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The Importance of Vernal Pools in the Downeast Lakes Community Forest

May 12, 2020

A vernal pool, or ephemeral pool, is a body of water, usually about a foot deep, which serves a valuable ecological role. As the name suggest these pools are only available seasonally in the forest and spend parts of the year without standing water. These pools can vary in size and are distinguished by the lack of fish.

Spotted Salamander Eggs
Wood Frog Eggs

In the spring, there are certain species that utilize these pools to complete phases of their life cycle. For example, some species of salamander and frog require vernal pools to mate and lay their eggs.  Ideally, researchers surveying these ponds conduct their surveys between May 5th – May 20th for wood frogs and May 5th-June 5th for spotted and blue spotted salamanders for breeding season records. Due to weather changes from year to year, there is flexibility in the dates that research is recorded. It is worthwhile to note the state of Maine recognizes certain levels of egg masses as significant depending on the species (>10 egg masses for blue spotted salamanders, >20 egg masses for yellow spotted salamanders, >40 egg masses for wood frogs).  The state considers the pool as significant if there are any fairy shrimp present at the time of the survey.

Other animals like birds and turtles may rely on pools as an alternative water source throughout the year. These vernal pools can grow a variety of plants in and around them. They might be found surrounded by hemlock and red maple in the Downeast Lakes region. Within the vernal pool sphagnum moss, graminoids, and ferns may be present. All of which provide cover and feed for pool dwelling insects, amphibians, and reptiles.

 What research are herpetologists and Downeast Lakes Land Trust conducting?

  • Partnering with Inland Fish and Wildlife this spring DLLT is surveying newly discovered vernal pools. Here’s an example of a what a day in the field looks like:
  • Among the researchers, a designated scribe is elected. This person makes all sort of records vegetation on the shore and in the pool, GPS points, observers present, date, and time on the datasheet. Usually this person is centrally located so they can hear everyone present.
  • Two other researchers will walk on opposite shores of the vernal pool conducing a visual survey of obligate and facultative species in or near the water. Researchers keep note of rare and endangered species that may use vernal pools, such as Blanding’s turtles or spotted turtles, in addition to the more common species.  Another researcher using a handheld GPS device will walk the perimeter of the pool to upload to a mapping program called GIS upon return to the office to add to maps.
  • Researchers may choose to enter a pool to look at species present to confirm or refute identification. They try to minimize the amount of substrate that is kicked up. Findings should be recorded. All specimens should be returned to the pool on conclusion of exploration if removed.
  • The information at the end of the day gets input into a computer and stored in the DLLT office. This information is shared with the managing forester and the wildlife subcommittee to make sure these valuable pools in the Community Forest are protected properly.

If you are interested in Vernal Pools you can find them across the community forest by hiking any one of our trails. We ask that you do not disturb any egg masses or wildlife using the pools for habitat. Don’t forget to take your camera to photograph what you see and share it with us via social media or in our annual photo contest.