future generations.”

Dr. Wes Tunnell, associate director of the Harte Research Institute, said, “In the past Texas had huge oyster reefs, several of which have been completely or nearly decimated. People are beginning to realize the importance of habitat restoration. The Nature Conservancy’s focus on oyster reef restoration is very timely and can have a big benefit to Texas’ coastal ecology. Oysters improve water quality and provide great habitat for aquatic wildlife, particularly fish.”

The report, written by scientists across five continents, from conservation organizations as well as academic and research institutions, focuses primarily on the distribution and condition of native oyster reefs. The report’s analysis found that in the majority of individual bays around the world, there has been a greater than 90 percent loss of oyster reef habitat. In some areas, the loss of oyster reef habitat exceeds 99 percent.

The driving forces behind the decline of oyster reefs include destructive fishing practices, coastal over-development, and associated effects of upstream activities such as altered river flows, dams, poorly managed agriculture and poor water quality. Many of these threats have been around for decades and even centuries, but today there are two main issues that impede oyster recovery efforts.

According to the report, the first is a widespread lack of awareness that shellfish habitats are in trouble. In nearly all cases, shellfish are managed as fisheries, meaning they are viewed solely as a commodity but are not valued for the intrinsic role they play in keeping marine ecosystems healthy and intact. The second challenge is the common perception that as native shellfish decline, non-native shellfish can act as an ecologically suitable replacement. Unfortunately, previous introductions of non-native oysters and other shellfish into new areas have spread disease and have had other negative impacts on the surrounding environment.

The report lays out specific recommendations drawn from examples around the world, such as the need to elevate native, wild oyster reefs as a priority for habitat management and conservation, and to make better use of protected area policies for the benefit of shellfish.


In the Lone Star State, The Nature Conservancy of Texas owns more than 30 nature preserves and conservation projects and assists private landowners to conserve their land through more than 100 voluntary land-preservation agreements. The Nature Conservancy of Texas protects some 250,000 acres of wild lands and, with partners, has conserved 750,000 acres for wildlife habitat across the state. Visit The Nature Conservancy of Texas on the Web at

The Nature Conservancy is a leading conservation organization working around the world to protect ecologically important lands and waters for nature and people. The Conservancy and its more than 1 million members have protected nearly 120 million acres worldwide. Visit The Nature Conservancy on the Web at

Contact information

Clay Carrington
The Nature Conservancy of Texas
(210) 392-9458

Jay Harrod
The Nature Conservancy
(501) 614-5081

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