What restoring oysters would mean for NC’s economy, environment

Earlier this month more than 200 people gathered in Raleigh for an Oyster Summit organized by the N.C. Coastal Federation to share information necessary to develop an action plan for restoring and sustaining North Carolina’s oysters. Participants, including fishermen, scientists, local and state government leaders and oyster enthusiasts, recognized that revitalizing the oyster resource would simultaneously enhance estuarine health and the state’s economy.

Annual oyster landings data from the late 1880s show how productive our coastal waters were for growing oysters. By the turn of the 20th century, oysters continued to provide a lucrative fishery with nearly a million bushels harvested each year. Since the 1902 peak in landings, the oyster population has been in a steep decline due to a confluence of factors – overharvesting, degradation of oyster reef habitat and mortality caused by the introduction of nonnative disease organisms. This oyster population decline, along with pollution-driven closures of shellfish waters, has led to harvest levels over the past 50 years remaining below 10 percent of historic highs.

For 20 years, North Carolina has actively committed to reversing this trend. Blue ribbon advisory panels have been convened to guide oyster revitalization, and tens of millions of dollars have been invested in oyster research, habitat repair and protection, and increased oyster cultivation. Despite progress and lessons learned, the job is not done.

North Carolinians are well-acquainted with the culinary delights offered by oysters. What is not yet so widely appreciated are the substantial and varied environmental benefits they provide.

Recent breakthroughs in oyster research, made largely by researchers at the UNC-Chapel Hill Institute of Marine Sciences and their collaborators, quantify magnitudes and estimate economic values of “ecosystem services” provided by shallow-water oysters and the reef habitats they create. These services and their annual value per acre of reef include providing reef habitat that augments production of many commercially valuable fishery species, such as red drum and blue crab ($1,669); stabilizing shorelines and protecting waterfront property from storm damage ($348, assuming only 1 percent of oyster reefs are located where property needs protection); clarifying estuarine waters via filtration, thereby promoting growth of seagrass meadows, the home of bay scallops, delicious shrimp and many valuable finfishes ($523); and reducing nitrogen pollution in estuaries, the cause of nuisance algal blooms and fish kills ($1,640).

These four processes associated with shallow-water oyster reefs provide total annual ecosystem benefits of $4,180 per acre, much more the $356 value of oysters harvested annually off an acre of today’s degraded reefs.

To complement results from shallow-water reefs, analogous field measurements were extended to a newly created larger, deep-water reef in Pamlico Sound: the 18.6-acre Crab Hole oyster sanctuary. This created oyster reef stimulates a higher rate of nitrogen removal per acre than the shallow-water reefs and serves as a target area for valuable recreational fishing, another quantifiable ecosystem service.

However, Crab Hole does not protect the shoreline because of its great distance from shore. Scaling up ecosystem services of this deeper-water oyster reef illustrates dollar values for a larger project projected over longer time frames: The Crab Hole reef yields a total of $973,000 in environmental benefits if the reef lasts only five years and progressively much more if it lasts longer.

Some state leaders in Raleigh recognize the benefits of oyster restoration and understand that an expanded oyster population grows local economies on the coast, while also enhancing the environment and seafood availability. All benefits are intertwined when it comes to oyster reef restoration and likewise oyster aquaculture. Oysters represent natural capital, returning dividends in the form of valuable services to the environment and to people. A bill has been introduced in the General Assembly that is intended to continue successful oyster restoration efforts and jumpstart other innovative initiatives.

This issue has significant statewide implications for tourism, environmental protection and targeted economic development. If the discussion and planning that took place at the Oyster Summit can be implemented, North Carolina’s oyster population may once again flourish under conditions of a recharged coastal and statewide economy.

Dr. Charles “Pete” Peterson, a professor at UNC-Chapel Hill’s Institute of Marine Sciences, served two terms on the N.C. Marine Fisheries Commission.