1. Tracking habitat use and dietary shifts in migratory species is vital to conservation and management. Yet, conventional animal tracking often precludes tracking small juveniles at critical life stages where recruitment bottlenecks often manifest.
2. Stable isotope analysis (SIA) in consecutive laminae in eye lenses, a protein‐rich depositional tissue, has emerged as a promising tool in fishes to develop long‐term interpretive records of dietary histories using a single archival tissue. Currently, studies using fish eye lenses to study SIA in diets have primarily been conducted in marine environments using δ¹³C and δ¹⁵N to identify resource partitioning, ontogenetic shifts and lifelong trophic histories. To date, no studies have examined freshwater taxa nor used δ³⁴S isotopes.
3. We placed juvenile (Chinook Salmon) Oncorhynchus tshawytscha in experimental enclosures in three different freshwater habitats (hatchery, river and seasonal floodplain), each with isotopically distinct and well‐characterized food webs. This experimental approach allowed us to directly measure diets and quantify tissue turnover rates in eye lenses as well as the isotopic fractionation among fish tissues (fin and muscle tissue) in distinct habitat types using stable isotopes δ¹³C, δ¹⁵N and δ³⁴S.
4. Bulk eye‐lens stable isotope measurements were analysed for juvenile salmon lenses and were found to be consistent with the isotopic values of rearing habitats. Slight additional isotopic fractionation was only found in δ¹³C. We then successfully applied the method to a larger, reproductively mature adult salmon captured in freshwater and inferred juvenile habitat use.
5. SIA in eye lenses using three dietary isotopes (δ¹³C, δ¹⁵N and δ³⁴S) has significant potential for answering critical questions about migration, diet, foraging ecology and life history of migratory aquatic animals on Earth. Such information would have immediate application towards conservation management of diverse species and habitats at multiple scales.

中文翻译：

---

推进鱼眼镜头的饮食重建

1. 追踪栖息地的使用和迁徙物种的饮食变化对于保护和管理至关重要。但是，常规的动物追踪通常无法在关键的生命阶段（其中经常会出现招募瓶颈）追踪小型幼体。
2. 连续晶状体中晶状体中的稳定同位素分析（SIA）是一种富含蛋白质的沉积组织，已成为鱼类中使用单个档案组织发展饮食历史的长期解释记录的有前途的工具。目前，采用鱼眼镜头的研究，研究SIA在饮食已经主要在海洋环境中使用δ进行¹³ C和δ ¹⁵ N到确定资源分配，个体发育的变化和终身营养历史。迄今为止，还没有研究探讨了淡水类群也没用过δ ³⁴小号同位素。
3. 我们在三个不同的淡水生境（孵化场，河流和季节性洪泛区）的实验性围栏中放置了少年（奇努克鲑鱼）Oncorhynchus tshawytscha，每个围场都有同位素不同且特征明确的食物网。该实验方法使我们直接测量的饮食和量化组织周转率在眼透镜，以及在使用稳定同位素δ不同的生境类型鱼组织（鳍和肌肉组织）中的同位素分馏¹³ C，δ ¹⁵ N和δ ³⁴小号。
4. 分析了鲑鲑鱼晶状体的大块目镜稳定同位素测量值，发现与饲养生境的同位素值一致。轻微额外同位素分馏仅在δ发现¹³ C.然后，我们成功地应用该方法在淡水和推断少年栖息地利用所捕获的大，生殖成熟的成年鲑鱼。
5. SIA在使用三个饮食同位素眼透镜（δ ¹³ C，δ ¹⁵ N和δ ³⁴ S）有回答的关键问题有关迁移，饮食，觅食生态和地球上的洄游性水生动物的生活史显著的潜力。这些信息将立即应用于多种规模的不同物种和生境的保护管理。