Sargassum

Full Title: Linking habitat to recruitment: evaluating the importance of pelagic Sargassum to fisheries management in the Gulf of Mexico

Lead Investigator (Institution): Frank Hernandez (The University of Southern Mississippi) frank.hernandez@usm.edu

Co-investigators (Institution): Chuanmin Hu (University of South Florida)Kevin Dillon (The University of Southern Mississippi)Glenn Zapfe (NOAA), and Walter Ingram (NOAA)

Technical Monitor: Mandy Karnauskas (mandy.karnauskas@noaa.gov)

Award Amount: $1,770,853

Award Period: June 1, 2017 – May 31, 2020

Summary: Sargassum is thought to serve as nursery habitat for recreationally and commercially important fishes in the Gulf of Mexico, such as gray triggerfish and mahi mahi. However, information about the nursery function of Sargassum for juvenile life stages of these fishes is lacking, and little is known about the environmental factors that drive variability in Sargassum abundance and distribution. To evaluate the nursery function and importance of Sargassum to fisheries in a way that is useful to fisheries managers, and to better understand the ocean and climate conditions that result in “good” Sargassum years, the researchers will measure variability in the distribution and abundance of Sargassum in the northern Gulf of Mexico. They will also assess the nursery-role function of Sargassum relative to its location and variability in different habitats (open ocean vs. nearer to shore) and the morphology (i.e. thickness) of Sargassum mats. Additionally, they will develop and test the usefulness of including measures of the capacity for Sargassum to serve as juvenile fish nursery habitat (i.e. habitat indices) in population assessments of  recreationally and commercially important fish species associated with Sargassum. These habitat indices will be developed using data collected from satellites and ships in the field.  In total, this project will assess the relationship between Sargassum and the recruitment of managed fish species by considering the quality of the Sargassum habitat (in terms of available food resources, growth, and environmental conditions) for juvenile fishes associated with Sargassum.