Barreiro-Jueguen, S. (Santiago)

Sarralde-Vizuete, R. (Roberto)

English

Sarralde-Vizuete, Roberto

Barreiro-Jueguen, Santiago

Digital.CSIC

Information about tagged Patagonian toothfish (Dissostichus eleginoides) tagged in the CCAMLR Convention Area and recovered in the SIOFA management area by two Spanish vessels in 2017/18

Repositorio Institucional Digital del IEO

WG-FSAThis paper is presented for consideration by CCAMLR and may contain unpublished data, analyses, and/or conclusions subject to change. Data in this paper shall not be cited or used for purposes other than the work of the CAMLR Commission, Scientific Committee or their subsidiary bodies without the permission of the originators and/or owners of the data.Commission for the Conservation of Antarctic Marine Living ResourcesCommission pour la conservation de la faune et la flore marines de l’AntarctiqueКомиссия по cохранению морских живых pесурсов АнтарктикиComisión para la Conservación de los Recursos Vivos Marinos AntárticosWG-FSA-18/5324 September 2018Original: EnglishInformation about tagged Patagonian toothfish (Dissostichuseleginoides) tagged in the CCAMLR Convention Area and recoveredin the SIOFA management area by two Spanish vessels in 2017/18R. Sarralde and S. BarreiroInformation about tagged Patagonian toothfish (Dissostichus eleginoides) tagged in the CCAMLR convention area and recovered in the SIOFA management area by two Spanish vessels in 2017-2018. R. Sarralde & S. Barreiro Centro Oceanográfico de Canarias, Instituto Español de Oceanografía  Introduction Patagonian (Dissostichus eleginoides) and Antarctic toothfish (D. mawsoni) have circumpolar distributions and are generally associated with bathymetric features between 500 and 2250m (Eastman, 1993, Dunn et al., 2012). Patagonian toothfish are found around South America from Ecuador to Uruguay, and in the sub-Antarctic and Antarctic.   Information about tagged specimens released in the CCAMLR convention area but recaptured outside this area should be easily shared between RFMOs and CCAMLR. That is the reason why the Scientific Committee at the SC-CAMLR-XXXV meeting noted that the Secretariat has engaged in initial consultations with the Secretariat of the Southern Indian Ocean Fisheries Agreement (SIOFA) among others RFMOs  that operate toothfish tagging programs in areas adjacent the Convention Area in order to discuss how they may share data on toothfish tagging programs where such data exchange may help to reduce duplication of effort and develop efficiency in and management.   Eleven tagged  specimens of patagonian toothfish (D. eleginoides) that have been released in the CCAMLR management area have been recovered by two Spanish vessels fishing in the Indian ocean within the  SIOFA management area (Figure 1).     Figure 1. The SIOFA management Area,  including management subareas mentioned in this analysis.  3b 7   Methods   Two Spanish fishing vessels have been working in the SIOFA management area in 2017 (16/09/2017-27/02/2018) and 2018 (04/05/2018-16/08/2018).   The fish recaptured had two conventional  T-bar tags. All specimens  have been photographed  together with the tag identification, sampled for length, weight and sex and the otoliths were extracted. One of the recaptured fish had aditionally a PIT tag inside the muscle.   The trajectory have been calculated in ArcGIS and the distance traveled is linear. Obviously, the real trajectory is much longer tan the one calculated.   Results  From the eleven patagonian toothfish (D. eleginoides) tagged and  recovered, the release data from one of them is missing. It has likely been released in the 58.5.1 division.   The time elapsed between the release and recapture has been between 3 and 10 years at liberty (Table 1). All fish were small at  release (between 75-93 cm) being the maximum increment in weight 5 kg and 26 cm in length.   