Hillmann, E., K.E. DeMarco and M La Peyre. 2016. Establishing a baseline of estuarine submerged aquatic vegetation resources across salinity zones within coastal areas of the northern Gulf of Mexico. Journal of the Southeastern Association of Fish and Wildlife Agencies. 3:25-32.
Coastal ecosystems are dynamic and productive but vulnerable to changes associated with global climate change. Despite their limited areal extent, submerged aquatic vegetation (SAV) exists in coastal ecosystems as foundation species and performs important ecological functions including provision of habitat and food resources. However, limited understanding of factors controlling SAV distribution and abundance within the extensive fresh to saline coastal habitats along the northern Gulf of Mexico (nGoM) restricts the ability of models to accurately predict resource availability. We sampled 384 potential coastal SAV sites across the nGoM in 2013 and 2014, and examined community and species-specific SAV distribution and biomass in relation to year, salinity, turbidity and water depth. After two years of sampling, 14 species of SAV were documented, with three species (Ceratophyllum demersum, Myriophyllum spicatum, Ruppia maritima) accounting for 54% of above-ground biomass collected. Total aboveground SAV biomass was higher in fresher habitats as compared to saline habitats and salinity and water depth were dominant drivers of species assemblages. Changes in salinity and water depths predicted by climate change models for the northern Gulf of Mexico coast will likely alter SAV production and species assemblages; these changes may affect habitat and food resources for dependent faunal species. Understanding the environmental drivers that influence SAV distribution across salinity zones will ultimately enable more accurate predictive modeling and management of SAV resources under different scenarios of restoration and climate change.