Boaters in Lake Cataouatche have noticed that submerged plants in the popular waterway seem to be disappearing, but a biologist with the Louisiana Department of Wildlife and Fisheries says that residents shouldnít be too concerned.
"There are a number of things that could affect Hyrdilla, but first of all people have to realize that submerged vegetation is cyclical," Gary Vitrano, with the LDWF, said. "We will see a process where a plant will dominate and then will have a crash and then another period of partial recovery."
Hydrilla is a plant species that grows underwater in large masses and oxygenates the water. The loss of Hydrilla in the area caught the attention of many because after Hurricane Katrina there was an explosion of the grass-like vegetation in the lake.
"It pretty much filled the entire lake and its peak density was around 2006 and 2007," Vitrano said.
He adds that biologists donít know exactly what caused the Hydrilla explosion, but that Katrina probably paved the way by removing other native plants.
"Hydrilla also reproduces from seeds and breaking apart and re-rooting," Vitrano said.
Vitrano said that biologists began to see the Hydrilla diminish before hurricanes Ike and Gustav in 2009, but that those two storms likely had a drastic affect on the plant.
"Those two hurricanes scoured the lake and pulled big rafts of Hyrdilla from the lake to the shore," he said. "After Ike and Gustav, pretty much a lot of the Hydrilla was gone."
Vitrano said that Hydrilla is also affected by salinity routines, turbid water and other predators or biological controls that might be unseen.
"There is a lot of speculation because you canít really pinpoint a cause so everyone has their own theory," he said.