Bureau of Commercial Fisheries Symposium on Red Tide^ 



By 



JAMES E. SYKES, Fishery Biologist (Research Administration) 



ABSTRACT 



In October 1964, the Bureau of Commercial Fisheries held a Red- Tide Sym- 

 posium at St. Petersburg Beach, Fla. Purposes were to review progress on red-tide 

 research in recent years, to exchange views on the nature of current investigations, 

 and to determine where emphasis should be placed in further studies. Abstracts of 

 presentations by 14 participating scientists are included in this report. Eleven 

 areas of red-tide research were cited as needing attention in continuing studies. 



INTRODUCTION 



Sporadic concentrations of the red-tide or- 

 ganism, Gymnodinium breve , are associated 

 with fish mortality and hunnan disconnfort. 

 Although outbreaks of red tide are observed 

 in various parts of the Gulf of Mexico, their 

 most frequent occurrence has been noted in 

 the coastal waters of west Florida. 



Red-tide research in the Bureau of Com- 

 mercial Fisheries began on a limited basis 

 in the Gulf of Mexico in 1947. A major re- 

 search program began at the Bureau's Bio- 

 logical Laboratory, Galveston, Tex., in 1954. 

 Subsidiary stations were established on 

 the west coast of Florida, at Sarasota, 

 Fort Myers, Naples, and St. Petersburg 

 Beach. The objectives of field and laboratory 

 studies on G^ breve , were to determine its 

 incidence and distribution in Gulf coastal 

 waters and to increase the knowledge of 

 ecological conditions responsible for starting 

 blooms. 



Field data were obtained routinely at sta- 

 tions between Anclote Key and Florida Bay on 

 the west coast of Florida, in both Gulf and 

 estuarine waters. To relate the occurrence of 

 G. breve to its environnnent, data were col- 

 lected on temperature, salinity, copper, in- 

 organic phosphate, total phosphate, nitrogen, 

 calcium, silicon, alkalinity, depth, cloud cover, 

 water transparency, and wind speed, duration, 

 and directio,n. In addition to the survey of Gulf 

 and inshore waters, intensive sampling was 

 carried out during blooms or so-called out- 

 breaks of the organism. Water samples and 

 collections of G. breve also were supplied to 

 the Galveston Laboratory for culturing. Prac- 



■'• Contribution No. 17, Bureau of Commercial Fisheries 

 Biological Station, St. Petersburg Beach, Florida. 



tically all of the data obtained during field 

 work in Florida have been published. 



In January 1962 the Bureau of Comnnercial 

 Fisheries Biological Station at St. Petersburg 

 Beach was detached fronn the Laboratory at 

 Galveston and made a separate research unit. 

 Funds were appropriated for estuarine ecologi- 

 cal research, with particular reference to the 

 effects of engineering alterations on euryhaline 

 organisms, food chains, and, ultimately, conn- 

 mercial fisheries dependent on the estuarine 

 environment. Although the Station's funds were 

 not earmarked specifically for red-tide in- 

 vestigations, research continued from January 

 1962 to August 1963 in conjunction with the 

 estuarine program. The heavy bloom of 

 G. breve in April 1963 was responsible for the 

 appropriation of new funds for research on 

 red tide in September 1963. Screening of com- 

 pounds for control of the organism continued 

 at Galveston, but the major research program 

 was shifted to Florida. 



The 1963 bloom differed from previous ones 

 in that it infiltrated the inshore waters of 

 Tampa Bay and appeared to kill greater num- 

 bers of fish than any bloom previously re- 

 corded there. In response to the urgency of 

 the situation. Station personnel cooperated with 

 the Florida Board of Conservation Marine 

 Laboratory in field studies during the outbreak 

 and in recording associated hydrologic, plank- 

 tonic, and fishery data. These data and some 

 interpretations were assembled in a minneo- 

 graphed report which was issued jointly bythe 

 two laboratories. 



The renewed appropriation led to an exami- 

 nation of possible approaches to the red-tide 

 problem with available facilities and special- 

 ists. It was imperative that the approach be 



