Martins Neto João, Bernardino Angelo F, Netto Sérgio A
Marine Science Laboratory, University of Southern Santa Catarina, Tubarão, Brazil.
Department of Oceanography, Universidade Federal do Espírito Santo, Vitória, Brazil.
Mar Environ Res. 2021 Oct;171:105470. doi: 10.1016/j.marenvres.2021.105470. Epub 2021 Sep 2.
Rhodolith beds increase the seabed complexity and are hotspots of biodiversity. Despite the crucial ecosystem services provided by rhodoliths, they are threatened by global change and local anthropogenic impacts. In this study, conducted on one of the largest beds of calcareous algae in the world located on the continental shelf of eastern Brazil, we tested whether the higher complexity of the seabed within rhodolith beds could explain the spatial biodiversity patterns of free-living nematodes. Our results show that beds with the highest densities of rhodoliths are associated with higher sedimentary organic matter (OM) contents and by a different biochemical composition. The higher OM nutritional quantity and nutritional quality, as shown by higher biopolymeric C contents and higher values of the protein to carbohydrate ratio, respectively, were associated with higher abundance, biomass, and diversity of nematode genera, thus supporting our hypothesis. Though based on a correlative approach, the results of this study suggest that a decrease in density of rhodoliths caused by human impacts may affect benthic biodiversity and, consequently, the range of ecosystem services they provide.
石枝藻床增加了海床的复杂性，是生物多样性的热点地区。尽管石枝藻提供了至关重要的生态系统服务，但它们受到全球变化和局部人为影响的威胁。在这项研究中，我们对位于巴西东部大陆架上世界最大的钙质藻床之一进行了研究，测试了石枝藻床内海床较高的复杂性是否能够解释自由生活线虫的空间生物多样性模式。我们的结果表明，石枝藻密度最高的藻床与更高的沉积有机质（OM）含量以及不同的生化组成相关。分别由较高的生物聚合碳含量和较高的蛋白质与碳水化合物比率所显示的更高的OM营养量和营养质量，与线虫属的更高丰度、生物量和多样性相关，从而支持了我们的假设。尽管本研究基于相关方法，但结果表明，人类影响导致的石枝藻密度下降可能会影响底栖生物多样性，并进而影响它们所提供的生态系统服务范围。
