Estimation and Comparison of Epiphyte Loading on Holopelagic Sargassum flfluitans Collected in the North Atlantic Ocean and the Gulf of Mexico Gulf and Caribbean Research

Sargassum natans and S. fluitans (collectively referred to as Sargassum) are holopelagic brown macroalgae found throughout the Atlantic Ocean and Gulf of Mexico (Coston—Clements et al. 1991). The structural complexity of the Sargassum thallus, which includes blades and pneumatocysts, provides surface area for sessile epibiota, including hydroids, bryozoans, polychaetes, diatoms, and other microalgae (Weis 1968, Maples 1984, Stoner and Greening 1984, Calder 1995, Rooker et al. 2006). Combined, Sargassum and its associated epibiota create a productive base “community” relative to the surrounding and often oligotrophic open ocean environment (Dooley 1972). As a result, diverse assemblages of fishes (>100 species), sea turtles (4 species), seabirds (>20 species), and invertebrates (>145 species) are found in association with Sargassum (SAFMC 2002, Wells and Rooker 2004, Wang and Hu 2016), which provides refuge from predators, enhanced feeding opportunities, and serves to concentrate organisms with flotsam—seeking behaviors (Dooley 1972). Sargassum is often referred to as a nursery habitat because many of the associated fishes and sea turtles are juveniles, including commercially and recreationally important fish species such as Gray Triggerfish (Balistes capriscus), Dolphinfish (Coryphaena hippurus), Tripletail (Lobotes surinamensis), and Greater Amberjack (Seriola dumerili), among others (Wells a Grant no. NA17NOS4510099