engaged in abundance -survey operations or on oyster vessels which do not have hot 

 water tanks when pressed into starfish control during emergencies. Most of the 

 seed-oyster companies operate one or more vessels exclusively for starfish control 

 and these are generally equipped with long vats or tanks into which the whole mop 

 frame may be dipped. These tanks are filled with water at a temperature of about 

 150° F. (66° C). At this temperature, the starfish are not only killed, but are 

 softened so that they are washed out of the mop as it is lowered for the next 

 dragging operation. Two mops are used, one on each side of the boat, and only 

 about two minutes are required for the hot-water dip. Thus, the mops are in use 

 most of the time and a large area can be covered more effectively than with the 

 dredge or hand-picked mop. 



Lime has been found to kill starfish even when only a few small particles 

 settle on the aboral surface. The chemical is only slightly soluble in water 

 and is quite cheap and readily available. The lump lime may be shoveled over the 

 boat rail to be disintegrated and dispersed as it settles to the bottom. Effective 

 coverage in this manner is difficult, as some quantity may be carried away by 

 tide and currents. Loosanoff and Engle (1942) developed an apparatus for dis- 

 tributing a lime suspension immediately over the bottom. A stream of water from 

 a centrifugal pump picked up the fine lime and the suspension was forced through 

 a hose line to a distributor pipe which was carried a short distance above the 

 bottom on a pair of wheels. This apparatus permits even distribution with little 

 loss to tide and currents, but its use has not been widely adopted because of the 

 expense and difficulty of obtaining the required new equipment. 



A fourth control method, the Flower suction dredge, utilized the principle 

 of the vacuum cleaner. A wide funnel-shaped collector was carried on wheels at 

 a short distance above the bottom. The distance could presumably be adjusted to 

 permit removal of either light material only or almost anything loose, including 

 mud and sand. A large centrifugal suction pump discharged this mixture into a 

 rotating' screen which separated the larger solid material and dumped it onto a 

 conveyor. It was reported that the desired selectivity of bottom material was 

 hard to obtain and that operating costs »tere excessively high. Its use would not 

 be justified except in periods of maximum abundance of starfish. 



There have been intermittent efforts over a period of years to find some use 

 for starfish, interest in the subject being stimulated by recurring periods of 

 abundance . 



The benefits to be derived from the discovery of some economically practical 

 or even profitable means of using starfish would be threefold: 



(1) The oystermen would receive some return for starfish brought in, and 

 inasmuch as all are now discarded, anything received would cut control 

 cost by that extent. 



(2) The creation of a market for starfish would, it may be assumed, lead 

 to independent efforts towards their capture and to new sources of 

 income for certain groups. 



(3) Theoretically, at least, there would be a reduction of the starfish 

 population in the whole area to a point where the peaks of abundance 

 would no longer occur. This event would, of course, simplify the 

 control of starfish on the leased beds and a second, and probably 

 even larger saving to the oystermen would result thereby. 



