three days later. The whole picture . . . 

 is one of usually low or absent brevis 

 populations during all of 1953-54, but 

 with sudden erratic, scattered flare-ups 

 to enormous numbers. . . , [p. 13.] 



"Much attention has been directed 

 toward recognition of red water from 

 boats and planes ... it is frequently 

 possible to spot patches of bloom in 

 this way. In Peconic Bay it has been 

 possible to spot blood- red concentra- 

 tions of a related dinoflagellate, Cochlo- 

 dinium as far as a half-mile away from 

 a small cabin cruiser. However, no 

 such vivid discolorations have been 

 noted in hunting for brevis either by 

 boat or by air, and red water has fre- 

 quently been all but impossible to locate, 

 or has been a slightly brown discolora- 

 tion rather than red. . . . any water 

 located in such a manner must be ex- 

 amined microscopically. . . . [p. 13.] 



". . . Considering the tendency of phy- 

 toplankton to accumulate in the topmost 

 few inches in lakes, ponds and even 

 streams as a direct response to light, 

 it is evident that brevis presents no 

 such clearcut response. ... a trend to 

 accumulate in deep water is sometimes 

 evident and will be more closely in- 

 vestigated in future work. [p. 14-15.] 



". . . Since much of our idea of the 

 distribution of brevis has been based 

 until now either on surface samples or 

 (perhaps) on dead fish, these observa- 

 tions suggest that currently accepted 

 distribution patterns, or areas of in- 

 festation, be accepted tentatively, for 

 depths greater than ten feet. [p. 15.] 



"... In the light of past experiences 

 with algicides, it seems probable that 

 one of rather high specificity and very 

 high killing power can be developed for 

 brevis . . . . control of brevis in the 

 shallow inshore areas along the coast 

 by the use of plane-dispersed algicides 

 must not be discounted, until very 

 thoroughly evaluated, [p. 18.] 



' ' Gymnodinium brevis requires small 

 quantities of organic substances in its 

 nutrition. Wilson (13), in his culture 

 medium, includes vitamins and soil ex- 

 tract. These are present to some extent 

 in Gulf water, and Odum, Hynes and 

 Slater (16), have shown that charcoal 

 may effectively remove them by ad- 

 sorption. Since the organic portion of 



the substrate is very small, only small 

 quantities of charcoal are needed. This 

 work is in its preliminary stages, and 

 there is no field work at present to show 

 the effectiveness of carbon. Experi- 

 ments are underway to show how effec- 

 tively it strips out the growth-promoting 

 matter, how many other organisms are 

 affected, how long its effects last, and 

 to what extent it penetrates (how deep 

 it is effective), [p. 18.] 



"Carbon has three other characteris- 

 tics which recommend it. It is rela- 

 tively cheap, and the supply is inex- 

 haustible and readily available. It is 

 not in itself toxic; it will not harm fish. 

 There is no reason why it should affect 

 organisms which have no organic re- 

 quirements. Finally it has been shown 

 by Block (17) that it will adsorb the 

 water borne toxin of brevis . The effect 

 of this would be to cleanse water 

 already poisoned. Clearly charcoal and 

 activated carbon need a very careful 

 investigation, [p. 18.] 



"Biophysics has demonstrated many 

 ways, principally through wave action, 

 of affecting living microorganisms. 

 Here again the work at the University 

 of Florida is just beginning. It has 

 already been shown, however, that there 

 is no useful killing action in a high- 

 frequency radio field. Cultures of five 

 organisms, including brevis , were un- 

 affected in glass containers in such a 

 field. ... [p. 18.] 



The authors mentioned phosphorus as 

 a possible cause of red tide and gave 

 the following table of phosphorus values. 



ppm 



2-19-53 Peace River, Arcadia, Odum 0.850 



2-19-53 Peace River, Punta Gorda, Odum. 0.240 



3-30-53 Placlda (Peace Estuary), Odum.... 0.028 



4- 1-53 EI Jobean (Peace Estuary), Odum. 0.144 



4-17-53 Bokeelia (Peace Estuary), Odum.. 0.024 



3- 7-54 Peace River, Punta Ckjrda, Odum 



and Hynes 0.670 



3-18-54 St. James Point (Peace Estuary), 



Odum and Hynes 0.040 



4- 3-53 Klssimmee River above L. Okee- 



chobee, Odum 0.018 



2-19-53 Lake Okeechobee, Moore Haven, 



Odum 0.039 



2-19-53 Caloosahatchee Estuary, Sanibel, 



Odum 0.009 



2-19-53 Caloosahatchee Estuary, Punta 



Rassa, Odum 0.060 



3-30-53 Caloosahatchee Estuary, Ft. 



Myers Beach, Odum 0.042 



3- 6-54 Caloosahatchee Estuary, Ft. 



Myers, Odum and Hynes 0.094 



3- 6-54 60 miles off Naples, Odum 0.001 



3- 6-54 70 miles off Naples, Odum 0.042 



3- 6-54 80 miles off Naples, Odum 0.001 



49 



