SciTech

A scientist and a fisherman team up to solve NC’s oyster crisis

Neils Lindquist, left, and David Cessna inspect oyster beds in front of the UNC Institute of Marine Sciences in Morehead City.
Neils Lindquist, left, and David Cessna inspect oyster beds in front of the UNC Institute of Marine Sciences in Morehead City. UNC Research

There’s an environmental and economic oyster crisis along the North Carolina coast and around the world: Oyster populations are drastically low compared to their numbers a century ago. In North Carolina, the population is down 90 percent from its peak.

But two men in Carteret County think they have found a way to reverse this trend. One, Neils Lindquist, is a scientist. The other, David “Clammerhead” Cessna, is a fishermen.

Against big odds, these two have worked together for the past six years to figure out the best way to increase oyster populations in the estuaries of the North Carolina coast. Those waters were once abundant with oysters, but now their populations have been decimated because of overharvesting and habitat destruction.

Over the past few decades, local scientists and conservationists have developed methods to restore oyster populations. One of the more successful efforts is the creation of man-made oyster-shell sills: A pile of loose oyster shells or marl is placed in shallow water, creating a barrier that runs parallel to shore; the rock or shell material can also be placed inside mesh bags. Plants can be added around the sill to create a living shoreline. The idea is that oyster larvae will attach to it underwater and create an oyster reef.

While this is still an effective practice for oyster restoration, Lindquist called upon the local knowledge of Cessna – a seventh-generation Down East fishermen in Carteret County – to improve upon traditional methods. Together, they’ve experimented with different types of materials to develop the most effective way to restore oyster populations.

Their improve method for restoration bypasses marl and oyster shells and instead uses an ephemeral, plant-based material to create structures for oyster larvae to attach to. Cessna, who left his job in construction to return to his love of fishing, is using his building skills to create reefs.

Environmental advantages

The plant-based reef material can be molded into different shapes and sizes, from flat square mats to long, rod shapes, pyramids, and something that Cessna refers to as a cow patty.

The duo has tested new material and a variety of reef shapes behind the Institute of Marine Sciences in Morehead City on the busy Bogue Sound waterway.

Lindquist says their method is showing marked improvements over traditional oyster sills.

“We create reefs that can withstand tremendous wave and currents and we’ve had material in the water for almost 10 months now and we’ve seen it not move an inch,” he says.

There are several advantages to using plant-based material to build reefs. With the traditional sill method, if oysters fail to grow and cover the mesh bags, the bags eventually tear open, the shells scatter, and the plastic ends up in the environment.

The new biodegradable substrate material eventually disintegrates in the water and the concrete crumbles into small pieces and becomes part of the sediment bed.

Each three-dimensional structure is also elevated above the bottom, allowing oyster larvae to settle on all sides of the substrate. This design results in more oysters, healthier waterways and a more prosperous fishing industry.

New habitats

In addition to creating micro-habitats, another advantage to these rigid structures is that they can be anchored in place in intertidal areas with strong waves and currents. Lindquist says more water movement carries more food to the reef, resulting in faster growing oysters.

Lindquist says they have been able to cut that time by almost half, growing high quality oysters in only 12 to 15 months.

Oysters are economically important in North Carolina, providing local jobs and a product that is sent to seafood markets and restaurants across the state and internationally. The state’s annual oyster harvest over the past few years has been $250 million, according to Lindquist.

Lindquist and Cessna have leased another testing site in the Newport River – an intertidal area – where a small portion of the 1.3 acres was covered with the substrate. Their conservative estimate is that 3.6 million oysters have grown at the site, though it’s probably more like five to six million.

Oysters were not growing in this area before the reefs were built, giving Lindquist and Cessna hope that their approach can be used to create thriving oyster habitats in places where they didn’t previously exist.

Lindquist also hopes the new material and the methods they’ve found for growing oysters will create opportunity for conservationists and even waterfront homeowners who want to create a living shoreline in their own backyard.

Jared Brumbaugh is a reporter/producer for Public Radio East in New Bern. This article originally appeared on the website www.publicradioeast.org

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