Reef Flat 



The Looe Key Reef Flat is roughly the shape of an isosceles triangle, 

 its base facing south towards the Straits of Florida and the apex pointing 

 landward to the north. On this landward side there is a "jery gradual 

 transition from the seagrass coral association of the Patch Reef area into 

 the Reef Flat, marked mainly by the beginning of extensive sand flats and 

 an elevation of the bottom to about 2 m in depth. The bottom consists 

 primarily of calcareous sand, rubble, coarse sediments and extensive sea- 

 grass beds, a mixture of turtle grass, manatee grass and algae. 



The rock and rubble grass beds of the Reef Flat provide excellent 

 habitat for small invertebrates. Abundant populations of other organisms, 

 such as brittle stars, small crustaceans, small gastropods, pelecypod 

 mollusks, and echinoderms abound in this area. The Reef Flat together 

 with the Patch Reef serve as nursery areas for juvenile fish and the sea- 

 grass beds of both zones are feeding grounds for deep-water fish migrating 

 to these areas at night. 



Fore Reef 



The Fore Reef zone of Looe Key is a wel 1 -developed and especially 

 spectacular formation. This zone is the principle diving attraction for 

 both local residents and tourists. Its main portion is a high profile 

 spur and groove system, bordering the Reef Flat in 'jery shallow water 

 and sloping down to a sand bottom in 9-11 m of depth with some of the 

 spurs showing a profile of up to 7 m high, caused mainly by the vigorous 

 construction activity of "mountainous" star coral ( Montastraea annularis ). 

 Massive growths of fire coral ( Mijlepora complanata ) are mainly found in 

 the shallowest part of the spurs, with substantial concentrations of 

 elkhorn coral immediately seaward of the fire coral complex. Almost all 

 of the species of fish encountered in the reef system can be found here, 

 with the exception of some species which prefer deeper water and can only 

 be observed beyond a depth of 10 m. The whole system, from easternmost 

 to westernmost spur, is about 1500 m long and, at the main center portion, 

 about 350 m wide, (Antonius ^. a]_. , 1978). 



Deep Reef 



The western half of the Fore Reef is intersected by a deeper reef, 

 which begins here as a finger-like extension of scattered coral outcrops 

 just beyond the terminus of the spur and groove system. From here, a 

 reef flat of 10-12 m depth stretches several hundred meters to the west 

 without showing much profile, representing a comparatively shallow subzone 

 of the Deep Reef. 



Sponges are fairly common and grow to larger sizes in the Deep Reef 

 than in the Patch Reefs. Octocorals are dominant, but stony corals are 

 more numerous than in the Patch Reefs. Towards the south, the Deep Reef 

 gradually changes into a slope of increasing steepness with considerable 

 profile caused by surge channels. 



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