At play in the Charles, the resurgent otter
Local sightings hint at river's health
The day before New Year's Eve, Maury Eldridge was kayaking on the Charles River in Needham near the Dover line when he spotted a pair of slender brown animals sitting on a chunk of ice.
As he paddled closer, the pair of North American river otters dived into the water. A few moments later, they reappeared through a hole in the ice and stared right at Eldridge, who quickly grabbed his camera.
"I get excited about seeing any animals in the wild, but the rarer they are, the more exciting it is," said Eldridge, a Needham psychologist who kayaks year round, and goes on the river after his morning appointments several times a week. "I love to see otters - their movements and curiosity and playfulness."
Eldridge was not the only one excited by the sighting. The Charles River Watershed Association hailed the documented presence of otters so close to Boston as a mark of important progress. "It is a sign of the health of the river," said Rebecca Scibek Wickham, outreach coordinator for the local environmental group. "From our perspective, this shows that the river is becoming cleaner, and it is able to support more wildlife."
The 3- to 4-foot-long aquatic members of the weasel family have rebounded from a sharp decline during the 20th century. Otters, which are native to most of the United States and Canada, were wiped out in large sections of their range, mainly because of water pollution and human incursion into their habitats.
Otters dine on fish, frogs, and other aquatic life and are near the top of the food chain, which makes them vulnerable to concentrations of harmful chemicals. Pollution also tends to kill off their food supply.
"They are not found in areas that are contaminated or polluted," said Norman Smith, director of the Massachusetts Audubon Society's Blue Hills Trailside Museum in Milton. Improved water quality and wetlands preservation have sparked a resurgence of river otters, which, at least in Massachusetts, are not on endangered or threatened lists.
"We categorize them now as common," said Laura Hajduk, a biologist for the state Division of Fisheries and Wildlife. "Having otters present means their food supply is there. It's obviously a good thing."
Otter sightings in the Charles, which winds from Hopkinton to Boston, are rare but not unheard of. Eldridge saw an otter in the river about five years ago but was unable to photograph it. He said he spoke recently with another kayaker who said he had seen one last year. Otters tend to be wary of humans, who are more likely to encounter mink or fishers - other members of the weasel family.
Otters, which have webbed feet and can swim up to 7 miles an hour, are graceful animals in and out of water. They are known for their spectacular slides on mud and snow.
"They are one of those creatures that are very charismatic to watch," said Hajduk. "It draws a lot of attention to them."
After Eldridge's close encounter with the otters, he paddled his kayak to the river bank and saw where they had been. "I saw a slide mark in the snow and a fish carcass. Their footprints were all over the bank," he said.
The Trailside Museum has an outdoor otter exhibit, which includes a steep slide on which otters have entertained visitors for years. The museum has had a series of otters, sometimes housed in pairs.
The museum now has only one, a 2-year-old female born in captivity in Louisiana. Like her predecessors, she delights visitors with her acrobatic movements.
"The otters are very popular," said Smith. "It's what people remember about Trailside after they come here."
Robert Preer can be reached at firstname.lastname@example.org.