14 ABOUT LOBSTERS 



None of these had moved from one area to the other— 

 a distance of about ten miles. 



These tagging results, which are in general agree- 

 ment with those reported from other countries, show 

 that lobsters are not truly migratory. The great ma- 

 jority of tagged lobsters which have been recaptured 

 were caught very close to the place where they were 

 liberated. The few that do move appreciable distances 

 seem to do so in a more or less random manner. Of 

 more than 50,000 tagged lobsters, only three moved as 

 much as sixty miles. It appears, therefore, that the lob- 

 ster population is made up of a series of separate, inde- 

 pendent stocks with very little mixing between areas. 

 This conclusion is confirmed by the striking differences 

 in the color, shape, sizes and sex ratios of lobsters from 

 different areas. Rather marked differences have been 

 observed in stocks separated by only a few miles. There 

 is no evidence in the tagging results to suggest that 

 lobsters make seasonal migration on and off shore. It 

 is possible that in certain areas lobsters leave the im- 

 mediate shore line and move into somewhat deeper 

 water as winter approaches, but the tagged lobsters 

 gave no indication of such behaviour. 



In a later article, Dr. Wilder and R. C. Murray write: 



It seems evident from our taggings that offshore 

 and onshore movements have no appreciable effect on 

 the catch of lobsters. How then do fishermen get the 

 impression that such movements occur? Actual changes 

 in the abundance and activity provide a logical ex- 

 planation. 



In the fall of the year the shallow inshore waters 

 are relatively warm, the deeper offshore waters, con- 

 siderably cooler. When the season opens, lobsters are 

 plentiful and trap readily in the warm inshore waters. 

 Intensive fishing soon reduces the inshore stocks, the 

 shallow water cools rapidly, and the remaining lobsters 

 become less active and harder to catch. As a result, the 



