Leibniz Centre for Tropical Marine Research (ZMT), Fahrenheitstraße 6, 28359, Bremen, Germany.
Department of Marine Ecology, Faculty of Biology and Chemistry, University of Bremen, Leobener Straße UFT, 28359, Bremen, Germany.
Nat Commun. 2023 Feb 22;14(1):985. doi: 10.1038/s41467-023-36617-7.
Anthropogenic pressures are restructuring coral reefs globally. Sound predictions of the expected changes in key reef functions require adequate knowledge of their drivers. Here we investigate the determinants of a poorly-studied yet relevant biogeochemical function sustained by marine bony fishes: the excretion of intestinal carbonates. Compiling carbonate excretion rates and mineralogical composition from 382 individual coral reef fishes (85 species and 35 families), we identify the environmental factors and fish traits that predict them. We find that body mass and relative intestinal length (RIL) are the strongest predictors of carbonate excretion. Larger fishes and those with longer intestines excrete disproportionately less carbonate per unit mass than smaller fishes and those with shorter intestines. The mineralogical composition of excreted carbonates is highly conserved within families, but also controlled by RIL and temperature. These results fundamentally advance our understanding of the role of fishes in inorganic carbon cycling and how this contribution will change as community composition shifts under increasing anthropogenic pressures.
人为压力正在全球范围内重构珊瑚礁。要准确预测关键珊瑚礁功能的预期变化，就需要充分了解其驱动因素。在这里，我们研究了海洋硬骨鱼类维持的一种研究较少但很重要的生物地球化学功能的决定因素：肠道碳酸盐的排泄。我们从 382 条珊瑚礁鱼类（85 种和 35 科）中综合了碳酸盐排泄率和矿物组成，确定了预测这些因素的环境因素和鱼类特征。我们发现，体重和相对肠道长度（RIL）是预测碳酸盐排泄的最强因素。与体型较小、肠道较短的鱼类相比，体型较大和肠道较长的鱼类每单位质量的碳酸盐排泄量不成比例地减少。排泄出的碳酸盐的矿物组成在科内高度保守，但也受 RIL 和温度的控制。这些结果从根本上提高了我们对鱼类在无机碳循环中的作用的理解，以及随着人为压力下群落组成的变化，这种贡献将如何变化。
