Mutshinda Crispin M, Finkel Zoe V, Irwin Andrew J
Department of Mathematics and Statistics, Dalhousie University, Halifax, Nova Scotia, Canada.
Department of Oceanography, Dalhousie University, Halifax, Nova Scotia, Canada.
PLoS One. 2025 Jun 4;20(6):e0323675. doi: 10.1371/journal.pone.0323675. eCollection 2025.
The North Atlantic Ocean has large seasonal blooms rich in diatoms and dinoflagellates which can contribute disproportionately relative to other primary producers to export production and transfer of resources up the food web. Here we analyze data from the Continuous Plankton Recorder to reconstruct variation in the surface ocean diatom and dinoflagellate community biomass over 6 decades across the North Atlantic. We find: 1) diatom and dinoflagellate biomass has decreased up to 2% per year throughout the North Atlantic except in the eastern and western shelf regions, and 2) there has been a 1-2% per year increase in diatom biomass relative to total diatom and dinoflagellate biomass throughout the North Atlantic, except the Arctic province, from 1960-2017. Our results confirm the widely reported relationship where diatoms are displaced by dinoflagellates as waters warm on monthly to annual time scales. The common assumption that gradual ocean warming will result in a decadal-scale shift from diatoms to dinoflagellates was not supported by our analysis. Predicting the effects of climate change likely requires consideration of the consequences for the whole community, the simultaneous change of multiple environmental variables, and the evolutionary potential of plankton populations.
北大西洋有大量季节性水华，富含硅藻和甲藻，相对于其他初级生产者而言，它们对食物网中资源的输出生产和转移贡献不成比例。在此，我们分析了连续浮游生物记录器的数据，以重建北大西洋60年间表层海洋硅藻和甲藻群落生物量的变化。我们发现：1）除了东部和西部陆架区域外，北大西洋各地的硅藻和甲藻生物量每年下降高达2%；2）从1960年至2017年，除了北极地区外，北大西洋各地相对于总硅藻和甲藻生物量而言，硅藻生物量每年增加1% - 2%。我们的结果证实了广泛报道的关系，即在月至年时间尺度上，随着水温升高，硅藻被甲藻取代。我们的分析不支持海洋逐渐变暖将导致从硅藻到甲藻的十年尺度转变这一普遍假设。预测气候变化的影响可能需要考虑对整个群落的后果、多个环境变量的同时变化以及浮游生物种群的进化潜力。
