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LPBF Advises Public of Algae Bloom in Northwest Corner of Lake Pontchartrain

  • Please note that this satellite imagery helps with identifying potential HABs, but the information needs to be confirmed by sampling
  • There are some issues with low level clouds, and the resolution of the images near shore. Therefore there may be some inaccuracy in the images near land formations.
  • Satellite images should be used as a guide, as images are compiled over a seven day period, therefore there may be lake conditions that have changed

Additionally, LPBF has aerial photography and boat observations that suggest the presence of blue green algae or cyanobacterial blooms near the north shore of Lake Pontchartrain.  Aerial surveillance has observed the presence of these microorganisms from the Tangipahoa River to Slidell.

Algal blooms, or “Harmful Algal Blooms” (HABs), can be toxic, and the LPBF advises the public to keep themselves and their pets away from the blooms.  Blooms are usually noted for their green or blue-green appearance, scummy or viscous consistency, and the presence of odors.  Both the EPA and CDC advise against direct and indirect contact with these materials; it is generally unsafe to swim in water with algal blooms, and even boaters may be exposed to the toxins of the blooms through water spray.

The toxins in the bloom can lead to serious health effects such as rashes, stomach or liver illness, respiratory problems and neurological effects.

The algal blooms can also have a negative impact on the marine ecosystem, causing fish kills, and causing ‘dead zones’ or oxygen depleted areas that can cause a severe impact to oysters and other bottom species of fish.

LPBF warned that the opening of the Bonnet Carre Spillway might cause algal blooms in Lake Pontchartrain as the freshwater from the Mississippi River delivered a high concentration of nutrients to the lake.  Algae are naturally present, but harmful blooms form during conditions that include high nutrient concentrations, warm temperatures, ample sunlight, and slow moving winds.

LPBF recognizes it was necessary to open the spillway due to the high level of the river during this flood.  We were already on the alert for a bloom and we will continue to monitor it and advise the public so they can take the necessary precautions to stay safe during this period.

Depending on weather conditions, we still expect the lake to return to normal conditions in the next two to three months.

With the opening of the Bonnet Carre Spillway, LPBF has expanded beyond its weekly monitoring of the lake from 10 sites, and has sampled 40 points around the lake and into the Mississippi Sound. LPBF has been working in collaboration with the US EPA, State of Louisiana, regional universities, and the State of Mississippi DMR.  Those sites are illustrated on the enclosed LPBF Monitoring Map. LPBF also conducts flyovers of the area.

LPBF is currently monitoring factors including water temperature, dissolved oxygen, salinity, turbidity, and microbiological analyses. LPBF incorporates this testing and additional analyses as well as other data collected to produce reports posted on the LPBF website, www.saveourlake.org.  LPBF also publishes ‘Hydrocoast Maps’ every two weeks that illustrate the effects of the Spillway opening as it progresses. LPBF is liaising with the EPA to obtain samples of the new bloom to monitor for the presence and concentration of harmful algal bloom toxins.

Helpful Links:

https://www.epa.gov/nutrientpollution/harmful-algal-blooms

https://www.cdc.gov/habs/index.html