Blackwater rivers, such as the Waccamaw River, are the most abundant type of freshwater lotic system on the Coastal Plain of the eastern United States. Blackwater streams are threatened by anthropogenic disturbances due to the increased urbanization of the Coastal Plain. The increased development can potentially lead to an increase in phosphorous and nitrogen inputs that may affect phytoplankton and heterotrophic bacterioplankton production. Accurate assessment of ecological integrity is a prerequisite for understanding how human impacts modify water quality. One way to assess ecological integrity is through the analysis of the species composition, diversity, and functional organization of the resident community (i.e. bioassessment). Aquatic bryophytes, in particular, have been used to assess and monitor water quality because they are particularly sensitive to chemical pollutants. As nonvascular plants, they are particularly sensitive to anthropogenic disturbance including climate change, eutrophication, and salinity since they absorb nutrients and water directly through their cell walls creating a direct relationship between the environment and the plant. Thus, responses of bryophytes can potentially be used to monitor ecosystem disturbance. The aquatic bryophyte genus Fontinalis has been used in several physiological and hydrochemcial studies due to its large size and relative abundance. This bryophyte species is dominant in many blackwater rivers including the Waccamaw River and will therefore be used to assess the following core questions:
- What are the water quality variables that are influencing the surface area, growth rate and biomass of Fontinalis sulliantii?
- What is the effect of light availability on the growth and biomass of Fontinalis sullivantii?
- Could Fontinalis sullivantii be used as a bioindicator for the Waccamaw River or similar low gradient blackwater river system?