Assessing the impacts of anthropogenic and physiographic influences on grass shrimp in localized salt-marsh estuaries

Abstract

The complexity and severity of ecological impacts associated with coastal development demand that resource managers explore new spatial analytical techniques combined with multidisciplinary scientific expertise for proactive coastal zone management. Arising from these environmental concerns and the identified need for adequate databases and integrated models, a long-term study of the impacts of urbanization on localized estuaries of the South eastern United States was initiated in 1990. A goal of this study was to examine the role of Geographic Information Processing (GIP) to integrate data and scientific expertise for the identification, assessment, and modeling of anthropogenic and physiographic relationships within estuaries. This goal is being achieved through the implementation and utilization of a multi-agency Geographic Information System (GIS) and the development and validation of spatially explicit models. This work presents spatial modeling efforts that incorporate land use and land cover characteristics with fisheries data to assess and predict the impacts of anthropogenic and natural influences on key species that inhabit critical estuarine wetlands and streams. A spatial assessment of two small, high-salinity estuaries suggests that upland development adjacent to critical estuarine habitat limits the population size and distribution of adult and larval grass shrimp ( Palaemonetes pugio (Holthuis)). Modeled spatial distributions of adult populations suggest the existence of estuarine ‘deserts’ — wetlands and stream reaches adjacent to commercial and residential land use void of natant fauna. This paper's approach is being developed for coastal resource managers to predict the impact of proposed landscape modifications prior to occurrence of changes.