Mitigation Techniques

    Safe handling & release

    Safe handling and release refers to using best practice methods for dealing with bycatch species, to maximise their chances of survival after interacting with fishing gear. It can also include vessel manoeuvring to avoid taking bycatch species, for example, avoiding setting purse seines on whale sharks. Illustrated Guides and more general literature have been collected in the BMIS.

    Species Groups
    Marine Mammals , Sea Turtles , Seabirds , Sharks and Rays
    Fishing Gear
    Longline, Purse Seine, Gillnet

    FAD design & management

    Fish aggregating devices, or ‘FADs’, are floating objects, either natural or artificial, that attract and aggregate fish, including tuna schools. Silky and oceanic whitetip sharks are the main bycatch species in purse seine fisheries, incidentally caught when vessels fish on drifting FADs or entangled in the netting beneath FADs. Sea turtles are occasionally caught in seines and may be snared in the netting on, or under, FADs. Bycatch can be significantly reduced through effective FAD design (non-entangling, biodegradable) and management (e.g., limit FAD numbers & fishing seasons, shift a percentage of fishing effort to free schools, fish sharks from the net with handlines and release, target tuna schools greater than 10 tonnes, release sharks from deck using safe handling and release techniques).

    Species Groups
    Sea Turtles , Sharks and Rays
    Fishing Gear
    Purse Seine

    Spatial & temporal measures

    Spatial and temporal measures aim to avoid or minimise bycatch by either temporarily or permanently moving fishing out of an area (e.g., time and area closures, marine protected areas, 'move-on' guidelines), or requiring that particular mitigation techniques be adopted in an area. They include fleet or vessel communication schemes, such as the Hawaii-based 'Turtlewatch', a dynamic means of avoiding bycatch 'hotspots'.

    Species Groups
    Marine Mammals , Sea Turtles , Seabirds , Sharks and Rays
    Fishing Gear
    Longline, Purse Seine, Gillnet

    ALDFG - management of abandoned, lost, discarded fishing gear

    Management of abandoned, lost, discarded fishing gear (ALDFG) refers to the management of fishing gear (onboard and deployed, e.g., FADs) and retrieval of lost gear as a means of reducing fisheries bycatch and environmental damage. Tuna RFMOs have adopted binding measures and data collection protocols, as well as encouraging voluntary measures, to address the issue.

    Species Groups
    Marine Mammals, Sea Turtles, Seabirds, Sharks and Rays
    Fishing Gear
    Longline, Purse Seine, Gillnet

    Auditory deterrents and attractors

    Using sound to discourage or distract bycatch species from interacting with fishing gear. Auditory deterrents are not generally considered useful in reducing bycatch of seabirds, turtles and sharks, except in limited circumstances. In the main, this is because the feasibility and long-term effectiveness of an acoustic deterrent is affected by habituation. Acoustic deterrents (e.g., pingers) are used with some success for marine mammals, in particular, cetaceans.

    Species Groups
    Marine Mammals, Sea Turtles, Seabirds, Sharks and Rays
    Fishing Gear
    Longline, Purse Seine, Gillnet

    Seabird Saver

    The Seabird Saver is a recently developed technology combining a laser and an optional acoustic deterrent. It has been designed for longline, purse seine and trawl fisheries, among others, with the aim of scaring many different seabird species from interacting with bait, catch or discards. ACAP regards lasers as unproven & not recommended, with concerns about safety for both seabirds & humans.

    Species Groups
    Seabirds
    Fishing Gear
    Longline, Purse Seine