The stormwater connection to a viable fishery: NC crabs in decline

This post is the first in a series of posts by the graduating class of the Master in Coastal and Ocean Policy program.  As part of their capstone, each student is working on a policy analysis of a coastal topic of interest to them.  

First up...

Doug Barker is a graduate student in the Master of Coastal and Ocean Policy Program at the University of North Carolina Wilmington. His interest in fisheries related issues stem from previous experience as a fishing guide on the Outer Banks of North Carolina and participating in water quality studies during his academic career. Living in the coastal region of North Carolina over the past 20 years, he has developed personal relationships with people who participate in both the commercial and recreational fisheries. 

The North Carolina blue crab fishery is the state’s largest commercial fishery. In fact, North Carolina is second in the nation for blue crab production. However, in recent years, the blue crab fishery has declined and the North Carolina Division of Marine Fisheries (NCDMF) listed the blue crab as a species of a concern.  

Catches in the commercial blue crab fishery experienced an upward trend peaking in the mid-to-late 90s at an estimated average catch of 40 million lbs. Since 2005, average catches have declined by a third to approximately 27 million lbs. Scientists attribute the decline to deterioration in estuarine water quality caused by stormwater runoff. Failure to revitalize the blue crab fishery threatens the livelihoods of fishermen, the vibrancy of coastal culture, and the state’s economic role in the production of US seafood.  

The northeast portion of the state supports the largest fishing grounds for the fishery. Development and agriculture increased rapidly over the last several decades corresponding to the time period of the decline in blue crab catches. What people do not realize is that activities such as development and agriculture, including pork and poultry farming, have far reaching affects on the coastal estuarine systems. One could argue that there are too many fishermen fishing for the same resource, yet participation in the fishery has been decreasing since the late 1990s. Data collected on catch per unit effort indicates a decrease in overall catches. Both trends in participation and catch per unit effort indicate a decline in the fishery.  

Reduced water quality from stormwater runoff impacts reproduction and the survival of the blue crab species. Pollutants introduced from urbanized areas accumulate on roofs, sidewalks, and roadways. The agriculture industry use fertilizers and accumulate massive amounts of animal waste. The vast majorities of these pollutants are washed away by rainwater flowing through river basins entering the state’s watersheds. Problems associated with stormwater runoff impacting the blue crab fishery include harmful algal blooms from increased nutrient introductions, low dissolved oxygen levels in the water, sediment pollution from increased erosion, decreases in ideal salinity levels, and chemical introductions. All of these conditions have occurred in state waters and continue to be issues that influence the lifecycle and biology of the blue crab. 

The NCDMF implemented a Blue Crab Fishery Management Plan (FMP) for effectively managing the fishery in order to maintain a sustainable fishery. Current regulations in the FMP take a passive approach to the problem with water quality in regards to non-point source pollution. The management strategy addressing water quality related to non-point source pollution is primarily voluntary and incentive based. According to the Draft 2015 Coastal Habitat Protection Plan, the inspection and permitting process for the agricultural industry do not have consistent measures in place that monitor water quality. Certain feedlot operations require permitting and annual inspections, yet concentrated animal feeding operations (CAFOs) for pork and cattle do not have water quality measures in place. Poultry CAFOs are inspected based on complaints lodged with state regulators. The management strategy further emphasizes the need for improvement to current agricultural and construction practices reducing sediment and nutrient influxes.  

So, why should anyone care about the decline in the blue crab industry? 

Research conducted by North Carolina Sea Grant discussed that globalization impacts North Carolina’s declining seafood industry as a whole. The study recommended continued access to the waterfront and improvements to water quality are necessary encourage the viability of the seafood industry. The problem with water quality isn’t just an issue for crab fisherman, but for all people who live and enjoy North Carolina’s waterways. The conflict in values over the utilization of the coastal zones presents problems that can be attributed to poor water quality. The declining water quality adversely affects marine ecosystems and has introduced swimming advisories and closures to shellfish harvest. Our health, our ecosystem’s health, and a part of North Carolina’s heritage can be affected by non-point source pollution.