REPORT OF THE 2007 MEETING OF THE SUB-

COMMITTEE ON ECOSYSTEMS (Madrid, Spain -

February 19 to 23, 2007)

2. Considerations on prioritising future work and data needed to

support that work

• Ecological Risk Assessment (ERA) framework may be a good way to prioritize research activities

• The goals of CLIOTOP research concerted with the ToRs of the SC

• Data needs: observer data in combination with other sources of information, such as logbooks, are necessary for the activities of the Sub-Committee which includes assessing the impact of tuna fisheries on the ecosystem. The Sub-Committee recognized that one of the present limitations for using existing observer data is the lack of access at the Secretariat, and it was recommended to build an observer program metadatabase.

3. Development of a Workplan for a seabird assessment

• 3.1 Data on seabird bycatch, seabird distribution and seabird population status and trend

– Bycatch rates were provided for longliners operating in Brazilian EEZ, Benguela current, Chinese Taipei fishing in ICCAT area, and Spanish longliners targeting swordfish in the Mediterranean.

– Birdlife Global Procelariiform Tracking database for albatross and petrels.

3.1 Data on seabird bycatch, seabird distribution and seabird

population status and trend

3.2 Assessment of the impact of ICCAT fisheries on seabird

populations1) Identify seabird species most at risk

2) Collate available data on at-sea distribution of these species;

3) Analyze the spatial and temporal overlap between species distribution and ICCAT longline fishing effort

4) Review existing by-catch rate estimates for ICCAT longline fisheries

5) Estimate total annual seabird by-catch (number of birds) in the ICCAT Convention area

6) Assess the likely impact of this bycatch on seabird populations.

3.2 Assessment of the impact of ICCAT fisheries on seabird

populations1) Identify seabird species most at risk:

Risk prioritization exercise: high priority for 41 populations

3.2 Assessment of the impact of ICCAT fisheries on seabird

populations3) Analyze the spatial and temporal overlap

between species distribution and ICCAT longline fishing effort

Preliminary LL effort estimates were computed.

4. Examination of the impact of different hook types on by catches

There is a long debate regarding the positive or negative effects of using circle vs. J hooks. Besides hook type, there are other factors such as shape of the hook, degree of offset and hook size that can affect the results obtained. In many experiments comparing the performance of each hook type, bait type was also a key element. In addition, the experimental design, the methodology selected to analyze the data, area-time-depth factors, fishing patterns, etc. could affect the outcome of the experiments. Therefore, the Sub-Committee considered that a simplification of the debate regarding hook types is not appropriate.

Review of 23 studies in 12 fisheries

4. Examination of the impact of different hook types on by

catchesAccording to available information, circle hooks generally tend to reduce the catch rate and increase survivorship of incidentally caught species (e.g., sea turtles, marlin), however, in some cases this result was conditional on the bait type used (i.e. blue sharks). In the case of targeted species for which information is available, catch rates seemed to be higher for some tuna species. But, in the case of other targeted species such as swordfish and bigeye tuna the circle hook effect was also dependent on the bait type (mackerel vs. squid). Overall, the Sub-Committee felt that the results of the studies reviewed during the meeting are encouraging and encourages the continuation of these types of studies since it is not clear that use of circle hooks alone, is the best technological solution to minimizing bycatch while maintaining productive fisheries in all cases.

5. Other matters

6. Recommendations

-Observer and logbook programs to quantify total catch (including bycatch) composition and disposition. -Construct a metadatabase describing the different national observer programs carried out in the past. Evaluate consistency in information. -Hiring a bycatch coordinator and include experts in seabird and turtle biology in the different delegations.-Develop educational materials identifying conservation issues and easily implemented mitigation measures.