Data from: Stable isotope-based location in a shelf sea setting: accuracy and precision are comparable to light-based location methods

Retrospective determination of location for marine animals would facilitate investigations of migration, connectivity and food provenance. Predictable spatial variations in carbon and nitrogen isotopes in primary production across shelf seas provide a basis for stable isotope-based location.
Here, we assess the accuracy and precision that can be obtained through dietary-isotope-based location methods. We build isoscapes from jellyfish tissues and use these to assign scallops of fixed and known individual location, and herring with well-understood population-level distributions in the North Sea.
Accuracy and precision for retrospective isotope-based location in the North Sea were of a similar order to light-based location devices, with 75% of individual scallops assigned correctly to areas representing c. 30% of the North Sea, with a mean linear error on the order of 102 km. Applying assignment methods to an alternative migratory species (herring) resulted in ecologically realistic assignments consistent with fisheries survey data.
Location methods based on dietary isotopes such as carbon and nitrogen recover the spatial origin of nutrients assimilated into tissues, and this may not correspond directly to the physical location if either the test animal or its prey is highly migratory. Stable isotope-based location can be applied to any marine-feeding organism or derived food product, but the ecological meaning of any assigned area will be more difficult to interpret for large, high trophic level, migratory animals with relatively slow isotopic assimilation rates.

对海洋动物进行回溯性位置测定，将助力其迁徙、种群连通性与食物溯源相关研究。陆架海初级生产过程中，碳、氮同位素呈现出可预测的空间异质性，为基于稳定同位素的地理定位方法提供了理论依据。
本研究评估了基于膳食同位素的地理定位方法所能达到的准确度与精密度。我们以水母组织为样本构建了同位素等值线图（isoscape），并利用该图谱对个体位置固定且已知的扇贝，以及种群分布已被充分阐明的北海鲱鱼开展地理归属分配。
北海海域基于同位素的回溯地理定位，其准确度与精密度与基于光感的地理定位设备处于同一量级：75%的个体扇贝被正确归属至约占北海总面积30%的海域，平均线性误差约为102千米。将该归属方法应用于另一种洄游物种（鲱鱼）后，所得地理归属结果符合生态学逻辑，且与渔业调查数据高度一致。
基于碳、氮等膳食同位素的地理定位方法，可追溯被生物体组织同化的营养物质的空间来源；但若受试动物或其猎物具有高度洄游性，该方法所得结果可能与受试动物的实际物理位置并不完全匹配。基于稳定同位素的地理定位技术可应用于所有海洋摄食生物或衍生食品，但对于体型较大、处于高营养级且同位素同化速率相对较慢的洄游动物而言，其归属区域的生态学意义将更难阐释。