In support of the National Fish Habitat Action Plan, we completed the estuarine and coastal components of the National Fish Habitat Assessment. We compiled and analyzed existing data on the condition of coastal fish habitats and added these data to an online map tool for coastal managers establishing fish habitat policies.
What We Did
For the coastal component of the assessment, we compiled national datasets of health indicators for estuaries and their surrounding watersheds and mapped them using a modified version of NOAA’s Coastal Assessment Framework. We modified the NFHAP Coastal Spatial Framework by identifying additional estuaries and state and federal marine waters using commonly recognized geographic regions. Indicators of disturbance to habitat health were screened to ensure data quality and were combined into four disturbance categories:
- River Discharge: included trends of river flow magnitude, duration of water flow pulses from storms and density of dams.
- Pollution: summarized the density of point source pollution sites, including national pollution discharge elimination sites, toxic release inventory sites, national superfund sites, and mines.
- Eutrophication: summarized measurements of chlorophyll a concentrations, occurrence of algal blooms, and dissolved oxygen and nutrient levels, using data from NOAA’s National Estuarine Eutrophication Assessment.
- Land Cover: summarized percent coverage and trends of urban, agricultural, and wetland land cover, using data from NOAA’s Coastal Change Analysis Program (C-CAP).
What We Found
The results of our assessments indicate that:
- Estuaries of the contiguous United States show patterns of habitat degradation similar to those of their tributary watersheds.
- Estuaries in the Mid-Atlantic and in southern California have a high risk of habitat degradation resulting from polluted runoff and other effects of the intense urbanization and agriculture.
- Estuaries of the Pacific Northwest and Downeast Maine have the lowest comparative risk of habitat degradation.
- Overall, 23 percent of the estuaries (by area) in the contiguous United States are at low or very low risk of habitat degradation, and 53 percent are at high or very high risk.
The results of this assessment are being used to guide regional-scale conservation planning by fish habitat partnerships.
The assessment will be used in planning conservation projects by the National Fish Habitat Board and other conservation groups. To follow up our work, we will:
- Continue to monitor and update the content and function of the assessment and web tools based on user feedback.
- Supplement data on additional indicators not included in the 2010 assessment report.
- Conduct statistical analyses to explore the linkages of estuarine condition indicators to fish and invertebrate species presence/absence.
- Work with the National Fish Habitat Partnership (NFHP) Coastal Assessment Team to complete a 2015 update to the assessment.