In 2016, a harmful algal bloom (HAB) broke out in Florida's Lake Okeechobee and the Okeechobee waterway. The cyanobacteria present during the 2016 Lake Okeechobee and Okeechobee Waterway Harmful Algal Bloom have been documented in a recently published USGS report.
Lake Okeechobee and the Okeechobee Waterway
Lake Okeechobee, the 730 square-mile lake, is an essential water source to South Florida and an important component to South Florida's flood protection system. Lake Okeechobee is at the center of the Okeechobee waterway, which extends from Fort Meyers in the west via the Caloosahatchee River, to Stuart in the east via the St. Lucie River. The HAB spread from Lake Okeechobee to Treasure Coast, the St. Lucie river's point of discharge to the Atlantic Ocean.
The Risks of Harmful Algal Blooms
HABs threaten the health of the organisms living within the water body, and those that interact with it. Biotoxins produced by HABs can adversely affect the health of organisms in the water body, such as shellfish and krill, in addition to organisms higher up in the food web that feed from the waterway, such as fish, birds, turtles. Additionally, the blooms utilize the dissolved oxygen in the water, therefore create hypoxic conditions, and choke the organisms in the water body from their oxygen supply. Additionally, the thick mat of algae that grows on the surface of the water body as a result of HAB prevents sunlight from reaching the photosynthetic plants growing within the water body.
The risk of human illness is related to ingestion of the toxins produced by the HAB. Human illness can be caused by the ingestion of organisms that have accumulated the toxin, such as shellfish, or direct ingestion through drinking water.
“One of the main human risks with these toxins is if a drinking water treatment plant unknowingly pulls some of the bloom into their facility. If that happens, the water often isn’t treated properly and the toxins can make it into finished drinking water," said Barry Rosen, USGS biologist and lead author, stated in an interview with Algae Industry Magazine.
The Culprits Identified
The USGS report, "Cyanobacteria of the 2016 Lake Okeechobee and Okeechobee Waterway Harmful Algal Bloom" published May 2017, documents four orders, ten families, and seventeen genera of cyanobacteria. This collection of cyanobacteria was collected before, during, and up to two weeks after the bloom.
Microcystis aeruginosa was the visible bloom during the outbreak, however, several other, less conspicuous cyanobacteria were present during the bloom. In an interview with Algae Industry Magazine, Barry Rosen stated “It is likely that no two blooms are exactly alike and there probably isn’t one single set of circumstances that can lead to a bloom. The complicated part scientists are dealing with is having dozens of different organisms with the potential to bloom, yet they all have their own specific parameters needed to make it just right for them.” Fluid Imaging Technologies analyzed a sample from the St. Lucie river during the outbreak and identified Microcystis as the culprit. You can read about it in these two previous blog posts: here and here.
The report is intended to help facilitate current and future studies of harmful algal blooms to better understand the timing of cyanobacteria blooms and their toxin production. Download the full USGS report here.
The FlowCam Cyano has been designed to detect and differentiate between cyanobacteria and other green algae for HAB and drinking water quality monitoring.
Ward, Carlton, Lake Okeechobee image, Visit Florida: A Guide to the Lake Okeechobee: http://www.visitflorida.com/en-us/things-to-do/florida-fishing/lake-okeechobee-clewiston-florida.html (accessed May 2017)
Rosen, B.H., Davis, T.W., Gobler C.J., Kramer, B.J., K.A. Loftin, 2017, Cyanobacteria of the 2016 Lake Okeechobee and Okeechobee Waterway Harmful Algal Bloom: U.S. Geological Survey Open File Report 2017-1054, 34 p., https://doi.org/10.3133/ofr20171054.
Algae Industry Magazine, 2017, Dissecting an Algal Bloom: http://www.algaeindustrymagazine.com/dissecting-algal-bloom/?utm_source=feedburner&utm_medium=email&utm_campaign=Feed%3A+AlgaeIndustryMagazine+%28Algae+Industry+Magazine%29 (accessed May 2017).
South Florida Water Management, Our Work: Lake Okeechobee: https://www.sfwmd.gov/our-work/lake-okeechobee (accessed May 2017)..
Chicoski, J.G., 2002, Okeechobee Waterway Map: US Army Corps of Enginners, http://www.saj.usace.army.mil/Portals/44/docs/Operations/owwmap%20revised%20hyperlinks.pdf (accessed May 2017).
Central and Northern California Ocean Observing System, Harmful Algal Bloom Impacts: http://www.cencoos.org/learn/blooms/habs/impacts (accessed May 2017).