Report of the Fifteenth Session of the IOTC Working Party on Tropical Tunas

The Fifteenth Session of the Indian Ocean Tuna Commission‘s (IOTC) Working Party on Tropical Tunas (WPTT) was held in San Sebastian, Spain, from 23 to 28 October 2013. The meeting was opened on 23 October 2013 by the Chair, Dr Hilario Murua (EU-Spain), who welcomed participants to San Sebastian, Spain. A total of 46 participants attended the Session (47 in 2012), including one invited expert, Dr. Andrew Cooper, from Simon Fraser University, Canada. The following are a subset of the complete recommendations from the WPTT15 to the Scientific Committee, which are provided at Appendix XII.
Japan data collection and processing systems
The WPTT THANKED Japan for addressing some of the concerns raised by the WPTT in 2012, and RECOMMENDED that Japan and the IOTC Secretariat continue joint work, in cooperation with other countries having longline fisheries, to address other issues identified by the WPTT, as the lack of specimens of small size from the samples and discrepancies in the average weights estimated using the available catch-and-effort and length frequency data. (para. 62)
Taiwan,China data collection and processing systems
NOTING that in recent years fishers from the Taiwan,China longline fleet have been collecting both length and weight measurements for the same specimens, the WPTT RECOMMENDED that the measured lengths and lengths derived from weight measurements are compared in order to validate the reliability of this dataset (para. 67)
Length Frequency inter-sessional meeting guidelines
NOTING the size data issues (discrepancies in catch, effort and notably size data (low sampling rate, uneven distribution of sampling in regard to the spatial extent of the fishery) in the Japanese and Taiwan,China tropical tuna data sets) identified by the WPTT in 2012 and 2013 and the Scientific Committee in 2012, the WPTT RECOMMENDED that an inter-sessional meeting attached to the WPDCS and WPM on data collection and processing systems for size data from the main longline fleets in the Indian Ocean, be carried out in early 2014, under the guidelines contained in Appendix IV. (para. 74)
The WPTT NOTED that the data collection and processing systems used for distant-water longline fisheries tend to apply to all oceans AGREEING that it is likely that the issues identified for the Indian Ocean also apply to other areas. In this regard, the WPTT RECOMMENDED that the IOTC Secretariat informs other tuna-RFMO Secretariats about the issues identified and facilitates participation of their staff to the WPDCS, where required. (para. 75)
India fisheries
NOTING the potential utility of the longline CPUEs derived from the research surveys conducted by the ―Fishery Survey of India‖, the WPTT RECOMMENDED that as a high priority, India undertake a standardisation of the CPUE series, with the support of the IOTC Secretariat, and for this to be presented at the next WPTT meeting. (para. 92)
Analysis of the Time-Area Closures (including Resolution 12/13)
NOTING that the objective of Resolution 12/13 is to decrease the overall pressure on the main targeted stocks in the Indian Ocean, in particular yellowfin tuna and bigeye tuna, and also to evaluate the impact of the current time/area closure and any alternative scenarios on tropical tuna population, the WPTT reiterated its previous RECOMMENDATION that the SC request that the Commission specify the level of reduction or the long term management objectives to be achieved with the current or alternative time area closures, as these are not contained within Resolution 12/13. (para. 245)
Review of the draft, and adoption of the Report of the Fifteenth Session of the WPTT
The WPTT RECOMMENDED that the Scientific Committee consider the consolidated set of recommendations arising from WPTT15, provided at Appendix XII, as well as the management advice provided in the draft resource stock status summary for each of the tropical tuna species under the IOTC mandate: (para. 271)
o Bigeye tuna (Thunnus obesus) – Appendix VII
o Skipjack tuna (Katsuwonus pelamis) – Appendix VIII o Yellowfin tuna (Thunnus albacares) – Appendix IX
A summary of the stock status for tropical tuna species under the IOTC mandate is provided in Table 1.