These facts are mentioned by way of indicating that re¬ 
productive processes of fishes appeared to be normal. 
No evidences of teratological phenomena were discover¬ 
ed in the course of examining fish specimens, but more 
careful studies will be carried out on specimens shipped 
to the National Museum during the next two or three years. 
In the process of studying the fish population at 
Bikini during 1947 various observations concerning other 
marine types were also made. It was found, for example, 
that the reef between Bikini and Amen Islands above the 
mean low tide level did not appear to be in as healthy a 
condition as it was in 1946. The blue Heliopora coral 
heads on the ocean reef opposite the sand spit at the 
western tip of Bikini Island were largely dead, whereas 
in 1946, the outer edges were formed almost entirely 
of living polyps. In 1947 the dead corals were covered 
by a fine, filamentous algal growth. Various reef 
situations at Namu and Bikini Islands are contaminated 
by tarry substances and oil from target ships; around 
such deposits animal life is scanty if not entirely 
lacking. These tar deposits, however, are not in evidence 
below the mean low tide level. 
For two months after arrival in Bikini lagoon early 
in 1946 it was possible to see objects in the water clearly 
at depths of over 100 ft. After the target ships assembled 
in June, however, the waters became less clear, and objects 
at depths of 35 ft to 40 ft were barely discernable. Dur¬ 
ing July and August of 1947 similar cloudiness of the water 
was observed, especially in the northeastern part of Bikini 
Lagoon. It was believed that disturbance of beach sands 
by wave action could not account fully for this increas¬ 
ed turbidity, and since Rongerick Lagoon is as clear as 
it was in 1946, doubt must be cast upon any theory that 
cloudiness of the water is a seasonal phenomenon. An 
explanation which appears to be more acceptable is that 
an increase in microorganisms in the water has occurred, 
due to the large amounts of sewage that have been dischar¬ 
ged into Bikini Lagoon. Actual concentrations of this sewage 
per unit of water volume may not be excessive, but it 
is well known that a very slight increase in the amount 
of fertilizing substances in water may give rise to a dis¬ 
proportionately great expansion of the microorganism popu¬ 
lation. The expansion begins when a certain threshold is 
passed, and phosphates and other chemical substances in 
the water become available for use by organisms. 
In conclusion, it may be stated that, with the excep- 
