PROGRESS IN BIOLOGICAL INQUIRIES, 1938 55 
Tn one test where 25 acres of starfish-infested oyster bottom were 
treated with calcium oxide at the rate of 480 pounds per acre, as many 
as 80 percent of the starfish were found to be affected by the chemical 
1 week after the beginning of the experiment. In an area where 280 
pounds of calcium oxide per acre were used, the chemical acted upon 
74 percent of the starfish. It is believed that much better results will be 
achieved when a suitable mechanical method insuring uniformity of 
distribution of the chemical over the treated area has been developed. 
Observations in the Milford Laboratory show that the particles of 
lime must come into direct contact with the body of the starfish to be 
effective. Particles of the chemical falling on the upper surface of 
the starfish imbed themselves in the delicate skin and rapidly cause its 
disintegration through caustic action, Lesions so created rapidly 
increase In size, spreading in all directions and involving the delicate 
respiratory and other structures found on the dorsal surface of the 
starfish. After several days the lesions penetrate the body wall, 
exposing the internal organs. Death usually follows very shortly. 
Starfish which are not hit by falling particles as the chemical is 
being applied may eventually come into contact with it by crawling 
on the bottom. Lime spread on the bottom retains its effectiveness 
for some time. 
Laboratory experiments conducted in large tide-fillng concrete 
tanks indicated that coarse grades of lime, even when used at the rate 
of 3 barrels (840 pounds) per acre, do not cover the bottom evenly 
but permit many starfish to escape. Finely powdered lime was found 
to be much more effective, even in concentrations as light as 280 
pounds per acre. 
To determine the effect of quicklime on other animals, experiments 
were carried out with oysters, flatfish, and lobsters, which support the 
most important fisheries in Long Island Sound. 
Oysters which were subjected for a period of 514 months to a very 
strong concentration of quicklime survived, although their growth 
and increase In weight were somewhat retarded. It must be consid- 
ered, however, that the concentration of lime in the tank was much 
greater than that expected to be used on natural beds, and that even 
if such a concentration were used, it would persist only a short time. 
Tt appears, therefore, that lime may be used without endangering the 
oyster population. Seed oysters survived in lime solutions as well as 
the adult oysters. 
Claims that spreading lime over oyster bottoms will restore the 
normal color of green oysters were not substantiated by field or lab- 
oratory observations. Treatment with lime had no effect on the green 
color of the oysters. : 
Large numbers of hard clams, soft clams, and two species of mus- 
sels kept in tanks to which a large quantity of lime was added at 
monthly intervals survived this exposure for a period of 6 months. 
Mortality among these animals was not noticeably higher than in the 
contro! tanks. Field experiments also showed that there was no mor- 
tality which could be attributed to the effects of lime among mollusks 
dredged from the beds where experiments in the eradication of star- 
fish were conducted. 
Experiments performed at the State Hatchery at Noank, Conn., 
showed that the fry of flatfish will survive for 1 hour in a 1: 1000 
concentration of lime provided they do not come in contact with solid 
