Non‑entangling biodegradable fish aggregating devices
Fish aggregating devices that, in addition to having no risk of entanglement, are constructed using only natural and/or biodegradable materials (e.g., bamboo, sisal, jute, palm leaves, coconut fiber, cotton) to further reduce the environmental impact of FADs on the oceans.
Fish aggregating devices that are constructed with no netting material, to minimize ghost fishing (entanglement of fauna, primarily sharks and turtles). For a FAD to be completely non‑entangling, it must use no netting materials either in the surface structure (raft) or the submerged structure. NEFADs using netting but built to minimize entanglement, such as using netting tied in bundles or using small size netting (< 7 cm stretched mesh), are called “lower entanglement risk FADs” (LERFADs).
Man‑made floating objects specifically designed to encourage fish aggregation at the device. They can be anchored to the ocean floor (anchored FADs) or set to drift in the open ocean (drifting FADs).
FADs are widely used as a fishing method due to its high efficiency, although they have been associated with several negative ecosystem impacts, such as bycatch and overfishing. Today, they support a large number of fishing vessels, especially purse seine fleets targeting tropical tunas in open oceans, but also artisanal pole‑and‑line vessels in shallow nearshore waters.
The deployment and use of FADs allows skippers to fish in remote areas where tuna schools were not very abundant or easily accessible before, to plan trips with greater certainty and efficiency, to make fewer “skunk sets” (sets where the school of tuna escapes) and to catch more skipjack tuna (a very productive and abundant tuna). FADs are equipped with some type of location device, ranging from simple radio beacons to sophisticated GPS, enabling the skipper or fleet manager to locate them remotely. The number of FADs deployed by a vessel or company increases their capacity because of increased options for “cherry picking” the FADs with more biomass underneath. But, there may come a point where high FAD density in an area is counter‑productive because of a saturation effect that reduces aggregation size.
See also HERFADs, LERFADs, NEFADs, BFADs, Bio-FADs, Jelly-FADs.
Fish aggregating devices constructed with natural or biodegradable materials that reduce the impact of beaching and debris. The term biodegradable is applied to a material or substance that is subject to a chemical process during which microorganisms that are available in the environment convert materials into natural substances such as water, carbon dioxide, and decompose organic matter and that are non-toxic for the marine environment. The time required for biodegradation of different materials varies. Some fishers believe that a FAD should last up to one year before degrading.
