Our Living Resources — Conshil & Marine Eiosxstems 



283 



West Indies spiny lobster {Fiiniilirus arfiiis) 

 have generally remained stable, despite large 

 increases in effort (Bohnsack et al. 1994). 



There is no guarantee, however, that any of 

 these trends will continue, especially if fishing 

 efforts increase or habitats become further 

 impaired. For example, annual pink shrimp 

 landings from the Dry Tortugas fluctuated 

 around 4.5 million kg (9.9 million lb) for about 

 40 years before plummeting to less than hall 

 that level in the mid-198()"s. Some of this 

 decline may be a result of environmental 

 changes caused by reduced freshwater inflow to 

 Florida Bay (Mclvor et al. 1994). Sponge and 

 seagrass die-offs in Florida Bay may eventually 

 reduce lobster and other fishery landings 

 because of lost juvenile habitat. Fishery landing 

 data will not necessarily reveal the full impact 

 of those removals on the ecosystem or its sus- 

 tainability. This is particularly true in complex 

 tropical ecosystems such as the Florida Keys 

 (Knowlton 1992). The annual removal of mil- 

 lions of kilograms of shrimp and spiny lobster is 

 expected to affect their fish predators, while the 

 removal of large numbers of predators may 

 affect abundances and interactions of their prey. 

 Fishing is a particular concern because it tends 

 to target top predators, which are often the key- 

 stone species important for maintaining com- 

 munity structure (Knowlton 1992). 



The widespread ecosystem changes docu- 

 mented in the Florida Keys and elsewhere in the 

 Caribbean are of special concern to the long- 

 term status of coral reef fish communities 

 (Richards and Bohnsack 1990; Hallock et al. 

 1992). These changes include unexplained sea 

 urchin mass mortalities, major coral loss and 

 coral bleaching, shifts from coral- to algal-dom- 

 inated substrates, extensive algae blooms, and 

 numerous fish kills. Porter and Meier (1992) 

 reported a loss of coral diversity between 1984 

 and 1991 at six locations and a decrease in 

 abundance at five locations in protected areas 

 between Miami and Key West. Although Porter 

 and Meier ( 1992) could not determine the spe- 

 cific causes responsible for the changes, they 

 noted that continued equal rates of loss over 

 long periods would not allow the historical 

 coral reef community structure of the Florida 

 Keys to be sustained. 



Algal fouling that may be related to leaching 

 of nutrient-enriched groundwater (NOAA 

 1995) has recently caused severe damage to 

 Algae Reef off Key Largo, and may be spread- 

 ing to nearby Horseshoe Reef. Whether caused 

 by increased nutrient enrichment, human alter- 

 ation of historically freshwater runoff from the 

 Everglades, reduced natural flushing effects 

 associated with humcanes during the last 20 

 years, or a combination of factors, continued 

 deteriorauon of Florida Bay water quality ulti- 



mately will seriously alter the fish community 

 structure of the bay and affect the Florida Keys 

 ecosystem as well. 



Recommendations 



Realistic goals and objectives must be estab- 

 lished to protect and restore Florida Keys 

 ecosystems and their fish resources to allow 

 optimal sustainable economic use while pre- 

 serving biodiversity. Research efforts should 

 focus on obtaining a better understanding of 

 ecosystem dynamics and the effects of human 

 interactions in order to generate and test predic- 

 tive management models. Marine sanctuaries 

 should have scientific reference sites and be 

 used to develop strategies to reduce user con- 

 flicts. To be effective, management efforts must 

 be international and must include cooperation 

 between all levels of government and users. 

 Because it is possible to love a reef to death 

 (Fishman 1991), increased public education, 

 understanding, awareness, and appreciation of 

 the complex nature of reef fish communities 

 and the effects of human activities within the 

 Florida Keys ecosystem are especially impor- 

 tant. Although efforts are needed to restore 

 habitats, primary emphasis should be to prevent 

 further habitat degradation from human activi- 

 ties. 



Objective measures of fish populations, 

 habitat conditions, and ecosystem function 

 should be developed and monitored. Standard 

 measures are needed to compare ecological 

 impacts of dift'erent fisheries (Bohnsack et al. 



Florida Keys habitat showing rep- 

 resentative reef fishes. 



