Evaluation of turtle exclusion and escapement devices for hoop-nets

Published source details Fratto Z.W., Barko V.A., Pitts P.R., Sheriff S.L., Briggler J.T., Sullivan K.P., McKeage B.L. & Johnson T.R. (2008) Evaluation of turtle exclusion and escapement devices for hoop-nets. Journal of Wildlife Management, 72, 1628-1633.
Share Tweet Email

Actions

This study is summarised as evidence for the following.

	Action	Category
	Install escape 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 escape devices on fishing gear: Tortoises, terrapins, side-necked & softshell turtles

A replicated, randomized, paired, controlled study in 2006 along a river in Missouri, USA (Fratto et al. 2008) found that hoop nets modified with either a chimney or loose-weave mesh escape device caught fewer turtles than unmodified hoop nets in a catfish fishery. Modified hoop nets caught fewer turtles (chimney: 27 turtles caught in 13 of 49 nets, loose-weave mesh: 27 in 17 of 50 nets) than unmodified nets (166 in 33 of 50 nets). Thirteen of 27 turtles (48%) died in chimney-modified nets and 11 of 26 turtles (42%) died in loose-weave mesh modified nets compared to 101 of 166 turtles (61%) in unmodified nets (results were not statistically tested). Fewer target channel catfish Ictalurus punctatus were caught in modified nets (chimney: 8 individuals, loose-weave: 4) compared to unmodified nets (44 individuals). Numbers of flathead catfish Pylodictis olivaris caught in chimney-modified nets were similar (11 individuals) but numbers caught in loose-weave mesh modified nets were lower (1) than numbers caught in unmodified nets (26). Unmodified hoop nets (six hoops, 90 cm maximum hoop with 38 mm mesh, 3.7 m long) and hoop nets modified to allow turtles to escape with the addition of a section of larger loose-weave mesh or an escape chimney were deployed in pairs along four river stretches in May–July 2006 (50 unmodified nets, 49 chimney nets, 50 loose-weave nets) using a randomized block design. Nets were set for 48 hours at a time over nine weeks. The catch of turtle and commercially targeted catfish species was recorded.

(Summarised by: Maggie Watson, Katie Sainsbury)
Install exclusion devices on fishing gear: Tortoises, terrapins, side-necked & softshell turtles

A replicated, randomized, controlled, paired study in 2006 along a river in Missouri, USA (Fratto et al. 2008) found that hoop nets modified with an excluder device caught fewer turtles and fewer target fish than unmodified hoop nets in a catfish fishery. Modified hoop nets caught fewer turtles (18 turtles caught in 11 of 50 nets) than unmodified nets (166 turtles caught in 33 of 50 nets). Ten of 18 turtles (56%) died in modified nets compared to 101 of 166 turtles (61%) in unmodified nets (results were not statistically tested). Fewer target catfish species were caught in modified nets (15 individuals) compared to unmodified nets (70 individuals). Unmodified hoop nets (six hoops, 90 cm maximum hoop with 38 mm mesh, 3.7 m long) and modified hoop nets (addition of a tight mesh covering the net entrance to reduce the entrance to 30 cm diameter) were deployed in pairs along four river stretches in May–July 2006 (50 nets/type) using a randomized block design. Nets were set for 48 hours at a time over nine weeks. The catch of turtle and commercially targeted catfish species was recorded.

(Summarised by: Maggie Watson, Katie Sainsbury)