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The USGS has redeployed its seasonal water-quality sensor at the OMSI dock on the Willamette River.
The USGS Oregon Water Science Center has redeployed its seasonal water-quality sensor at the Oregon Museum of Science and Industry (OMSI) dock on the Willamette River in Portland. The sensor is now live and will operate through the spring, summer, and early fall of 2025—capturing continuous data during the time of year when harmful algal blooms are most likely to occur.
This sensor was first deployed in 2023 to help address growing concerns about harmful cyanobacterial blooms in the lower Willamette River, particularly those exiting the upstream Ross Island Lagoon. The instrument collects near real-time data on key indicators such as temperature, pH, dissolved oxygen, specific conductance, chlorophyll, and phycocyanin (a pigment specific to cyanobacteria). These measurements help researchers and public health officials track environmental conditions that may contribute to blooms, and provide the public with valuable, up-to-date information about the river’s health.
The sensor supports ongoing collaborations among USGS, state and local agencies, and community organizations to improve understanding of algae and cyanobacteria dynamics and inform public safety decisions. Live data from the OMSI dock station is available on the sites data page: Willamette River below Holgate Channel, Portland, OR.
These data can also be analyzed using the USGS Data Grapher. For more background information read the 2023 feature story.
USGS scientists also analyze water samples and data from the Willamette River in the Portland area to get an idea of what types of phytoplankton, particularly toxin-producing cyanobacteria, are present and if conditions indicate an algal bloom.
Using a plankton net tow, we collected samples at the Oregon Museum of Science and Industry (OMSI) dock the week of April 21, 2025. Here are some of the plankton observed and photographed with a microscope.
Hydrologic technician, Ann McGowan, shows OMSI representative a water quality sensor deployed in the Willamette River near OMSI. This sensor monitors water temperature, dissolved oxygen, chlorophyll, blue green algea, specific conductance and pH. The sensors need cleaned every 4-6 weeks.
Hydrologic technician, Ann McGowan, shows OMSI representative a water quality sensor deployed in the Willamette River near OMSI. This sensor monitors water temperature, dissolved oxygen, chlorophyll, blue green algea, specific conductance and pH. The sensors need cleaned every 4-6 weeks.
Hydrologist Kurt Carpenter demonstrated gathering a water sample from the Willamette on the docks at OMSI. The netting gets pulled through the water and is then funneled into a sample bottle.
Hydrologist Kurt Carpenter demonstrated gathering a water sample from the Willamette on the docks at OMSI. The netting gets pulled through the water and is then funneled into a sample bottle.
Hydrologic technician, Ann McGowan, shows OMSI representative a water quality sensor deployed in the Willamette River near OMSI. This sensor monitors water temperature, dissolved oxygen, chlorophyll, blue green algea, specific conductance and pH. The sensors need cleaned every 4-6 weeks.
Hydrologic technician, Ann McGowan, shows OMSI representative a water quality sensor deployed in the Willamette River near OMSI. This sensor monitors water temperature, dissolved oxygen, chlorophyll, blue green algea, specific conductance and pH. The sensors need cleaned every 4-6 weeks.
Hydrologist Kurt Carpenter demonstrated gathering a water sample from the Willamette on the docks at OMSI. The netting gets pulled through the water and is then funneled into a sample bottle.
Hydrologist Kurt Carpenter demonstrated gathering a water sample from the Willamette on the docks at OMSI. The netting gets pulled through the water and is then funneled into a sample bottle.