ABSTRACT
Introduction The Oceanic Regime of the Florida Keys, Dry Tortugas, and coasts of Broward and Palm Beach Counties encompasses all the peripheral areas that are under more than 200 m of seawater. Some of these adjacent areas, which extend seaward from the edge of the shallow continental shelf, plunge to depths of over 400 m, making them the deepest ecosystems classified within the Coastal Marine Ecological Classification Standard (CMECS) system. The Florida Keys Oceanic Regime actually takes into account three separate macrohabitats that reside within different bathymetric ranges. The first of these, the Deep Coralline Algal Beds, occurs in depths of over 200 m along southwestern Florida and the areas north of the Dry Tortugas, at the mouth of the South Florida Bight. In contrast, the second macrohabitat, the Deep Softbottom Terraces, extends from the Palm Beaches all the way to the Marquesas Keys and occurs in much deeper areas, with depths ranging from 200 to 480 m. The third macrohabitat, the Open Oceanic Pleuston, represents all the molluscan communities that float on the offshore sea surface, well above the abyssal seafloor of the deep Florida Straits. The molluscan faunas of each of these disparate deep-water environments are still poorly studied and may contain many new, undescribed species.
