The Central Valley Regional Water Quality Control Board, had staff in Discovery Bay on May 02, 2019 collecting water samples for a nutrient loading assessment study they are conducting. During the sampling, staff noted small clumps of visible cyanobacteria at three of the sampling locations.
These locations were the Yacht Harbor near the BoardWalk Grill, Pebble Bay along the deep channel and at the mouth of Discovery Bay and Indian Slough.
A water sample was collected at the Yacht Harbor for cell identification under the microscope. The cyanobacteria identified included Aphanizomenon sp., which was the dominant cyanobacteria within the sample, Dolichospermum sp. and Pseudanabaena sp. No Microcystis sp. were observed in the samples.
The amount of cyanobacteria observed in these areas was low and no toxin testing has been done.
Discovery Bay are cautioned to be aware that cyanobacteria are starting to appear in the area and to exercise care when recreating in the water. The California Water Quality Monitoring Council’s Harmful Algal Bloom (HAB) Portal provides information on healthy water habits that all water users should follow to protect themselves from a potential HAB. Additional information on algae blooms can be found here: https://cchealth.org/eh/hab/
Field Photos:Taken at the Yacht Club on May 02, 2019 during mid-morning. (~10:00 am). Water appeared green in color and cyanobacteria were observed suspended in the water column and at the surface.