An Illustrated Field and Laboratory Guide to the Seaweeds of Gray’s Reef National Marine Sanctuary

This field guide to the seaweeds of Gray’s Reef is intended to help visitors and researchers identify the macroscopic or multicellular, benthic (attached) plants living in or near the Sanctuary. These seaweeds belong to four divisions (major groupings) of plants, the Cyanophyta (Cyanobacteria or blue-green algae), the Chlorophyta (green algae), the Phaeophyta (brown algae), and the Rhodophyta (red algae). This flora of the sanctuary was prepared by SCUBA diving to make collections during the winter, spring and summer growing seasons. Sixty-eight species were collected. Dudresnava georgiana and some of the plants described here, but not placed in a particular species are endemics (known only from this limited area). Many, such as Codium isthmocladum. Sargassum filioendula. and Botrvocladia occidentalis are common species of the warm-temperate biogeographic region which lies along the southeast coast of the United States. Identification of the species in the sanctuary raises interesting questions about their life histories, ecology, and biogeography and some of these questions are included in the comments following each species description. 1988 Grant no. NA84AA-H-CZ016 NOS (National Ocean Service) Library Public Domain 1935