Department of Integrative Marine Ecology, Stazione Zoologica Anton Dohrn, Sicily Marine Centre, Lungomare Cristoforo Colombo, 90142, Palermo, Italy; National Research Council-Institute for Marine Biological Resources and Biotechnologies (CNR-IRBIM), Largo Fiera della Pesca 2, 60125, Ancona, Italy; Department of Life and Environmental Sciences, Polytechnic University of Marche, 60131, Ancona, Italy.
Department of Earth and Marine Sciences (DiSTeM), University of Palermo, Via Archirafi 20-22, 90123, Palermo, Italy; NBFC, National Biodiversity Future Center, Palermo, 90133, Italy.
Mar Environ Res. 2024 Oct;201:106701. doi: 10.1016/j.marenvres.2024.106701. Epub 2024 Aug 19.
Global marine biodiversity loss impairs entire ecosystems and their stability. Robust biodiversity estimates are key to inform policies and management strategies, and need to consider the contribution of diverse habitats, including those for which estimates of biodiversity are scattered or totally absent. This study assessed the fish diversity associated with three main coastal habitats (rocky bottoms, Posidonia oceanica meadows, sandy bottoms), and their role in shaping the overall coastal fish diversity, also in relation to potential environmental and anthropogenic drivers affecting patterns of fish diversity in coastal areas. Using underwater visual census, we sampled 62 sites distributed on the three habitats, for a total of 496 replicates. We assessed the contribution of each habitat to β-diversity, divided into Local Contribution to β-diversity (LCBD), a comparative indicator of the contributions to β-diversity of each habitat, and Species Contribution to β-diversity (SCBD), which measures the relative importance of each species in affecting β-diversity. Finally, we modelled species diversity in relation to potential environmental and anthropogenic drivers. Overall, 72 species were recorded, with the highest species richness observed on rocky bottoms (56 species, 16 unique to this habitat), followed by P. oceanica (38 species, 0 unique) and sandy bottoms (32 species, 14 unique). Sandy bottom assemblages had a significantly higher contribution to LCBD than P. oceanica meadows and rocky bottoms, and two of the five species with the highest contribution to SCBD are exclusively associated with sandy bottoms. Finally, sea surface temperature, sea surface salinity, and habitat were highlighted as significant predictors of species richness. Our findings, aside from highlighting the environmental drivers of coastal fish diversity in the Mediterranean Sea, unravel the potential key role of sandy bottoms in contributing to overall coastal fish diversity and can inform conservation planning.
全球海洋生物多样性的丧失损害了整个生态系统及其稳定性。稳健的生物多样性估计是为政策和管理策略提供信息的关键，需要考虑到各种生境的贡献，包括那些生物多样性估计分散或完全缺失的生境。本研究评估了与三种主要沿海生境（岩石底部、波西多尼亚海草甸、沙质底部）相关的鱼类多样性，以及它们在塑造沿海鱼类整体多样性方面的作用，同时还考虑了影响沿海地区鱼类多样性模式的潜在环境和人为驱动因素。我们使用水下视觉普查法，在这三种生境中采样了 62 个地点，共采集了 496 个样本。我们评估了每个生境对 β-多样性的贡献，分为局部对 β-多样性的贡献（LCBD），这是一个比较每个生境对 β-多样性的贡献的指标，以及物种对 β-多样性的贡献（SCBD），它衡量了每个物种在影响 β-多样性方面的相对重要性。最后，我们将物种多样性与潜在的环境和人为驱动因素相关联。总的来说，记录了 72 种物种，其中在岩石底部观察到的物种丰富度最高（56 种，16 种为该生境特有），其次是波西多尼亚海草甸（38 种，0 种特有）和沙质底部（32 种，14 种特有）。沙质底部的群落对 LCBD 的贡献明显高于波西多尼亚海草甸和岩石底部，对 SCBD 贡献最高的五个物种中有两个仅与沙质底部有关。最后，海面温度、海面盐度和生境被突出为物种丰富度的重要预测因子。我们的研究结果不仅突出了地中海沿海鱼类多样性的环境驱动因素，还揭示了沙质底部对整体沿海鱼类多样性的潜在关键作用，并为保护规划提供了信息。
