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State of New Jersey Department of Environmental Protection

Algal Bloom Remote Sensing

NJDEP’s Water Monitoring, Standards and Pesticide Control (WMSPC), in cooperation with the NJ Forest Fire Service and Rutgers University, conduct aircraft remote sensing using phycocyanin measurements for estimating the presence of cyanobacteria Harmful Algal Blooms (HABs) in select NJ lakes. Phycocyanin measurements are used to estimate the cell density and the spatial extent of cyanobacteria. This information is used by WMSPC to strategically deploy staff to collect HAB samples for laboratory analysis. Laboratory analysis of cell density, species and cyanotoxins are used to confirm the presence of HABs and to determine if a recreational Alert level is triggered. To detect potential blooms and assess the status of previously confirmed HABs, the plane flies one day a week (generally on Tuesday) or as needed over lakes with a known history of HABs. Other lakes may be considered and added, however the flight path and phycocyanin sensor resolution is limited to larger lakes. Other screening and status monitoring is performed on smaller lakes via on-site surveys. The overall goal is to inform response actions for public health and safety of NJ residents. To learn more about cyanobacteria and the potential threat to health they may cause, visit DEP’s HAB Page. Alert Postings and laboratory analysis results can be found on the HAB Interactive Map.

Year Month Day

Estimated Cells per ml
0 - 10,000
10,000 - 20,000
20,000 - 40,000
40,000 - 60,000
60,000 - 80,000
80,000 - 100,000
> 100,000

Continuous Monitoring

Select Wavelength Measurement


This interactive map reflects estimated cyanobacterial cell count concentrations in freshwaters through wavelength reflectance signatures (remote sensing). Values displayed through this interactive map may not reflect Alert Postings and results obtained through lab analysis. These estimates are only used to provide guidance as a screening tool for when and where physical water samples need to be collected for laboratory cell counts and species identification. High cell count measurements do not necessarily indicate that a toxic species is present, and they do not estimate toxin presence. The health risks associated with high cell counts are not known until DEP lab staff confirm the species identification, cell count, and toxin concentrations. Alert Postings and laboratory analysis results can be found on the HAB Interactive Map.

Phycocyanin levels> 12 ug/l are not necessarily harmful to human health or shellfish for consumption but do give the Bureau information on where to target more intensive boat sampling. Results from boat samples can be obtained by calling the Bureau at 609-748-2000.

NOTE: Data is posted to the website as soon as possible after the plane lands. On days when we experience dense fog, these conditions can cause light scattering to saturate the remote sensor. This light scattering effect compromises the sensor's ability to accurately measure Phycocyanin 'a' in NJ's marine waters. This compromised data is removed from the database as part of routine QA/QC.

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Last Updated: February 3, 2020