Keller Martha, Mustin Walter
J Zoo Wildl Med. 2017 Mar;48(1):121-130. doi: 10.1638/2016-0072.1.
The Cayman Turtle Farm raises thousands of green sea turtles ( Chelonia mydas ) annually under aquaculture conditions. Historically, the turtles have been raised in tanks without routine access to a shade structure. The purpose of this study was to determine the effects of adding a shade structure on curved carapace length (CCL) and weight gain of green sea turtles. In addition, water and cloacal temperatures were compared across treatment groups and shade cover preferences observed. Ninety turtles were split equally into three treatment groups for this 8-wk study. In the first group turtles were kept in tanks in full sun, the second group in half-shaded tanks, and the third group in tanks completely covered with shade cloth. Time-lapse cameras mounted above half-shaded tanks were used to determine turtle shade structure preferences throughout the day. There were no differences in CCL among treatment groups. Significant increases in weights were noted in turtles kept in full sun and half-shaded tanks versus the fully shaded tanks. Significantly higher water and cloacal turtle temperatures were noted in the full-sun tank compared with the half-shaded or completely shaded tanks. A significantly lower number of turtles was observed in the sun in the half-shaded tanks, indicating a possible preference by turtles for a shade structure. Results suggest that providing shade structures for sea turtles results in a significant decrease in both overall water temperature as well as a reduction in maximum high daily temperatures. Results also suggest that turtles exhibit a preference for shade structures when it is provided as an option. From these results, we recommend that a shade structure be provided when housing green sea turtles in outdoor enclosures.
开曼海龟养殖场每年在水产养殖条件下饲养数千只绿海龟（蠵龟）。从历史上看，这些海龟一直饲养在没有常规遮阳结构的水箱中。本研究的目的是确定添加遮阳结构对绿海龟的曲背甲长度（CCL）和体重增加的影响。此外，还比较了各处理组的水温与泄殖腔温度，并观察了对遮阳覆盖的偏好。在这项为期8周的研究中，90只海龟被平均分为三个处理组。第一组海龟饲养在全日照的水箱中，第二组饲养在半遮阳的水箱中，第三组饲养在完全覆盖遮阳布的水箱中。安装在半遮阳水箱上方的定时摄像机用于确定海龟一整天对遮阳结构的偏好。各处理组的CCL没有差异。与完全遮阳的水箱相比，全日照和半遮阳水箱中的海龟体重显著增加。与半遮阳或完全遮阳的水箱相比，全日照水箱中的海龟水温与泄殖腔温度显著更高。在半遮阳水箱中，在阳光下观察到的海龟数量显著减少，这表明海龟可能更喜欢遮阳结构。结果表明，为海龟提供遮阳结构会使总体水温显著降低，同时也会降低每日最高温度。结果还表明，当有遮阳结构可供选择时，海龟会表现出对它的偏好。基于这些结果，我们建议在室外围栏中饲养绿海龟时提供遮阳结构。
