Long Island's river otter population faces deadly obstacles in comeback

If a semiaquatic animal — a kayaker, for example, or a river otter — were to set off from the mouth of the Carmans River and head upstream, she would paddle through the wetlands and pine-oak forest of the Wertheim National Wildlife Refuge, past tidal creeks lined with black tupelo and sassafras trees, winterberry and spartina.

After about 3 meandering miles, the travelers would come to a dam that blocks the route to Hards Lake beyond.

The kayaker could carry her craft up a stairway at the left and continue her trip. But it’s hard to imagine a more forbidding place for the otter: a 10-foot-high dam flanked by concrete walls, surrounded by a chain-link fence. The stairway’s first step is set too high for her to climb out. On the opposite wall, a metal chute to aid migrating fish would also be out of reach of her short legs. Behind her she would hear the chronic wheeze of traffic on Sunrise Highway.

Last March a river otter, apparently confronting exactly this obstacle, must have traveled back downstream and climbed the riverbank, intending to cross over Victory Avenue. But she never made it to the lake — she was struck by a car and killed.

This 18-pound otter was very likely one of a group that has settled near Big Fish Creek in the Wertheim refuge, one outpost of a small population that has colonized parts of Long Island after an absence of 200 years. Her death — event code NY214878 in the state’s necropsy report — was the 24th known otter strike on Long Island’s roads in the past 10 years, according to the Department of Environmental Conservation’s records. "They don’t have a high reproductive rate," Mike Bottini, a wildlife biologist at Seatuck Environmental Association, said, "so losing even one is going to set back the recolonization."

And when a mother is killed, her young frequently become casualties as well, as they will often starve without her care. Those deaths remain unnoticed and uncounted. 

Otters from Oyster Bay to Orient Point

North American river otters, once ubiquitous across the continent, were eradicated on Long Island and in much of their range by the early 19th century — wiped out by the fur trade, habitat destruction and water pollution. But starting in the 1970s, a ban on the international trade of otter pelts, the federal Clean Water Act and various reintroduction efforts helped otters reclaim some of their former territories.

Experts believe the first otters to venture back to Long Island may have paddled across the Sound via Fishers, Great and Little Gull and Plum islands. According to Bottini, river otters were first documented on the Island in 2008, and now inhabit streams and ponds on the North Shore from Oyster Bay to Orient Point and throughout the Peconic Estuary; more recently they have appeared in several watersheds on the South Shore. Bottini wouldn't hazard a guess at the present population but he believes their numbers are slowly increasing in spite of the road hazards.

But these pioneers are trying to navigate a landscape that is vastly changed since their ancestors explored its waterways two centuries ago.

Like most animals, otters must roam to find food, shelter and mates. But today their wanderings are circumscribed by sprawling towns and dissected by highways. All this human infrastructure "is creating smaller blocks of habitat that are not big enough to sustain wildlife populations long-term," said Alissa Fadden, connectivity manager at The Nature Conservancy in New York.

America’s 4 million miles of roads are a significant cause of population decline for many species, from Florida panthers to pronghorn to desert tortoises. Even the nation’s most pristine wilderness areas are not safe: In October, Grizzly 399, a famous resident of Grand Teton National Park, was struck and killed by a motorist.

"Even less busy roads can be a major barrier for the smallest creatures," Fadden said. Many will find it too frightening to cross, limiting their access to the things they need to survive; many others are killed in the attempt.

The nexus of dams and roads on Long Island multiplies the challenge: the dam presents one obstacle, and the road built over it another. Otters are strong swimmers, but their long, lithe bodies and short legs are not suited for scaling a dam.

"As amazing as they are in the water, they can’t manage that climb," said Enrico Nardone, director of Seatuck. "It’s sad how many times we have known that river otters have colonized an area because one of them gets killed."

'Quagmire of red tape' for permits

On another bank of the Carmans River, Bottini was searching the ground for signs that an otter had visited. Otters are social animals, and playful — a group is called a romp of otters — but they are mostly nocturnal and shy of humans. The best way to track them is to look for their scat, which they leave in collective latrines, close to water for a quick escape. Bottini said this behavior probably allows the animals to let one another know where they are and to avoid conflict.

He pushed aside some newly fallen leaves and pointed to some earthy nuggets speckled with shards of pinkish-orange shell: the remnants of a recent meal of crayfish or crab. "It’s fairly fresh," he said, perhaps a few days old. "But it’s not an unpleasant smell. A little fishy."

Bottini’s investigations that day were part of his efforts to survey where otters are living and which routes may put them in the path of cars, and ultimately to find ways to keep them from becoming roadkill. Otters are "creatures of habit," he said, so if conservationists can identify tracks where they have crossed, or where bodies have been found, that’s a good spot to begin. Even a makeshift stairway can be enough to provide safe passage.

After an otter was killed near a dam at Pepperidge Lake in Eastport a few years ago, Bottini, his Seatuck colleagues Nardone and John Turner along with Luke Ormand, the environment analyst for the Town of Brookhaven, saw that the creature couldn’t navigate a tight culvert running under East Moriches Road. Together the group built steps out of scavenged cinder blocks to let otters avoid the road.

They installed a trail camera in the culvert to see if the otters would use the stairs, and within a few weeks, Nardone recalls, "they were up and down, up and down," bounding over the steps like children in a playground.

Since then, Seatuck’s Long Island River Otter Project has mapped every known roadkill site on the Island and every dam that could force otters to risk a road crossing. But getting permits to install otter stairs, including wetlands permits from the DEC, is a "frustrating quagmire of red tape," Bottini wrote in an email, especially since Seatuck doesn't own the dams in question. The first three structures he built were not permitted, but they didn’t touch the dam and didn’t harm wetland habitat; no one has objected, Bottini said. 

DEC spokesperson Bill Fonda wrote in an email to Newsday that the agency will consider permit applications and "can work with Seatuck to ensure any project is safe and suitable for otters and has no adverse impacts on other species or habitats."

Bottini has already identified promising sites for more otter passages, and he’s hoping they can get built soon.

One of those sites is Hards Dam, where the simplest fix would be to alter the existing fish ladder. Future otter explorers would need just a small leg up to scramble over and continue their romp toward the lake.