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Cyanobacteria in Freshwater Ponds
Close-up of Cyanobacteria genus Dolichospermum
Example of a cyanobacteria bloom
Please refer to the following links for more information:
Association to Preserve Cape Cod:
https://apcc.org/our-work/science/community-science/cyanobacteria (Includes map showing test results for a limited number of Cape ponds)
Current Water Bodies with Cyanobacteria Advisories in Falmouth:
POTENTIAL FOR CONCERN CATEGORY - 10/20
Ashumet and Deep Ponds
Weekly report from the Association to Preserve Cape Cod
2025
Falmouth_Biweekly_Report_for_the_Week_of_20_October_2025
Falmouth_Off-week_Report_for_the_Week_of_29_September_2025
Falmouth_Biweekly_Report_for_the_Week_of_8_September_2025
Falmouth_Biweekly_Report_for_the_Week_of_25_August_2025
Falmouth_Bi-weekly_Report_for_the_Week_of_11_August_2025
Falmouth_Offweekly_Report_for_the_Week_of_4_August_2025
Falmouth_Biweekly_Report_for_the_Week_of_28_July_2025
Falmouth_Biweekly_Report_for_the_Week_of_14_July_2025
Falmouth_Off-week_Report_for_the_Week_of_7_July_2025
Falmouth_Biweekly_Report for_the_Week_of_30_June__2025
Falmouth Off-week Report for the Week of 23 June 2025
Falmouth_Biweekly_Report_for_the_Week_of_2_June__2025
Falmouth Biweekly Report for the Week of 16 June 2025 PART2
2024
Falmouth biweekly Report for the Week of October 21, 2024
Falmouth Biweekly Report for the Week of October 14, 2024
Falmouth biweekly report for Week of 7 October 2024
Falmouth biweekly report for the Week of 30 September 2024
Falmouth biweekly report for the Week of September 16, 2024
Falmouth biweekly report for the week of 9 September 2024
Falmouth biweekly report for the week of 26 August 2024
Falmouth biweekly report for the week of 19 August 2024
Falmouth biweekly report for the week of 12 August 2024
Falmouth biweekly report for the week of 29 July 2024
Falmouth Biweekly Report for the week of 15 July 2024
Falmouth Biweekly Report for the Week of 01 July 2024
Falmouth Cyanobacteria report for the week of 6-17-2024
2023
Falmouth Biweekly report 11.6.23
Falmouth Biweekly Report for the Week of October 30, 2023
Falmouth Biweekly report 10.24.23
Falmouth Biweekly for the Town of Falmouth Week of October 16th 2023
Falmouth Biweekly Report for the Week of October 09, 2023
Falmouth Biweekly Report for the Week of September 18, 2023
Falmouth Biweekly Report for the Week of September 4, 2023
Falmouth Biweekly Report for the Week of August 28th, 2023
Falmouth Biweekly Report for the Week of August 14, 2023 (2)
Falmouth Biweekly report for the week of August 7th, 2023
Falmouth Biweekly report for the week of July 31st, 2023
Falmouth Biweekly report for the week of July 17th 2023
Falmouth Biweekly Report for the week of July 10, 2023
FALMOUTH CYANOBACTERIA REPORT 6-5-2023
Falmouth Cyanobacteria Sampling Report 6-19-2023
Falmouth Bi-weekly Report for the Week of 7-3-23
2022
Falmouth Cyanobacteria Report 10-24-2022
Falmouth Cyanobacteria Sampling Report - 10-18-2022
Falmouth Cyanobacteria Sampling Report - 9-19-2022
Falmouth Cyanobacteria Sampling Report 7-25-2022
Falmouth Cyanobacteria Sampling Report 7-18-2022
FALMOUTH CYANOBACTERIA REPORT 7-11-2022
2021
Falmouth Cyanobacteria Sampling Report - 9/7/2021
Falmouth Cyanobacteria Sampling Report - 8/24/2021
Falmouth Cyanobacteria Sampling Report - 8/10/2021
Falmouth Cyanobacteria Sampling Report - 7/27/2021
Falmouth Cyanobacteria Sampling Report - 7/13/21
About Cyanobacteria
Cyanobacteria, also referred to as blue-green algae, are commonly found in the phytoplankton community of aquatic ecosystems. They form the base of the food web of freshwater ponds and streams that flow into coastal estuaries and the ocean but occasionally they grow rapidly in fresh water and form scums or mats in the water. Some blooms can produce toxins harmful to people and animals. Blooms on Cape Cod are most common in summer and early fall. Cyanobacteria blooms can change the water’s appearance from slightly discolored to resembling pea soup or thick paint. Blooms frequently appear blue or green but could be another color, such as brown or red. These blooms can also give the water a bad odor or taste. Health concerns from cyanobacteria blooms and their toxins include skin and eye irritation from topical exposure to gastrointestinal symptoms, liver damage and neurological damage when large amounts of toxins are ingested.
If you see water that appears to have an algae-type bloom, do not come into contact with or ingest the water. Prevent contact and ingestion by children and pets and contact the Falmouth Health Department so it can be investigated.
Causes of Harmful Cyanobacteria Blooms:
Harmful levels of Cyanobacteria, referred to as blooms, can be caused by a combination of factors including warm water temperatures and high nutrient levels from sources such as fertilizer, human waste from leaking septic systems, storm water runoff and pet and wildlife waste.
Please refer to the following links for more information:
Association to Preserve Cape Cod:
https://apcc.org/our-work/science/community-science/cyanobacteria (Includes map showing test results for a limited number of Cape ponds)
Example of an algae bloom without scum
Example of an algae bloom with scum