SGER: Radiometric Dating of Whalebones: A Method for Studying Succession and Persistence of Whalefall Chemoautotrophic Assemblages

Stephens OCE 9902095 1987年在圣卡塔利纳盆地以及后来在其他一些地点发现了生活在海底鲸鱼身体上的化学自养群落，这引发了关于它们对深海生物学的作用和重要性的问题，因为这些群落在分类学上与其他深海减少环境，如热液喷口相似。鲸鱼坠落具有生物学意义，原因如下：1)它们作为深海亲硫物种的垫脚石的潜在作用；2)它们增加深海的生物多样性；3)它们可以提供对人类影响的洞察，例如污水污泥的安置，对海洋环境的影响。需要了解群落演替和鲸骨化学自养组合的持续时间的知识，以可靠地估计鲸鱼坠落栖息地的丰度，并了解鲸鱼坠落群落的动态及其作为嗜硫物种的垫脚石的潜在作用。对几个生活在长达六年前被实验性放置在海底的身体上的群落的时间序列观察提供了关于早期演替的信息，但目前还没有方法可以准确地估计在海底发现的骨骼的年龄。这项研究将开发和应用放射化学方法来估计海底鲸骨群落的年龄。对已知年龄的样品进行的初步测量得出的计算年龄与已知的骨龄很好地吻合，从而证实了该方法的可行性。将使用其他已知年龄的鲸鱼骨骼，包括在海底种植了5年多的鲸鱼身体的样本，对这些方法和假设进行进一步的测试。一旦成功建立了这项技术，随后将对在海底发现的两具骨骼(年龄未知)的骨骼进行应用。测年技术将有助于确定鲸鱼秋季化学自养群落的演替和发育模式以及持续时间。

Stephens OCE 9902095The discovery of chemoautotrophic communities living on seafloor whale-fall carcass in the Santa Catalina Basin in 1987 and later at a number of other locations has raised the question about their role and importance for deep-sea biology because these communities bear taxonomic similarities to other deep-sea reducing environments, such as hydrothermal vents. Whale-falls are of biological significance for the following reasons: 1) their potential roles as stepping-stones for sulfophilic species in the deep-sea; 2) they enhance the biodiversity of the deep-sea; and 3) they can provide insights into anthropogenic influences, such as sewage sludge emplacement, on the marine environment.Knowledge of community succession and the persistence times of whale-skeleton chemoautotrophic assemblages is needed to reliably estimate the abundance of whale-fall habitats and to understand the dynamics of the whale-fall communities and their potential roles as stepping stones for sulfophilic species. Time series observations of several communities living on carcasses that were experimentally placed on the seafloor up to six years ago are providing information regarding early succession, but currently there is no method available to accurately estimate the ages of skeletons discovered on the seafloor.This study will develop and apply radiochemical methods for estimating the ages of seafloor whalebone communities. Preliminary measurements performed on samples of a known age yielded calculated ages that are in good agreement with the known bone ages, thus confirming the feasibility of the methods. Further testing of the methods and assumptions will be performed using additional whale bones of known age, including samples from a carcass that was planted for over 5 years on the seafloor. Upon successful establishment of the technique, application to bones from two skeletons discovered on the seafloor (of unknown age) will follow. The dating techniques will be useful for determining the patters of succession and development and the persistence times of whale-fall chemoautotrophic communities..