It is dark except for your flashlight and the stars above. You are wearing hip waders and a warm jacket. There was no water here in autumn. Now in March the water is halfway up your waders. You are surrounded by thousands of frogs; their peeping is loud enough to regret not wearing ear plugs. The wetland surrounding you is less than half an acre. You shine your flashlight into the water. The illuminated water quickly fills with fairy shrimp, creatures you never have seen before tonight. They dance within a foot of your waders. Dozens of other species of insects and amphibians writhe in the water, too. It is a plethora of life.

Experiences like this explain how David Celebrezze got hooked on vernal pools.

Celebrezze began his involvement with central Ohio's vernal-pool-monitoring efforts years ago when he worked for the Ohio Environmental Council. He has continued his efforts after becoming the coordinator for the Columbus GreenSpot program.

A vernal pool is a seasonal wetland. They typically are in wooded areas with an average size of half an acre, though Celebrezze has seen pools as small as 6 feet by 6 feet with wood frogs breeding in them, a sign of a thriving pool because wood frogs are notoriously picky when it comes to breeding location.

Most years, a vernal pool will dry by the end of the year so it cannot support fish. As a result, vernal pools are accommodating to many species that otherwise would be prey for fish.

Vernal pools are the only habitat in which you can find fairy shrimp and the only habitat where spotted salamanders will breed, making these two their iconic species.

In addition to hosting an array of wildlife, vernal pools serve an important role in the water cycle.

Environmental Protection Agency studies have shown that a 1-acre vernal pool can store 1 million gallons of water a time. Acting as giant sponges, they prevent flooding by holding rainwater and slowly releasing it.

Surprisingly, they also are free of mosquitoes. Vernal pools are "predator-rich" when it comes to mosquitoes, thanks to such mosquito hunters as salamanders, frogs and midges.

Because vernal pools are so ecologically important, monitoring them is an important project here in central Ohio.

Volunteer monitors like Celebrezze identify otherwise-unknown vernal pools, note what species are present and estimate the quantity of each observed critter.

These observations help central Ohio ecologists identify trends in vernal-pool health. The larger the group of monitors and the more detailed the data set they produce, the more likely they are to convince developers to partner with ecologists on responsible regulations that ensure vernal pools are allowed to thrive.

The Ohio Wetlands Association will hold two vernal-pool workshops in March; information is available at ohwetlands.org.

Celebrezze also plans two daylight vernal-pool tours in May and June for Go Green Hilliard members; more information is available at gogreenhilliard.com.

Peter Spreitzer is the newest member of the Hilliard Environmental Sustainability Commission.