BIOLOGY OF BIKINI ATOLL — SCHULTZ 311 



only one or two 3- to 6-foot-long sharks feeding on the sick fish, the 

 diver can keep watch of them. However, when two or three of these 

 voracious creatures became too boUl, as happened on one or two oc- 

 casions, the ichthyologists left the water. 



The searching for the demobilized fishes was done by means of a 

 face mask covering eyes and nose, swim fins on the feet, and a dipnet. 

 With a face mask, both hands were free to devote to picking up fishes, 

 some of which were rather slippery. A canvas glove as an aid for 

 holding slippery fish was used on one hand when necessary. Some 

 of the fishes affected appeared lifeless, but when touched were found 

 to be very much alive and quickly moved away unless caught in the 

 dipnet. Those fishes too small to pick up with the fingers were, with 

 a little practice, lifted from the bottom by inducing upward currents 

 through rapid movement of the hands or feet. A fish, thus suspended 

 for a few moments, was scooped up in the dipnet. Desirable fishes 

 frequently swam into the crevices of the corals and erected their spines, 

 making their removal difficult. With clear vision through the face 

 mask, these, too, were collected. 



A rubber boat, tied to one of the coral heads, served as a base from 

 which to work and was an added safety in case someone ran into 

 trouble under the rugged conditions under which we worked. This 

 boat held the preserving tank, and other gear. Three good swimmers 

 at Bikini picked up enough fish to keep one man busy preserving the 

 specimens in the rubber boat. On shore, one ichthyologist and a Navy 

 photographer took over 300 color pictures. 



Those fishes first to be affected by the rotenone were the damsel, 

 cardinal, butterfly, surgeon, and puffers; others such as needlefish, 

 half beaks, goatfishes, gobies, jacks, threadfins, and mullets were a 

 little slower in reacting to the treated water. The burrowing fishes, 

 namely, eels, appeared last, probably because it took longer for the 

 rotenone to diffuse into their habitats. Fish continued to appear for 

 over 6 hours after treatment, and I recovered eels that came out 8 

 hours after the cloud had passed their burrow. 



Care was exercised in picking up supposedly dead spiny fishes, and 

 especially moray eels, since they may inflict serious wounds. Scorpion 

 fishes, siganids, and other venomous species, even the stinging corals 

 and jell}' fishes, were treated with respect. 



The snake eels often appeared with about 6 to 12 inches of their 

 head section above the bottom. I grabbed them firmly and quickly, 

 then pulled out the remaining 2 or 3 feet of their bodies. A light touch 

 or a miss when grabbed usually caused the eel to withdraw into its 

 burrow, and the specimen was lost. 



The rotenone appeared to affect the fishes by constricting the capil- 

 laries of the gills, depriving the animals of an adequate oxygen sup- 



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