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

    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), or requiring that particular mitigation techniques be adopted in an area. They are predominantly mandatory (i.e., fisheries regulations) but can be voluntary and the areas that they apply to may be dynamic, e.g., around an ocean front, or static, e.g., around a seamount or below a specified latitude.

    Species Groups
    Seabirds, Marine Mammals, Sharks and Rays, Sea Turtles
    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. In recent years, tuna RFMOs, to varying degrees, have adopted binding measures and data collection protocols to address the issue.

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

    Night / day setting

    Night or day setting refers to the times of day when longliners set, soak and haul their lines. These variables are inherently linked to the duration of the soak (the period that the longline is in the water). Timing depends principally on the target species, but also varies among fleets and regions.

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

    Light Cues - attractors & deterrents

    Light attractors, including chemical lightsticks and battery-powered light-emitting diodes (LEDs), are attached near baited hooks on branchlines to attract fish. They also appear to attract sea turtles; strategies are needed to make them less attractive or invisible to turtles. Gillnet illumination has been shown to reduce both seabird and sea turtle bycatch.

    Species Groups
    Seabirds, Sharks and Rays, Sea Turtles
    Fishing Gear
    Longline, 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, except in limited circumstances, in reducing bycatch of seabirds, turtles and sharks. In the main, this is because the feasibility and long-term effectiveness of an acoustic deterrent is affected by habituation. Acoustic deterrents are used with some success for marine mammals.

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