BIOLOGY OF BIKINI ATOLL — SCHULTZ 307 



tides it is exposed except as the surf crashes over it, then some of the 

 water is forced back over the flat part of the reef, flowing seaward again 

 through the surge channels. 



Some of the surge channels, extending for 100 feet or more back into 

 the solid reef, are more or less roofed over or with perforations large 

 and small through which the water may pour or spout on the incoming 

 surge of a wave. They are lined with rich green and red algae, blue, 

 red, yellow, and green corals, and a host of brilliantly colored fishes 

 live in these clear waters. 



The red calcareous algae forming the chief surface growth on this 

 ridge were minutely pitted and creviced. Living among these perfora- 

 tions were several fishes, characteristic of the area. The little blunt- 

 headed blenny, Cirripectes^ appeared to favor this habitat, along 

 with pseudochromids, especially Plesiops. Numerous too was a little 

 viviparous orange-colored brotulid, several kinds of wrasse, eels, and 

 small filefishes and puffers. 



In the surge channels were the pempherids, surgeon and butterfly 

 fishes, and hiding during the day in the dark crevices were the bright 

 red soldier or squirrel fishes that come out at night to feed. Inver- 

 tebrates characteristic along this narrow zone were the slate-pencil 

 sea urchins and in the deeper crevices and pools the venomous sea 

 urchin with its long, purple, needlelike, poisonous spines. Octopi 

 were common, along with several kinds of shrimp and crabs. 



OPEN-WATER HABITAT 



Contrasted with the atoll rim and its coral-algal growths was the 

 open-water habitat of the atoll, in which a great variety of fishes 

 thrived that never sought the protection of the reefs. In these waters 

 occurred very small fishes, moderate-sized ones, and the giants. Some 

 are predaceous — the tunas, jacks, and sharks — whereas others, such 

 as the manta and the round herring, lived by feeding on the small 

 pelagic organisms in the water. This latter species, 2 or 3 inches 

 long, occurs in big schools. It was seen daily near the ships anchored 

 in the lagoon. 



Cruising slowly around Bikini lagoon, one saw now and then big 

 manta rays. However, in the middle of the broad Enyu channel, 

 during 1946 and 1947, almost every day one to several occurred at 

 at the surface with the tips of their broad pectoral fins moving slowly 

 up and down. 



To capture one of these giant fish, 10 feet across, required prepara- 

 tion. A spear, fitted on the end of a long wooden shaft, with lines 

 attached, was made. To the spear point was fixed about 75 feet of 

 tiller rope lashed to an empty steel drum with the excess rope wound 

 around it. This gear was then placed at the bow of a picket boat, 



