Here’s a trick to try if the ice gets thick enough: Go to Jordan Pond in Acadia National Park on Mount Desert Island and stand next to the water. You’re on National Park land.

Now, step onto the ice. Whose land are you on now? The answer depends on whom you talk to, and the debate’s fierce. But something swimming beneath the surface may soon make the question moot.

Ownership of Acadia’s nine Great Ponds is a source of friction between the National Park Service and Maine’s Department of Inland Fish and Wildlife (IF&W). Both agencies claim jurisdiction through differing laws, with park officials contending the waterways are theirs through the federal mandate that governs all National Parks and state officials laying claim by a colonial-era ordinance called the Great Ponds Act.

For the past hundred years, it’s been largely the state that has cared for Acadia’s Great Ponds, with IF&W officials stocking the nine lakes and ponds with native and non-native gamefish. But in the mid-1990s, National Park staff began to assert that IF&W fishery management practices were at odds with National Park policy. While the U.S. National Park Service allows fishing, it tries only to stock species native to the area. Not only was IF&W stocking non-native species, park officials complained, but park staff often only learned of it after the fact.

“The extent of National Park Service participation in these activities is to occasionally open locked gates for state biologists to gain access to a pond or lake,” wrote Acadia Resource Management chief David Manski in a 2000 report.

The Park Service asked IF&W for co-jurisdiction over the waters and an end to non-native stocking. IF&W officials resisted, arguing the state had scientifically managed the waters for decades. If the park were allowed to carry out its proposals, IF&W argued, there wouldn’t be enough fish to satisfy anglers, and that would be a disaster for both the park and IF&W.

“The people would probably hang us from the highest gallows,” said Greg Burr, IF&W regional biologist. “They would probably burn the park down — I’m serious.”

The jurisdictional conflict left hard feelings on both sides. One Acadia biologist said that until recently, he didn’t feel comfortable even calling his IF&W counterparts on the phone.

Over the years, both sides realized a final victory could only be won in the courts. But while both Acadia and IF&W officials believe they’d win a court case, neither side wants to initiate a lawsuit. To do so would be too costly for the financially strapped agencies and do too much public-relations damage. Instead, the conflict reached a stalemate.

But 2006 has brought signs of reconciliation, and, ironically, it seems a fish may bring the two sides together.

Acadia and IF&W biologists, along with a host of other groups, are working together to study the mysterious sea-run brook trout, one of the few fish that divide their time between fresh and saltwater. Historically found in 17 U.S. states, sea-run brook trout have disappeared in all but a few areas. They’ve fallen prey to introduced non-native species and been blocked from spawning grounds by dams and roads. Maine is one of the trout’s last great strongholds, with prime habitat right in park boundaries.

This last year, the collaborative team tagged over a thousand trout near Seal Harbor with a small radio device to track their movements. From this information, biologists hope to gain much-needed information about the species. At present, so little is known about the trout that no one yet can say whether it belongs on the Endangered Species list, nor why it swims out to sea while other brook trout stay in freshwater.

“Nobody knows now,” said Bruce Conner, Acadia biologist. “Nobody has clue one.”

Sea-run brook trout make a great candidate for collaboration between Acadia and IF&W, partly because the species happens to fit both agencies’ priorities. The trout are a prize for anglers, being two to four inches larger than regular brook trout.

“Size matters to anglers,” said Burr.

The trout also may play a vital, yet undetermined, role in the health of coastal ecosystems. Connery said Northwest salmon with similar lifecycles have recently been found not only to enrich waterways, but inland ecosystems as well. If brook trout disappear, the ramifications for the local ecosystem could be far-reaching.

“You may be slowly squeezing the lifeblood out of these coastal systems,” he said.

Both sides agree the time is right to work together. To begin with, collaboration helps stretch thin budgets. There’s also a growing awareness that true conservation efforts tend to make boundary issues obsolete. But perhaps most importantly, the two groups realize they must provide a united front to gain the trust of their local constituencies, or even greater ecological trouble may loom.

Ken Elowe, IF&W’s director of resource management, estimates that five to ten Maine waterways get stocked independently by dissatisfied fishermen every year, and the results are disastrous.

“All it takes is someone with a bucket to slop the wrong species in and you’ve changed the ecological pattern of the lake forever,” Elowe said.

Officials on both sides hope the brook trout project will bring about future collaborations and the end of the jurisdictional rivalry. Connery felt the relationship between the two agencies was at its highest point in 15 years. While there’s still obvious tension between some Acadia and IF&W staff, many hope it will dissipate over time.

“In every kind of relationship there are bumps in the road,” Manski said. “But you work through them.”