Submersed aquatic vegetation (SAV) communities are highly productive ecosystems that provide significant ecological benefits to coastal areas, including essential calories for wintering waterfowl. However, the potential effects of sea-level rise is posing new questions about the future availability of SAV for waterfowl and other coastal wildlife. Of primary concern is the fact that rising seas have the potential to increase salinities in fresh and brackish marshes on the Gulf of Mexico’s coast, changing the distribution and composition of SAV communities, and affecting valuable waterfowl habitat and food resources. Not enough is known about the relationship between salinity and SAV to predict how this important food resource will respond to higher salinity levels, creating difficulties for waterfowl conservation planning.
This project identified the relationship between SAV, salinity, and other environmental variables as a first step in understanding how sea-level rise might affect food availability for waterfowl. The study examined coastal marshes of the northern Gulf of Mexico from Mobile Bay, AL, to the Nueces River, TX. Researchers compared SAV distribution and composition across a range of salinity levels, and found that water depth and salinity were the primary factors in determining the amount of SAV resources in a particular marsh. Surprisingly, researchers also found that brackish marsh tended to produce quantities of SAV waterfowl food resources similar to those in fresh marsh environments. The study also found some evidence that saline marshes contain less waterfowl food resources than brackish, intermediate, and fresh marshes.
This work will directly benefit efforts of the Gulf Coast Joint Venture, Gulf Coast Prairies Landscape Conservation Cooperative (LCC), and Gulf Coastal Plains and Ozarks LCC in forecasting the effects of sea-level rise on the distribution, abundance, and diversity of SAV resources and the priority fish and wildlife populations that depend upon them.
This project was co-funded by the South Central Climate Adaptation Science Center and the Gulf Coast Prairie Landscape Conservation Cooperative and Gulf Coastal Plains and Ozarks LCC. An alternate reference to this project can be found here.