BOWDOINHAM Maine (Reuters) - The number of baby lobsters in the Gulf of Maine has dropped by half since 2007, a phenomenon that has puzzled scientists as the population of adult lobsters remains near a record high, contributing to robust catches.

Scientists note that baby lobsters take eight years to reach harvestable size, meaning the dip could yet be felt by the state's 4,200 lobstermen, who last year hauled in a record catch worth $365 million, representing nearly 70 percent of Maine's total seafood harvest.

Despite the record hauls, scientists, including University of Maine researcher Rick Wahle, who founded the baby lobster study in 1989, contend over-fishing is not likely the culprit. The lobster industry, they note, is among the country's most closely regulated.

"This remains the most productive lobster habitat on the planet," Wahle said. "The evidence points elsewhere."

Instead, Wahle and other researchers believe shifting ocean currents, wind and weather patterns may have led drifting lobster larvae astray, contributing to the decline.

The survey relies on divers who use vacuum cleaner-like suction tubs and traps to count baby lobsters on the rock ocean floor of the New England and Canadian coasts.

Scientists said it is unclear whether the decline in the count of young lobsters will eventually cut into the high harvests, which have pushed prices down and left lobstermen scrambling to find new markets.

"We don't know if we're coming to a stable period, or if we're going to come back down to Earth," said Carl Wilson, Maine's state lobster biologist. "But I think for the first time, we're starting to see a change in the system."

(Reporting by Dave Sherwood; Editing by Scott Malone and Dan Grebler)

[Lobster dinner via Shutterstock]