ABSTRACT

Kemp’s ridley turtles (Lepidochelys kempii) are critically endangered sea turtles that forage seasonally in Chesapeake Bay, a large estuary on the east coast of the United States. Most of the Kemp’s ridley turtles foraging in the bay are immature. When tracking these animals, satellite transmitter retention times have been low compared with adult marine turtles of other species. The immature Kemp’s ridleys’ small size and rapid growth leads to shorter, more variable deployments, limiting the use of data. These limited data leave critical questions remaining about the animals’ habitat usage that are difficult to answer without substantially more deployments. A novel sensitivity analysis using simulated deployments indicated that too few animals were tagged with satellite transmitters to identify all possible home-range areas in the Bay. We used simulation to create animal deployments of equal duration to address biases (differing lengths of deployments and time between locations) in home-range analyses and boost the information available from relatively short deployments. Combined home ranges from simulated deployments identified important areas for these animals in the south-western portions of the Chesapeake Bay and in the nearshore areas of the Bay north to the middle of the Bay. These areas represent opportunities for managers to mitigate impacts from boating, dredging, military activities and fishing, and could inform critical habitat designations under the United States Endangered Species Act. Habitat modelling may be needed to identify additional important areas in the Bay where animals were not observed via satellite tracking.

摘要

肯普的里德利龟（Lepidochelys kempii）是极度濒危的海龟，它们在美国东海岸的一个大型河口切萨皮克湾季节性捕食。坎普在海湾觅食的大多数里德利龟都不成熟。追踪这些动物时，与其他物种的成年海龟相比，卫星发射器的保留时间很短。不成熟的肯普（Kemp）的ridleys体积小且增长迅速，导致部署时间更短，变化更多，从而限制了数据的使用。这些有限的数据留下了有关动物栖息地使用情况的关键问题，如果不进行大量部署，这些问题很难回答。使用模拟部署进行的新颖敏感性分析表明，用卫星发射器标记的动物太少，无法识别海湾中所有可能的家庭范围区域。我们使用模拟来创建等长的动物展开，以解决家庭范围分析中的偏差（展开长度和位置之间的时间不同），并从相对短的展开中获取可用信息。从模拟部署中得出的综合范围，确定了切萨皮克湾西南部分以及该湾以北至该湾中部的近岸区域中这些动物的重要区域。这些领域为管理人员提供了减轻划船，疏,、军事活动和捕鱼的影响的机会，并且可以为根据《美国濒危物种法》指定的关键栖息地提供信息。可能需要进行生境建模，以识别在海湾中通过卫星跟踪未观察到动物的其他重要区域。