Concord — July 12, 2008 — Eight years after it became illegal to use lead fishing tackle on New Hampshire lakes, four loons were recently found dead of lead poisoning, the Loon Preservation Committee said. The committee suspects the lead ban – which prohibits the use of lead sinkers and the use of lead jigs smaller than 1 inch – doesn’t go far enough.
Two of the dead loons were found to have ingested larger lead jigs, which are legal. When the ban took effect in 2000, biologists thought it was unlikely that loons would eat anything larger than an inch, an assumption that proved to be wrong.
“If you have a lead jig bigger than an inch, loons will ingest those too,” said John Cooley, a senior biologist with the Loon Preservation Committee. “They’ll go after fish with jigs in them and eat them.”
A jig is a type of fishing lure composed of a hook and a head. The head can be several shapes; some are round, but others are made to look like small fish heads to attract bigger, predator fish. Loons have been known to eat fish hooked with jigs that manage to break free from fishermen’s lines, Cooley said.
The fish are usually injured, which makes them easier for the loons to catch. When loons eat the fish, they eat the jigs, too. Loons have also eaten jigs directly off anglers’ lines. The lead tackle ends up in the loons’ gizzards, where pebbles grind up the food that they eat. The pebbles grind up the lead sinkers and jigs too, and the loons get sick and die within a few weeks.
These most recent deaths are alarming because of their number. In the past five years, an average of 4.6 loons have died from lead poisoning each year. (From 1995 to 1999, before the ban on lead tackle, 7.4 loons died each year.) To have four die in a span of two weeks is cause for concern, Cooley said.
“It’s a little bit of a surprise to have that many come in that quickly,” he said.
The four loons – all male – were found dead between June 25 and July 6 on four different bodies of water, including the Deering Reservoir in Deering. They were given necropsies, or animal autopsies. Two died from ingesting lead jigs and two had ingested lead sinkers. Although the sinkers are illegal, the committee said it sees these recent deaths as evidence that some anglers still use them.
“Some anglers don’t think that using one of the old lead weights still in their tackle boxes could really affect our loon population,” said Harry Vogel, director of the committee, in a press release. “But losing even one adult loon has a measurable impact on a population as small as New Hampshire’s.”
A count last year revealed 528 loons in New Hampshire, Cooley said. Of those, 446 were breeding adults. Loons don’t breed until they’re 6 or 7 years old, and each pair has about two chicks per year. The species’ survival depends on adult loons living long enough to breed again and again, he said.
“Basically, loons are like people or elephants or redwood trees,” Cooley said. “They’re a long-lived species and they’re slow to mature. . . . So each adult is contributing a lot to the population in its lifespan. If we lose one adult as it’s entering its breeding prime, suddenly the population loses.”
After historic lows in the 1960s and 1970s, New Hampshire’s loon population has held steady for the past 10 years, Cooley said. But the loss of four or five loons is enough to send it downward, he said.
“Losing four in two weeks is a big blow,” Vogel said. “It’s very disturbing to see this many lead-killed loons . . . at such an early point in the season. If this trend continues, it’s going to be a really bad year.”
The committee would like to see fishermen leave their lead tackle at home – even if some of it is still legal. But David Duffy, vice president of the New Hampshire Bass Federation, said discontinuing the use of lead jigs may be tougher for anglers than abandoning lead sinkers. Jigs are more costly, he said.
“If something were to change and there was a ban on all lead, that would be a huge impact,” he said. “Jigs are $3 to $4 to $5 apiece. If a fisherman owns a lot of them, he’s not going to throw them out.”