Department of Anthropology, Trent University, 1600 West Bank Drive, Peterborough, ON, K9L 0G2, Canada; School of Archaeology and Ancient History, University of Leicester, University Road, Leicester, LE17RH, UK; Department of Anthropology, University of British Columbia, 6306 NW Marine Drive, Vancouver, BC, V6T 1Z1, Canada.
Institute for the Oceans and Fisheries, University of British Columbia, Aquatic Ecosystems Research Laboratory, 2202 Main Mall, Vancouver, BC, V6T 1Z4, Canada; Department of Earth, Ocean and Atmospheric Sciences, University of British Columbia, 2020 - 2207 Main Mall, Vancouver, BC, V6T 1Z4, Canada; Hakai Institute, PO Box 309, Heriot Bay, BC, V0P 1H0, Canada.
Mar Environ Res. 2020 Sep;160:104982. doi: 10.1016/j.marenvres.2020.104982. Epub 2020 Apr 8.
Isotopic studies of archived fish scales have tremendous potential to develop long-term retrospectives that provide important insights into how humans have altered aquatic ecosystems. However, fish specimens in museum archives and other repositories typically date to time periods when the impacts of industrial societies may have already caused profound environmental changes. Archaeological fish bones offer an opportunity to bridge this key temporal gap by providing samples spanning from the recent past to as far back as the Pleistocene. Collagen is the primary protein component of both fish scale and bone, but the comparability of isotopic compositions from these tissues has not been established experimentally. To lay the framework for integrating isotopic datasets from these tissues, we compare δC and δN of bone and scale collagen, as well as other tissues, from fish with life-time controlled diets. Results show that while there is no difference in δC between scale and bone collagen, there may be a very slight but meaningful inter-tissue offset in δN (<0.3‰). We discuss potential sources of δN variation in scale and bone collagen measurements. Because there is no difference in scale and bone δC, and the observed offset in δN is very small (less than analytical uncertainty in many studies), our findings demonstrate that collagen isotopic compositions from these tissues should be directly comparable when integrating datasets from modern and ancient samples to build more powerful, millennium-scale isotopic times series. In linking isotopic compositions of collagen from modern, historical (scales), and archaeological (bones) fish, our findings open the way for more nuanced contextualization of how ecosystems functioned prior to large-scale exploitation and how they have responded to mounting anthropogenic pressures in the intervening centuries.
鱼类鳞片的同位素研究具有巨大的潜力，可以建立长期的回溯分析，为了解人类如何改变水生生态系统提供重要的见解。然而，博物馆档案和其他存储库中的鱼类标本通常可以追溯到工业社会可能已经造成深刻环境变化的时期。考古学鱼类骨骼提供了一个机会，可以通过提供从最近到更新世的样本来弥合这一关键的时间差距。胶原蛋白是鱼类鳞片和骨骼的主要蛋白质成分，但这些组织的同位素组成的可比性尚未通过实验来确定。为了为整合这些组织的同位素数据集奠定框架，我们比较了来自具有控制饮食的鱼类的骨骼和鳞片胶原蛋白以及其他组织的 δC 和 δN。结果表明，虽然鳞片和骨骼胶原蛋白的 δC 没有差异，但 δN 可能存在非常微小但有意义的组织间偏移（<0.3‰）。我们讨论了鳞片和骨骼胶原蛋白测量中 δN 变化的潜在来源。由于鳞片和骨骼的 δC 没有差异，并且观察到的 δN 偏移非常小（在许多研究中小于分析不确定性），因此我们的发现表明，当整合现代和古代样本的数据集以建立更强大的、千年尺度的同位素时间序列时，这些组织的胶原蛋白同位素组成应该是可以直接比较的。通过将现代、历史（鳞片）和考古（骨骼）鱼类的胶原蛋白同位素组成联系起来，我们的发现为更细致地了解生态系统在大规模开发之前的运作方式以及它们在 intervening 几个世纪中如何应对不断增加的人为压力提供了途径。
