564 



U. S. BUEEAU OF FISHERIES 



(a) Off Mount Desert, Me., April 25-May 2; July 16-23; and 

 October 4-10. 



(b) In the offshore waters, including BroAvns Bank, Georges Bank, 

 Cashes Ledge, and Phitts Bank, August 2-7, and September 4-9. 



(c) On Nantucket Shoals, August 18-21, and October 18-22. 



Tablk 3. — A summary of the fish tagged from 1923 to 1930 



BY SPECIES 



BY LOCALITIES 



Browns Bank and vicinity 



Georges Bank 



New Hampshire and Maine 



Massachusetts, north of Cape Cod_ 

 Massachusetts, south of Cape Cod. 

 New York and New Jersey 



Total. 



2,113 



2,002 



19, 581 



645 



29,857 



717 



54,915 



468 



1,316 



210 



8 



3,426 



12 



287 



3,943 



2,323 

 2,010 



23, 007 

 657 



30, 992 

 1,185 



60, 174 



1 For more details of the fish tagged from 1923-1928 see Report of the Commissioner for 1928, pp. 631-632. 



Tablk 4. — A summary of the ^lumber of cod, pollock, and haddock tagged and 

 recaptured during the years 1923-1930, inclusive 



Much the same results were shown by the recapture records of 

 tagged cod during 1930 as in preceding years. Up to the present 

 time tag returns as high as 35 per cent have been reported for certain 

 lots of cod tagged near shore on grounds often fished ; while offshore, 

 on grounds less frequently visited, they have been as low as 1 per cent. 

 Wliile fishing intensity has much to do with this disparity in the 

 numbers of fish recaptured, other things, such as the physical con- 

 ditions under which the fish were caught at the time of tagging, the 

 security of attachment of the tag, the season of the year, and whether 

 the marked fish belonged to a school that remained localized for some 

 time or was on the point of migrating, have much to do with the 

 percentage subsequently recaught. 



Alongshore within the Gulf of Maine to the northward of Cape 

 Cod marking experiments have shown that a good part of the stock 

 of cod present at any given time remains localized for a year or more, 

 that small numbers migrate eastward to Nova Scotia, and that to 

 the northward of Cape Ann only stragglers move southward. These 

 shore waters constitute an important cod nursery for they support 

 a large number of 1, 2, and 3 year old fish. 



