The Paleoecology of Pinnipeds on the Pacific Rim

太平洋沿岸鳍足类的古生态--最近的研究表明，人类，包括史前人类，在塑造它们所居住的生态系统方面发挥了重要作用，而且我们今天熟悉的一些生态系统在最近的过去运行方式有所不同。历史和古生态数据为保护社区考虑未来的管理决策提供了重要的背景信息，特别是对于最近经历了种群数量下降的物种。我们的首要目标是探索环境和人为因素如何相互作用，在过去5000年里产生太平洋东北海岸的生态变化。对这些变化最完整的记录是在沿海考古遗址发现的，在那里可以研究过去陆地和海洋生态系统的动物群，以调查古生态变化。此外，认识到主要的生态变化对于考古学家试图破译人类人口和资源利用的变化将是重要的。在过去的研究中，人们利用同位素和考古数据对北方毛海豹进行了研究，以表明该物种在过去1000年里改变了它的繁殖和迁徙行为。毛海豹骨骼的年代测定也表明，当地繁殖群体的崩溃并不是整个太平洋边缘同步的。在这项研究中，我们将通过构建同位素组成、存在/缺失、相对丰度和年龄/性别分布的时间序列，研究自中全新世以来四个不同羽足物种的觅食、迁徙、断奶和迁出行为的变化。此外，我们还将开发两种新的方法来评估鳍足类的断奶年龄。第一个项目将使用鳍足牙齿的生长结构作为断奶年龄和母体投资的指标。另一种是生物地球化学方法，利用骨骼生长系列和牙齿牙本质中氮同位素比率的变化。我们将重点关注四个羽足动物多样性中心--阿留申群岛东部、美加边境、俄勒冈海岸和海峡群岛。该项目将包括广泛的文献搜索，并将现有的动物群信息汇编到一个关于东北太平洋边缘全新世羽足动物动态的数据库中。广泛的影响-这项研究将展示如何从考古数据中收集对受威胁物种生态的洞察。这对残存种群中的物种来说很重要，他们目前的生态可能会受到最近的开发或环境变化的影响。我们将研究的四个物种中，有三个目前正在经历种群数量的快速下降，但这些下降的原因还远不清楚。这项研究将提供这些物种在很长一段时间内的生态基线数据，并表明它们过去是否经历了与人为或环境扰动有关的类似下降。我们将与保护生物学家合作，将我们的数据提供给那些制定管理决策的人。为此，我们将在2004年冬天共同主办一次由加州大学环太平洋分校资助的会议，届时将有考古学家、历史学家、海洋哺乳动物生态学家、保护生物学家和社会科学家汇聚一堂。我们的目标是在今天这些物种的生态背景下评估这些物种的考古和历史记录，然后制定策略，将这些信息整合到保护政策制定者的决策过程中。这个项目的一个更直接的影响将是加州大学洛杉矶分校的研究生和本科生的教育。此外，我们对海洋哺乳动物生态的史前方法在2002年和2003年被开发成COSMOS(加州州立数学与科学暑期学校)的一个模块。一组不同的学生(8-12年级)参加了一个为期4周的课程，该课程整合了实地、实验室和课堂练习，旨在向有学术知识和积极性的年轻人介绍科学。

The Paleoecology of Pinnipeds on the Pacific RimIntellectual Merits - Recent studies have shown that humans, including prehistoric people, play a major role in shaping the ecosystems they inhabit, and that some of the ecosystems we are familiar with today operated differently in the recent past. Historical and paleoecological data provide crucial contextual information for the conservation communities considering future management decisions, especially for species that have witnessed relatively recent population declines. Our overarching goal is to explore how environmental and anthropogenic factors interacted to generate ecological shifts on the northeastern Pacific coast over the past 5000 years. The most complete record of these changes is found in coastal archaeological sites, where the faunas of past terrestrial and marine ecosystems can be studied to investigate paleoecologic shifts. Furthermore, the recognition of major ecological shifts will be important for archaeologists attempting to decipher changes in human demography and resource utilization. In past studies, northern fur seals were studied using isotopic and archaeological data to show that the species has changed its breeding and migratory behavior over the past 1000 years. Fur seal bones were also dated to show that the collapse of local breeding colonies was not synchronous across the Pacific margin. For this study, we will investigate changes in foraging, migratory, weaning, and haul-out behavior in four different pinniped species since the mid-Holocene through construction of time series on isotopic composition, presence/absence, relative abundance, and age/sex distribution. In addition, we will develop two new methods to assess weaning age in pinnipeds. The first will use growth structures in pinniped teeth as proxies for weaning age and maternal investment. The other is a biogeochemical approach that uses changes in the N isotope ratios in bone growth series and tooth dentin. We will focus on four centers of pinniped diversity - the eastern Aleutian Islands, the US-Canadian border, the Oregon coast, and the Channel Islands. This project will include an extensive literature search and compilation of existing faunal information into a database on Holocene pinniped dynamics along the NE Pacific margin.Broader Impacts - This study will show how insights into the ecology of threatened species may be gleaned from archaeological data. This is important for species in relict populations, whose current ecology may be shaped by recent exploitation or environmental change. Three of the four species we will study are presently undergoing rapid population declines, but the causes for these declines are far from clear. This study will provide baseline data on the ecology of these species over deep time, and indicate whether or not they experienced similar declines in the past in relation to anthropogenic or environmental perturbations. We will work with conservation biologists to make our data available to those making management decisions. To this end, in winter 2004 we will co-host a conference, funded by the UC-PACRIM, which will bring together archaeologists, historians, marine mammal ecologists, conservation biologists, and social scientists. Our goal is to evaluate the archaeological and historical record of NE Pacific pinnipeds in the context of the ecology of these species today, and then to develop strategies for integrating this information into decision-making processes of conservation policy makers. A more immediate impact of this project will be the education of graduate and undergraduate students at UCSC. In addition, our prehistoric approach to marine mammal ecology was developed into a module for COSMOS (California State Summer School for Mathematics and Science) in 2002 and 2003. A diverse group of students (grades 8-12) took part in a 4-week course that integrated field, laboratory, and classroom exercises designed to introduce scholarly and motivated young people to science.