Collaborative Proposal: Radiometric Dating of Whale Bones-a Tool for Study of Succession and Persistence of Whale Fall Chemoautotrohic Assemblages

大卫卡德科克雷格史密斯1987年在圣卡塔利纳盆地首次发现了生活在海底鲸鱼尸体上的化能自养群落。 随后在太平洋的发现和化石记录证实，这种群落在现代海洋中广泛存在，并在进化的时间跨度内发生。 鲸鱼坠落环境所支持的生物群落在分类学上与其他深海还原环境，如热液喷口相似，其平均间距可能比喷口区小一个数量级。 鲸鱼的坠落具有重要的地理学意义，原因如下：1）它们增强了深海的生物多样性; 2）它们可以提供对人类影响的深入了解，例如下水道污泥的安置和持久性有机污染物（POP）对海洋环境的影响; 3）它们作为深海嗜硫物种的垫脚石的潜在作用。拟议的工作将继续发展放射化学方法（使用钍、氡和铅同位素），以估计海底鲸须群落的年龄。使用放射化学方法对已知年龄的骨骼样本进行初步测量，得到的同位素年龄与已知年龄非常一致。 拟议的工作将进行下列工作：1）为以前开发的测年技术制定最后议定书，并向科学界提供这一产品; 2）开始研究测年骨材料的脂质含量和脂质特性，以评估脂质在倒下的鲸鱼骨骼中的停留时间; 3）试图评估污染记录，特别是持久性有机污染物（多氯联苯、滴滴涕）在年代久远的鲸鱼骨骼遗骸中;和4）确定的发展速度，演替模式，和持续时间的鲸鱼秋季化能自养社区。

AbstractOPP-0096422 & OPP-0095904P.I.s David Kadko & Craig SmithThe first discovery of chemoautotrophic community living on a seafloor whale-fall carcass was made in the Santa Catalina Basin in 1987. Subsequent discoveries in the Pacific and the fossil record confirm that such communities are widespread in the modern ocean and have occurred over evolutionary timespans. The communities supported by the whale-fall environment bear taxonomic similarities to other deep-sea reducing environments, such as hydrothermal vents, and may occur with an average spacing of an order of magnitude smaller than that for vent fields. Whale-falls are of biogeographical significance for the following reasons: 1) they enhance the biodiversity of the deep-sea; 2) they can provide insights into the effect of anthropogenic influences, such as sewage sludge emplacement and persistent organic pollutants (POPs) on the marine environment; and 3) their potential roles as stepping stones for sulfophilic species in the deep-sea. The proposed work will continue to develop radiochemical methods (using thorium, radon and lead isotopes) for estimating the ages of seafloor whalebone communities. Preliminary measurements, using radiochemical methods, performed on known age bone samples yield isotopic ages that are in good agreement with known ages. The proposed work will undertake the following: 1) establishment of a final protocol for the dating techniques previously developed and make this product available to the scientific community; 2) initiate the study of lipid content and lipid characterization on dated bone material to assess the residence time of lipids within fallen whale skeletons; 3) attempt to assess a record of pollution, particularly persistent organic pollutants (PCB, DDT) within well-dated skeletal remains of whales; and 4) determine rates of development, patterns of succession, and persistence times of whale-fall chemoautotrophic communities.