Since the filter feeders required little maintenance, they were 

 placed at more stations (2A, 2B, 3A, 3C, 5A, 5B, 6A, 6B, 7A, 7B, 

 lOA, and lOB). Stone crabs and sea urchins had to be confined in 

 specially built cages and required feeding three times per week, 

 consequently, they were limited to Stations 3A, 3C, 7A, 7B, lOA, 

 and lOB. 



The sea whip, Pterogorgia anceps , is a common, nearshore, Caribbean 

 homy coral, which was known to be sensitive to the effluent. Large 

 numbers of P. anceps were located east of the turning basin in two 

 to three meters of water. They were pried loose from the substrate 

 and mounted in PVC holders. Two-foot (60cm) lengths of half inch 

 diameter (1cm) PVC pipe were split longitudinally for about three 

 inches (8cm) and the bases of the sea whips forced into the splits. 

 The elasticity of the PVC clamped the stalks firmly enough to hold the 

 colonies in place. At the designated stations, the free end of a 

 holder was forced into the sediment or into the coral wall. Two 

 specimens were placed at each station and divers checked their con- 

 dition twice a week. Dead colonies were replaced monthly. 



Sea squirts {Acidia nigra) are filter feeding tunicates and were 

 extremely common in the Key West area. Specimens were collected 

 attached to loose rocks and moved, along with their rocks, to the 

 biological stations. Five specimens were placed at each station. 

 Unfortunately, whenever a specimen was bruised or otherwise damaged, 

 it was almost immediately attacked and eaten by fish at the station. 

 Because of their susceptibility to predation, they yielded poor data 

 as transplant organisms. 



Turtle grass (Thalassia testudinwn) was also vulnerable to predator 

 pressure. Because of the dearth of algae and turtle grass near the 

 Safe Harbor biological stations, herbivorous fish rapidly cropped 

 transplants to the roots. While the roots survived for a time, the 

 intensity of fish feeding prevented regrowth and the transplants died. 

 At the control station, turtle grass survived the transplantation for 

 the entire study period. 



Stone crabs (Menippe mercenaria) were easily maintained in experi- 

 mental cages but specimens were periodically released by sport divers. 

 On several occasions the cages were found opened and empty. A sign 

 reading, "Danger, Poison, U.S. Government Survey, $1,000 fine for 

 tampering", was placed on the cages and the releases stopped for 

 several months. There were five stone crabs located at each station. 

 Three times per week the stone crabs v/ere fed either fish or squid 

 by SCUBA divers. Missing or dead animals were replaced every month. 



Sea urchins (Lyteohinus variegatus) were maintained in individual 

 cages and fed turtle grass three times per week. Escapes were rare 

 and sport divers did not molest the cages. Dead urchins were replaced 

 as they died for the first few months and then every month for the 

 remainder of the study. 



35 



