|Signage used in North Carolina to indicate a closed down shellfishing area due to excessive fecal coliform levels.|
While many hope or assume their food comes from the local area or from within the state’s coast, it is common that the actual answer is usually, Louisiana, Maine, Washington, or even China.
This may come as a surprise to many because North Carolina’s coast is host to abundant shellfish habitats and harvesting areas. Shellfish are considered an important natural resource to North Carolina’s coast and are protected under the Coastal Area Management Act. However, elevated levels of fecal coliform bacteria in coastal waters have impacted shellfish harvesting areas in the state, particularly in southeastern North Carolina where coastal development has increased. The high quantity and concentration of development in the southeastern part of the state has caused a decline in water quality in the rivers, creeks, and bays in the area.
Fecal coliform describes a group of bacteria with potential health risks that are found in the feces of warm-blooded animals such as people, pets, livestock, and wildlife. The Clean Water Act (CWA), establishes federal water quality standards including limitations on fecal coliform concentrations for swimming and for shellfish harvesting waters. Shellfish harvesting areas with fecal coliform bacteria levels that exceed water quality standards are closed down either temporarily or permanently.
North Carolina’s Coastal Area Management Act (CAMA) assigns responsibility for carrying out CWA quality standards to the Shellfish Sanitation and Recreational Water Quality Section within the NC Division of Marine Fisheries. Yet, despite their efforts they are not adequately addressing and protecting water quality. Currently, cities and towns can adopt their own land-use plans to mitigate stormwater runoff, but it is not mandatory under CAMA. As a result, few follow through with the recommendation.
Scientists link increased shellfish closures from heightened fecal coliform levels to an increase in population and impervious surfaces. Population increase, especially on the coast, leads to more development. More development creates more impervious surfaces. Impervious surfaces transport fecal coliform into coastal waters via stormwater runoff. Since 2000, the Shellfish Sanitation and Recreational Water Quality Section has permanently closed 2,318 acres of productive shellfish waters due to stormwater runoff.
|The relationship between the percent of impervious surface coverage to the density of fecal coliform bacteria in five watersheds in southeastern North Carolina. Graph credit to M. Mallin|
Increased closures of polluted shellfish harvesting waters are an indicator of poor water quality, which has public health, economic, and cultural impacts. Eating polluted shellfish can make people sick with illnesses such as Shigella, Salmonella, and Hepatitis A. Increased shellfish closures reduce access to various commercial shellfish fisheries that are economically beneficial to the state and citizens involved in the industry. The shellfishing industry has also long been a cultural part of coastal communities, and increased shellfish closures are a detriment to keeping that culture alive and thriving.
Effective stormwater mitigation is critical for protecting the public health and the economic and cultural dimensions of shellfish.
Improved and mandatory land use and stormwater plans under CAMA that better account for nonpoint pollution sources like stormwater runoff are key to reducing shellfish pollution. Implementing Low Impact Development (LID) strategies also helps mitigate stormwater runoff through development strategies such as rain gardens, pervious surfaces, and rain cisterns. Increasing incentives to implement LID strategies such as, tax cuts and reducing green infrastructure permit pricing, may assist in making these development strategies more appealing. As well, increasing outreach and education efforts to inform the public about the dangers and impacts of fecal coliform pollution and stormwater runoff aim to inform and involve the public in solutions.