Best practices for the collection of longline data to facilitate research and analysis to reduce bycatch of protected species

Dietrich KS, Cornish VR, Rivera KS, Conant TA (2004) Best practices for the collection of longline data to facilitate research and analysis to reduce bycatch of protected species. NOAA, Sydney, Australia

Workshops focusing specifically on the reduction of sea turtle, marine mammal, and seabird incidental catch (i.e., bycatch) in longline fisheries have recommended the need for standardized data collection procedures employed by fisheries observers onboard commercial longline fishing vessels (Anon. 2003; Donoghue et al. 2003; Food and Agriculture Organization (FAO) 1998/1999a/1999b; FAO and BirdLife International 2004; Inter-American Tropical Tuna Commission (IATTC) 2004; Long and Schroeder 2004). However, these reports lack sufficient detail regarding what these standardized data collections should be. The development and implementation of data collection standards for longline fishery observer programs is challenging at many levels. First, there is the lack of detail in the recommendations regarding what data collections need to be standardized. Second, observer programs worldwide have diverse objectives that may make standardization seem unfeasible or unwarranted. For example, if bycatch monitoring is not the primary objective of a given observer program, increasing observer data collection responsibilities regarding seabirds, sea turtles, and marine mammals may be seen as infringing on the ability of an observer to collect data for a program’s primary objectives. Finally, instituting the use of consistent data fields at the observer program level may impact long-term data series, add to database management costs, and increase time required for observer training. Despite these challenges, there are benefits to standardizing certain aspects of observer data collection procedures for longline fisheries. Information collected consistently could improve global assessments of the impacts of longline fisheries on bycatch species, and facilitate research to develop gear modifications or changes in fishing practices to reduce bycatch. To facilitate research and analysis of factors influencing bycatch of marine mammals, sea turtles, and seabirds in longline fisheries, a workshop was organized to develop “best practices” in observer data collections. The workshop was held in conjunction with the International Fisheries Observer Conference, November 8-11, 2004, in Sydney, Australia. The objectives of the workshop were to: • Share information on current data collection practices and methodologies (i.e., why are certain variables collected, which variables are collected, and how are they collected by observer programs worldwide). • Solicit information from data users on variables that are critical, preferred, optimal, or not important to facilitate research and analysis to reduce bycatch of protected species. • Identify data not being gathered systematically that might facilitate research and analysis to reduce bycatch of protected species. • Coordinate with observer program staff to understand data collection limitations. • Recommend best practices for observer data collection in longline fisheries that would facilitate research and analysis to reduce bycatch of protected species, in the form of a prioritized list of variables and consistent procedures. • Establish a network to continue to develop, refine, and implement best practices. Prior to the workshop, two web-based surveys were developed and distributed to observer program managers and data users worldwide. The objectives of the survey were to ensure broad input from researchers and observer program staff who may not be able to attend the workshop, and to provide a base of information from which to focus discussions during the workshop. At the workshop, participants discussed the results of the surveys and need to develop best practices for observer data collections. Critical and preferred variables were identified, based on the responses provided by data users in the pre-workshop survey and discussions by workshop participants. The list of variables represents “best practices” that should be included in the collection of longline data by fisheries observers (Table 1). The workshop participants generally agreed with the list of variables identified as critical or preferred by data users in the pre-workshop survey, but in some cases other variables were added to the list based on further discussions at the workshop. (Refer to Table 1 in pdf format.) Optimal data specific to bycatch species was identified by data users in the pre-workshop survey and workshop participants. They recommended the following variables and material be collected when possible: • Collection of whole carcasses (seabirds) or parts/biopsies (sea turtles and marine mammals) • Photographs and species identification forms • Age (as derived from collection of teeth or other samples) • Sex (observed, or blood sample/biopsy dart if cannot be observed) • Size of animal (type of measurements vary by species, and may be limited to an estimate of total length if animal is not boarded) • Time and location of capture of bycatch species within the set (although there may be constraints on the precision of these variables) Systematic sightings of protected species around gear during gear deployment/retrieval • Tags (presence/absence, attached prior to release) • Evidence of depredation on catch (by marine mammals or other species), including species of fish damaged, description of type of damage, photographs of damaged fish, and number of fish damaged. Data variables considered not important for data collection were not discussed in detail at the workshop, as there were very few responses in this category. The lack of responses indicating a particular variable was not important made interpretation of the survey results difficult and subject to potential bias. When incorporating these best practices into observer data collections, workshop participants recommended that each program should: • Establish a process for periodically reviewing and prioritizing data needs, in coordination with data users. Priorities may be set according to fishery-specific data needs, but should incorporate broader priorities where possible. • Clearly communicate data collection priorities to all stakeholders. • Establish and disseminate metadata for observer databases that describe each variable collected, how it is collected and when data collection methodologies change, why it is collected (long-term operational vs. short-term research project), and the level of precision of measurements. • Identify which variables are or can be derived from other variables; consider eliminating collection of variables that can be derived from other variables. • Ensure the use of standard and objective definitions and data collection methodologies. • Clarify when data are “reported” (by the vessel) as opposed to “measured independently” (by the observer). • Strive to meet data collection needs while keeping observer health and safety a priority. • Keep informed regarding current bycatch reduction research and emerging data needs to support research.

Workshop conveners and participants believe that the workshop was a success, but was only a first step toward implementing best practices in observer programs globally. Workshop participants recommended that next steps should include: • Dissemination of the results of this workshop to all observer programs and data users, and to Regional Fisheries Management Organizations (RFMOs). • A follow-up assessment of how well recommended variables are being incorporated into observer program data collections, including those programs that may not have been represented in the initial survey or at the workshop, as well as programs that are involved in bycatch reduction research. • The establishment of a longline working group, or use of new or existing listservs, as a vehicle for sharing information and further developing best practices in sampling design, data collection methodologies, and observer training. • Development of best practices for observer data collection to facilitate research and analysis to reduce bycatch of protected species for other gear types (such as purse seine, trawl, and gillnet). In conclusion, workshop participants recognized that decisions regarding the incorporation of these best practices would necessarily be made at the program level, but that these decisions should be informed by consideration of data needs to facilitate bycatch assessments and research on protected species bycatch on a global scale.