Images
December 15, 2025 - Bloom off California
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Swirls of green curled across the Pacific Ocean off of northern California in early December 2025. The Moderate Resolution Imaging Spectroradiometer (MODIS) on NASA’s Aqua satellite acquired this true-color image of the brilliant tones on December 11. Well inland, a thick layer of low cloud (fog) lays over the California Central Valley.
The bright colors are the result of a large floating colony of phytoplankton—microscopic plant-like organisms that live in these waters year-round. When conditions are right (adequate light, favorable water temperatures, and plenty of nutrients), the tiny organisms can reproduce explosively to create massive blooms that can easily be seen from space.
There are many types of phytoplankton, ranging from diatoms and dinoflagellates to coccolithophores and cyanobacteria. Most types are harmless or helpful, consuming carbon dioxide and releasing oxygen while forming the backbone of the marine food web. However, a few types can be harmful, especially those that produce biotoxins (chemicals that can be harmful to living things).
According an article published by the National Oceanic and Atmospheric Administration (NOAA) on December 14, “A record breaking algal bloom continues to expand across the North Pacific reaching as far north as the Aleutian Islands and as far south as southern California. Amidst well-above average sea surface temperatures across the North Pacific and along the western coastline of North America, a toxic algal bloom has developed with far reaching consequences for sea life as well as regional and local economies.”
The bloom, which began in May, is responsible for the deaths of at least 9 Fin whales near Kodiak Island, Alaska this summer. More recently, the presence of a toxin called domoic acid led to closures or recreational razor clam harvests in Oregon and Washington, closure of portion of the Dungeness crab fishery in Washington, and the closure of some sardine and anchovy fisheries in California. Some, but not all, of the closures and health warnings were lifted on December 12, according to the California Department of Fish and Wildlife.
Image Facts
Satellite:
Aqua
Date Acquired: 12/11/2025
Resolutions:
1km (144.6 KB), 500m (337 KB), 250m (578.4 KB)
Bands Used: 1,4,3
Image Credit:
MODIS Land Rapid Response Team, NASA GSFC
Swirls of green curled across the Pacific Ocean off of northern California in early December 2025. The Moderate Resolution Imaging Spectroradiometer (MODIS) on NASA’s Aqua satellite acquired this true-color image of the brilliant tones on December 11. Well inland, a thick layer of low cloud (fog) lays over the California Central Valley.
The bright colors are the result of a large floating colony of phytoplankton—microscopic plant-like organisms that live in these waters year-round. When conditions are right (adequate light, favorable water temperatures, and plenty of nutrients), the tiny organisms can reproduce explosively to create massive blooms that can easily be seen from space.
There are many types of phytoplankton, ranging from diatoms and dinoflagellates to coccolithophores and cyanobacteria. Most types are harmless or helpful, consuming carbon dioxide and releasing oxygen while forming the backbone of the marine food web. However, a few types can be harmful, especially those that produce biotoxins (chemicals that can be harmful to living things).
According an article published by the National Oceanic and Atmospheric Administration (NOAA) on December 14, “A record breaking algal bloom continues to expand across the North Pacific reaching as far north as the Aleutian Islands and as far south as southern California. Amidst well-above average sea surface temperatures across the North Pacific and along the western coastline of North America, a toxic algal bloom has developed with far reaching consequences for sea life as well as regional and local economies.”
The bloom, which began in May, is responsible for the deaths of at least 9 Fin whales near Kodiak Island, Alaska this summer. More recently, the presence of a toxin called domoic acid led to closures or recreational razor clam harvests in Oregon and Washington, closure of portion of the Dungeness crab fishery in Washington, and the closure of some sardine and anchovy fisheries in California. Some, but not all, of the closures and health warnings were lifted on December 12, according to the California Department of Fish and Wildlife.
Image Facts
Satellite:
Aqua
Date Acquired: 12/11/2025
Resolutions:
1km (144.6 KB), 500m (337 KB), 250m (578.4 KB)
Bands Used: 1,4,3
Image Credit:
MODIS Land Rapid Response Team, NASA GSFC
