and south to Baltimore Canyon (Fig. 1, Table 1). The 

 lobsters were taken with otter trawls or traps (five 

 localities only) at depths of 35-300 fathoms (64-549 m), 

 then tagged and released within a day after capture and 

 within 2.7 nautical miles (5 km) of the capture site. 

 Tagging methodology has been described previously by 

 Cooper (1970). Essentially, the tag consists of coded 

 polyvinyl chloride tubing with a polyethylene monofila- 

 ment leader and stainless steel anchor implanted in the 

 right or left dorsal extensor muscle below the carapace. 

 The anchor is inserted with the aid of a hypodermic nee- 

 dle through the connecting membrane between the 

 carapace and the first abdominal segment. The mem- 

 brane breaks down at ecdysis to permit withdrawal of the 

 lobster from the old exoskeleton and the implanted tag is 

 thus retained through successive molts. 



The tagging program and its objectives were initially 

 well advertised with letters and poster notices being sent 

 to all New England and Middle Atlantic state fisheries 

 commissioners, to all vessel captains known to engage in 

 the offshore lobster fishery, and to all major buyers and 

 wholesalers of lobsters. Port agents of the National 

 Marine Fisheries Service were specially briefed and then 



maintained continuing liaison with the lobster fishermen 

 and dealers. 



In a preliminary paper Cooper and Uzmann (1971) 

 reported 400 returns from 5,710 releases through 1969 

 (7.0% reported recapture); in 1970 and 1971 additional 

 releases raised the total number tagged and released to 

 7,326, of which a cumulative total of 945 recoveries had 

 been reported to us as of 15 December 1972. Thus, the ac- 

 cumulated reported recaptures is currently 12.9% and in- 

 creasing at a decreasing rate annually by virtue of 

 natural mortality of the tagged population, tag loss, non- 

 recognition of tags, possible emigration into areas with 

 little or no commercial fishery, removal and nonreporting 

 by U.S. fishermen and various elements of the foreign 

 fishing fleet, and possibly, increased incidence of non- 

 reporting because of fishermen apathy. We offer the last 

 theoretical reason because renewed publicity and an in- 

 crease in the tag return reward from $1.00 to $5.00 in Oc- 

 tober 1971 failed to elicit a significant increase in the tag 

 return rate despite a significant input (1,142) of newly 

 tagged lobsters in that calendar year. This hypothesis is 

 further supported by calculations of expected returns per 

 annum under the condition of exponential decline of the 



Table 1. — Summary of offshore lobster tagging, 1968-71: station references, releases, and recaptures.' 





Composite 



Original 



Plot position 





Number 



Number 





station 

 number 



station 

 number(s) 







Canyon or 

 shelf region 



of 



of 



Year 



Lat.N 



Long.W 



releases 



recaptures 



1968 



1 



(1-3) 



40° 17' 



68°02' 



Oceanographer Canyon 



42 



3 





2 



(4) 



39°59' 



69°36' 



Veatch Canyon 



13 



3 





3 



(5) 



39°31' 



72° 13' 



Hudson Canyon 



146 



9 





4 



(6) 



40°05' 



71°09' 



Block Canyon 



52 



7 





5 



(7-8) 



40°04' 



70°27' 



Atlantis Canyon 



264 



29 





6 



(9, 11) 



39°57' 



69°56' 



Veatch Canyon 



149 



22 





7 



(10) 



39°56' 



69°41' 



Veatch Canyon 



99 



10 





8 



(12) 



39°59' 



70°03' 



Veatch Canyon 



50 



4 





9 



(13) 



40°03' 



70° 17' 



Atlantis Canyon 



143 



19 





10 



(14) 



40° 13' 



70°30' 



Atlantis Canyon 



39 



3 





11 



(15) 



40°12' 



70° 15' 



Atlantis Canyon 



84 



6 





12 



(16) 



40°12' 



71°14' 



Block Canyon 



57 



3 





13 



(17-19) 



40°05' 



71°47' 



Block Canyon 



482 



40 





14 



(20-21) 



40°05' 



71°38' 



Block Canyon 



266 



25 





15 



(22) 



41°42' 



66°52' 



Leg, Georges Bank 



46 



10 





16 



(23-26) 



40°33' 



68°39' 



SW Georges Bank 



479 



59 





17 



(27-28) 



40°31' 



67°42' 



Lydonia Canyon 



223 



27 



Total 













2,634 



279 



1969 



18 



(29, 30, 32) 



39°59' 



69°29' 



Veatch Canyon 



1,350 



213 





19 



(31) 



4O°03' 



69° 16' 



Veatch Canyon 



751 



104 





20 



(33-35) 



40°59' 



66°34' 



Corsair Canyon 



387 



44 





21 



(36) 



40°32' 



67°47' 



Lydonia Canyon 



166 



23 





22 



(37-38) 



41°12' 



66°35' 



Corsair Canyon 



422 



46 



Total 













3,076 



430 



1970 



23 



(48,50) 



40°16' 



68°25' 



Oceanographer Canyon 



301 



34 





24 



(49, 51) 



40°26' 



68°20' 



Oceanographer Canyon 



173 



22 



Total 













474 



56 



1971 



25 



(57-58) 



40°00' 



71°12' 



Block Canyon 



60 



10 





26 



(59, 63) 



39° 14' 



72°20' 



Hudson Canyon 



54 



1 





27 



(60-62) 



37°55' 



73°59' 



Baltimore Canyon 



194 



11 





28 



(64) 



39° 10' 



72°38' 



Hudson Canyon 



29 



3 





29 



(65-66) 



40°00' 



69°29' 



Veatch Canyon 



805 



155 



Total 













1,142 



180 



Grand Total 













7,326 



945 



'The original releases are treated as 29; composites of two or more stations have within-group variation of less than 10 

 days, 10' latitude, and 10' longitude. Original station numbers are shown in parentheses. 



