Fish aggregating devices (FADs) are artificial floating objects, specifically constructed to attract pelagic fish. Typically, they consist of a floating raft, submerged synthetic netting. Many this days have a “marker” of a satellite buoy that allows a fishing vessel to return to a specific location. They can be anchored or drifting ones, and they are as many design types as people deploying them!
Many fish species naturally congregate near objects floating in the ocean, a fact that is the basis of FADs existence. How they work still debated, but here is a good talk about then.
FADs have become widely adopted as a means of improving fisheries production. In most cases, the effects of FADs—both positive and negative—are not monitored, and there is no real information on the true impacts of sometimes very costly FADs on local fisheries.
A good manual on their design use and cost efectivines has been produced by SPC here
The Pew Environment Group evaluated that FAD deployments have more than doubled since 2006 in the eastern Pacific Ocean alone. Without being as scientific my personal evaluation trouhj my wrk documents, will say the same about the western pacific.
Still, there are few regulations for fishermen or vessel owners to follow, and no penalties for deliberately abandoning FADs at sea when they are no longer deemed useful or productive.
Some RFMOs have measures intended to improve the monitoring of drifting FADs, but the overall lack of standarised regulation makes counting these objects difficult.
Information on FAD deployments remains hard to find. Much of the data that would be needed to develop a precise estimate of their numbers exist but are confidential as industry invest heavily on the construction and electronics of it (just think how much 3 km of Polyethylene line will cost!) and they don't want other companies to use their FADS, so this information proprietary
In 2012 Pew took on the task of developing a ‘back of the envelope’ estimate of how many drifting FADs are currently in use, while acknowledging that it would be a challenging exercise and the results both imperfect and preliminary. Collating data gathered using three separate methodologies, they estimated that in 2011 the number of drifting FADs put into the oceans each year ranges from 47,000–105,000.
Using data on fishing obtained since then, along with new scientific research and an examination of recent trends in FAD use and technology, Pew has produced updated estimates indicating that the total number of drifting FADs deployed in 2013 ranged from 81,000 to 121,000. The upper estimate has increased by 14 percent since the calculations for 2011.
Other analyses have come to similar conclusions. For instance, the European Commission released a report in 2014 estimating that 91,000 drifting FADs are deployed annually. Meanwhile, new initiatives are underway to better track and understand FAD use. For example, three French purse seine companies, operating in the Atlantic and Indian oceans, provided researchers with detailed tracking data of FAD movements to create the most extensive analysis yet of how FADs move in those ocean areas.
Parties to the Nauru Agreement, a group of eight Pacific island states that have the world’s largest skipjack fishery within their waters, plans to implement an electronic tracking system that will allow monitoring of FAD numbers and locations in near real time to better understand the impact on the tropical tuna fishery. This will provide useful data to fisheries scientists and managers on the use of tens of thousands of drifting FADs in the western and central Pacific Ocean.
Starting in 2017, the Inter-American Tropical Tuna Commission (IATTC) will require vessels to provide additional FAD data and physically mark their FADs with unique identification codes.
Given the practical and feasible steps available to improve FAD management, they have been calls on RFMOs and fishing entities to:
- Harness the data collected by drifting FADs to develop science-based regulatory measures for use of the devices to minimize bycatch and catches of vulnerable species,
- Establish comprehensive monitoring and tracking systems to accurately quantify and monitor FAD use, improve tuna stock assessments, and ascertain the contribution of FADs to marine debris.
- Set up licensing and registration systems to hold vessels accountable for the FADs they deploy.
Recently I quoted Dr. Shelton Harley presentation at the TunaForum in Fiji, where he reckon (and I totally agree) that sun powered/satellite data transmission capable Sonar devices attached to FADs are a massive game changer and complex development.
In the past the vessel had to go to their FADs and then see if there was fish around it; with this technology fleet managers from the desk somewhere in the world can direct the vessels to the FADs that are showing signal. Here is an example of what you can buy this days.
As anything in fisheries, there are no easy answers… in these aspects i always refer to something I learned many years ago: “the risk is never in the substance, is always in the dose”