PROBLEMS OF RESEARCH AND DEVELOPMENT 



THE STATUS OF RESEARCH 



Before 1950, yery little was known about the biology of the relatively 

 few estuarine and marine fish and shellfish sought by sport and commercial 

 fishermen. Following World War II, interest in fishing as a vocation and an 

 avocation began to increase and with it the need to understand the life his- 

 tory of the more important species. In the 1950' s and 1960's many papers were 

 written about a variety of marine resource topics and collectively new biolog- 

 ical concepts began to emerge. Most significant among the findings was that 

 most coastal fish and shellfish are estuarine dependent. Studies revealed 

 that at least part of the life cycle of over three- fourths of the major com- 

 mercial and sport species along the coast of Florida depended upon the shallow 

 estuarine areas (nursery grounds) where food and protection were abundant. 

 The biological richness and importance of these nursery grounds were difficult 

 to convey to the general public, and thousands of acres were lost to indis- 

 criminate dredge and fill projects before protective legislation finally was 

 passed. 



Research, now more advanced and better funded, reflects even more the 

 importance of estuaries for sustaining fish and shellfish. Some of the fish- 

 ery research needs or requirements in Florida were reported by Cato (1979). 



HABITAT ALTERATION 



For the majority of fish species studied, the quantity and quality of 

 habitat is a major limiting factor in species abundance. The alteration of 

 habitat has been greatly reduced in Florida by protective regulations. No 

 longer can developers move freely into marshes or estuarine areas and indis- 

 crimately dredge and fill to create waterfront (canal) home sites such as Boca 

 Ciega Bay, near St. Petersburg. Although dredging determined to be "in the 

 public interest" continues, the massive projects of the 1950's and 1960's now 

 are a rarity. Habitat loss today is more subtle; an acre or two, a small boat 

 channel, a causeway, all of which have cumulative effects. Not only are estu- 

 arine areas being reduced, but the productivity of the remaining areas is 

 declining. The decline in productivity is caused largely by the loss or 

 diversion of freshwater inflow in estuaries and by municipal and industrial 

 pollution. 



The dependence of most coastal fish and shellfish on estuaries is clear 

 evidence that increased coastal habitat protection is paramount. Some of the 

 current water and land use changes and development practices that are still 

 damaging to estuaries are (1) diversion of freshwater inflow from estuaries, 

 (2) diking or impounding estuarine marshlands for mosquito control, (3) 

 indiscriminate spraying of pesticides in or near estuaries, and (4) the con- 

 struction of causeway, bridges, and other structures that seriously disrupt 

 normal water current patterns. 



Land management practices several miles upstream from brackish waters 

 also may have serious effects on the estuarine habitat. For example, clear 

 cutting can cause siltation and rapid salinity changes downstream that are 



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