Monday, March 21, 2011

Caddo Lake Community Meeting - April 7th, 2011

The Caddo Lake Community Meeting, hosted by the Caddo Lake Clearinghouse will be on:

DATE: April 7th, 2011
TIME: 5:30 - 7:15 PM

Karnack Community Center
15593 FM 134 (at the intersection of FM 134 and T.J. Taylor Avenue)

  • Aquatic Vegetation Control on Caddo Lake (including talks regarding the Giant Salvinia Eradication Project)
  • Texas Master Naturalists Presentation
  • Texas Mussel Watch Program Presentation
  • Updates on Enviornmental Flows, Paddling Trails, LHAAP Cleanup, and paddlefish establishment
refreshments provided by Caddo Lake Institute

Spring Weevil Study Commences

It's documented that correct water temperature is critical for the development of salvinia weevils. As the water temperature increases from 62.6 F to 69.9 F many activities such as feeding, oviposition (egg-laying), and egg-hatch begin. However, spring temperatures (in a water body such as Caddo) at which these activities begin have apparently not been reported. Therefore, a study has begun to determine the temperature and date in which egg-laying occurs on Caddo Lake. It's hoped that the results will help further guide our efforts to control giant salvinia using weevils.

To do this, 30 cages (the same cages from the overwintering study) containing 12 adult weevils with fresh salvinia along with temperature loggers were placed on the lake last week. Each week for the next 10 weeks, three cages will be removed at random and the salvinia within will be extensively searched for adults, newly emerged adults (which will have a red color), and any larvae present (larvae will be found tunneling through the rhizome of the plant). We will be looking for the time and temperature at which "significant numbers' of larvae are present in all the cages.

Also, some recent local publicity regarding Caddo Lake and this project appeared in the Marshall News Messenger on March, 20, 2011.

Friday, March 4, 2011

Cold Winter Helped...Salvinia Expected To Recover

We've been fortunate this winter to have had a series of cold spells that knocked back the giant salvinia a great deal. It's expected that much of the dead, brown material that is floating will take several weeks to sink out of sight.
Despite this cold weather, we've found several very thick mats around the lake that show survival of green material under the insulating top layer. It's anticipated that these spots will be major expansion points as summer approaches. The first two pictures show the freeze damaged salvinia with green material showing through. These areas should provide good weevil sites for our early season stockings.

On another note, in late February, we completed the re-filling of our weevil tanks with Caddo Lake water. With the warm, sunny weather we've been experiencing lately, the giant salvinia in these tanks has been greening up nicely. Hopefully, our weevils will flourish and be ready for placement on the lake in the very near future!

Finally, here is a recent article about the Caddo Lake salvinia project in the Winter 2011 edition of "TX H2O":