Minnesota's beloved loons may get a piece of the $18.7 billion Gulf oil spill settlement announced last week — perhaps as much as $39 million over the next 15 years.Minnesota and Wisconsin would be the only states outside the Gulf Coast region to share in the payout, largely because scientists here have proved that the birds migrate every year to the warm waters of the Gulf of Mexico, and that, since the disastrous spill in 2010, many have returned contaminated with carcinogens and other toxins that they pass onto their eggs.

By federal law, any money that comes to Minnesota from the largest environmental settlement in the nation's history could be used only to increase the population of 12,000 loons nesting here, according to top wildlife officials at the Minnesota Department of Natural Resources (DNR).

They have proposed a plan that would preserve and create critical nesting sites on Minnesota's lakes, as well as a program to encourage anglers to stop using lead weights and jigs, a leading cause of death for the birds.

Just how approximately $18.7 ­billion will be distributed isn't clear yet. The settlement, announced last week by the U.S. Department of Justice, would give $5.5 billion to the Gulf states, provide $5.9 ­billion to settle claims by state and local governments for economic losses, and use $600 million for other claims and federal expenses related to the spill.

The largest piece — $8.1 billion, including $1 billion that BP already paid — is dedicated to restoring natural resource damage, plus an additional $700 million for future damage that has not yet been identified.

Specifics still must be approved by the federal judge overseeing the case.

But Minnesota wildlife officials said they have been working with experts from the federal agency to estimate loon deaths, and to predict how the population would increase if their plan were implemented.

"The goal is to produce thousands of loons that would not exist otherwise," said Rich Baker, a DNR wildlife biologist.

Loyal birds

Loons are not the only birds from the Upper Midwest that migrate to the Gulf every year. Others include white pelicans, great blue herons, egrets, spotted sandpipers and ducks.

But the state was able to make a clear case for loons, Minnesota's state bird, thanks in part to sophisticated migration research conducted by scientists from the U.S. Geological Survey who were tracking them with radio markers and satellite transmitters. They found that 85 percent of the birds winter in the Gulf. The adults come back to their nesting sites every year, while the juveniles stay in the Gulf or wander up and down the Atlantic coast for two years before coming north to breed.

"Eventually, they will come back," said Kevin Kenow, a biologist with the USGS in La Crosse, Wis. "They have a strong fidelity to where they were hatched."

The high-tech tracking devices also provide enough detail to detect how deep the birds dive; while in the Gulf they will go to depths of 100 feet or more, all the way to the contaminated bottom.

Residue from the spill "is still there, and they are picking it up," said Carrol Henderson, head of the DNR's nongame wildlife division. "They are diving seven or eight times every half-hour."

Testing on dead loons and broken or abandoned eggs — 142 samples in all — showed that 36 were contaminated with carcinogens that come from petroleum.

But it's too soon to determine what effect it has on loons or their offspring because of the bird's long breeding cycle. The young loons who were most exposed in 2010 are only now beginning their decades of breeding.

Run over by boats

The birds face many hazards in Minnesota as well, including such predators as raccoons and skunks, curious humans and lethal motor boat props.

"The two most traumatic weekends for loons are Memorial weekend, when loons are on their nests, and the Fourth of July, when chicks get run over by boats," Henderson said. "We need to realize that we need to share the lakes with them."

And about 10 percent of loons die from lead poisoning from the sinkers and jigs they pick up when they forage for fish or scoop up pebbles they need for their crops.

But loons are also a significant danger to themselves because they compete fiercely for nesting sites, a key element in the state's plan to increase their numbers.

If approved, the state plan would use the money over the next 15 years to permanently preserve 160 500-foot stretches of natural, sloping shoreline on lakes across the state that the birds use for nesting, the only time they leave the water. That's expensive, because it is often ideal land for recreational development and cabins.

In addition, it would pay for 750 nesting platforms that have proved to work in areas where natural sites are gone.

While the payouts haven't been confirmed, they could be a significant financial boost for the bird, which now gets very little in the way of dedicated conservation money.

"This is species specific," Henderson said. "It helps to show that we don't want anyone messing with our loons."

Josephine Marcotty • 612-673-7394