III. THE RESOURCE 



° General Biology of Coral Reefs 



The reefs off eastern Florida begin at Fawrey Rock near Miami and 

 extend all the way to the Dry Tortugas. There is little coral grovifth 

 along the Florida west coast due to the limiting nature of the colder 

 water and sediment content of the Gulf of Mexico. Looe Key Reef is a 

 submerged section of this east coast Florida reef tract located 6.7 

 nautical miles southwest of Big Pine Key in the Lower Florida Keys. 

 The proposed sanctuary area includes a Fore Reef, Reef Flat, Patch Reef, 

 Deep Reef and Deep Ridge. 



Coral reefs such as Looe Key are among the most biologically produc- 

 tive of all natural communities. Looe Key supports a wide variety of 

 life: fish, sponges, molluscs, crabs, octopi , starfish, shrimp, feather 

 duster worms and octocorals. The octocorals — fanlike, fernlike--are among 

 the most decorative creatures on the reefs. 



The rich colors of the reefal organisms also provide an attraction 

 to swimmers. Looe Key, because of its wide range in depth, is accessible 

 to both the beginning swimmer and the experienced diver. In addition to 

 contributing to aesthetic experiences, colors are used by organisms for 

 identification, camouflage, and signals, and to establish territoriality 

 and attract mates. The solid substrate formed by the corals at Looe Key 

 provides for this tremendous diversity of life, all directly or indirectly 

 dependent upon the corals and coral rock for shelter, food or for a place 

 to attach and grow. On the seaward slope, the reef flat and on the sandy 

 bottom around the reef, one finds animal communities or assemblages 

 different from those on the reef itself. In the soft bottom areas, grasses 

 and algae cover the sediment and they in turn support still different 

 communities. 



Many fish and invertebrates leave the safety of the Fore Reef at 

 night to search the nearby Reef Flat and Patch Reefs for prey. These areas 

 are also used as nursery grounds for juvenile fish. On the other hand, 

 sessile reef species often feed on planktonic stages of animals found away 

 from the Fore Reef in other habitats. The Reef Flat zone consists of rock 

 and rubble areas which serve as excellent habitat for small invertebrates. 

 The Fore Reef and surrounding communities form a complex and intricate 

 ecosystem which owes its evolution primarily to the corals' unusual ability 

 to extract dissolved salts from the ocean and convert them into the limestone 

 reef formations. 



° General Ecological Relationships 



Reefs depend upon two basic factors: solar energy and chemical 

 nutrients. Sunlight and nutrients in combination are utilized by plants 

 in the process called primary productivity. The majority of the plants at 

 Looe Key engaged in primary productivity are algae, microscopic in size 

 and sheltered within the tissues of soft and hard corals, sea anemones and 

 sponges. This is a form of symbiosis (mutual aid) in which algae produce 

 the food and in return receive shelter and sustenance from the corals. 



