The Bluefin Tuna Fishery in the Bay of Biscay: Its Relationship with the Crisis of Catches of Large Specimens in the East Atlantic Fisheries from the 1960s

130 Pages·2019·8.751 MB·English

by  José Luis Cort , Pablo Abaunza

SPRINGER BRIEFS IN BIOLOGY
José Luis Cort
Pablo Abaunza
The Bluefin Tuna Fishery
in the Bay of Biscay
Its Relationship with the
Crisis of Catches of Large
Specimens in the East
Atlantic Fisheries from the
1960s
SpringerBriefs in Biology
More information about this series at http://www.springer.com/series/10121
é
Jos Luis Cort Pablo Abaunza
(cid:129)
fi
The Blue n Tuna Fishery
in the Bay of Biscay
Its Relationship with the Crisis of Catches
of Large Specimens in the East Atlantic
Fisheries from the 1960s
JoséLuisCort PabloAbaunza
CentroOceanográficodeSantander SpanishInstitute of Oceanography
SpanishInstitute of Oceanography Madrid,Spain
Santander, Cantabria, Spain
ISSN 2192-2179 ISSN 2192-2187 (electronic)
SpringerBriefs inBiology
ISBN978-3-030-11544-9 ISBN978-3-030-11545-6 (eBook)
https://doi.org/10.1007/978-3-030-11545-6
LibraryofCongressControlNumber:2018967411
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Atlanticbluefintuna(CourtesyofGrupBalfegó)
Acknowledgements
Thanks are extended to Bernardo Pérez and Pablo Barquín (IEO, Santander) for
their help in preparing the graphics and manuscripsts of the present study; to
JuanJ.Navarro(GrupBalfegó)forpermissiontousetheimagesprovided;toCesar
González-Pola(IEO)forthedesignoftheFig.2.2showingthecurrentsintheBay
of Biscay; to the Institute of Marine Reseach in Norway (IMR) for providing the
photograph of Fig. 5.11; to Øyvind and Magnus Tangen for providing figures
presented at theSantander Symposium; to Taylor and Francis Group for allowing
the publication of several figures and tables from two publications; to Victor Díaz
del Río, oceanographer geologist of the IEO, for the description of the Strait of
Gibraltar in the times of Neanderthal man; to Francisco Abascal (IEO) for facili-
tating the geolocation of Fig. 7.3; to Carlos Palma, ICCAT biostatistician, always
willingtoclarifyandfacilitateinformation,andforfacilitatingtheFigs.2.4and8.3;
and to Antonio Di Natale (Genoa Aquarium), for the revision of the manuscript.
vii
Contents
1 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1
References . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4
2 Some Characteristics of the Bluefin Tuna. Its Geographical
Distribution, Areas and Fishing Systems. . . . . . . . . . . . . . . . . . . . . . 7
References . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14
3 Two Stocks . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19
References . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20
4 The Bluefin Tuna Catch in the Strait of Gibraltar. A Review
of Its History . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 23
4.1 Over 30,000 Years Ago . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 23
4.2 Phoenician-Roman Empire . . . . . . . . . . . . . . . . . . . . . . . . . . . . 27
4.3 Modern Age. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 30
4.4 Recent History . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 31
References . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 33
5 The Present State of Traps and Fisheries Research in the Strait
of Gibraltar . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 37
5.1 Chronology and Description of Two Symposiums
and the ICCAT-GBYP Project. . . . . . . . . . . . . . . . . . . . . . . . . . 47
5.1.1 World Symposium on Bluefin Tuna in Santander
(2008). . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 48
5.1.2 ICCAT-GBYP Project . . . . . . . . . . . . . . . . . . . . . . . . . . 62
5.1.3 Symposium on Bluefin Tuna Traps Fisheries
(ICCAT-GBYP 2011) . . . . . . . . . . . . . . . . . . . . . . . . . . 63
References . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 72
ix
x Contents
6 Bluefin Tuna Fishing in the Bay of Biscay . . . . . . . . . . . . . . . . . . . . 79
6.1 History. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 79
6.2 The Fishing Itself . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 80
References . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 84
7 Research Related to Bluefin Tuna Fishing in the Bay of Biscay . . . . 85
7.1 Historical Antecedents . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 85
7.2 Birth and Geographical Origin of Bluefin Tuna in the Bay
of Biscay . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 86
7.3 Migrations in and from the Bay of Biscay . . . . . . . . . . . . . . . . . 87
7.4 Bluefin Tuna Migrations to and from the Bay of Biscay.
Conventional Tagging. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 88
7.5 Electronic Tagging . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 91
7.6 Age and Growth of Bluefin Tuna in the Bay of Biscay.
Age-Length Key and Length-Weight Relationship . . . . . . . . . . . 91
7.7 A Fin Ray Sample that Confirms the Nature of Visible
Rings. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 93
7.8 Other Studies on Bluefin Tuna . . . . . . . . . . . . . . . . . . . . . . . . . 96
7.9 Official Bluefin Tuna Catches in the Eastern Atlantic
(ICCAT, 1950–2016) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 96
7.10 Historical Series of Catches in the Bay of Biscay. . . . . . . . . . . . 97
7.11 Biological Sampling. Demographic Structure of Catches. . . . . . . 99
7.12 Fishing Effort and Abundance Index . . . . . . . . . . . . . . . . . . . . . 104
References . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 105
8 A Publication that Sheds Light on the Disappearance
of the Eastern Atlantic Bluefin Tuna Spawner in the 1960s . . . . . . . 109
References . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 118
9 Epilogue . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 121
9.1 Epilogue . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 121
References . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 122
Abstract
AbriefdescriptionismadeoftheAtlanticbluefintuna,Thunnusthynnus(L.),from
the point of view of its biology, geographic distribution and population dynamic.
WiththeStraitofGibraltartrapsasareferenceandprovidingavisionfromancient
times to the present, scientific activities on this fishing gear are reviewed in an
attempttoexplainthereasonsbehindthecrisisofthecatchesinthisfishery,which
beganatthebeginningofthe1960sandwhichhasbeenextendeduntilrecenttimes.
Inordertodosoandbasedonarecentpublicationontheissue,theBayofBiscay
fishery ispresented asa fishery with a long tradition on which numerous scientific
studies have beencarried outandwhosedata areofgreat importanceintheABFT
assessment group of SCRS (ICCAT’s scientific committee). Traditionally, the
catches of this fishery have been made up of juvenile specimens (<40 kg) making
upmorethan97%innumberoffishesaccordingtoa62-yearseriesstudied(1949–
2010). From an analysis of the population, it has been shown that the impact of
massive fishing of juveniles in this fishery between 1949 and 1962, together with
that of juveniles in Morocco (the Atlantic part) possibly caused the decline of the
traditionaltrapsfisheryofspawnersintheStraitofGibraltarandthecollapseofthe
spawner fisheries in the north of Europe from the 1960s. This situation continued
until2007,theyearfromwhichaPluri-AnnualRecoveryPlan(PARP)wasadopted
byICCATfortheeasternstock.SincethePARPwasimplemented,juvenilecatches
have disappeared from almost all the fisheries, a scenario that coincides with a
considerable recovery of the spawning stock biomass in the easter Atlantic and
Mediterranean, according to the results of the latest SCRS assessments.
(cid:1) (cid:1) (cid:1) (cid:1)
Keywords Atlantic Bluefin Tuna Traps Strait of Gibraltar Bay of Biscay
Juveniles Fishing
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