This info is not in the chronological order that I have been using to relay pond observations, but its interesting to me just the same.
My immediate neighbor, to the east, has a small pond that dries up every summer. The pond fills during the rainy season via a ditch that extends a few thousand yards across a hay field to a copse of trees that hide a very tiny, marshy, pondlet. In the summer, the pondlet has maybe a couple inches of water. Nevertheless, the neighbors pond quickly becomes saturated with zooplankton when the water warms in the spring. I harvest the zooplankton with a fine mesh net with a collection bottle at the end. I transfer the thick, soupy, zooplankton solution to my pond just for the fun of it. I also bring a tiny amount into the house to observe in mason jars just to observe and learn. There are always a myriad of swimming creatures of different sorts. The beginnings of the food chain are fascinating to me.
The question it poses is how do the zooplankton get there? Or perhaps, what are the vehicles that introduce the zooplankton. Obviously, the first is transfer by field overflow from the pondlet. Second, is the question.....do the zooplankton have a mechanism to survive drought in the pond bottom soil? I am not talking a few here and there, I am describing zooplankton so thick, you can see with unaided eye from the pond bank. We know that mosquito eggs can stay viable for long stretches of time in dry soil, only to be activated by moisture. Do various species of zooplankton have the same survivability, or do they just have the ability to reproduce at an amazing rate?
I have solar powered dock lights on my floating dock that shine green lights into the pond water from a few inches above water line. During warm water seasons, the zooplankton become visible soon after dark. Tiny BG will soon appear below the lights and feed on the ZP. If I move the lights, the ZP will follow. If I use a bright white light, the ZP will follow, but the BG will scatter. Just something to ponder while I avoid work.