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2 nd Meeting of the Meeting of the Working Group to DevelopIntegrated and Coordinated Atlantic Bluefin Tuna Management Strategies(Marseille, France – 17-20 May 2004)MOVEMENTS OF BLUEFIN TUNA(THUNNUS THYNNUS L.) TAGGED INTHE MEDITERRANEAN SEA WITHPOP-UP SATELLITE TAGSbyG. De Metrio, G.P. Arnold, J.M. de la Serna, B.A. Block,P. Megalofonou, M. Lutcavage, I. Oray, M. Deflorio

ACKNOWLEDGEMENTS• CEFAS (UK): J. Wooltorton, A.A. Buckley, A. Emery, R.J. Turner, S. Dye, L. Fernand• Fish Farmers and Processors: G. Mendez, N. Anbar, M. Ultanur, Turkish Bluefin TunaFarmers Association, companies AKUA-DEM and DARDANEL (Istanbul, Turkey)• Hopkins Marine Station, Stanford University (USA): B.A. Block, S. Beemer, A. Seitz, A.Boustany• IEO Istituto Espanol de Oceanografia, Malaga (SP): J.M. De La Serna, J.L. Cort, J.M. OrtizDe Urbina, D. Macias, V. Ortiz De Zarate, D. Godoy, E. Alot, P. Rioja• Istanbul University, Faculty Of Fisheries (TR): S. Karakulak, D. Gokturk• Marine Biological Association, Plymouth (UK): D. Sims• Microwave Telemetry: P. Howey• Ministry of Agriculture of Turkey and of Turkish Republic of Northern Cyprus• Monterey Bay Aquarium (USA): C. Farwell• New England Aquarium, University of New Hampshire: M.E. Lutcavage• Pfleger Institute of Environmental Research Oceanside, California (USA): M. Domeier• Planetek Italia (I): G. Sylos Labini, M. Pappalepore, F. Albanese• Section of Zoology-Marine Biology, Department of Biology, University of Athens (GR):C. Yannopoulos, D. Damalas• Trap owners and Captains: A. Ramirez, V. Zaragoza, A. Diana• Tuna Club of Porto Vecchio (Corsica, FR): M. Camus, J. Renaud• Wildlife Computers: R. Hill, M. Braun

TUNASAT A (1998-2001)EU-funded Project 97/3975 involving Italy,CEFAS (UK), Spain and Greece pluscollaboration with Barbara Block (HopkinsMarine Station, Stanford University, USA) andUS Tuna Research & Conservation Center.TUNASAT B (2003-2004)Project funded by Italian Ministry ofAgriculture and Forestry Policies involvingCEFAS (UK), University of Istanbul, TurkishBFT Farmers Association plus collaborationwith Molly Luctavage (University of NewHampshire, USA).

TUNASAT A - OBJECTIVESEvaluate practicalities of using pop-up tagsGain experience for future projects withlarge pelagic fishDescribe migrations and movements ofbluefin tuna within Mediterranean andbetween Mediterranean and North Atlantic

TUNASAT A - FISH AND TAGS84 bluefin tuna (42 - 230 kg)61 pop-up single-point satellite tags (PTT100 -Microwave Telemetry) – 132 mm length, 21mm dia, 76 g weight23 pop-up archival satellite tags (PAT -Wildlife Computers) – 143 mm length, 22 mmdia, 76 g weightProgrammed pop-up time 5 to 300 days

TUNASAT AFISH CAPTURE & TAGGING TOOLSFish caught by: Traditional traps (Sardinia, Spain) or pens(Spain): underwater tagging with sportfishing gun or harpoon Sports fishing (Corsica waters): taggingwith T-shaped stick or by hand-stick ondeck Hand-line fishing (Aegean Sea): by handstickon deck

TUNASAT ATAGS & TOOLS• 61 average values of temperature• Argos location on surfaceUnderwater guns used to attach the tagsPop-up Single-point Satellite tagPTT-100 - Microwave Telemetry• pressure data• temperature data at depth• light level (to estimate longitudes)• Argos location on surfacePop-up Archival Satellite tagPAT - Wildlife ComputersOther tools used to attach the tags

1998 1999and Tuna trap of Barbate(Strait of Gibraltar, Spain)

2000Tuna pens atPuerto Mazarron

TUNASAT ATAG DETECTION RATESTags deployedRecapturedArgos detection ratePTT-100 tags 61 4 (7%)1257(21%)PAT tags 232 (9%)1321(62%)23 (30%) transmitted valid dataPTT-100 & PAT tags return ratesin the Western Atlantic (USA): 56 - 93%

On-shoretrials

Operationaltags

Relative PTT-100 signal strengths (dB)

BLUEFIN MOVEMENTS Pop up locations related to size of fishTotal tags located:23Tags located inthe Mediterranean:16 (70 %)13 (81%) ( 42 - 100 kg)3 (19%) (150 - 170 kg)Tags located inthe eastern Atlantic:7 (30 %)(150 - 230 kg)

WESTERN MEDITERRANEAN

Corsica

Chlorophyll-a concentration in thecentral MediterraneanChlorophyll-a from SeaWiFS

ATLANTIC - South of Gibraltar

Chlorophyll-a concentrationfrom SeaWiFS

ATLANTICNorth of UK

Greenland SeaTemperature20151050ABCTag 23328 - 239 days (27 July 1998)-50 10 20 30 40 50 60Observations - 4 day intervals

2015105ABCTemperature

99-606

TUNASAT B - FISH & TAGGING43 bluefin tuna (31 - 155 kg)20 PTT-100 (archival) tags23 PAT tagsProgrammed pop-up time 34 to 300 daysFish caught by purse seine (14) or in pens (19)All fish tagged by hand-stick on deck

EASTERN MEDITERRANEAN

Depth (m)Maximum depths of bluefin in Med0100200300400500600700800900 PAT tag 41805 (FL = 125 cm; RW = 35 kg)1000110012007-ago-03 10-ago-03 13-ago-03 18-ago-03 21-ago-03 24-ago-03 28-ago-03 31-ago-03 3-set-03 6-set-03Depth (m)0100200300400500600700800900PAT tag 6086 (FL = 168 cm; RW = 81 kg)1000110012004-giu-03 7-giu-03 14-giu-03 19-giu-03 28-giu-03 5-lug-03 9-lug-03 13-lug-03 20-lug-03 23-lug-03 26-lug-03Depth (m)0100200 PAT tag 41799 (FL = 137 cm; RW = 45 kg)3004005006007008009001000110012005-ago-03 8-ago-03 14-ago-03 18-ago-03 21-ago-03 28-ago-03 1-set-03 4-set-03 8-set-03

WORKING HYPOTHESESAdult bluefin ( 100 kg) remain in westernMediterranean after spawning and feed inareas of high primary productivityAfter spawning large bluefin (150-230 kg)migrate into the eastern North Atlantic(a) south towards Cape Verde Islands or(b) north to Iceland and the Norwegian SeaSome large bluefin move to and fro betweenthe Alboran Sea and Atlantic, feeding onboth sides of the Strait of GibraltarNo evidence of transatlantic migrations,despite progressive increase in probabilityof tag detection from east to west