PF, I have always considered phyto, sun, and wind as a more consistent producer of oxygen than the actually growing plants. Am I mistaken?
BTW, Todd is right about the challenges here. A one acre pond in April can become a 3/8 acre pond by September. My 1/4 acre forage pond can easily be 1/10 acre before I can take action. My fish kills are legendary.
One year we try for a plankton bloom and the next year we have all kinds of noxious weeds to spray. It's nice and sunny around here.
In most ponds, Aquatic plants are the primary producers of oxygen. The Sun helps with photosynthesis, but without plants it just heats up the water, which lowers O2 levels. Higher temps, lower O2, crashes occur in Summer. You just are not going to get consistent O2 from wind or wave action in small ponds. You do not have the surface area exposed for it. A few small ripples if you have wind at all just does not do it. Phytoplankton is huge, could be a pond's number one oxygen producer. It is an aquatic plant. Single celled, bottom of the totem pole, but a pond backbone. I encourage any kind of aquatic plants, and phyto is probably the best. Bear in mind, those same plants take oxygen back at night. Your lowest levels are going to be before sun up. If those fish are gulping at the surface, you know you are right on the edge.
Some of my best fish farmers up here have oxygen diffusers, and aggressive aeration. That would be my thought with this pond also.
Beleive it or not, I have way worse drawdowns than that. My 1/4 acres ponds are bone dry in September. My bigger ponds lose 75% to 90% of volume. The fish kills are almost a matter of time without very close management. I am reworking a bad die off pond now. We can have stretches of a week of triple digits with no wind, and years of droughts consecutive. Luckily, this season is my best this decade. My best pond has not dropped a foot yet.
It's a high wire act here also. Or Forrest Gump's box o chocolates. You never know what you are going to get. I think prevention is a key, but I rarely get a call from someone who thinks that way. I am there after everything is dead, dying, overrun and unfishable. I am undoing years if not decades of no or mismanagement.
My thoughts remain the same. And you have to plan for these potential conditions. Keep the numbers low. Monitor oxygen, especially right before sun up. If you have a brood pond, harvest it aggressively, before the long hot drawdown summers. Your lowest total fish population should be during Summer. Don't treat a pond all at once. Don't treat a small pond with herbicides unless there is no recourse. Don't leave dead material in the water. Don't overfeed. If you can, add oxygen, or aerate. Shade, and add water.
This was a Floridone created fish kill. And that chemical does not really have that happen very often. You should start slow, even half dosage and wait. It does not go away, and will continue to work an entire season, just slow. Smaller ponds are unforgiving. One small mistake and they crash and burn.
