Behavior of Hatchling Sea Turtles During Their Off-Shore Migration

海龟是大型海洋爬行动物，是许多第三世界国家蛋白质的重要来源。所有种类的海龟都受到威胁或濒临灭绝。这种不幸的情况是由于过度捕捞成年种群、破坏鸟巢和偷猎鱼卵，以及被选为筑巢地点的原始海洋海滩现在是人类娱乐和土地开发的主要地区。一项主要的保护措施包括保护最脆弱的海龟--那些几乎没有防御能力的小海龟--在将它们放入海中之前，在大水箱里饲养它们大约一年。在自然条件下，孵化出来的幼崽会在夜间从巢中出来，沿着海滩爬行，然后迁徙到海里。在海上放生的幼崽被剥夺了这种经历。在许多迁徙动物中，如鸟类和鲑鱼，幼崽在迁徙时感受到的线索，在成年后被个体用来寻找合适的繁殖地。如果海龟的行为类似，被剥夺了海滩外迁徙的孵化后的海龟可能会存活下来，但成年后，无法找到合适的海滩筑巢。目前的研究项目的长期目标也是为了促进幼崽的存活，但Salmon和Wyneken博士认为，健全的保护措施必须建立在对幼崽如何迁徙以及在旅途中何时最容易受到捕食者攻击的彻底了解的基础上。因此，Salmon和Wyneken博士将试图确定黑头海龟如何完成它们在佛罗里达州东海岸和它们的目标--墨西哥湾流的马尾藻--之间30公里的迁徙。萨蒙和威尼肯博士将跟踪携带无线电发射器的幼崽，以确定旅程需要多长时间，将进行实验，以确定什么线索指导他们，并将确定哪些捕食者在旅程的不同部分带走幼崽。有了这种理解，萨蒙和威尼肯博士应该能够具体说明在什么条件下，孵化出来的幼崽可以在捕食者最不可能捕获它们的地方被放入海中，并在适合它们完成迁徙的条件下被释放。潜在的好处有几个：重新建立足够的种群进行智能收获；洞察一种迷人而壮观的海洋动物的迁徙行为和生态；基于对动物生物学的透彻了解，实施合理的保护做法。

Sea turtles are large marine reptiles, which are an important source of protein in many third-world countries. All species of sea turtles are either threatened or endangered. This unfortunate situation comes about because of overfishing of adult stocks, nest destruction and poaching of eggs, and because the pristine oceanic beaches chosen as nest sites are now prime areas for human recreation and land development. A major conservation thrust involves the protection of the most vulnerable sea turtles--the small and virtually defenseless hatchlings--by rearing them for about a year in large tanks before releasing them into the sea. Under natural conditions, hatchlings emerge from nests at night, crawl down-beach, and migrate out to sea. Hatchlings released at sea are deprived of this experience. In many migratory animals, such as birds and salmonid fishes, cues perceived by young as they migrate are used later by individuals as adults to find suitable breeding sites. If sea turtles behave similarly, hatchlings deprived of their off-beach migration may survive but, as adults, be unable to locate appropriate beaches in which to nest. The long-term goal of the present research project is also to promote hatchling survival, but Drs. Salmon and Wyneken believe that sound conservation practices must be based upon a thorough understanding of how hatchlings migrate and when, during their journey, they are most vulnerable to predators. Thus, Drs. Salmon and Wyneken will attempt to determine how loggerhead sea turtles complete their 30-km migration between the East coast of Florida and their goal, the Sargassum matts of the Gulf Stream. Drs. Salmon and Wyneken will follow hatchlings bearing radio transmitters to determine how long the trip takes, will do experiments to determine what cues guide them, and will determine what predators take hatchlings at various portions of their journey. Armed with this understanding, Drs. Salmon and Wyneken should be able to specify under what conditions hatchlings might be released into the sea at locations where predators are least likely to capture them, and under conditions that are ideal for the completion of their migration. The potential benefits are several: reestablishment of sufficient stocks for intelligent harvesting; insights into the migratory behavior and ecology of a fascinating and magnificent marine animal; and the implementation of sound conservation practices based upon a thorough knowledge of the animal's biology.