Phytoplankton Regulation in a Eutrophic Tidal River (San Joaquin River, California)
<p>As in many U.S. estuaries, the tidal San Joaquin River exhibits elevated organic matter production that interferes with beneficial uses of the river, including fish spawning and migration. High phytoplankton biomass in the tidal river is consequently a focus of management strategies. An unu...
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| Format: | Article |
| Language: | English |
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eScholarship Publishing, University of California
2005-03-01
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| Series: | San Francisco Estuary and Watershed Science |
| Subjects: | |
| Online Access: | http://escholarship.org/uc/item/9jb2t96d |
| _version_ | 1811270157784317952 |
|---|---|
| author | Alan D. Jassby |
| author_facet | Alan D. Jassby |
| author_sort | Alan D. Jassby |
| collection | DOAJ |
| description | <p>As in many U.S. estuaries, the tidal San Joaquin River exhibits elevated organic matter production that interferes with beneficial uses of the river, including fish spawning and migration. High phytoplankton biomass in the tidal river is consequently a focus of management strategies. An unusually long and comprehensive monitoring dataset enabled identification of the determinants of phytoplankton biomass. Phytoplankton carrying capacity may be set by nitrogen or phosphorus during extreme drought years but, in most years, growth rate is light-limited. The size of the annual phytoplankton bloom depends primarily on river discharge during late spring and early summer, which determines the cumulative light exposure in transit downstream. The biomass-discharge relationship has shifted over the years, for reasons as yet unknown. Water diversions from the tidal San Joaquin River also affect residence time during passage downstream and may have resulted in more than a doubling of peak concentration in some years. Dam construction and accompanying changes in storage-and-release patterns from upstream reservoirs have caused a long-term decrease in the frequency of large blooms since the early 1980s, but projected climate change favors a future increase. Only large decreases in nonpoint nutrient sources will limit phytoplankton biomass reliably. Growth rate and concentration could increase if nonpoint source management decreases mineral suspensoid load but does not decrease nutrient load sufficiently. Small changes in water storage and release patterns due to dam operation have a major influence on peak phytoplankton biomass, and offer a near-term approach for management of nuisance algal blooms.</p> |
| first_indexed | 2024-04-12T21:55:52Z |
| format | Article |
| id | doaj.art-14dc37afc65b4eff93d7aa9a89da8c0b |
| institution | Directory Open Access Journal |
| issn | 1546-2366 |
| language | English |
| last_indexed | 2024-04-12T21:55:52Z |
| publishDate | 2005-03-01 |
| publisher | eScholarship Publishing, University of California |
| record_format | Article |
| series | San Francisco Estuary and Watershed Science |
| spelling | doaj.art-14dc37afc65b4eff93d7aa9a89da8c0b2022-12-22T03:15:18ZengeScholarship Publishing, University of CaliforniaSan Francisco Estuary and Watershed Science1546-23662005-03-0131ark:13030/qt9jb2t96dPhytoplankton Regulation in a Eutrophic Tidal River (San Joaquin River, California)Alan D. Jassby0University of California, Davis<p>As in many U.S. estuaries, the tidal San Joaquin River exhibits elevated organic matter production that interferes with beneficial uses of the river, including fish spawning and migration. High phytoplankton biomass in the tidal river is consequently a focus of management strategies. An unusually long and comprehensive monitoring dataset enabled identification of the determinants of phytoplankton biomass. Phytoplankton carrying capacity may be set by nitrogen or phosphorus during extreme drought years but, in most years, growth rate is light-limited. The size of the annual phytoplankton bloom depends primarily on river discharge during late spring and early summer, which determines the cumulative light exposure in transit downstream. The biomass-discharge relationship has shifted over the years, for reasons as yet unknown. Water diversions from the tidal San Joaquin River also affect residence time during passage downstream and may have resulted in more than a doubling of peak concentration in some years. Dam construction and accompanying changes in storage-and-release patterns from upstream reservoirs have caused a long-term decrease in the frequency of large blooms since the early 1980s, but projected climate change favors a future increase. Only large decreases in nonpoint nutrient sources will limit phytoplankton biomass reliably. Growth rate and concentration could increase if nonpoint source management decreases mineral suspensoid load but does not decrease nutrient load sufficiently. Small changes in water storage and release patterns due to dam operation have a major influence on peak phytoplankton biomass, and offer a near-term approach for management of nuisance algal blooms.</p>http://escholarship.org/uc/item/9jb2t96dbloomsclimatedamsestuarylightnutrientsphytoplanktonriversstreamflowturbidity |
| spellingShingle | Alan D. Jassby Phytoplankton Regulation in a Eutrophic Tidal River (San Joaquin River, California) San Francisco Estuary and Watershed Science blooms climate dams estuary light nutrients phytoplankton rivers streamflow turbidity |
| title | Phytoplankton Regulation in a Eutrophic Tidal River (San Joaquin River, California) |
| title_full | Phytoplankton Regulation in a Eutrophic Tidal River (San Joaquin River, California) |
| title_fullStr | Phytoplankton Regulation in a Eutrophic Tidal River (San Joaquin River, California) |
| title_full_unstemmed | Phytoplankton Regulation in a Eutrophic Tidal River (San Joaquin River, California) |
| title_short | Phytoplankton Regulation in a Eutrophic Tidal River (San Joaquin River, California) |
| title_sort | phytoplankton regulation in a eutrophic tidal river san joaquin river california |
| topic | blooms climate dams estuary light nutrients phytoplankton rivers streamflow turbidity |
| url | http://escholarship.org/uc/item/9jb2t96d |
| work_keys_str_mv | AT alandjassby phytoplanktonregulationinaeutrophictidalriversanjoaquinrivercalifornia |