Abstract Several scientific expeditions surveyed the ocean during the 19th century, gathering a wealth of interdisciplinary data as well as samples of different kinds. The latter are currently held by museums worldwide, and are the subject of study in different sciences, offering a unique opportunity to access information which is not readily available elsewhere. This is the case for re-search involving the offset in 14C (or radiocarbon) activity between the ocean and the atmosphere, termed the Marine Reservoir Effect (MRE), which is responsible for apparent 14C ages in marine material. The quantification of this discrepancy is crucial for the 14C dating tool since corrections must be applied for the accurate calibration of marine 14C ages. Nevertheless, the difficulty of finding suitable material for assessing the MRE contributes to the current scenario of scarce and patchy data. Here we propose the use of samples collected during well-documented 19th-century scientific expedi- tions in order to overcome the lack of information that prevents the use of many museum specimens in MRE studies. Approximately 60 mollusk shells and a sea urchin, collected from the coast of Brazil, were analyzed for their radiocarbon age, δ13C and δ18O. The MRE is variable, with considerably high values occurring at specific spots along the shoreline. The data indi- cate a rather large area of upwelling influence on the southeastern coast of Brazil and possible dissolution of 14C-free limestone in the northeast. The results shed light on processes affecting the 14C concentration of Brazilian coastal waters, bearing implications for palaeoenvironmental and archaeo- logical studies performed in the region. Moreover, the data generated in this study will be useful for the validation of 14C simulations in numerical models. Finally, this paper offers a discussion of the importance of natural history collections which looks beyond the preservation of our biodiversity.

中文翻译：

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19 世纪的探险和巴西海岸的放射性碳海洋水库效应

摘要 19 世纪，多次科学考察对海洋进行了调查，收集了大量跨学科数据以及不同种类的样本。后者目前由世界各地的博物馆收藏，是不同学科的研究主题，为获取其他地方不易获得的信息提供了独特的机会。涉及海洋和大气之间 14C（或放射性碳）活动抵消的研究就是这种情况，称为海洋水库效应 (MRE)，它是造成海洋物质 14C 年龄明显的原因。这种差异的量化对于 14C 年代测定工具至关重要，因为必须应用更正才能准确校准海洋 14C 年龄。尽管如此，很难找到合适的材料来评估 MRE，这导致了当前数据稀缺和零散的情况。在这里，我们建议使用在 19 世纪科学考察期间收集的样本，以克服信息缺乏的问题，这些信息阻碍了许多博物馆标本在 MRE 研究中的使用。对从巴西海岸收集的大约 60 个软体动物壳和一个海胆的放射性碳年龄、δ13C 和 δ18O 进行了分析。MRE 是可变的，在沿海岸线的特定地点出现相当高的值。数据表明巴西东南沿海有相当大的上升流影响区域，东北部可能有无 14C 的石灰岩溶解。结果揭示了影响巴西沿海水域 14C 浓度的过程，对在该地区进行的古环境和考古研究产生影响。此外，本研究中生成的数据将有助于验证数值模型中的 14C 模拟。最后，本文讨论了自然历史收藏的重要性，它超越了保护我们的生物多样性。