Urbanization, wastewater dischargers, and agricultural runoff, among others, all affect the water quality in the Lower Cape Fear River. Urbanization means increased traffic, more land development, fewer trees, and less flood control. It also means more people are relying on services provided by water and sewer utilities, farmers, and fishermen. Utilities exist to provide us with water and dispose of our waste, and we eat the food provided by farmers and commercial fishermen. But our community’s relationship with the river doesn’t have to be negative.
Rainfall carries runoff loaded with nutrients, pesticides, wastewater, and heavy metals to the river, all of which threaten human and fish health. The Nature Conservancy investigated the sources of input by mapping the lower Cape Fear watershed and figured out where this input is highest. This information will guide future conservation efforts. Learn more about TNC's methods here.
Nutrient loading is a major pollutant and one of the biggest contributors to water quality degradation. Both human and fish health is impacted by pollution. Findings indicate that toxic algal blooms can cause hypoxia and fish mortalities, high concentrations of dissolved organic nitrogen hinder migratory fish navigation toward natural spawning sites, and elevated levels of nitrite in fish can result in a decreased capacity for carrying oxygen. These are just a few of the studies that link poor water quality to fish health.
Water Quality
Fish Passage
Anadromous fish, such as shad and herring, are born in the upper portions of the Cape Fear River and then swim downstream to the ocean where they mature, before migrating back upstream to spawn. Their journey isn’t an easy one to begin with, and was made more difficult after the construction of three navigational locks and dams built between 1915 and 1935.
These obstructions block migratory fish from spawning grounds and nursery habitat, which limits fish reproduction. Dams also alter the flow of water, and migratory fish like American shad and striped bass prefer faster flow to aid in their movement upriver (Burdick and Hightower (2006)).
The Action Plan for Migratory Fish (APMF) aims to improve fish habitat and passage, which will improve spawning conditions, increase water flow, and decrease nutrient loading into the river. APMF has made significant progress in making migratory routes accessible for fish by modifying dams, but there is still much work to be done.
Habitat
Migratory fish aren’t the only wildlife threatened by human impacts. The Cape Fear is a diverse riverine system, comprised of a wealth of plants and wildlife – some of which have shown astounding resiliency, while others are known to be extremely sensitive to environmental changes.
Dredging, increased sediment loads, runoff, deforestation, and land development all hinder the success and productivity of these habitats, which in turn reduce and degrade the services they provide. The growing economies of surrounding communities rely on the abundance of these natural resources, so it’s important that we work together to protect them in order to see these benefits.
Economic Benefits
The Cape Fear, if properly cared for, can be a treasure trove for communities that depend on the river for access to clean drinking water, healthy fisheries, recreational opportunities, and tourism.
Improving the habitat and water quality of migratory fish species will increase the potential for benefits to multiple stakeholders. As a way of demonstrating this, NC Division of Marine Fisheries (NCDMF) quantified the economic importance of migratory fish species, such as American shad and striped bass, by collecting recreational and commercial fishing data that demonstrates the value of these fisheries to North Carolina.
Restoring migratory fish passage and improving water quality will increase economic contribution of these fisheries in the long run. As a result of these actions, whole communities will reap the social, ecological, and economic benefits. Better water quality means healthier fish, and healthier fish will lead to a more robust economy.
