Novoa Anai, Talley Theresa S, Talley Drew M, Crooks Jeffrey A, Reyns Nathalie B
Department of Environmental and Ocean Sciences, University of San Diego, San Diego, California, United States of America.
Department of California Sea Grant Extension Program, Scripps Institution of Oceanography, University of California San Diego, La Jolla, California, United States of America.
PLoS One. 2016 Feb 3;11(2):e0148220. doi: 10.1371/journal.pone.0148220. eCollection 2016.
A combination of historical bivalve surveys spanning 30-50 years and contemporary sampling were used to document the changes in bivalve community structure over time at four southern California and one northern Baja California estuaries. While there are limitations to the interpretation of historic data, we observed generally similar trends of reduced total bivalve species richness, losses of relatively large and/or deeper-dwelling natives, and gains of relatively small, surface dwelling introduced species across the southern California estuaries, despite fairly distinct bivalve communities. A nearly 50-year absence of bivalves from two wetlands surveyed in a Baja California estuary continued. A combination of site history and current characteristics (e.g., location, depth) likely contributes to maintenance of distinct communities, and both episodic and gradual environmental changes likely contribute to within-estuary temporal shifts (or absences). We highlight future research needed to determine mechanisms underlying patterns so that we can better predict responses of bivalve communities to future scenarios, including climate change and restoration.
结合跨越30至50年的历史双壳贝类调查和当代采样，记录了南加州四个河口和北下加利福尼亚州一个河口双壳贝类群落结构随时间的变化。虽然历史数据的解读存在局限性，但我们观察到，尽管各河口双壳贝类群落差异明显，但南加州各河口普遍呈现出相似的趋势：双壳贝类物种总数减少，体型较大和/或栖息于较深处的本地物种数量减少，体型较小、栖息于表层的外来物种数量增加。下加利福尼亚州一个河口调查的两个湿地已近50年没有双壳贝类。地点历史和当前特征（如位置、深度）的综合作用可能有助于维持不同的群落，而偶发和渐进的环境变化可能导致河口内部的时间变化（或消失）。我们强调，未来需要开展研究以确定这些模式背后的机制，以便我们能够更好地预测双壳贝类群落对未来情景（包括气候变化和恢复）的反应。
