After tracking Caspian seals for nearly a year, researchers say they have gained new knowledge of the animals' migration habits and hunting patterns that may help efforts to save the species from extinction.

Researchers at the University of Leeds, along with scientists from Estonia, Kazakhstan, Russia and Northern Ireland, tracked the endangered seals as part of a four-year study to learn more about their behavior with the hope of improving conservation efforts.

The seals are found only in the waters of the Caspian Sea, where their population has declined by 90 percent since the start of the 20th century. Until the early 1990s, Caspian seals were intensely hunted, though since being ideclared an endangered species their threats are largely unintentional: Drowning in fishing nets meant for sturgeon and habitat loss due to human activities.

The hope is that by learning more about what they do and where they go, conservationists can improve protection of the species.

"The data from telemetry studies such as this can help identify key areas of seal habitat which might be incorporated into future protected areas, and planning other human activities, such as oil and gas developments so they don't impact on seals," Dr. Simon Goodman, a biological sciences researcher at the University of Leeds, said in a press release. "To date there have been limited efforts to protect Caspian seals from their many threats, but this is the kind of information needed to help prioritize areas for special protection, and how to most effectively set up and manage them."

From 2009 to 2012, researchers tagged 75 adult seals, using satellite technology to track their movements during both hunting and mating seasons, for more than 11 months. The researchers found both migration and hunting habits during warmer months varies greatly from one seal to the next, which they did not expect.

Based on their findings, published in the journal Marine Ecology Progress Series, the researchers say the seals can be broken down into three groups: Those that stay in the shallow waters of the north Caspian Sea, traveling short distances and never diving more than 5 meters for short periods; those that travel hundreds of kilometers from Kazakhstan to deeper waters off Azerbaijan and Iran, sometimes diving more than 200 meters; and those staying on the edge of deep waters in the north making dives between 10 and 25 meters deep.

During the autumn and winter, researchers report, the animals remain in the north part of the sea, breeding on ice that forms at the start of each year.

Although the researchers are still analyzing data from the study, they think some seals may do less traveling for food to save energy for breeding later in the year, while others find greater reward in hunting while competitively excluding other animals.

"Some of the findings really surprised us -- for instance one seal swam 14,400 kilometers in a year, and many of the seals we tracked during the summer stayed at sea for around six months without coming back to land," Goodman said. "It was also remarkable how much difference in behavior there was between individual seals."