I remember seeing tiny fish in a shallow pool of water no more than a couple inches deep. My dad said that they must’ve been left there a by a wading bird that transported the eggs stuck to its legs. “That’s how a lot of ponds end up with fish, but these won’t make it. This is a vernal pool.”
A vernal pool is a temporary pool of water that has no true inlet or outlet and usually occurs in the springtime. The soil required for vernal pools to hold water is usually high in silt and clay.
Vernal pools rarely host fish, so amphibian and insect species unable to withstand competition or predation can flourish. Vernal pools have great variances in acidity and salinity. For these reasons there are organisms that live only in or around vernal pools. One is the fairy shrimp, a tiny crustacean used as fish food.
Over 80 percent of vernal pool plants are annuals that bloom simultaneously. Wildflowers may include yellow carpet, meadowfoam, goldfields, and sky blues.
- Saturday, March 26, 2016, 1 p.m. to 3 p.m.
11101 Taloncrest Way
Due to population growth and development, only about 13 percent of the vernal pools that once occurred in California remain. Naturalist Mike Kelly is hosting walks to see the plants and animals that live in or around the short-lived pools.