A Guide to the Seaweeds of Florida

Abstract

AbstractA review of Florida seaweeds indicates a highly diverse flora within a large coastal zone (over 700 km) spanning more than 7° of latitude, containing tropical, subtropical, and temperate communities. Surprisingly, there have been relatively few detailed floristic studies of Florida seaweeds, except for the Florida Keys and on the east coast. The patterns are a reflection of the early predominance of winter visitors and lack of resident phycologists. The seaweeds of the west coast of Florida were virtually ignored until the 1950s. We estimate that the state's seaweed flora consists of at least 670 taxa including 219 green, 97 brown, 349 red algae, and at least 3 species of Vaucheria. Such a compilation is significantly higher than the numbers of taxa recorded for Florida by Taylor (1960), as well as those for North Carolina (i.e. Schneider & Searles, 1991), and Caribbean reefs (Littler & Littler, 2000). The majority of Florida seaweeds have tropical/Caribbean affinities, although a significant temperate component also occurs, presumably reflecting the influence of the northern floras of the Gulf of Mexico and south‐eastern coast of the US. The tropical nature of the state's flora is supported by the R/P and R + C/P indices of Feldman (1937) and Cheney (1997) with these ratios being 3.6 and 5.8, respectively. Florida's seaweed diversity is enhanced by the extensive salt marsh and seagrass communities of the west coast, plus the coral reef habitats of the Florida Keys. The present review summarizes several important historical studies, conspicuous geographic patterns, the type of communities, and the structure of a guide to the seaweeds of Florida. The guide will also serve as a historical reference for possible anthropogenic impacts in the future.