RESULTS 



Distribution of G. breve by Area and Time 



1954. .-G. breve occurred in areas A, B, 

 and C throughout most of the year in both 

 estuarine and neritic waters (fig. 6). Most 

 G. breve were found in areas B and C, from 

 Venice south to the Florida Everglades. There 

 was no sampling in area D. From January- 

 February, G. breve occurred only in areas A 

 and B (table 1). During March-June, the 

 organism was found widely distributed in both 

 estuarine and neritic waters of areas A through 

 C. Numbers of G. breve at this time remained 

 less than 1.000/1. (fig. 6). Although G. breve 

 incidence decreased during July and August 

 (table 1), isolated G. breve concentrations as 

 high as 10,000/1. were noted in areas B and 

 C (fig. 6). From September-December, G. 

 breve was densest in areas B and C, mainly 

 from Boca Grande south to Cape Romano. 

 At that time, G. breve concentrations in- 

 creased to oveT' 500,000/1., and fish kills 

 occurred off Wiggins and Gordon Passes near 

 Naples. 



1955. --Essentially, 1955 is not considereda 

 red-tide year. The incidence of G. breve in 

 all areas during 1955 was less than in 1954 

 (table 1). The highest incidence and numbers 

 of G. breve were noted during January-Feb- 

 ruary in areas B and C, from Sanibel Island 

 to Cape Sable. The January maximum (1,250,- 

 000/1.) appeared to be a carryover from the 

 previous calendar year and was noted 7 miles 

 south of Sanibel Island. During the rest of the 

 year, widespread low concentrations of G^. 

 breve were observed in all areas (fig. 6). In 

 contrast to 1954, G. breve occurred infre- 

 quently throughout the summer and fall of 1955. 

 G. breve was absent in the relatively few 

 samples taken in area D south of Cape Sable 

 to the Florida Keys. 



1956. --No fish kills occurred, and G. breve 

 remained below 1,000/1. in all areas. The 

 yearly incidence of G. breve increased in 

 area A, remained essentially the same in area 

 B, and decreased in area C as connpared to 

 1955 (table 1). In area C, G. breve was noted 

 only in the neritic waters (fig. 6). No G. breve 

 was found in area D. 



Table 1. --Bimonthly and yearly incidence of G_. breve given in percentage for all samples 



in areas A to C (1954-57) 



Area 



Jan. -Feb. Mar. -April May-June July-Aug. Sept. -Oct. Nov. -Dec. 



Yearly 

 Total 



(r^54) 



Total 



63.9 



55.8 



49.1 



33.3 



48.6 



75.9 



(1955) 



Total 



37.2 



5.3 



1.4 



2.3 



0.4 



6.5 



(1956) 



A 



B 

 C 



1.4 



0.7 



To-.al 



0.7 



1.7 



1.1 



2.6 



6.4 



15.6 



(1957 



Total 



11.4 



14.8 



10.3 



11. f 



60.8 



78.8 



