Scientists have traced the genetic makeup of lake trout, a feat that should boost efforts to rebuild populations of the prized fish in the Great Lakes and other North American waters where they’ve been hammered by invasive species, overfishing and pollution, officials said Tuesday.

U.S. and Canadian researchers completed a reference genome, or digital genetic map, for lake trout. It will help explain characteristics that enabled the species to evolve and spread across its vast range, with certain types becoming better suited to particular locations and depths.

The data also will provide vital information for managers of programs that stock lakes with young trout to supplement natural reproduction, said Marc Gaden, spokesman for the Great Lakes Fishery Commission, a U.S.-Canadian agency that funded the research.

“Lake trout are widely distributed across North America, and there are huge variations in habitat use, shape, size, body mass, color,” Gaden said. “We need to understand why they look the way they do, why some types are more successful in some habitats than others, why some types in hatcheries do better than others.”

The team of experts with several U.S. and Canadian universities and government agencies published their genome report Aug. 5 in the journal Molecular Ecology Resources. William Taylor, chairman of the fishery commission and a Michigan State University fisheries ecologist, described it as “a vital missing link in our efforts to restore lake trout.”

Lake trout long dominated the Great Lakes as a predator fish and are common in other large North American lakes.

They sustained aboriginal tribes for generations and were a primary target of post-settlement commercial fishing operations.

Their numbers in the Great Lakes plummeted in the last century with the invasion of sea lamprey, an eel-like parasite that attaches to fish and sucks their bodily fluids.

Researchers eventually developed a poison that is applied to tributary rivers where the lamprey spawn, keeping them in check.

But habitat loss, overfishing, pollution and other invaders have hampered efforts to bring back the lake trout. Although they can live for decades, it takes about seven years for them to become sexually mature — and many don’t survive long enough to reproduce.

Agencies continue to stock them in all the Great Lakes except Lake Superior, where the species has recovered well, Gaden said.

Development of the reference genome should help managers fine-tune those efforts.

“The more you can understand what makes this organism tick, the more you can do to take steps to rehabilitate it,” he said.

Genomes of salmonids, a family that includes lake trout, are harder to compile than those of many other animals, the research team said.

“Having a publicly available map of the lake trout genome removes most of the initial hurdles associated with doing conservation-oriented genomic research, makes it significantly easier to compare results across studies, and will hopefully quicken the pace of scientific discovery,” said Seth Smith of Michigan State University, the study’s lead author.

Shawn Sitar, a fisheries research biologist with the Michigan Department of Natural Resources who wasn’t involved with the study, said returning lake trout to their historically influential role in the Great Lakes will require understanding differences between their types at the sub-species level — which the genome research will support.

“We see them in different habitats, functioning in ecologically different ways, living differently,” Sitar said. “If you want to restore a forest ecosystem, you don’t put in one just one tree. You want to restore the integrity of what the ecosystem was originally.”

The U.S. Department of Energy on Tuesday announced a new kind of climate observatory near the headwaters of the Colorado River that will help scientists better predict rain and snowfall in the U.S. West and determine how much of it will flow through the region.

The multimillion-dollar effort led by Lawrence Berkeley National Laboratory launches next week.

The team has set up radar systems, balloons, cameras and other equipment in an area of Colorado where much of the water in the river originates as snow.

More than 40 million people depend on the Colorado River.

Alejandro Flores, an associate professor of hydrology at Boise State University, said the weather in mountainous areas is notoriously difficult to model and the observatory will be a “game changer.”

“We have to think about the land and the atmosphere as a linked system that interact with each other,” he said in a call with reporters. “Up until now, there have been a lack of observations that help us understand this critical interface.”

The West is in the midst of a more than 20-year megadrought that studies link to human-caused climate change.

That, along with increased demand on the Colorado River led to the first-ever shortage declaration in August, and there’s an increasing threat of deeper, more widespread water cuts. Arizona, Nevada and Mexico won’t get their full allocations of river water next year.

Scientists will use the observatory to gather data on precipitation, wind, clouds, tiny particles, humidity, soil moisture and other things.

Along with a better understanding of the hydrology, they hope to learn more about how wildfires, forest management, drought and tree-killing bugs, for example, play a part in water availability.

A big issue in predicting water supply in the West centers on soil moisture and content, said Ken Williams, the lead on-site researcher and Berkeley Lab scientist. The monsoon season largely was a dud across the Southwest for the past two years, which means more melting snow soaks into the ground before reaching streams and rivers when it does rain, he said.

Climate experts said during a separate briefing Tuesday that southern Arizona and parts of New Mexico have seen impressive rainfall totals so far this monsoon season, with Tucson marking its wettest July on record.

Mike Crimmins, a professor at the University of Arizona, called it an “amazing reversal” for the desert city.

Some parts of the Southwest have seen as much as four times their normal precipitation levels.

But Crimmins noted other spots like Albuquerque, New Mexico, are either at average levels or still lagging.

“We have both really wet conditions for the short term, but we also have longer-term drought still hanging out there because we have these longer-term deficits that we cannot solve with just one or two or even three months of precipitation,” he said.

To reverse the longer-term trends, the region would need to see back-to-back wet winters and summers that are hard to come by, Crimmins said.

The new climate observatory, called the Surface Atmosphere Integrated Field Laboratory, brings together federal scientists, university researchers and others to build on a previous effort to study part of the upper Gunnison River basin in Colorado that shares characteristics with the Rocky Mountains.

For the Rio Grande basin, the data could help water managers as they juggle longstanding water sharing agreements among Colorado, New Mexico, Texas and Mexico, Williams said.

It also could help improve weather forecasting and experiments to modify the weather, such as cloud seeding to produce more precipitation.

The data will be available to other researchers and provide a benchmark for any collection beyond the two-year project, scientists said.