Full Title: Gulf-wide assessment of habitat use and habitat-specific production estimates of nekton in turtlegrass (Thalassia testudinum)

Lead Investigator (Institution): Kelly M. Darnell (The University of Southern Mississippi) kelly.darnell@usm.edu

Co-investigators (Institution):Zachary Darnell (The University of Southern Mississippi),Delbert L. Smee (Texas A&M University-Corpus Christi),Charles W. Martin (University of Florida), andMargaret O. Hall (Florida Fish and Wildlife Conservation Commission)

Technical Monitor: Terry McTigue (terry.mctigue@noaa.gov)

Award Amount: $992,136

Award Period: June 1, 2017 May 31, 2020

Summary: Seagrass beds serve as habitat for many commercially and recreationally important finfish and shellfish during some stage of their life. In the northern Gulf of Mexico, turtlegrass, a type of seagrass, is a critical foundation species that provides energy for food webs and shelter and foraging grounds for many species. The more that is known about how turtlegrass supports finfish and shellfish species and if or how that changes in different parts of the Gulf of Mexico, the more fisheries managers will be able to consider how changing seagrass abundance is impacting certain fisheries. This project is a management-driven, three year Gulf of Mexico-wide assessment of turtlegrass habitat use by finfish and shellfish and an evaluation of the specific ways it supports blue crabs, a commercially important species which has seen recent declines in harvest in many Gulf states. The researchers will determine the abundance, diversity, age, and mix of juvenile and adult animals that use turtlegrass as habitat in Florida, Louisiana, and Texas. Additionally, they will measure the relationships in these three states between blue crab growth and mortality and characteristics of the turtlegrass such as plant density and height. Finally, they will develop separate statistical models for Florida, Louisiana, and Texas that will estimate blue crab production in turtlegrass based on crab abundance, growth, and mortality data. The data collected by this study and the models developed will provide critical information for resource management across the Gulf of Mexico.