Seasonal and interannual variation in lower Columbia River phytoplankton (2005-2018): environmental variability and a decline in large bloom-forming diatoms
- 17 June 2021
- journal article
- research article
- Published by Inter-Research Science Center in Aquatic Microbial Ecology
- Vol. 87, 29-46
- https://doi.org/10.3354/ame01967
Abstract
Understanding the influence of biotic and abiotic factors on riverine phytoplankton dynamics is challenging, particularly as anthropogenic stressors such as eutrophication, invasive species, and climate change alter these relationships. We examined a 14 yr (January 2005 to December 2018) dataset of phytoplankton and water quality variables, along with zooplankton and nutrient concentrations, from the Columbia River (the largest river in the US Pacific Northwest) to identify seasonal and interannual patterns of phytoplankton assemblage structure and their environmental associations. Non-metric multidimensional scaling, cluster, and indicator species analyses revealed: (1) a diatom/flagellate cluster in spring/summer, associated with chlorophyll a, discharge, ciliates, and Sarcodina; (2) a cyanobacteria/chlorophyte cluster in late summer/early fall, associated with higher water temperatures, increased clarity, the invasive copepod Pseudodiaptomus forbesi, and veligers of the invasive Asian clam Corbicula fluminea; and (3) a mixed-taxa winter cluster of minimal abundance and biomass. Nutrients were not strongly associated with the observed structural patterns. Phytoplankton bloom duration varied interannually, between years with short springtime blooms vs. years when blooms extended across multiple months. Springtime blooms of the diatom Asterionella formosa decreased in recent years, giving way to blooms of a mixed diatom assemblage. Further, high temperature, low discharge, and more invasive zooplankton were associated with cyanobacterial blooms, suggesting that increased temperature and reduced river flows predicted due to climate change in the Pacific Northwest may lead to further impacts on the late summer/early fall Columbia River plankton community.Keywords
This publication has 93 references indexed in Scilit:
- Eco-physiological adaptations that favour freshwater cyanobacteria in a changing climateWater Research, 2012
- Distinguishing human and climate influences on the Columbia River: Changes in mean flow and sediment transportJournal of Hydrology, 2011
- Use of flow management to mitigate cyanobacterial blooms in the Lower Darling River, AustraliaJournal of Plankton Research, 2010
- Global warming benefits the small in aquatic ecosystemsProceedings of the National Academy of Sciences of the United States of America, 2009
- The influence of impoundments on riverine nutrient transport: An evaluation using the Soil and Water Assessment ToolJournal of Hydrology, 2008
- Effects of river regulation on water quality in the lower Mokelumne River, CaliforniaRiver Research and Applications, 2005
- Silicon Retention in River Basins: Far-reaching Effects on Biogeochemistry and Aquatic Food Webs in Coastal Marine EnvironmentsAMBIO, 2000
- SPECIES ASSEMBLAGES AND INDICATOR SPECIES:THE NEED FOR A FLEXIBLE ASYMMETRICAL APPROACHEcological Monographs, 1997
- Non‐parametric multivariate analyses of changes in community structureAustralian Journal of Ecology, 1993
- Nonmetric multidimensional scaling: A numerical methodPsychometrika, 1964