Algae Bloom Update – June 2019

LPBF Advises Public of Algae Bloom in Lake Pontchartrain

  • The Louisiana Department of Health issued a health advisory for swimming in the Pontchartrain Basin
  • Satellite imagery has identified a potential HAB, 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 

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.

Algae are naturally present, but harmful blooms form during conditions that include high nutrient concentrations, warm temperatures, ample sunlight, and slow moving winds. Cyanobacteria are capable of producing strong toxins.

LPBF recognizes it was necessary to open the spillway due to the high level of the river during this flood.  Depending on weather conditions, we still expect the lake to return to normal conditions in the next two to three months.

LPBF has been working in collaboration with the US EPA, State of Louisiana, and regional universities.  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