Analysis of stable isotope ratios to investigate stock structure of red emperor and rankin cod in northern Western Australia

The ratios of stable isotopes O-18/O-12 and C-13/C-12, in sagittal otolith carbonate from two tropical demersal teleosts, red emperor Lutjanus sebae and Rankin cod Epinephelis multinotatus, from several locations in northern Western Australia. differed between sites. On a broad scale, fish from the four locations, Shark Bay, Ningaloo, Pilbara, and Broome had stable isotope values that were sufficiently different to indicate separate stocks, and it is appropriate to manage these populations of the two species independently in these areas. On a smaller scale, there may be limited mixing of these species between the Pilbara trawl fishery and the trap and line fisheries operating out of Onslow and Broome. Values of stable oxygen isotopes were strongly related to sea surface temperature, although there were some sites in shallow water where low values of stable oxygen isotopes indicated that fish were living in warm water. The use of stable oxygen and carbon isotope values is a valuable, cost effective method of determining the degree of mixing of fish stocks. [References: 16]

本数据集收录了采自西澳大利亚北部多个海域的两种热带底栖硬骨鱼（tropical demersal teleosts）——红皇帝笛鲷（Lutjanus sebae）与兰金鳕（Epinephelis multinotatus）的矢耳石碳酸盐（sagittal otolith carbonate）样品的稳定同位素比值数据，具体为氧同位素O-18/O-12与碳同位素C-13/C-12，不同采样点间的同位素比值存在显著差异。宏观尺度上，来自鲨鱼湾（Shark Bay）、宁格鲁（Ningaloo）、皮尔巴拉（Pilbara）以及布鲁姆（Broome）四个海域的鱼类，其稳定同位素值差异显著，足以证明它们分属不同种群，因此在上述海域应对这两个物种的种群实施独立管理。微观尺度上，皮尔巴拉拖网渔业（trawl fishery）作业区与昂斯洛（Onslow）、布鲁姆运营的陷阱及延绳钓渔业作业区间，这两个物种的种群交流可能较为有限。稳定氧同位素值与海表温度（sea surface temperature）呈显著相关，但部分浅海采样点的低氧同位素值却表明栖息于此的鱼类生活于暖水环境中。稳定氧、碳同位素比值分析是一种兼具应用价值与成本效益的鱼类种群混合程度评估方法。引用文献：16篇。