Traditional isotope sclerochronology employing isotope ratio mass spectrometry has been used for decades to determine the periodicity of growth increment formation in marine organisms with accretionary growth. Despite its well-demonstrated capabilities, it is not without limitation. The most significant of these being the volume of carbonate powder required for analysis with conventional drill-sampling techniques, which limit sampling to early in ontogeny when growth is fast or to species that reach relatively large sizes. In species like Astarte borealis (Schumacher, 1817), a common component of Arctic boreal seas, traditional methods of increment analysis are difficult, because the species is typically long-lived, slow growing, and forms extremely narrowly spaced growth increments. Here, we use Secondary Ion Mass Spectrometry (SIMS) to analyze δ¹⁸O in 10-μm-diameter spots and resolve the seasonal timing of growth increment formation in Astarte borealis in the southeastern Baltic Sea. In the individaul sampled here, dark growth increments can form in either the fall, winter, or spring. Furthermore, growth increment data from two populations (RFP3S = 54.7967° N, 12.38787° E; WA = 54.86775° N, 14.09832° E) indicate that in the Baltic Sea, A. borealis is moderately long-lived (at least 43 years) and slow growing (von Bertalanffy k values 0.08 and 0.06). Our results demonstrate the potential of A. borealis to be a recorder of Baltic Sea seasonality over the past century using both live- and dead-collected shells, and also the ability of SIMS analysis to broaden the spectrum of bivalves used in sclerocrhonological work.

几十年来，采用同位素比质谱法的传统同位素硬化年代学已被用于确定具有增生性生长的海洋生物中生长增量形成的周期性。尽管其功能已得到充分展示，但它并非没有限制。其中最重要的是使用传统钻取采样技术进行分析所需的碳酸盐粉末体积，这将采样限制在生长快速时的个体发育早期或达到相对较大尺寸的物种。在像Astarte borealis这样的物种中(Schumacher, 1817) 是北极北海的常见组成部分，传统的增量分析方法很困难，因为该物种通常寿命长、生长缓慢，并且形成间隔极窄的生长增量。在这里，我们使用二次离子质谱法 (SIMS) 分析了 10 微米直径点中的δ ¹⁸ O，并解析了波罗的海东南部Astarte borealis生长增量形成的季节性时间。在这里采样的个体中，暗生长增量可以在秋季、冬季或春季形成。此外，从两个群体生长量数据（RFP3S = 54.7967°N，12.38787°E; WA = 54.86775°N，14.09832°E）表明，在波罗的海，A.北欧化工中等寿命（至少 43 年）且生长缓慢（von Bertalanffy k值 0.08 和 0.06）。我们的研究结果表明，A.borealis有潜力成为过去一个世纪波罗的海季节性的记录器，使用活体和死体收集的贝壳，以及 SIMS 分析拓宽硬化时间学工作中使用的双壳类动物谱的能力。