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Clear Lake

Clear Lake, having an area of more than 68 square miles and more than 100 miles of shoreline, is the largest natural, freshwater lake located entirely within California. It is also one of the oldest lakes in North America, being at least 450,000 years old. The lake is relatively shallow and warm and is surrounded by coastal mountains covered with heavy forestation. The area supports an abundance of wildlife including deer, bear, mountain lion, otter, California king snake, and giant salamander. Also found by the lake are ducks, pelicans, grebes, herons, egrets, osprey, and bald eagles. This plethora of wildlife stands in contrast with the harsh conditions in the rest of northern California’s mountain, so humans were attracted to the area as far back as 12,000 years ago, with European settlers arriving around 1845.

The same qualities that attracted humans thousands of years ago continue to attract residents and visitors. Adjacent to the lake and within the immediate watershed are pockets of dense agricultural land and urban centers. Much of the Clear Lake’s shoreline is now developed with the exception of a number of parks and reserves which offer campgrounds, hiking, and bike trails. There are swimming beaches and 11 public boat ramps. Clear Lake has been called the best bass fishing lake in the nation by various professional bass fishing organizations. The record bass here is 17.52 pounds. Other fish also thrive in this environment, including hitch, crappie, channel catfish, bluegill, and carp.

CyanoMap Report

Unfortunately, smaller organisms prosper in Clear Lake as well. Although the intensity varies annually, cyanobacteria typically bloom in the lake three times a year – spring, summer, and late summer. Cyanobacteria populations increased significantly in the 1930’s due to human development in the watershed and fueled by an overabundance of nutrients from agricultural runoff and other erosion. In the 1970’s the Environmental Protection Agency instituted protection measures including erosion control, improved agricultural practices, and gravel mining regulation.

CyanoMap has initiated a pilot with the hopes of developing decision support tools at Clear Lake and across the region. Clear Lake has a long history of harmful algal blooms, with the first report of a canine death after exposure in 1927. Residents, tribal agencies, local health officials, businesses and other stakeholders in this region are already engaged in visually monitoring the lake for signs of harmful blooms; a number of federal grants support some of this work. CyanoMap will enable these stakeholders to compare and analyze satellite data with real-time observations of the local water surface and relevant human and animal health events. The information will be served openly and collaborate with ongoing programs at multiple levels (local, state, Federal, private businesses). Clear Lake is used for recreation, irrigation and as a drinking water supply. While many in the community are concerned about the blooms and their health effects, there is currently no formalized way to report, track, or research localized blooms or their effects, and no widespread use of satellite imaging data to confirm or predict algal blooms or conduct eco-epidemiological modeling.