In the open ocean, tuna purse-seine operators profit from large pelagic fishes' propensity to aggregate around drifting objects. They do so by fishing around FADs that have been deliberately set adrift for fishing purposes, and which are monitored by electronic tracking beacons. These drifting FADs (dFADs) are tools that have greatly increased catches of tuna around the globe. In fact, global catch of tuna from around dFADs accounts for about 43% of the 4.2 million tonnes of skipjack, bigeye, and yellowfin caught annually. However, the uncontrolled proliferation of dFADs deployed throughout the world's oceans is a major concern of fisheries managers, environmentalists, and fishermen alike due to the impacts of dFAD fisheries on juvenile bigeye and yellowfin tuna, vulnerable sharks and sea turtle species, and the broader marine environment.
DFADs are often constructed of purse seine netting and usually have a panel of net suspended below the raft or float to a depth of 15 meters (50 feet) or more. This webbing can entangle associated animals, including marine turtles, cetaceans and oceanic sharks. Lost or abandoned dFADs become marine debris and can impact coral reefs or other coastal areas
The global purse seine fleet deploys tens of thousands of dFADs every year. Most of these have satellite tracking devices attached. The data on their whereabouts already exist, but scientists do not have access to those data.
In November 2011, over 150 industry, science, and fisheries policy experts from 40 countries attended the International Symposium, “Tuna Fisheries and FADs,”* to discuss the challenges with FAD fisheries, and recommend best practices for responsible management of the world's most prominent tuna fishing gear.
1. Data Gaps and Need for Additional Information
Significant data gaps and information needs were noted, which must be addressed to allow for the effective management of global purse seine fisheries. More and higher quality data on dFADs and the fishing operations that use them are necessary for management purposes. Basic data gaps could be addressed by requiring FAD logbook submission to RFMOs.
Basic technical data are needed on:
2. Collaborative Research Needs
Scientists and managers need more understanding and better data on the way dFADs are constructed, deployed and fished by fleets in different oceans. These parameters are highly technical, requiring close collaboration and understanding of the fisheries and should, at minimum, include:
Significant data gaps were also recognized on the ecological impacts of dFAD use, including the need to understand the life span and movement of dFADs in relation to tuna and bycatch species.
More and higher quality data on bycatch entanglement, species specific bycatch levels, discard levels, fate of discards and the broader ecological significance of bycatch/discard removals from the pelagic ecosystem need to be collected and processed.
3. FAD Management Plans
The development and adoption of standardized dFAD Management Plans was considered a key element towards effective regional management of dFADs. Currently, efforts are in place to adopt dFAD management plans and some regional fishery management organizations (RFMOs) require this of each member. It was recognized that these should be adopted by all fishing entities and should include:
Management options to maintain or reduce fishing effort by controlling some aspect of the fishery that contributes to total fishing effort, include: