and also as a concentrated solution. 

 These tests were conducted during red 

 tide outbreaks on the west coast of 

 Florida in 1952, 1953, 1954, and 1957. 

 Copper sulphate dissolves rapidly in 

 sea water supersaturating the ambient 

 water with copper. The resulting con- 

 centration is many times that of the 

 required lethal level as determined in 

 laboratory toxicity experinnents, but 

 this high concentration does not last 

 long. The bulk of the copper precip- 

 itates as the basic carbonate and is 

 dispersed by tides and currents and 

 the copper concentration is reduced 

 to an ineffective level." [p. 87.] 



The report gives details of the leach- 

 ing rate of copper ore and of the 

 copper ore experiments. For the re- 

 sults see Marvin et al. (1961). 



MARVIN, KENNETH T, 



1960. Chemical control experiments, fii 

 Galveston Biological Laboratoryfishery 

 research for the year ending June 30, 

 1960, p. 43-45. U.S. Fish Wildl. Serv., 

 Circ. 92. 



The need is pointed out for a chemical 

 toxic to G^. breve at low concentrations, 

 selective as to the organism it affects, 

 and without the precipitating character- 

 istics of copper. 



Results of 16 replicate experiments 

 at six concentrations of CUSO4. 5 H2O 

 indicated that the critical concentration 

 of copper for 100-percent mortality of 

 G. breve lies between 0.39 and 0.80 

 ug.at./l. 



The screening of 4,000 compounds 

 revealed the following numbers toxic to 

 G. breve at five concentrations shown 

 below: 



^ Occludes confounds too insoluble to test. 



The author points out that there are 

 several errors in this type of large- 

 scale testing. 



MARVIN, KENNETH T., LARENCE M. LANS- 

 FORD, and RAY S. WHEELER, 

 1961. Effects of copper ore on the ecology 

 of a lagoon. U.S. Fish Wildl. Serv., 

 Fish. Bull. 61:153-160. 



Laboratory experiments had shown 

 copper as lethal to Gymnodinium breve 

 at a minimum concentration of about 

 0.5 ug.at./l. (0.03 p.p.m.). The experi- 

 ment was to discover whether immersed 

 copper ore could raise the dissolved 

 copper content of the water sufficiently 

 to destroy G. breve and, if so, whether 

 other organisms would be seriously 

 affected. 



After a 9-month study of the flora and 

 fauna of a small (230-acre feet) salt- 

 water lagoon, 60 tons of copper ore were 

 added. The average copper levels in the 

 lagoon did not attain toxic levels. It was 

 concluded that use of copper ore is not 

 a feasible control method. 



MARVIN, KENNETH T., and RAPHAEL R. 

 PROCTOR, JR. 

 1961. Chemical control. In Galveston Bio- 

 logical Laboratory fishery research 

 for the year ending June 30, 1961, 

 p. 59-60. U.S. Fish Wildl. Serv., Circ. 

 129. 



See Marvin and Proctor (1964). 



MARVIN, KENNETH T., and RAPHAEL R. 

 PROCTOR, JR. 

 1964. Preliminary results of the systematic 

 screening of 4,306 compounds as "red- 

 tide" toxicants. U.S. Fish Wildl. Serv., 

 Data Rep. 2, 3 microfiches (i + 85 p.). 



Each compound was tested at five 

 concentrations ranging from 0.01 to 

 1.0 p.p.m. Because of variation in 

 solubility some differences occurred 

 between the actual concentration tested 

 and that shown. The chemicals were 

 tested for their efficiency in killing 

 Gymnodinium breve over a 24-hour test 

 period. A culture of G. breve stock 

 containing from 1 to 2 million organisms 

 per liter was used. 



The objective was to discover com- 

 pounds 100 percent lethal to G, breve 

 at the 0.04 p.p.m. level. The total re- 

 sults were: 



Concentration 

 in p.p.nn. 



0.01 



.04 



.10 



.40 

 1.00 



Number 

 toxic 



55 



191 



284 



740 



1,047 



Not toxic at 1.00 3,259 



53 



