North Carolina removed 4 to 7 tons of abandoned crab pots from coastal waters; fishermen recycled the metal into 700 feet of new oyster-reef structure

Picture the seafloor along a coastline: rusting wire cages with bait still dangling, waiting to snag anything that passes by, that no one has checked for years. The crabber who set them down may have lost track of them in a storm or after a passing boat's propeller had sliced through the line, but the trap never knew. Ghost fishing is one of those ocean issues that few outside the fishing industry even know about, but it's one that marine biologists take seriously, because a lost trap doesn't stop working just because no one is checking it. According to the NOAA Marine Debris Program, a pilot project along the North Carolina coast decided to take a page from nature's playbook by using abandoned traps as building blocks for a new reef.

Marine life lost

While ghost gear may seem like an isolated problem, it carries a real economic cost. A 2016-published assessment titled “Ecological and Economic Effects of Derelict Fishing Gear in the Chesapeake Bay 2015/2016 Final Assessment Report,” by researchers at the Virginia Institute of Marine Science in conjunction with NOAA's Marine Debris Program, found that abandoned equipment was responsible for the capture and death of more than six million blue crabs a year in the Chesapeake Bay, about three and a half million of which died directly in the pots. That same assessment tied an active effort to pull thousands of derelict traps out of the water between 2008 and 2014 to an estimated 38 million pounds in additional commercial crab harvest, worth $33.5 million to the regional economy over that period.

North Carolina's approach to the problem was characteristically low-key: from June 2013 to May 2014, the North Carolina Coastal Federation worked with commercial watermen in Pamlico Sound to remove derelict blue crab pots and use the wire to create a reef structure for growing eastern oysters. An estimated four to seven tons of abandoned equipment was removed and turned into roughly 700 linear feet of new oyster reef. The funding for the equipment removal project was provided with the help of volunteer workers, including watermen and college students. The same fishermen who often lose pieces of their own equipment to ghost fishing were also among the workers removing derelict traps and nets.

Waste not, want not

The specific decision to make the new reefs out of the wire from old traps was based partly on the virtues of native oysters as a keystone species. Besides acting as water filters, oyster reefs can help protect shorelines from erosion and provide nurseries for fish and crabs, making the restoration of reefs a worthy cause in itself. However, oyster populations had been on the decline for decades due to a combination of overharvesting, pollution, and disease, according to a widely circulated 2011 paper titled “Oyster Reefs at Risk and Recommendations for Conservation, Restoration, and Management,” by Beck and collaborators in the journal BioScience, which also noted that roughly 85 percent of the world's oyster reefs vanished, leaving some bays have "functionally extinct." So the construction of 700 feet of new reef is actually 700 feet more than there was before, and with relatively little loss of other resources.

The catch

All of that aside, one pilot program in one ground can't begin to make up for the years of ghost fishing that have affected coastal marine life in areas throughout the country. Scaling up such a model would require consistent funding from public sources, monitoring of the reefs and, critically, persuading more fishermen to give up gear with real value to them personally. A recovered crab pot in working condition is often worth more to its owner intact than as scrap: North Carolina Coastal Federation staff have noted that recycling the wire brings in only a few cents a pound, while a replacement pot costs upwards of $50, so fishermen have every reason to reclaim their own gear rather than hand it over for reef-building. That personal incentive to keep or reuse a pot is separate from, and can work against, the broader economic gain the region sees when derelict gear is removed altogether and crab harvests recover.

What the North Carolina example does show is that waste doesn't have to stay waste; debris can become habitat, and that the people most likely to notice marine debris in the first place are often the same ones positioned to turn it into new habitat, improving the local ecosystem and the regional economy at the same time. It's a lesson that a rising number of consumers interested in sustainable seafood might find valuable.