Behavior of Hatchling Sea Turtles During Their Off-Shore Migration

海龟是一种大型海洋爬行动物，是许多第三世界国家重要的蛋白质来源。所有种类的海龟不是受到威胁就是濒临灭绝。造成这种不幸情况的原因是成年种群的过度捕捞、巢的破坏和蛋的偷猎，以及被选为巢址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——那些几乎毫无防御能力的小海龟——在大水箱里饲养大约一年，然后把它们放归大海。在自然条件下，雏鸟在夜间从巢中出来，沿着海滩爬行，然后迁徙到海里。在海上被放生的小海龟没有这种体验。在许多迁徙动物中，如鸟类和鲑科鱼类，幼崽在迁徙时感知到的线索后来被成年个体用来寻找合适的繁殖地点。如果海龟的行为类似，被剥夺了离岸迁徙能力的幼龟可能会存活下来，但成年后却无法找到合适的海滩筑巢。目前研究项目的长期目标也是提高幼龟的存活率。Salmon和Wyneken认为，合理的保护措施必须建立在对幼崽如何迁徙以及在迁徙过程中什么时候最容易受到捕食者攻击的透彻理解的基础上。因此,Drs。Salmon和Wyneken将尝试确定红海龟如何完成从佛罗里达东海岸到它们的目标——墨西哥湾流马尾藻垫之间30公里的迁徙。Drs。萨尔蒙和维内肯会跟踪携带无线电发射器的幼崽，以确定旅程需要多长时间，他们会做实验，以确定什么线索可以引导它们，并确定在不同的旅程中，哪些捕食者会带走幼崽。有了这样的认识，dr。Salmon和Wyneken应该能够明确规定，在什么条件下，幼仔可以在捕食者最不可能捕获它们的地方被放归大海，并在最理想的条件下完成它们的迁徙。潜在的好处有几个：重新建立足够的种群进行智能采收；深入了解一种迷人而宏伟的海洋动物的迁徙行为和生态；以及基于对动物生物学的全面了解而实施的合理保护措施。

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.