Study

Bycatch reduction device conserves diamondback terrapin without affecting catch of blue crab

  • Published source details Rook M.A., Lipcius R.N., Bronner B.M. & Chambers R.M. (2010) Bycatch reduction device conserves diamondback terrapin without affecting catch of blue crab. Marine Ecology Progress Series, 409, 171-179.

Actions

This study is summarised as evidence for the following.

Action Category

Install exclusion devices on fishing gear: Tortoises, terrapins, side-necked & softshell turtles

Action Link
Reptile Conservation
  1. Install exclusion devices on fishing gear: Tortoises, terrapins, side-necked & softshell turtles

    A replicated, paired, controlled study in 2008 in tidal creeks in Virginia, USA (Rook et al. 2010) found that using a plastic rectangular device (a ‘bycatch reduction device’) to reduce the size of entry holes to crab pots reduced the unwanted catch of diamondback terrapins Malaclemys terrapin in a blue crab Callinectes sapidus fishery. Crab pots with devices caught fewer terrapins (0.01 terrapins/pot/day, 2 individuals) compared to pots without devices (0.20 terrapins/pot/day, 46 individuals). Terrapins caught in traps with devices were smaller on average (5.1 cm shell depth) than terrapins caught in traps without devices (4.3 cm shell depth). Commercially-targeted blue crabs caught in pots with devices had 1.5–2.0 mm wider shells than crabs caught in pots without devices. Catch rates and weight of commercially-targeted crabs were similar between pots with and without devices (see original paper for details). Devices were 4.5 x 12 cm plastic rectangles that were fitted on each of the four entrances of a recreational-style crab pot with chimney (see original paper for details). Crab pots were deployed in shallow-water in 10 pairs in two creeks in summer 2008 (one with and one without devices fitted). Traps were baited once a week for four weeks and checked after 48 h. Terrapin catch was only monitored on one creek.

    (Summarised by: Katie Sainsbury)

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