scholarly journals Powering Life in the Water: Phytoplankton in the San Francisco Estuary

2021 ◽  
Vol 9 ◽  
Author(s):  
Alexander E. Parker ◽  
Peggy W. Lehman
Keyword(s):  
Carbon Dioxide ◽  
Food Web ◽  
San Francisco ◽  
Aquatic Organisms ◽  
San Francisco Estuary ◽  
Phytoplankton Growth ◽  
Mathematical Equation ◽  
Aquatic Animals ◽  
Control Growth ◽  
Growth Change

Phytoplankton are probably the most important aquatic organisms that you have NEVER seen! Phytoplankton are nearly invisible and use sunlight, carbon dioxide, and nutrients in water to produce sugars that power the estuary food web. The amount of phytoplankton growth is important because phytoplankton are the food for aquatic animals like zooplankton and fish. Scientists working in the San Francisco Estuary are concerned because phytoplankton growth is low, and some animals are starved for food. Measuring phytoplankton growth is hard because growth is low and the conditions in the water that control growth change quickly. As a result, scientists created a mathematical equation, called a model, that brings together the number of phytoplankton available to grow, the amount of sunlight, and the muddiness of the water to estimate phytoplankton growth each day. This way, scientists can determine where and when food is available to power life in the San Francisco Estuary.

scholarly journals Are You a HAB Warrior?

2021 ◽  
Vol 9 ◽  
Author(s):  
Peggy W. Lehman ◽  
Tomofumi Kurobe ◽  
Timothy G. Otten ◽  
Melissa B. Peacock
Keyword(s):  
Climate Change ◽  
Carbon Dioxide ◽  
San Francisco ◽  
Harmful Algal Blooms ◽  
Algal Blooms ◽  
San Francisco Estuary ◽  
The Sun ◽  
Aquatic Animals ◽  
Carbon Dioxide Gas ◽  
Large Numbers

Microalgae and cyanobacteria are tiny, microscopic plant-like organisms that float in the water and grow using nutrients from the water, energy from the sun and carbon dioxide gas from the air. Most microalgae and cyanobacteria are helpful because, like grass for cows on land, they provide food for aquatic animals. However, some microalgae and cyanobacteria are poisonous and when large numbers of them occur, they are called harmful algal blooms, or HABs for short. HABs can poison both humans and animals through the food they eat, the water they drink, and even the air they breathe. HABs are increasing within lakes, rivers, oceans, and estuaries worldwide because of pollution and climate change. This article will tell you about HABs in San Francisco Estuary, USA: who they are, what they look like, why they occur, how they affect plants, animals and people, and things you can do as a HAB warrior to stay safe and prevent their spread.

scholarly journals Initial impacts of Microcystis aeruginosa blooms on the aquatic food web in the San Francisco Estuary

Hydrobiologia ◽  
2009 ◽  
Vol 637 (1) ◽  
pp. 229-248 ◽  
Author(s):  
P. W. Lehman ◽  
S. J. Teh ◽  
G. L. Boyer ◽  
M. L. Nobriga ◽  
E. Bass ◽  
...  
Keyword(s):  
Food Web ◽  
San Francisco ◽  
Microcystis Aeruginosa ◽  
San Francisco Estuary ◽  
Aquatic Food Web ◽  
Aquatic Food

The Role of Protistan Microzooplankton in the Upper San Francisco Estuary Planktonic Food Web: Source or Sink?

2011 ◽  
Vol 34 (5) ◽  
pp. 1026-1038 ◽  
Author(s):  
Gretchen Rollwagen-Bollens ◽  
Scott Gifford ◽  
Stephen M. Bollens
Keyword(s):  
Food Web ◽  
San Francisco ◽  
San Francisco Estuary ◽  
Planktonic Food

scholarly journals Supporting Restoration Decisions through Integration of Tree-Ring and Modeling Data: Reconstructing Flow and Salinity in the San Francisco Estuary over the Past Millennium

Water ◽  
2021 ◽  
Vol 13 (15) ◽  
pp. 2139
Author(s):  
Paul H. Hutton ◽  
David M. Meko ◽  
Sujoy B. Roy
Keyword(s):  
San Francisco ◽  
Tree Ring ◽  
San Francisco Estuary ◽  
Salinity Intrusion ◽  
Estuarine Ecosystem ◽  
Freshwater Flow ◽  
The Past ◽  
Decadal Scale ◽  
Tree Ring Data ◽  
Past Millennium

This work presents updated reconstructions of watershed runoff to San Francisco Estuary from tree-ring data to AD 903, coupled with models relating runoff to freshwater flow to the estuary and salinity intrusion. We characterize pre-development freshwater flow and salinity conditions in the estuary over the past millennium and compare this characterization with contemporary conditions to better understand the magnitude and seasonality of changes over this time. This work shows that the instrumented flow record spans the range of runoff patterns over the past millennium (averaged over 5, 10, 20 and 100 years), and thus serves as a reasonable basis for planning-level evaluations of historical hydrologic conditions in the estuary. Over annual timescales we show that, although median freshwater flow to the estuary has not changed significantly, it has been more variable over the past century compared to pre-development flow conditions. We further show that the contemporary period is generally associated with greater spring salinity intrusion and lesser summer–fall salinity intrusion relative to the pre-development period. Thus, salinity intrusion in summer and fall months was a common occurrence under pre-development conditions and has been moderated in the contemporary period due to the operations of upstream reservoirs, which were designed to hold winter and spring runoff for release in summer and fall. This work also confirms a dramatic decadal-scale hydrologic shift in the watershed from very wet to very dry conditions during the late 19th and early 20th centuries; while not unprecedented, these shifts have been seen only a few times in the past millennium. This shift resulted in an increase in salinity intrusion in the first three decades of the 20th century, as documented through early records. Population growth and extensive watershed modification during this period exacerbated this underlying hydrologic shift. Putting this shift in the context of other anthropogenic drivers is important in understanding the historical response of the estuary and in setting salinity targets for estuarine restoration. By characterizing the long-term behavior of San Francisco Estuary, this work supports decision-making in the State of California related to flow and salinity management for restoration of the estuarine ecosystem.

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