Cyanobacterial Harmful Algal Blooms in Central Park, New York

Cyanobacterial harmful algal blooms (cyanoHABs) can produce cyanotoxins that pose health risks to humans, pets, and wildlife that use freshwater lakes and ponds. While not often used for swimming or drinking water, human and animal contact with urban lakes can include boating, fishing, or use of shoreline walking paths. CyanoHABs are a persistent, annually recurring problem in several Central Park lakes. It is not known how cyanoHAB conditions (such as cyanotoxin concentration and phytoplankton community composition) vary among lakes within the park or whether the groundwater is impacted by the proximity cyanoHABs in surface waters. This study will explore the surface water and groundwater in Central Park by collecting samples in the summers of 2024 and 2025 at six lakes and three groundwater wells. The measured variables will allow us to better understand cyanoHAB dynamics in the lakes and surface and groundwater flow patterns, such as whether cyanotoxins are moving into the groundwater or nutrients are moving into surface water. Samples will be collected approximately monthly, July through September, each year.