Recap: Big Night: Adventures in Maine's Vernal Pools
- lura93
- 20 hours ago
- 3 min read
Few people are as passionate about Maine’s vernal pools and the amphibians who breed in them as Stephanie Allard, science professor at Washington County Community College – making her the perfect presenter to learn about the wonderful animals who set out on Big Night. Stephanie shared her enthusiasm and her findings with the audience on Sunday, March 22 at EAC.
“Being able to teach science in this area is such a privilege,” Stephanie says, owing to the extensive network of natural classrooms that comprise the Downeast region. Every springtime, lessons turn toward Big Night and the associated vernal pools that can be found all around us.
What is a vernal pool?
Vernal pools, Stephanie explains, are temporary habitats that some species use to breed to protect themselves from predators. Four species in Maine in particular – known as “obligate” species – require vernal pools to reproduce successfully. To qualify as vernal pools, habitats must be filled with water for at least three months in the springtime; be fishless; and have breeding populations of obligate species.
The obligate species in Maine are the wood frog, mole salamanders (yellow spotted and blue spotted), and the fairy shrimp.
Each of the species is incredibly special. Wood frogs have the ability to freeze solid and thaw within a single day without sustaining any cellular damage, Stephanie explains.
Yellow spotted salamanders have a unique pattern of spots on their body for every individual. Using these spots, scientists have tracked these salamanders going back to the same vernal pool year after year – for 25 years!
Blue spotted salamanders, meanwhile, “are like those rubber kids’ toys,” Stephanie says, recalling their large size, hefty weight, and general low mobility. “They’re so unreal.”
Spotted salamanders are the first known vertebrate species in the world to have developed an intercellular symbiosis with algae. That means there is algae actually growing inside spotted salamander eggs!
Fairy shrimp, meanwhile, are incredibly rare. Of the officially tracked vernal pools in Maine, only 5% have fairy shrimp in them. In her 29 years of monitoring and visiting vernal pools, Stephanie has never seen one. “If you find one, you better email me,” she advises.
Vernal pools also host other amphibians (“facultative” species, meaning they breed there but don’t require it like obligate species), including the famous spring peeper, bull frogs, and more.
Big Night
Big Night, being the night when many local amphibians congregate together in their favorite vernal pool, is triggered by the first spring rain when the air is between 40 and 45 degrees with a thawed ground. Along with being a major opportunity for amphibians to pass on their genes, it's also a time of great danger as many of them look to cross roads despite their slow speeds and minimal protection.
Vernal pools are in danger due to development that destroys them directly as well as the nearby habitat. Some individuals travel for 600’ to their “home” pool; that effectively means that any area up to 600’ away is its extended habitat. Acid rain is another problem that is causing vernal pools to be inhospitable.
Vernal pools are covered by the Maine Department of Inland Fisheries and Wildlife; they maintain a database of “significant pools” based on breeding data. To qualify as significant, they must have either more than 40 wood frog egg masses, more than 20 spotted salamander egg masses, or any population of fairy shrimp. Once qualified, those pools are protected from development, along with 250’ around them. “250’ is not a huge protection, but it’s something,” Stephanie says.
Last year, 5,308 pools were surveyed, and about 21% were found to be significant.
Get involved
Maine Big Night will train people to become citizen scientists with a fully online course. Once trained, you can “adopt a pool” for a commitment of monitoring it for at least one hour between March 15 to May 15, with both daytime and nighttime hours accepted. People in Washington County are particularly needed.
Stephanie has signed up to adopt two vernal pools on the website and will be leaving them open to others if they wish to join her on future outings. To do so, complete the online certification and sign up to adopt the pools by Boyden’s Lake.
