Cod bycatch in otter trawls and in longlines with different bait types in the Georges Bank haddock fishery

  • Published source details Ford J.S., Rudolph T. & Fuller S.D. (2008) Cod bycatch in otter trawls and in longlines with different bait types in the Georges Bank haddock fishery. Fisheries Research, 94, 184-189.


This study is summarised as evidence for the following.

Action Category

Use a different bait type

Action Link
Marine Fish Conservation

Use an alternative commercial fishing method

Action Link
Marine Fish Conservation
  1. Use a different bait type

    A replicated, controlled study in 2003–2005 in an area of seabed on the Georges Bank in the North Atlantic Ocean, USA (Ford et al. 2008) found that using a fabricated bait instead of a natural bait reduced the amount of unwanted cod Gadus morhua in a bottom longline fishery for haddock Melanogrammus aeglefinus. Overall, the average weight of cod/haddock caught was lowest with the fabricated bait (<0.01 kg cod/kg haddock); and herring bait caught less cod (0.01–0.03 kg cod/kg haddock) than squid bait (0.02–0.07 kg cod/kg haddock). Data were obtained from records of 147 longline trips (621 deployments, 78 or 92 m depth) conducted by commercial fishers from October 2003–June 2005, under special permits to fish in an area closed to groundfish fishing since 1994. Three bait types were tested: three fabricated baits combined for analysis (‘Norbait’ based on herring, mackerel or both), squid and herring (species not reported).

    (Summarised by: Chris Barrett/Natasha Taylor)

  2. Use an alternative commercial fishing method

    A replicated study in 2005–2006 of four seabed areas in the Gulf of Maine, USA (Ford et al. 2008) found that fishing using longlines reduced the capture of unwanted cod Gadus morhua compared to otter trawls in a haddock Melanogrammus aeglefinus fishery. In all four areas fished, the ratio of cod weight to haddock weight was smallest with a longline compared to an otter trawl (longline: 0.01–0.07 otter trawl: 0.2–0.83 cod/haddock caught). In addition, the ratio of cod weight to all target species (including winter flounder Pseudopleuronectes americanus and yellowtail flounder Limanda ferruginea) was smallest when using a longline (longline: 0.01–0.05, otter trawl: 0.2–0.46). In June 2005 - January 2006 a total of 146 longline hauls and 159 otter trawl hauls were sampled on the Georges Bank. All longliners fished with 12/0 circle hooks. Longliners fished mainly in depths shallower than 50 m whereas otter trawlers fished in deeper waters also. Data were obtained from fishers and fisheries observers. Specifications of the otter trawl gears were not described.

    (Summarised by: Chris Barrett)

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