Hard times for vernal habitat

Related Photos

Eric Hutchins, habitat restoration specialist at NOAA, rescues and moves a toad that got stuck in the Little River Fish Ladder on Tuesday. He has moved it repeatedly in recent days. Allegra Boverman
Kristen Ferry, a consultant at NOAA, checks on the status of the Little River Fish Ladder off Magnolia Avenue on Tuesday. Allegra Boverman
A spotted salamander egg sac at the fish ladder, unusual as it normally lay eggs in a vernal pool. Allegra Boverman

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April 18, 2012

Hard times for vernal habitat

By Richard Gaines Staff Writer The Gloucester Daily Times Wed Apr 18, 2012, 01:54 AM EDT

The mild, relatively dry winter leading into what is so far a nearly rain-free spring has not produced an official drought, with Cape Ann reservoirs and ground water levels still more a worry than an immediate threat to people.

But all manner of fauna associated with spring — birds, frogs, salamanders as well as sea-living herring which must make their way upstream to spawn in freshwater ponds — are suffering from what is measuring out as one of the driest springs in living memory, federal and state officials said Tuesday.

According to the U.S. Geological Survey, the Ipswich River, which drains a 125-square mile basin just to the north, is at an 80-year low level for the date.

Through the first three months of 2012 — and not counting the first half of April that has produced about a half inch of sprinkles rather than the "April showers" celebrated worshipfully since the writing of the song in 1921 — precipitation in the northeastern sector of Massachusetts has been off by about 50 percent.

Only 5.39 inches has fallen in the region this year, after snow conversion to equivalent in rainwater, according to the state Department of Conservation and Recreation.

A normal April would add about 4.25 inches, and that would charge the vernal pools, the depressions in the craggy granite of Cape Ann that flood in spring and then dry out in summer.

These are essential habitats — providing a fish-free medium — that give amphibians their best chance to have eggs hatch and newborns waddle or hop away to life in the woodlands or at pond's edge.

Eric Hutchins, a habitat resource specialist with the National Oceanic and Atmospheric Administration who grew up in Gloucester and lives in Rockport, has made a personal and professional study of the vernal pools of Cape Ann, and can't remember a spring like this.

"Without a doubt, it's the lowest water level I've ever seen," said Hutchins.

Spotted salamanders, among the first amphibians to lay, have already put down "lots of eggs" that have dried up, he said.

"Toads are laying eggs about now, and if (conditions) remain on this trajectory, wood frogs, salamanders and toads, even if the eggs hatch" would not have much of a chance, Hutchins said.

"The natural vernal pools are very shallow," while the man-made, abandoned quarries, are deeper, said Hutchins, but even many of these are drying or dried already.

Fortunately, he explained, the species that use the vernal pools as nurseries live longer than one year, and so, "a bad year class is what we're looking at," he said.

Birds and fish are also stressed by the ultra-dry conditions, he said.

Robins arriving at the end of their northern migration to feast on worms for protein-energy to build nests, lay and nurture eggs and feed their young, instead have found have the ground sidewalk-hard and dry and few worms.

Earthworms depend on moist soil for lubrication allowing movement, and to maintain biochemical activities and avoid dehydration. Instead of being drawn up by the spring rains, worms are burrowed deep down in moist underground out of birds' reach.

"Robins may be targeting alternate food sources, and can build up to three nests (and three fledges) a year," said Hutchins. "They can be resilient."

Alewives, a species of herring that live in the ocean but return to fresh water ponds to spawn — and are an important forage fish for cod, tuna, bluefish and stripers — are not so lucky.

Hutchins and Kristen Ferry, a contractor for NOAA, met with the Times on Tuesday at the fish ladder to Lilly Pond at the end of the Little River to count — or not count, as it were — alewives.

The water temperature on the ladder coming from the pond was 66.2 degrees Fahrenheit, and the water level on the ladder was less than two inches as it goes over each step. Normally, they said, there would be six inches of water at the steps, enough for the 8- to 11-inch spawners to swim up and up and up until they reach the pond where they were born from eggs.

Thirty-seven fish were counted on the ladder three weeks ago, but on Tuesday, there were none. While water temperatures were high enough to trigger the reproductive urge, so little was there that getting up the ladder was probably impossible, they said.

Kathy Baskin, director of water policy at the state's Executive Office of Energy and Environmental Affairs and co-chairman of the state Drought Management Task Force, said biologists at recent meetings have mentioned the vernal pool problem, but as yet groundwater levels have not yet triggered a "drought advisory." What is required, she said, was three consecutive months of levels below normal.

"It takes a lot of rain to undo drought conditions," Baskin said.

For perspective, however, Hutchins also noted that the last ultra-dry April, in 2006, was followed by the epic May flood rains of the so-called "Mother's Day Storm."

Richard Gaines can be reached at 978-283-7000 x3464, or rgaines@gloucestertimes.com.