quantities that often amaze visitors, it 

 is useful to think back to how productive 

 these waters must have been. 



that win not be 

 ever-increasing 

 A catastrophic 



possible; merely 



Their future productivity remains to 

 be determined. Present productivity can 

 be maintained, although 

 easy considering the 

 developmental pressures, 

 decline is certainly 

 maintaining the current economic and 

 development growth rates will provide that 

 effect. This point was well made by one 

 of the reviewers of this manuscript whose 

 comments I paraphrase here: Insidious 

 gradual change is the greatest enemy, 

 since the observer is never aware of the 

 magnitude of change over time. A turbid- 

 ity study in Biscayne Bay showed no sig- 

 nificant differences in turbidity between 



consecutive years during 1972 and 1977, 

 but significant change between 1972 and 

 1975 (or between 1973"and 1976). In other 

 words, south Biscayne Bay was signifi- 

 cantly more turbid in 1977 than 1972, but 

 a 2-year study would not have uncovered it 

 (J. Tilmant, National Park Service, Home- 

 stead, Florida; personal communication). 

 To properly manage the region, we must 

 understand how it functions. Decades ago 

 it would have been possible to maintain 

 productivity just by preserving the area 

 and restricting human influence. Now 

 water management decisions a 100 miles 

 away have profound changes on the fisher- 

 ies. Enlightened multi-use management 

 will require a greater knowledge of the 

 complex ecological interactions than we 

 possess today. 



Figure 27. Scallop on the surface of a shallow Halodule bed in Western Florida Bay. 



95 



