I've approx a 1/4 acre pond. This winter was the first time I've been able to aerate without airline icing problems causing it to cease mid winter. This winter is also the first time fish (besides minnows) have made it through 'til spring, which I've very happy about. I had my diffuser set directly below the dock in about 5ft of water, with 8.5ft being the ponds max depth. No snow was removed from the ice elsewhere. The diffuser's open water hole size varied with winter temps from 4ft to 15ft.
What I've recently observed is Yellow Perch eating aglae that was growing on ropes hanging from the dock. The water also seems to be tinted greenish which is unusual. Normally my ponds water is very clear. The water temp a foot below the surface, near the hole cause by the diffuser, is right at 32F. I've noticed no dead fish yet.
Here's the questions I have: 1)Why is the water now tinted greenish? Evidence of a bloom? In water that cold? If so, why now in a pond that's always been very clear, even during warmer water temps? 2)Why are the Perch active, eating, near the surface when the water is so cold? Are they forced to because of a lack of food under the ice? Could low oxygen levels at lower depths have driven them to this open area? Could the solar radiation be warming them enough to make this cold water tolerable? Why only the Perch? They make up only 10% of the fish in the pond , with BG and LMB in the mix, yet are 100% of the fish I've viewed.
