were of the type ordinarily used in 

 that bay. English sport fishermen, co- 

 operating with F. S. Russell (1934a), 

 left marked hooks in a number of 

 giant bluefm tuna in the North Sea in 

 1933. Since no returns resulted from 

 all of these efforts, interest in the 

 matter subsided again. 



The first successful tagging of 

 Atlantic bluefm tuna was achieved 

 by Westman and Neville ( 1 942), who 

 marked 23 small bluefm tuna with 

 celluloid disc tags off New York Har- 

 bor during the 1941 fishing season. 

 They obtained two returns in the same 

 locality and season, after periods of 

 less than 75 days at large. Interest in 

 such matters of course ceased with 

 the outbreak of World War 11. 



Cooperating sport fishermen 

 used numbered hooks furnished by 

 Schuck and Mather to mark giant 

 bluefm tuna off the Bahamas in 1950 

 and 1951, and off Rhode Island in 

 1952 (Mather 1963). Rivas (1954) 

 also used the numbered hook method 

 to mark giant tuna off the Bahamas 

 in 1952 and applied strap tags to the 

 opercles of some of these fish, like- 

 wise utilizing the cooperation of rod 

 and reel anglers. The only result from 

 all these efforts was the return, about 

 fifteen years after its recovery, of a 

 numbered hook from a fish recap- 

 tured from Wedgeport, Nova Scotia. 

 The release data for this hook, which 

 had been sold by a tackle dealer in 

 eastern Long Island, New York, had 

 not been reported, and our efforts to 

 retrieve this information were unsuc- 

 cessftil. The fish probably had been 

 released, or broken free, off eastern 

 Long Island, but of course this is 

 uncertain. 



Interest in tuna tagging was re- 

 vived when the California Depart- 

 ment of Fish and Game developed 

 the dorsal loop tag and used it suc- 

 cessftilly on small Pacific tunas (Wil- 

 son 1953). Mather, with the coopera- 

 tion of a few interested sport fisher- 

 men, proved the feasibility of mark- 

 ing small Atlantic bluefin with the 

 dorsal loop tag in Massachusetts wa- 

 ters during the 1954 fishing season. 

 He concurrently developed the dart 

 tag, with which even very large fish 

 could be marked rapidly once they 

 were brought alongside the boat 

 (Mather 1960, 1963). The successful 



Cooperative Game Fish Tagging Pro- 

 gram of the Woods Hole Oceano- 

 graphic Institution, which has been 

 conducted jointly with the National 

 Marine Fisheries Service since 1974, 

 developed from these beginnings. 

 Subsequently agencies in other At- 

 lantic and Mediterranean nations have 

 marked bluefin tuna and other large 

 pelagic species with interesting and 

 important results. 



e. Summary of Bluefin Tuna 

 Tagging Programs 



A summary of the more impor- 

 tant programs, with the major areas 

 and dates of operation and major lit- 

 erature references for each, follows: 

 Canada — Fisheries Research Board 



of Canada (now Environment 



Canada). 



St. Andrews Biological Laboratory 



— Northwestern Atlantic- 1963- 

 present, Beckett (1970), Burnett 

 etal. (1977). 



France — Institut Scientifique et 

 Technique des Peches Maritimes- 

 Bay of Biscay and Portugal- 1 968- 

 present, Aloncle (1973). 



Italy — Centro Sperimentale della 

 Pesca-Tyrrhenian Sea-1962- 

 present. Arena and Sar^ (1967), 

 Arena and Li Greci (1970). 



Morocco — Institut des Peches 

 Maritimes du Maroc-Atlantic 

 coast of Morocco- 1972- 1 973, 

 Lamboeuf(1975). 



Norway — Fiskeridirektoratets 

 Havforskningsinstitutt-West 

 coast of Norway-1957-1962, 

 Hamre(1965). 



Spain — Instituto de Investigaciones 

 Pesqueras — Cadiz area, Spain- 

 1960-1967, Rodriguez-Roda 

 (1963, 1964c, 1969a). 



United States of America — Woods 

 Hole Oceanographic Institution 

 and National Marine Fisheries 

 Service — Northwestern Atlan- 

 tic and adjacent waters- 1954- 

 present and 1 974-present, respec- 

 tively, Mather (i960, 1962, 1969, 

 1974a), Mather et al. (1967, 

 !974b), Mason etal. (1977). 

 The results of tuna tagging have 

 been summarized and briefiy de- 

 scribed by the FAO Panel of Experts 



for the Facilitation of Tuna Research 

 (1972), Mather and Mason (1973, 

 1976), Mason (1975), and Mason et 

 al. (1977). 



2. Definitions 



Direct migration-This term is used 

 to designate the movement of a 

 fish which presumably could not 

 have been repeating an annual 

 migratory pattern when recap- 

 tured. It does not imply that the 

 fish has travelled on a straight 

 course from one point to another. 



Trap fisheries-Special terms of the 

 trap fisheries have been defined 

 in Section 1IB4. 



3. Hypothetical Migration Model 



Subject to some variations be- 

 tween successive ages and overlaps 

 between age groups, and some re- 

 gional differences, we believe that 

 the basic migratory behavior of the 

 bluefin, through its life in the Atlan- 

 tic, may be summarized by age groups 

 as follows: 



Very Small Fish (Less Than 2.5 kg, 

 and Age 0) — Development from 

 egg to active predator is ex- 

 tremely rapid. Hatching occurs 

 within two days. The larvae be- 

 come active swimmers in 1 5 days, 

 and a length of 30 cm may be 

 attained within three months. The 

 first important movement of the 

 newborn fish is one of concen- 

 tration. They migrate from ex- 

 tensive spawning areas to lim- 

 ited nursery (feeding) grounds. 

 Growth during their first winter 

 is much slower than it was dur- 

 ing the warm season. 



Small Fish (2.5-32.0 kg, Ages 1-4, 

 Immature) — These fish make 

 annually repeated two-phase mi- 

 grations between limited warm 

 season coastal nursery areas and 

 little known, but presumably 

 more extensive, cold season win- 

 tering areas. The warm season 

 occurrence is typically in the sur- 

 face layers, with heavy feeding 

 and rapid linear growth, but no 

 decrease in the length-weight ra- 

 tio. The winter sojourn, on the 

 other hand, occurs at deeper lev- 

 els, and growth virtually ceases. 



97 



