Lake watchers monitor early algae bloom in Lake Pontchartrain

SLIDELL, LA (WVUE) - Record high temperatures are having an impact on Lake Pontchartrain.

Officials are monitoring a large algae bloom that has appeared earlier in the year then anyone can remember.

The lake is warm enough, but there's just enough algae on Mandeville's beach to keep Camryan Blackledge and her sister, Payton, from taking  a dip.

"Looks a little green from the algae buildup," said Blackledge.

Algae blooms are not uncommon in Lake Pontchartrain in mid-summer after a spillway opening. But due in part to this week's record heat, a sizable bloom has appeared along portions of the North Shore much earlier than usual - in fact, three months earlier.

"It is unusual. I don't know if I can recall seeing a visible algae concentration like this," said John Lopez with the Lake Pontchartrain Basin Foundation.

For the past week, he has been monitoring the bloom seen from Slidell in the east, to the Tangipahoa River in the western part of Lake Pontchartrain. The foundation sent up a plane last week and captured images of several square miles of discolored water west of the Causeway. The blooms have also been visible for thousands of feet off the Mandeville shoreline.

"There's a recipe for the algae bloom, and one is the  temperature," said Lopez.

The other ingredient is nutrients that may have been added to the water column by a wetlands restoration project in the Bayou Bonfouca marsh near Slidell, and the recent dredging of the Tangipahoa River in the western part of the lake.

"When they dredge sediment, they re-suspend organics, and it releases nutrients into the water," said Lopez.

Prevailing northerly winds have also made for a lake that's fresher than usual.

"The algae does get better with fresher water, and with the closure of the MRGO, we have a decreased salinity in the lake, and that can be a contributing factor," said Lopez.

While the blooms are cause for concern, there is some good news. The foundation sent another plane up Monday, and the pilot detected smaller blooms to the west.

"He said about a square mile," said Lopez.

The foundation says recent high winds may also be helping to break up blooms.

"She may play at the water's edge but she won't go near the water," said Blackledge as she played in the sand with her sister.

Lopez said there have been no reports of fish kills.

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