LIBERTY TOWNSHIP, N.J. (Warren County) — Elevated levels of cyanobacteria continue to be detected in Mountain Lake as seasonal monitoring resumes, according to the Mountain Lake Community Association.
Water samples collected April 8 showed cyanobacteria levels at 53,531 cells per milliliter, an increase from the 31,125 cells per milliliter reported by the New Jersey Department of Environmental Protection in March.
The association said the findings indicate the early spring bloom of blue-green algae first identified last month is ongoing.
For comparison, cyanobacteria levels measured in April last year were 62,875 cells per milliliter, while readings were lower in 2024 at 11,877 cells per milliliter and higher in 2023 at 161,732 cells per milliliter.
Officials said the lake is currently experiencing typical early-season conditions, with water temperatures ranging from 51 degrees at the surface to about 45 degrees near the bottom. Dissolved oxygen levels remain high, and water clarity was measured at 4.5 feet.
The lake is currently under a Harmful Algal Bloom advisory, which remains in effect. Residents are advised to avoid allowing pets to ingest lake water, and fish caught in the lake should not be consumed.
The association said it will continue monitoring water quality on a biweekly basis, with additional testing by the state expected in the near future. Updates will be provided as new information becomes available.
