In recent weeks, has your pond lost its appealing green color?  Have you noticed the water clearing and increased visibility in depth?  No concern.  It’s a fall decline in plankton growth.

Plankton is active in water temperatures above 60-65 degrees.  Like other pond critters, it begins winter slumber below that range.    Since plankton is active in upper zones of the water column, as densities diminish, water clears.

Plankton is a microscopic organism that contributes a valuable role in successful pond management.  It provides critical food to newly hatched fish.  Fry are spawned with a small yolk sack to nourish them through first days.  Once the yolk is absorbed, plankton becomes their primary food chain. If not present, fry survival rates decline significantly. By maintaining healthy plankton levels, you can double and even triple productivity of a fishery.  In depths over three-feet, plankton also serves as a barrier to prevent sunlight from reaching the bottom and promoting vegetation growth.

Plankton growth is generated by nutrients dissolved in the water.  Some ponds receive nutrients through runoff from adjacent agriculture fields.  Other sources may be intensely landscaped lawns or waste from fed fish.  If these aren’t present, pond managers apply fertilizers with high phosphorus ratings, like 12-61-0. If your pond doesn’t develop plankton, conduct a standard water analysis to insure alkalinity levels are in required ranges for plankton to thrive.

Measure plankton regularly with a white disk mounted on the end of a wooden dowel or attached to a string.  The disk should disappear from sight at 18-24 inches.  Record the readings.  If you observe fluctuations above or below this range, call us.  Lower readings may be a sign of deteriorating water quality.  Higher visibility may signal the need for adding slightly more fertilizer.  Either condition should be evaluated by a professional and corrected promptly.

It seems we just applied fertilizer, stocked threadfin shad, tilapia, and other spring startup projects. This newsletter has tips on winterizing ponds and facilities.  What a year!

Please accept our sincere thanks for blessing Texoma Hatchery with your business this season.  We’re field-testing a boatload of new products and procedures.  Staff is analyzing your program and preparing recommendations on how this improved science can take your management program to the next level in 2012.  We wish you and your family a memorable holiday celebration.

Merry Christmas and Happy New Year,

Bob Lusk – Chad Fikes – Joshua Flowers – Walter Bassano