Evaluating the Relationship Between Habitat Alteration and Resources Species Abundance in North Carolina Estuaries: Do Fish Respond to Anthropogenic Activities?

As habitat based management initiatives become more widespread in fisheries management and conservation it is important to be able to differentiate between areas impacted by human activities and those that are relatively untouched.  Cumulative impact approaches have been used to measure anthropogenic effects regionally and globally; however, there have been few attempts to test if these cumulative impacts result in lowered fish abundance or production.  The North Carolina Division of Marine Fisheries has developed a method for combining the effects of 23 different human activities into one metric of anthropogenic alteration in a specific area.  This measure of alteration is being used in site selection software as a metric to be minimized when selecting habitats for potential protection.  The assumption of this approach is the alteration metric is negatively related to measured fish abundance.  Long term fishery independent monitoring datasets in Albemarle and Pamlico Sound, North Carolina were used to test the relationship between alteration levels and abundance of resource species using generalized additive models.  For some species, there was a negative relationship between fish abundance and alteration scores indicating that the cumulative impact score reflects attributes of the habitat that influence fish abundance.  These results support the use of cumulative impact models for assessing habitat condition and will be incorporated into state level habitat protection planning initiatives.