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

opp -0096422; opp -0095904；1987年，人们在圣卡塔利娜盆地首次发现了生活在海底鲸鱼尸体上的化学自养群落。随后在太平洋的发现和化石记录证实了这样的群落在现代海洋中广泛存在，并且在进化的时间跨度中出现过。鲸落环境支持的群落在分类上与其他深海还原性环境（如热液喷口）具有相似性，并且可能比喷口场的平均间隔小一个数量级。鲸瀑具有以下生物地理意义：1)增强了深海的生物多样性；2)可深入了解人为影响，例如污水污泥淤积和持久性有机污染物对海洋环境的影响；3)它们作为深海中嗜硫生物的跳板的潜在作用。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）来估计海底鲸鱼群落的年龄。使用放射化学方法对已知年龄的骨样本进行初步测量，得出的同位素年龄与已知年龄非常吻合。拟议的工作将包括以下内容：1)为以前开发的测年技术制定最终协议，并使科学界能够获得该产品；2)开展年代骨材料的脂质含量和脂质表征研究，以评估脂质在鲸鱼骨架中的停留时间；3)尝试评估污染记录，特别是在年代确定的鲸骨遗骸中持久性有机污染物（多氯联苯、滴滴涕）；4)确定鲸落化自养群落的发育速率、演替模式和持续时间。

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.