Experiments with by-catch reduction devices to exclude diamondback terrapins and retain blue crabs
-
Published source details
Corso A.D., Huettenmoser J.C., Trani O.R., Angstadt K., Bilkovic D.M., Havens K.J., Russell T.M., Stanhope D. & Chambers R.M. (2017) Experiments with by-catch reduction devices to exclude diamondback terrapins and retain blue crabs. Estuaries and Coasts, 40, 1516-1522.
Published source details Corso A.D., Huettenmoser J.C., Trani O.R., Angstadt K., Bilkovic D.M., Havens K.J., Russell T.M., Stanhope D. & Chambers R.M. (2017) Experiments with by-catch reduction devices to exclude diamondback terrapins and retain blue crabs. Estuaries and Coasts, 40, 1516-1522.
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 |
 |
|
|
Install exclusion devices on fishing gear: Tortoises, terrapins, side-necked & softshell turtles Action Link |
|
|
|
Install exclusion devices on fishing gear: Tortoises, terrapins, side-necked & softshell turtles Action Link |
|
-
Install exclusion devices on fishing gear: Tortoises, terrapins, side-necked & softshell turtles
A replicated, randomized, controlled study in 2014–2015 in three brackish tidal creeks and a captive setting in Virginia, USA (Corso et al. 2017) found that modifying crab pots with red-painted rectangular funnels to reduce the size of entry holes (a ‘bycatch reduction device’) reduced the unwanted catch of diamondback terrapins Malaclemys terrapin compared to unmodified pots in a blue crab Callinectes sapidus fishery. Crab pots with red-painted funnels set in three tidal creeks caught fewer terrapins (10 individuals) than unmodified pots (58 individuals; no statistical tests were carried out). Trials in both a captive setting and in two tidal creeks found that red-painted funnels also reduced unwanted terrapin catch compared to unmodified pots and that orange, green and blue-painted funnels caught a similar number of terrapins to unmodified pots (see original paper for details). For crab pots set in three creeks, commercially-targeted legal-size blue crab catch was similar in pots with red-painted funnels (622 individuals) compared to unmodified pots (630 individuals). In a captive setting, crabs stayed in pots with funnels for longer (4 h, 45 individuals) compared to unmodified pots (1 h, 76 individuals). Red plastic rectangular funnels (5.1 x 15.2 cm) were fitted horizontally to each of the four entry points on 15 commercial-style crab pots with chimneys. The 15 modified pots were deployed paired with 15 unmodified pots in June–July 2015 in three creeks (587 trap nights, 3–6 pairs of pots/creek). All pots were baited. In separate trails in two creeks (June–July 2014) and in a captive setting (June 2015), orange, black, blue, green-painted and magnetized funnels were also tested (see original paper for details). The captive setting was a seawater tank and crabs and terrapins were monitored by video.
(Summarised by: Katie Sainsbury)
-
Install exclusion devices on fishing gear: Tortoises, terrapins, side-necked & softshell turtles
A replicated, controlled study in 2014 in two brackish tidal creeks in Virginia, USA (Corso et al. 2017) found that modified crab pots with wire rectangular funnels to reduce the size of entry holes (a ‘bycatch reduction device’) caught similar numbers of diamondback terrapins Malaclemys terrapin compared to unmodified pots and larger-sized terrapins compared to plastic rectangular funnels in a blue crab Callinectes sapidus fishery. Crab pots with wire funnels caught similar numbers of terrapins (22 individuals) compared to unmodified pots (20 individuals; no statistical tests were carried out). Terrapins caught in pots with wire funnels were larger (5.5 cm shell height) compared to terrapins caught in pots with plastic funnels (4.8 cm shell height). Commercially-targeted legal-size blue crab catch was similar in pots with wire funnels compared to unmodified pots (see original paper for details). Copper wire or plastic rectangular funnels (5.1 x 15.2 cm) were fitted horizontally to each of the four entry points on commercial-style crab pots with chimneys (five with copper wire funnels, 15 with plastic funnels, five with plastic magnetized funnels, and five unmodified pots). In total five groups of modified and unmodified pots were deployed in June–July 2014 at least 50 m apart in two locations (327 trap days). All pots were baited.
(Summarised by: Katie Sainsbury)
-
Install exclusion devices on fishing gear: Tortoises, terrapins, side-necked & softshell turtles
A replicated, randomized, controlled study in 2014–2015 in brackish tidal creeks and a captive setting in Virginia, USA (Corso et al. 2017) found that modified crab pots with magnetized rectangular funnels to reduce the size of entry holes (a ‘bycatch reduction device’) caught similar numbers of diamondback terrapins Malaclemys terrapin compared to unmodified pots in a blue crab Callinectes sapidus fishery. Crab pots set in two creeks with magnetized funnels caught similar numbers of terrapins (15 individuals) compared to unmodified pots (20 individuals; no statistical tests were carried out). Trials in a captive setting found similar results (see original paper for details). Commercially-targeted legal-size blue crab catch was similar in pots with magnetized funnels compared to unmodified pots (see original paper for details). Rectangular funnels (5.1 x 15.2 cm) were fitted horizontally to each of the four entry points on commercial-style crab pots with chimneys (four with magnetized funnels, 5 unmodified pots). Modified and unmodified pots were deployed in June–July 2014 at least 50 m apart in two creeks (327 trap days, 1–3 pots of each type/creek). All pots were baited. Separate trials in a captive setting were carried out in June 2015 and took place in a seawater tank and crabs and terrapins were monitored by video.
(Summarised by: Katie Sainsbury)
)_2023.JPG)