RELEASE RECAPTURE PARAMETERS ID CCAMLR SSRU sp length weigth Vessel Area length (cm) weigth (k) Days at liberty Distance (km) ∆ weigth ∆ length TR_01 58.5.2 TOA 76.5 4.42 TRONIO FAO 57-SIOFA SUBAREA 7 81.4 5.2 1112 155 0.78 4.9 TR_02 58.5.2 TOA 79.2 4.96 TRONIO FAO 57-SIOFA SUBAREA 7 80.2 5.2 1145 164 0.24 1 TR_03 58.5.1 TOA 61.4 2.07 TRONIO FAO 57-SIOFA SUBAREA 7 72.4 3.3 2373 1137 1.23 11 TR_04 58.5.1 TOA 73.4 3.86 TRONIO FAO 57-SIOFA SUBAREA 7 74.8 3.8 1292 1174 -0.06 1.4 TR_05 58.5.1 TOA 80.5 5.35 TRONIO FAO 57-SIOFA SUBAREA 7 87.8 5.55 2035 1192 0.2 7.3 IB_01 58.5.1 TOA 61 2.12 IBSA V FAO 51-SIOFA SUBAREA 3b 87 7.19 3353 1793 5.07 26 IB_02 58.6 TOA 70.9 3.57 IBSA V FAO 51-SIOFA SUBAREA 3b 87 5.91 2694 380 2.34 16.1 IB_03 58.6 TOA 66.8 2.7 IBSA V FAO 51-SIOFA SUBAREA 3b 75 4.02 1947 249 1.32 8.2 IB_04 58.5.1* TOA - - IBSA V FAO 51-SIOFA SUBAREA 3b 93 8.36 - - - - IB_05 58.5.1 TOA 66.5 2.6 IBSA V FAO 51-SIOFA SUBAREA 3b 82 5.01 2252 1665 2.41 15.5 IB_06 58.6 TOA - - IBSA V FAO 51-SIOFA SUBAREA 3b 68 2.76 3623 6 - - *Estimated, there is not release information available.  Specimens recaptured have traveled (straight line distance) from 6 to ~1800km, being 6 out of 10 a long distance movements exceeding 1000km (Figure 2).        Figure 2. Trajectory showing the years at liberty and distance traveled (km). 1       2  2 1 The movement pattern is different depending on the area that the fish was released. Fishes that have traveled a distance longer than 1000km were all released within the 58.5.1 Division and moved in both directions (West-Northwest and Southeast) while all fish released in the Division 58.5.2 or subarea 58.6 traveled smaller distances and with directed movements Southwest and Northeast respectively.       Discussion  Between 2006-2016 there were 210 records of Patagonian and 14 Antarctic toothfish where fish had made movements greater than 200km. Of the fish making long-distance movements 91% of D. eleginoides moved in a counter-clockwise direction around Antarctica. The median distance between release and recapture is 12km (max 5 708km) (CCAMLR, 2017).  All specimens recaptured in SIOFA but one have moved more than 100km. 6 out of 10 traveled a very long distance exceeding 1000km. Curiously the only one that was released in the same spot as recaptured is the patagonian toothfish with more days at liberty (close to 10 years).       In the Patagonian toothfish fishery around Heard and McDonald Island, movements of over 100km were often directed to the North-Northwest of the Kerguelen Plateau (Welsford et al., 2014), but looking at the movements of the specimens in these surveys the only two that have been released in the 58.5.2 division have traveled more tan 100km directed to the East, similar trajectory to 3 out of 5 specimens released in the 58.5.1 division which traveled very long distance, more than 1000km.   Unlike the fish tagged in the 58.6 subarea and 2 out of 5 in the 58.5.1 Division that have moved North-Northwest. Data from tagged patagonian toothfish recaptured in the SIOFA area are not usually reported as there are not a tagging program for the fishing vessels operating in the area. Most of the recaptures notified come from fish tagged in the CCAMLR convention area. Although the movement pattern and biology of the recaptured fishes in the two Spanish surveys are not significant in number, it is worth to pay attention to the particular characteristics  of the recaptured specimens that differs a bit from the general behaviour.        References  CCAMLR Secretariat. Long-distance movements of Patagonian (Dissostichus eleginoides) and Antarctic toothfish (D. mawsoni) from fishery-based mark-recapture data. WG-FSA-17/06.   Welsford, D.C., Péron C., Ziegler, P.E. and Lamb T.D. 2014. Development of the Patagonian toothfish (Dissostichus eleginoides) tagging program in Division 58.5.2, 1997-2014. Document WG-FSA-14/43. CCAMLR, Hobart, Australia: 27pp. 

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Information about tagged Patagonian toothfish (Dissostichus eleginoides) tagged in the CCAMLR Convention Area and recovered in the SIOFA management area by two Spanish vessels in 2017/18

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