The 8th Meeting of the Indian Ocean Tuna Commission’s (IOTC) Working Party on Ecosystems and Bycatch (WPEB) took place in Cape Town, South Africa, from 17 - 19 September 2012. The meeting was co-hosted by South Africa’s Department of Agriculture, Fisheries and Forestry (DAFF), and participants were welcomed by the Chief Director from Fisheries Research and Development, Dr Johann Augustyn.
The meeting was attended by approximately 50 fisheries scientists and managers from the IOTC region, including representatives from Contracting and Co-operating non-Contracting Parties (CPCs), as well as observers from key NGOs such as BirdLife International. The meeting was chaired by Dr Charles Anderson, with secretariat services provided by Dr David Wilson (Deputy Secretary, IOTC). Dr Ronel Nel (Chair of the Western Indian Ocean - Marine Turtle Task Force) attended the meeting at the request and on behalf of the IOSEA Secretariat.
The agenda of the meeting was dominated by shark bycatch issues; and a large number of papers were presented to the meeting – many related to stock assessments and trend analyses of longlining, purse seining and some gillnet fisheries. A number of papers were also presented to the review the ecological sensitivity (through Productivity-Sensitivity Analyses) of shark populations in the IOTC region. It was evident that the data collection on shark species is improving, but much biological data specific to the populations of the Indian Ocean still need to be obtained to do accurate ecological risk assessments. The meeting agreed that 5% observer coverage is a minimum standard of data collection to do any scientific assessment of bycatch interactions in these fisheries. An exciting new development mentioned was the video monitoring trials in progress in the pelagic longline fishing in Australia. It seems to be extremely useful to monitor bycatch, and may be an alternative to the compulsory logbooks kept by captains. Recognising that the impacts of the fisheries cannot be assessed in the absence of data, the WPEB recommended that the Scientific Committee call again on CPCs to provide bycatch data.
The meeting then turned its attention to the issues of marine turtles and sea birds. The IOTC Secretariat presented the data on marine turtles received to date, as has been the requirement, but similarly noted with significant concern the paucity of data from CPCs. The WPEB also recommended that marine turtles, as a group, be added to Resolution 12/03 on the recording of catch and effort by fishing vessels in the IOTC area of competence, with a view to repording the number of turtles caught in longline gear. The WPEB also noted (in accordance with Resolution 12/04) that “CPCs are obliged to ensure that fishermen are aware of and use proper mitigation, identification, handling and de-hooking techniques. Furthermore, it is mandatory that vessels keep on board all necessary equipment for the release of marine turtles, in accordance with handling guidelines in the IOTC Marine Turtle Identification Cards. The WPEB noted that appropriate equipment for longliners includes line cutters, dehooking devices and dipnets for safely bringing turtles onboard.”
There were very few turtle specific papers presented at the meeting. One report provided results of a study on the effect of hook style and bait type on the incidental bycatch of marine turtles on the Portuguese pelagic longline fishery in the Atlantic Ocean (Info Paper no. 33). It looked at the use of circle hooks in combination with monofilament leaders which may reduce the incidental catch and/or post-capture mortality of marine turtles and sharks. The meeting encouraged further research into the effectiveness of circle hooks and bait types.
Another presentation focused on a satellite tagging study that illustrated marine turtle distributions arising mostly from post-nesting females released from the Iles Eparses in the Western Indian Ocean. Of particular interest were the tracks of a few sub-adult loggerhead turtles caught by French pelagic longliners, rehabilitated at the Kelonia conservation centre in La Reunion, and then released from their capture area. These turtles migrated northwards towards the Oman turtle population, with a smaller fraction joining up with the South African loggerhead population. The extreme pelagic nature of the tracks made it clear why these loggerhead turtles are vulnerable to tuna-related fisheries.
The final presentation provided results of a study on European Union (EU) purse seine fishery interactions with marine turtles in the Atlantic and Indian Oceans over the last 15 years. “A total of 15 913 fishing sets were observed, including 6 515 on drifting Fish Aggregate Devices (FAD) and 9 398 on Free Swimming Schools (FSC). Over the study period, 597 turtles were caught, 86% being released alive at sea”. During a brief discussion of the results from these papers, it was suggested that the IOTC needed to consider time/area closures, especially along major migratory pathways. However, the meeting also agreed that such actions should be preceded with detailed investigations to first identify such areas.
