Mouillot David, de Juan Silvia, Trégarot Ewan, Villéger Sébastien, Casal Gema, Cornet Cindy C, Maréchal Jean-Philippe, Maynou Francesc, Meesters Erik, Simide Rémy, van der Geest Matthijs, Juhel Jean-Baptiste
UMR 9190 MARBEC, Univ Montpellier, CNRS, Ifremer, IRD, Montpellier Cedex 5, France.
Mediterranean Institute for Advanced Studies IMEDEA (UIB-CSIC), C/ Miquel Marques 21, Esporles, Balearic Islands CP, 07190, Spain.
Mar Environ Res. 2025 Sep;210:107351. doi: 10.1016/j.marenvres.2025.107351. Epub 2025 Jul 7.
Coastal and marine ecosystems are increasingly impacted by anthropogenic activities that act cumulatively with environmental changes, eroding biodiversity and its essential role in many ecosystem functions, including biomass production, which is vital for livelihood and food security. Understanding the links between socio-environmental factors, biodiversity, and fish biomass is essential for sustainable development. In this study, we use Structural Equation Models (SEM) to test, estimate, and explore complex relationships between these co-variates, distinguishing direct and indirect responses on five key coastal ecosystems across three ecoregions. In the Northwestern Mediterranean, fish biomass is positively linked to rocky habitats and taxonomic diversity but negatively influenced by sandy habitats. In the deeper rhodolith bed communities, taxonomic and functional richness, depth, and habitat coverage are the main correlates of fish biomass. In Northern Europe, sea surface temperature is a crucial factor directly influencing fish biomass, along with taxonomic richness, with depth and euphotic zone productivity playing significant roles. In the Lesser Antilles, taxonomic richness, depth, and live coral cover positively impact biomass, whereas terrace width has a negative effect, while no-take marine reserves boost taxonomic diversity. Across all ecosystems, taxonomic richness consistently enhances fish biomass, while entropy indices have negative impacts. Our results suggest that higher species diversity correlates with greater biomass, but that total biomass is dominated by a few species. Environmental factors, particularly habitat characteristics, outweigh direct anthropogenic influences like marine reserves. SEM reveal that, while pathways vary across ecosystems, taxonomic richness is a universal driver of fish biomass. Effective conservation and management strategies must consider these dynamics to mitigate human impacts and enhance the resilience of coastal ecosystems but also people livelihoods.
沿海和海洋生态系统正日益受到人为活动的影响，这些活动与环境变化累积作用，侵蚀生物多样性及其在许多生态系统功能中的重要作用，包括生物量生产，而生物量生产对生计和粮食安全至关重要。了解社会环境因素、生物多样性和鱼类生物量之间的联系对于可持续发展至关重要。在本研究中，我们使用结构方程模型（SEM）来测试、估计和探索这些协变量之间的复杂关系，区分对三个生态区域内五个关键沿海生态系统的直接和间接响应。在西北地中海，鱼类生物量与岩石栖息地和分类多样性呈正相关，但受到沙质栖息地的负面影响。在更深的红藻床群落中，分类和功能丰富度、深度和栖息地覆盖是鱼类生物量的主要相关因素。在北欧，海面温度是直接影响鱼类生物量的关键因素，与分类丰富度一起，深度和透光层生产力也发挥着重要作用。在小安的列斯群岛，分类丰富度、深度和活珊瑚覆盖率对生物量有积极影响，而阶地宽度有负面影响，而禁捕海洋保护区则提高了分类多样性。在所有生态系统中，分类丰富度始终会增加鱼类生物量，而熵指数则有负面影响。我们的结果表明，更高的物种多样性与更大的生物量相关，但总生物量由少数物种主导。环境因素，特别是栖息地特征，比海洋保护区等直接人为影响更为重要。结构方程模型表明，虽然不同生态系统的路径不同，但分类丰富度是鱼类生物量的普遍驱动因素。有效的保护和管理策略必须考虑这些动态，以减轻人类影响并增强沿海生态系统以及人们生计的恢复力。
