Hypoxia as a novel method for preventing movement-induced mortality during translocation of turtle eggs

Published source details Williamson S.A., Evans R.G., Robinson N.J. & Reina R.D. (2017) Hypoxia as a novel method for preventing movement-induced mortality during translocation of turtle eggs. Biological Conservation, 216, 86-92.
Share Tweet Email

Actions

This study is summarised as evidence for the following.

	Action	Category
	Relocate nests/eggs for artificial incubation: Sea turtles Action Link

Relocate nests/eggs for artificial incubation: Sea turtles

A replicated, randomized, controlled study in 2015 in laboratory conditions in Costa Rica (Williamson et al. 2017) found that olive ridley turtle Lepidochelys olivacea eggs artificially incubated in normal oxygen conditions had better hatching success, but were more vulnerable to being inverted, than eggs initially artificially incubated in low oxygen (‘hypoxic’) conditions. Hatching success of olive ridley turtle eggs initially incubated in any one of three hypoxic conditions was lower (Perspex box with nitrogen: 23 of 75 eggs; zip lock bag with nitrogen: 14 of 71 eggs; vacuum-sealed plastic bag: 34 of 79 eggs) than eggs incubated in normal oxygen conditions (53 of 78 eggs). Hatching success in hypoxic-maintained eggs was similar whether or not eggs were inverted during the incubation process, whereas when eggs were incubated in normal oxygen conditions, inverting eggs lowered hatching success (see original paper for details). For three days after collection, olive ridley eggs collected from six nesting females in October–November 2015 were either kept in normal oxygen conditions in a sand-filled incubator (78 eggs), or in one of three ‘hypoxic’ containers: a Perspex box filled with nitrogen (75 eggs), a plastic bag filled with nitrogen (71 eggs), or a vacuum-sealed bag (79 eggs; 13–24 eggs/hypoxic container, four containers/type). A subset of eggs from each treatment (normal oxygen: 10 eggs; Perspex box: 10 eggs; zip lock bag: 7 eggs; vacuum-sealed bag: 10 eggs) were inverted 180° horizontally after three days and compared to equivalent numbers of eggs/treatment that were not inverted. After experimental treatments, eggs were either buried in a hatchery or maintained in incubators and hatchlings were counted on emergence.

(Summarised by: Katie Sainsbury)