The Pacific Whale Foundation on Maui reported a total of 529 humpback whale sightings on Saturday from its annual Great Whale Count, including 335 pods, or groups of whales, and 62 calves.

More than 100 volunteer citizen scientists participated in the Great Whale Count, now in its 30th year.

While this year’s count was lower — with 455 fewer whale sightings than last year’s total of 984 whales — the foundation says there was a higher proportion of calves recorded.

“It’s possible that the peak of humpback whale season is occurring either earlier or later than it has historically,” said foundation senior research analyst Jens Currie. “The timing of the Great Whale Count is consistent from year to year, but there is no guarantee it will coincide with the whales’ schedule.”

There are an estimated 22,000 humpback whales in the North Pacific, and about 10,000 are thought to come to Hawaii over the entire migration season, which lasts from November to May, with the peak from January to March. The waters surrounding the islands of Maui, Lanai, Molokai and Kahoolawe are a popular destination for a large number of these wintering whales.

For 30 years, the Great Whale Count has been using the same criteria and data-collection methods to record whale sightings, offering a comprehensive data-set that allows researchers to identify trends and patterns.

There are 12 sites for the Great Whale Count shore-based scans: Kaanapali, Kahana, Lahaina, Launiupoko, Maalaea, Papawai/McGregor Point, North Kihei, South Kihei, Wailea, Makena and Hookipa. Trained volunteer observers at each site scan the water and record the number of humpback whale pods, individual whales in each pod, and any calves present within three nautical miles from the station.

Immediately following the scan, observers devote five minutes to recording conspicuous whale behaviors, such as breaches, pectoral fin slaps, tail slaps and head slaps. This scanning cycle is repeated from 8:30 to 11:45 a.m. Each location has the same number of observers each year.

The majority of sites reported lower than expected numbers this year, part of a downward trend since 2015, but the foundation says the overall trend in sightings is still increasing when considering the entire data-set from 1995 to present day.

“We remain encouraged by what we see in humpback whale population trends,” said senior research biologist Stephanie Stack. “The numbers this year do serve as a reminder that conservation and protection measures are still necessary for these animals to flourish.”

The Great Whale Count takes place as part of the annual Maui Whale Festival. Results from previous Great Whale Counts are available on Pacific Whale Foundation’s website.