Though once endangered, gray whales in the Pacific Ocean are now thriving. A record number of whale calves have been spotted by scientists in Alaska this summer.

57 pairs of mother and baby whales were recorded just during the month of July. In comparison, the previous record was 18, in 1982 and 2011, and that number included all whales sighted between late June and October. Although some of the sightings this year may have been duplicates, it’s clear that there’s a big population.

Things weren’t always so rosy for gray whales; until 1994, the Eastern North Pacific population of the species was officially considered endangered. In the Atlantic Ocean, grey whales became extinct from whaling in the mid-1800s. The western population in the Pacific is still under threat. Though whaling was internationally outlawed in 1949, with certain limited exceptions for indigenous populations in Russia and the Northwest, whales face illegal whaling and other dangers. Among the challenges are collisions with ships, noise pollution, entanglement in fishing gear, and impacts from coastal development.

In 1991, scientists recorded only one calf sighting in Alaska. Surveys were halted until 2008, when no calves were sighted. Now, there may be as many as 1000 calves, and 18,000-21,000 whales in total.

The calves are big babies: after a 12-13 month pregnancy, mother whales give birth to calves that are typically 14-16 feet long, and 2,000 pounds. They eventually grow to a length of 50 feet, and weigh about 80,000 pounds.

Image by Flickr user goingslo