also stated, ". . . Cysts form chains and when 

 culture is stirred these tend to remain to- 

 gether, but I have never seen a chain for- 

 mation of normal free swimming cells." 



There are several statennents that G, breve 

 affects the viscosity of the water when nu- 

 merous. Galtsoff (1948) stated, ". . . the water 

 had an oily appearance. When dipped up and 

 allowed to stand for 5 to 10 minutes, it be- 

 came thick, sometimes almost of a consistency 

 of Karo syrup, and slimy to the touch. . . ." 

 Gunter, Smith, and Williams (1947) reported, 

 "The water was viscid and slimy, having the 

 consistency of diluted syrup." Collier (USFWS, 

 1958) said, ". . . observing with a dissecting 

 microscope, the viscosity seenned to be caused 

 by the organisms agglutinating. While I watched 

 they started joining in long chains, long 

 branching chains. ..." 



There may be another answer to the high 

 viscosity. Martin and Nelson (1929) found 

 by killing Gynnnodinium sp. with special solu- 

 tions that they could observe a gelatinous 

 envelope as thick as the dianneter of the cell 

 itself. They stated, "Gelatinous envelopes 

 are common among dinoflagellates when en- 

 cysted, but not when active. The cells re- 

 ferred to in this connection were actively 

 nnotile. A similar envelope has been noted 

 occasionally surrounding other species of 

 naked dinoflagellates in the active condition, 

 but only when killed by the iodine or bi- 

 chloride methods. In red water plankton in 

 which Amphidinium fusiforme is the dominant 

 species, the Amphidinium cells tend to cling 

 together in clunnps, but no gelatinous envelopes 

 can be demonstrated. In many of the clumps 

 (although not in all), however, they may be 

 seen to be clustered thickly about a cell of 

 the Gymnodinium . This gelatinous envelope 

 may well be a factor of importance in hold- 

 ing the organisms together, once they are 

 massed by a favorable combination of light, 

 water temperature, and tidal currents." 



Conjugation of G. breve was discussed by 

 Wilson (USFWS, 1958). He said, "In the con- 

 dition I have called conjugation I have never 

 seen more than 2 orgcinisms attached together. 

 You may find them in various positions, but 

 there is always a stalk-like process between 

 two individuals." 



The size of G. breve is usually given as 

 between 20 and 30 1^ . Wilson (USFWS, 1958) 

 said, ". . . In certain cases in the field you 

 will see a fairly large form which appears 

 to have no chromatin material at all. . . ." 



CONTROL OF RED TIDE 



It is difficult to discuss control of red tide 

 without first discussing the type and scope 

 of the damage inflicted. This damage has 



three main aspects, 1) effect of red tide on 

 the tourist business, 2) effect on the sport 

 and commercial fisheries, and 3) effect on 

 public health. 



Damage from Red-tide Outbreaks 



Since red-tide outbreaks usually start in 

 the fall, just as the tourists are commencing 

 to move south, an outbresik can cause very 

 serious losses, especially at seaside com- 

 munities in which the accommodation of 

 tourists is often the chief, or son-ietimes 

 the only, major business. Rotting fish on 

 the beaches, cind sometimes acrid aerosols 

 containing toxin, will drive tourists away. 

 From this standpoint alone, control is highly 

 desirable. 



The effect on the fish populations has not 

 been nearly as severe as the layman imagines 

 when he hears of the death of millions of small 

 fishes. The percentage kill is doubtless low. 

 For instance. Lackey and Hynes (1955) stated, 

 "... the last localized outbreaiks of the 1953- 

 54 Red Tide are only a few weeks past, yet 

 sports fishing (grouper, speckled trout, 

 mackerel, and redfish) has been generally 

 good throughout the entire area. . . ." 



The kill of fishes by the 1946-47 red tide 

 was estimated by Gunter, Williams, Davis, 

 and Smith (1948) as 500 million fish. This 

 figure nnay sound large, but actually it is not. 

 If we realize that these fish will probably 

 run no less than 10 to the pound, the total 

 is only 50 million pounds. Every year about 

 1 billion pounds of menhaden are caught along 

 a 300-mile stretch of the northern Gulf, but 

 this enormous catch of a single species does 

 not appear to be harming the supply. 



The effect of red tide on public health is 

 rather debatable. For a short while during 

 severe outbreaks there will be aerosols from 

 breaking surf when the wind is blowing on- 

 shore. Long exposure close to, or on, the 

 beach can be very irritating to the respiratory 

 tract. A few people are so adversely affected 

 that they must leave until the outbreak is 

 over. More serious have been the questions 

 regarding the safety of seafood products, 

 shellfish in particular, during an outbreak; 

 however, the Gulf Coast Shellfish Sainitation 

 Research Center (1964) stated that, "... rig- 

 orous proof of the Red Tide organisnn as 

 the cause of shellfish toxicity remains to be 

 demonstrated." Since Gonyaulax and other 

 dinoflagellates occur, often in fair abundaince, 

 in the red-tide area of the coast, it seems 

 hardly fair even to attempt to indict G. breve 

 without very definite proof. Oysters tend to 

 occur, except when trauisplauited, in areas 

 with salinities belowthose tolerated by G. breve 

 (which is neritic), but well tolerated by several 

 species of estuarine dinoflagellates. 



12 



