By Juliet Eilperin
Washington Post Staff Writer
Monday, January 26, 2009
Early last summer, a group of 16 migratory dolphins that usually spend their time cruising off the East Coast ventured up New Jersey's Navesink and Shrewsbury rivers. As the weather turned colder, local residents and federal scientists waited to see if the animals would leave -- but they didn't.
Their presence triggered months of debate over whether the dolphins were trapped and should be rescued, as politicians, researchers and local residents argued over what to do when marine mammals find themselves in unfamiliar places. While the New Jersey dolphins have finally vanished -- at least three have died, and the remaining members of the group have either returned to the ocean or are now trapped under a frozen river -- the incident highlights the scientific and ethical questions that officials at the National Oceanic and Atmospheric Administration regularly confront.
"There's a push-pull between scientists, resource managers and the public," said Teri Rowles, the NOAA Fisheries Service's lead marine mammal veterinarian. "What's best to maintain a wild, healthy population -- that often may be in conflict with what the public wants in terms of removing animals within a particular situation."
Rep. Frank Pallone Jr. (D-N.J.), whose district includes the region where the dolphins found themselves, said NOAA should establish consistent criteria by which to judge such situations.
"The problem is, they don't have any standards," Pallone said in an interview, adding that he had expected the agency to intervene once weather conditions worsened. "What's the policy going to be, and what's it based on? And we can't have it change from one day to the next."
In fact, NOAA has an elaborate marine mammal stranding network that involves more than 100 partner organizations to help monitor and aid animals in distress. Each year, the groups deal with more than 5,000 marine mammals in trouble, including large whales, small cetaceans such as dolphins and porpoises, and pinnipeds such as seals and sea lions. In Hawaii alone, the large whale network has tried to disentangle 28 humpback whales since 2002; 53 percent of its attempts succeeded.
NOAA, which ultimately determines whether to attempt a rescue, takes several factors into account when deciding whether to intervene, Rowles said. If the animals are trapped as a result of human activity or if they are in danger of going extinct, federal authorities usually make an effort to extricate them. If the creatures are far outside of their usual habitat -- such as the 100 offshore bottlenose dolphins that got stranded in a lagoon in Long Key, Fla., in 2000, or the humpback whale cow and calf that swam into the Sacramento River in 2007 -- officials often seek to relocate them. On a few occasions, rescuers have helped young cetaceans that were incapable of moving on their own.
Some animals, of course, are easier to herd than others. Larger groups of marine mammals are often more willing to move than smaller ones, and certain species that find themselves out of their usual range, such as pilot whales or Atlantic white-sided dolphins, are more comfortable following a leader out of a tight bind.
The coastal bottlenose dolphins that swam upriver in New Jersey did not fit any of these categories, said NOAA officials and independent experts. Belonging to a population that numbers about 7,500, the group of 16 dolphins would normally not be that far inland, but they were not as far out of their usual habitat as ones that travel exclusively in the open ocean.
Dolphins have been stranded at least twice before in the Shrewsbury River, in 1993 and 2000, and rescue attempts in those instances largely failed. In 1993, the animals scattered and were not seen again; in 2000, the mother dolphin died while her calf survived, only to die later in a rehabilitation center.
Randall Wells, a senior conservation scientist at the Chicago Zoological Society who advised NOAA in both this year's New Jersey case and the one in 1993, said wildlife managers must respect the fact that animals sometimes seek to expand their range. Since 2005, the New Jersey shore has been home to a growing profusion of menhaden, a small fish that bottlenose dolphins eat -- a factor that may have lured the animals into the two rivers.
"The animals got to where they are under their own power. It wasn't human intervention that got them to where they are," said Wells, who manages the Mote Marine Laboratory's dolphin research program in Sarasota, Fla. He added that for humans to resist the idea that wild populations can shift over time "is insanely shortsighted on our part and doesn't give the animals credit for being adaptable."
Others challenge that reasoning. David DeGrazia, who chairs George Washington University's philosophy department and has written about dolphins' cognitive abilities, questioned whether federal officials would have responded the same way to humans in a similar predicament. "We should regard them to having the same moral entitlements as we have," DeGrazia said. "Even if they're not human, we're talking about individuals who matter a great deal, who are in distress."
Robert Schoelkopf, who directs the Marine Mammal Stranding Center in Brigantine, N.J., observed the dolphins getting thinner over time and accused NOAA of practicing "poor science" by letting the animals fend for themselves.
"We do strandings. That's what we do," he said, adding that he watched the river, which is now frozen, as the weather got colder. "That is not natural habitat for bottlenose dolphins."
NOAA scientists, who have performed eight vessel surveys of the area in the past seven months, said five dolphins remained in the river as of Jan. 13. Two days later, local residents saw multiple dolphins leaving the Shrewsbury River and heading into Sandy Hook Bay, and no dolphins have been seen in the area since then.
"We're optimistic that the dolphins have left the area," said Trevor Spradlin, a NOAA marine mammal biologist. "We'll know more in coming days. We plan to do a thorough survey of the area as soon as weather and ice conditions improve."