Potential mitigation measures were also mentioned during the meeting, including lights for gillnets which are said to reduce both turtle and shark bycatch, as per one of the 2011 finalists in the WWF Smart Gear competition. Recommendations were also made with regard to environmentally-friendly Fish Aggregating Devices (EcoFADs). As described in an IOSEA Profile of the Month for December 2010 (Designing ecological FADs to reduce entanglement of marine turtles), EcoFAD designs incorporate sisal ropes and reed/bamboo floats. In particular, it was recommended that the floatation devices be cylindrical in shape, to make it difficult for turtles to climb onto the rafts to bask; and the use of net material in both the raft construction and hanging strings was discouraged. These EcoFADs have been tested by EU purse seiners which are aiming for zero entanglement. The next WPEB meeting awaits more details.
The WPEB commented on the lack of new information on the development and implementation of national management plans focusing on the reduction of marine turtle bycatch in tuna fisheries. CPCs were urged to develop action plans and scientists participating in the WPEB were encouraged to report on progress at the next session of the WPEB. This may be an area where further intervention from IOSEA would be constructive. Following from this discussion it was noted that the IOTC Secretariat in combination with its IOSEA counterpart had engaged scientific services to review which turtle species/populations are vulnerable to tuna fisheries, in the form of an Ecological Risk Assessment. The outcomes of this study are to be presented to the IOTC Scientific Committee Meeting in Seychelles in December 2012, with recommendations to be forwarded to the IOTC Commission meeting at a later stage.
In the past, the IOSEA Secretariat has drawn attention to marine turtle interactions with tuna fisheries at previous meetings of the Working Party which, until then, had had minimal discussion of marine turtle issues. Since then, IOSEA and IOTC have collaborated in the preparation of an “Executive Summary” on the status of Indian Ocean sea turtles, as well as turtle identification cards for fishermen. IOTC has adopted (and since revised) fairly comprehensive resolutions aimed at reducing and mitigating marine turtle bycatch. The most recent iteration, Resolution 12/04, can be found on the websites of IOTC and IOSEA. Interest in effective data collection has increased and hopefully more information on turtle-fisheries interactions will be made available at future WPEB meetings.
* * * * *
The full report of the Working Party on Ecosystems and Bycatch meeting should be available shortly on the IOTC website. The final WPEB recommendation to be transmitted to the IOTC Scientific Committee reads as follows:
The WPEB RECOMMENDED that the SC note the following in regarding to the request to the WPEB outlined in Resolution 12/04:
- Develop recommendations on appropriate mitigation measures for gillnet, longline and purse seine fisheries in the IOTC area
Gillnet:The paucity of data on effort, spatial deployment and bycatch in the IOTC area of competence makes any recommendation regarding mitigation measures for this gear premature. Improvements in data collection and reporting of marine turtle interactions with gillnets, and research on the effect of gear types (i.e. net construction and color, mesh size and soak times) are necessary.
Longline: Current information suggests inconsistent spatial catches (i.e. high catches in few sets) and by gear/fishery. The most important mitigation measures relevant for longline fisheries are to:
- Encourage the use of circle hooks.
- Release live animals after careful dehooking/disentangling/line cutting (See handling guidelines in the IOTC marine turtle identification cards).
- Encourage CPCs to use IOSEA expertise and facilities to train observers and crew to increase post-release survival rates of marine turtles.
Purse seine: see c) below
- Develop regional standards covering data collection, data exchange and training
- The development of standards using the IOTC guidelines for the implementation of the Regional Observer Scheme should be undertaken, as it is considered the best way to collect reliable data related to marine turtle bycatch in the IOTC area of competence.
- The Chair of the WPDCS to work with the IOSEA MoU Secretariat, which has already developed regional standards for data collection, and revise the observer data collection forms and observer reporting template as appropriate, as well are current recording and reporting requirements through IOTC Resolutions, to ensure that the IOTC has the mean to collect quantitative and qualitative data on marine turtle bycatch.
- Develop improved FAD designs to reduce the incidence of entanglement of marine turtles, including the use of biodegradable materials
All FAD-directed purse seine fisheries should rapidly develop FADs based on the following three basic principles:
- The surface structure of the FAD should not be covered, or only covered with non-meshed material.
- If a sub-surface component is used, it should not be made from netting but from non-meshed materials such as ropes or canvas sheets.