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CBNERR

Priorities

Priorities for Stewardship Directed Research Include:

 

Water Quality

Water quality degradation of marine and estuarine environments is of global concern and the Chesapeake Bay and specifically the York River sub-estuary is no exception.  A growing population along with associated land use changes are primary factors causing water quality and habitat degradation in the Bay’s watershed and tributaries.  Critical management issues and threats to the York River System include 1) excess sediments which result in degraded habitat, reduced water clarity, and serve to transport toxic materials, pathogens and nutrients to water resources; and 2) excess nutrients, both nitrogen and phosphorus, that stimulate algal blooms and lead to oxygen deprived waters.  Stewardship staff have assisted the Reserve Research Program in implementing internally and externally funded research programs that focus on shallow water habitats and the watershed processes that directly relate to coastal water quality impacts. 

The shallow waters of the Chesapeake Bay and its tributaries are home to at least 16 species of underwater grasses, also termed SAV, which serve as critical habitat to commercially and ecologically important nekton.  As with other important cited estuarine habitats, underwater grasses have declined precipitously from historical abundances.  Results from Reserve-led research programs have directly supported SAV restoration initiatives in Chesapeake Bay and nutrient management strategies for tributaries in Chesapeake Bay.  More specifically, long-term datasets from Goodwin Island (located the mouth of the York River) have shown that eelgrass may be growing at or near it’s physiological tolerance and the combined effects of short-term exposures to very high summer temperatures, compounded by reduced oxygen and light conditions, may lead to long-term declines of this species from this system.

 

Temporal Change

The Chesapeake Bay and its tidal rivers encompass a diverse range of habitats with each being important to the general health of the Bay ecosystem. Critical Bay estuarine habitats include riparian forests, emergent tidal wetlands, seagrass beds, aquatic or oyster reefs, shallow waters (depth to 3 m or 10 ft) and open waters beyond the nearshore region.  Ecological services provided by these habitats include shoreline stabilization, hydrologic functions (e.g., flood protection, streamflow regulation), water quality remediation, airborne pollutant removal and habitat community functions (e.g., biodiversity, productivity/carbon sequestration, detritus export/storage, refuge and forage).  Due to regional growth and development, direct harvesting and natural causes, there has been a continued degradation, fragmentation and loss of critical estuarine habitats. Along with the degradation or loss of these habitats, the natural interactions, or connectivity, between these ecosystems may be diminished, or in some cases, entirely eliminated.

 

Impacts of Episodic Storm Events and Climate/Sea Level Rise on Critical Coastal Habitats

Tidal emergent wetlands are vulnerable to the effects of relatively high rates of sea level rise, erosion, and the potential for saltwater intrusion.  Tidal marshes must have the ability to accrete vertically (e.g., sediment deposition and root mass accumulation) or transgress inland in order reduce continued stress from increased flooding and eventual die-off.  Unfortunately, due to the desire to enhance viewshed and protect their properties from increased erosion and flooding rates, riparian property owners are expected to continue riparian and shoreline modifications resulting in additional loss or degradation of nearshore habitat and associated ecosystem services.  The permitted hardening of over 730 km (450 mi) of shoreline in Maryland and Virginia since 1993 illustrates the magnitude of impacts on fringing wetlands within Chesapeake Bay watershed through conventional shoreline protection measures. 

 

Ecological Services

The CBNERR Stewardship program has examined and will continue to assess the value of ecological services (e.g. erosion protection, nekton habitat value) of a variety of natural fringing wetlands and man-made shoreline protection structures through comprehensive literature reviews and selected field sampling projects to directly support better informed shoreline and water body management decisions. Ecological services provided by these habitats include shoreline stabilization, hydrologic functions (e.g., flood protection, streamflow regulation), water quality remediation, airborne pollutant removal and habitat community functions (e.g., biodiversity, productivity/carbon sequestration, detritus export/storage, refuge and forage).  Due to regional growth and development, direct harvesting and natural causes, there has been a continued degradation, fragmentation and loss of critical estuarine habitats. Along with the degradation or loss of these habitats, the natural interactions, or connectivity, between these ecosystems may be diminished, or in some cases, entirely eliminated.