52 DEPARTMENT OF THE :\AVAL HERVIGE 



6 GEORGE V, A. 1918 



year? The explanation appears to be this; the mating of male and female is largely 

 ■a matter of accident. It is said that the male does not seek out the females, but " tries' " 

 every lobster he meets, male and female alike. If a female does not chance to meet a 

 male, het eggs are not fertilized, and can produce no larvse. The fewer lobsters, there- 

 fore, and the wider the area over which they are distributed the less the chances are 

 for mating, and the fewer the number of berried lobsters. 



As showing how restricted grounds may promote mating, an-d therefore, iucronso 

 the number of berried females, the following facts appear to be significant : After 

 the close season began in June (1914), the department arranged to send 

 sixty-two commercial lobsters, forty-seven unberried females, and fifteen males to tlic 

 cement pound. These were dipped up and examined about once a week. Before our 

 plant closed (August 22} no few^er than nineteen out of the forty-seven females had 

 extruded eggs. By the end of September nine more had extruded eggs. Not counting 

 seven of the females which were young and under 9^ inches in length, the number 

 extruding eggs (twenty-eight) would amount to TO per cent of the forty females, a most 

 extraordinarily high percentage. 



How else can we explain this high percentage excepting on the hypothesis that 

 the restricted area within which they were confined promoted mating? "Whether the 

 eggs have been fertilized or not can only be determined by examining them from 

 time to time and watching for the development of the embryo — an easy task for any 

 well-trained biologist. 



In connection with this subject it is worth while to refer to the catch of 3,000 

 lobsters made in 1913 by Mr. Joseph W. Tidd, of Whale Cove, Digby county. Nova 

 Scotia. Mr. Tidd used 175 traps. The traps were set along the bay of Fundy, about a 

 mile northeast of Petite passage, and a quarter of a mile from shore. While the 

 number of males and females were about equal, only three of the latter bore eggs. 

 Wliy were there not about 700 berried females in place of three, if female lobsters 

 extrude eggs biennially ? Why were there not about 1,500 berried females if they extrude 

 their eggs annually? On either supposition there must be a very high percentage of 

 sterile females, or else, after extruding eggs in any season, they lose their eggs in 

 some way which we do not as yet understand, but simply guess at. 



To me the simplest explanation is that the facilities for mating are lactking. 

 There is and has been much over-fishing in the bay, and the animals are scarcer and 

 farther apart than they used to be. Moreover, lobsters are known to be eminently 

 local in their habits, and do not wander far from their natural burrows or shelters. 

 Perhaps their movements are restricted by the strong tidal currents which prevail in 

 the bay. These are possible reasons why there is relatively little mating and there- 

 fore few berried females. Assuming that this is the true explanation, one can readily 

 see the tremendous advantage of mating grounds. For after all is said and done, 

 there are only three important ways in which we can increase our lobster supply: 

 (1) by increasing the numbers of females which carry eggs; (2) by rearing the 

 larvtE to the fourth or fifth stage, and there is some doubt as to whether this can be 

 done economically; and (3) by limiting the catch of the larger and more mature males 

 and females. If some temporary tidal enclosures are constructed here and there along 

 the coast, as suggested elsewhere in this report, they could be used as mating enclosures 

 for commercial lobsters as soon as the open season has ended and the berried females 

 have been liberated in the sea. 



COXSTRUCTIOX OF THE PLANT. 



The carpenter work was ready for the shafting and gearing on June 23, but the 

 machinery was unfortunately delayed in transportation for over a fortnight at St. 

 John, and did not arrive until July 10. The rearing plant was started on its regular 

 work on July 17, and ran exactly one month, when our supply of hatching lobsters 



