Commercial coastal seabed trawling

  • Image, Commercial caostal seabed trawling.

    Archived 27 October 2016

    Seabed trawling, when fishing nets are towed near and along the ocean floor, can physically damage seabed (benthic) habitats and species. It can also stir up sediment from the seabed, shading or smothering marine species. For this measure, coastal areas are waters shallower than 250m.

    We classified Commercial coastal seabed trawling as supporting information.

    Key findings

    Seabed trawling and dredging are widespread in New Zealand coastal waters.

    From 2008 to 2012:

    • 64 percent of our inshore and shelf seabed environments identified in the Benthic-Optimised Marine Environment Classification (BOMEC) had at least 50 percent of their area trawled
    • seabed bottom trawling covered 48 percent (112,423 km2) of the BOMEC coastal environments (shallower than 250m).
    Note: BOMEC = Benthic-Optimised Marine Environment Classification. Data are from trawls by coastal vessels fishing at depths shallower than 250m. A–E = inshore and shelf, F–H = upper-slope, I–J = northern mid-depth, K = lower-depth steep slopes, L = southern mid-slopes. The trawl areas for classes F, I, J, and L are too small to display.

    Definition and methodology

    This supporting information reports on the area and proportion of seabed environments identified in the Benthic-Optimised Marine Environment Classification (BOMEC) (Leathwick et al, 2005) as less than 250m deep and trawled by commercial fishing vessels. BOMEC classes are broad surrogates for the different habitats that are affected.

    The BOMEC includes five inshore and shelf classes (A, B, C, D, and E), three upper-slope classes (F, G, and H), two northern mid-depth classes (I and J), and one southern mid-slopes class class (L).

    The commercial fishing year goes from 1 October to 30 September.

    Data quality

    We classified Commercial coastal seabed trawling as supporting information.

    Relevance

    relevance-partial This supporting information is a partial measure of the ‘Marine habitat modification by human activity’ topic.

    Accuracy

    accuracy-medium The accuracy of the data source is of medium quality.

    See Data quality information for more detail.

    References

    Leathwick, JR, Rowden, A, Nodder, S, Gorman, R, Bardsley, S, Pinkerton, M, …  Goh, A (2012). A Benthic-Optimised Marine Environment Classification (BOMEC) for New Zealand waters. New Zealand Aquatic Environment and Biodiversity Report No. 88. Available from http://fs.fish.govt.nz.

     

    Published 21 October 2015

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