This week, the levels of blue green algae in Georgica Pond have now increased above the NYSDEC threshold for a ‘bloom’ and thus Georgica Pond will be listed among the many bloom sites starting today. This will also trigger a press release by Suffolk County alerting the public; there will be seven (7) sites across Suffolk County listed tomorrow. There are also now four sites in NYC.
Blue green algae are a concern for human, animal, and ecosystem health as they can produce biotoxins, disrupt food webs, and cause low oxygen levels.
As a point of reference, in 2014 and 2015, the blue green algae bloom threshold was exceeded in late July and early August, respectively. The earlier bloom is almost certainly related to the closed nature of the Pond since early spring which has filled the Pond with nutrient-enriched freshwater and driven the salinity down to levels permissible for blue green algae.
The Gobler Lab has been continuously monitoring blue green algae this year. Levels through mid-June were undetectable but populations began to appear last week and this week, exceeded the threshold in the southern part of the Pond only. Levels in Georgica Cove and at the north of the Pond are elevated but below the NYSDEC threshold. Microcystin, a blue-green algae toxin, is present in Georgica Pond but below the drinking and recreational levels of concern (< 1 ug/L).
The Gobler Lab will continue to monitor and provide updates regarding the situation. Given the warm temperatures and closed nature of the Pond, it is likely levels of blue green algae in Georgica Pond will increase in the coming weeks.