Do you know what a fish aggregating device, or FAD, is? While over half of the world’s canned tuna is caught using FADs, many people are unfamiliar with them, including some fisheries experts and conservationists.
What is a FAD?
A fish aggregating device is an artificial object anchored or drifting in the open ocean to attract fish. Anchored FADs are stationary, providing fishermen a consistent, known location to collect fish, while drifting FADs float with the current, collecting fish as they move across the ocean. The devices are constructed out of a variety of materials, but they have several identifiable parts. A common style is composed of a surface float, often constructed of bamboo poles wrapped in synthetic netting or of large aluminum buoys; a satellite tracking buoy; and subsurface netting, which can stretch from 10 meters to 300 meters below the surface, to attract fish.
Tuna and other open-water species of fish naturally gather under flotsam. Tuna fishing vessels that use large nets to encircle entire schools of fish, known as purse seiners, capitalize on this behavior to increase catches of skipjack tuna. In fact, the major purse seine fishing fleets of the world set out tens of thousands of these FADs each year. They are put out for months or years at a time, often equipped with satellite tracking devices and echo sounders to detect their location as well as the amount of fish underneath them. These technologically advanced devices allow fishing vessels to determine where and when to return to set their nets so that they can catch the most fish.
While this gear increases the efficiency of fishing vessels—meaning less time is spent searching for schools of tuna—there are serious environmental consequences of unregulated FAD use. Given the growing use of anchored and drifting FADs by the tuna fishing industry, it’s important to understand the impacts of this fishing gear.
What's the problem with FADs?
The management of FADs is largely unregulated, and bycatch of vulnerable species is on the rise through their use. Thousands of these devices are abandoned at sea, contributing to marine debris, which become unmarked hazards to navigation and wash up on coastlines around the world. In addition to these problems, scientists don’t understand the overall impact that the widespread use of these devices is having on the marine ecosystem:
Bycatch—Skipjack tuna aren’t the only animals that are attracted to fish aggregating devices. High numbers of vulnerable marine species are caught when purse seine vessels set their nets around FADs, including severely depleted shark species, endangered sea turtles, and juvenile bigeye tuna, which are already overfished in the Pacific Ocean. The use of FADs has been steadily increasing for almost 30 years, and so have catches of these nontarget species, many of which are discarded dead.
Marine Debris—Since there are no regulations on how many FADs can be put in the water or on the collection of these devices, many of them are abandoned at sea. Drifting FADs are made of synthetic materials, contributing to growing oceanic garbage patches, and unmarked, anchored FADs pose a serious threat to navigation, especially for smaller vessels.
Lack of Management—The organizations responsible for management of these devices—the regional fisheries management organizations— have done little to rein in the use of this fishing gear. Major fishing countries are reluctant to accept restrictions. Given the lack of oversight and limited data, it is hard to determine the impact of the widespread use of these devices on the marine environment.
What can be done?
Governments must manage this fishing gear by calling for limits on how many FADs can be released each year as well as requiring companies to track and recover their devices. Because the tracking technology is already in place, an effective management system is not outside the realm of possibility.
The responsible use of FADs requires:
- Limiting the number deployed in the ocean.
- Reducing the overfishing of bigeye tuna and other vulnerable species by limiting the use of FADs.
- Monitoring and retrieving these devices to avoid marine debris.
- Requiring that FADs be made out of biodegradable material.
- Sharing data on FADs with scientific and fisheries management organizations to better understand the consequences of their use.
What can you do?