Giant manta rays were thought to flee monsoons -- then, tags showed them 1,300 feet down

Giant manta rays in Papua New Guinea challenge prior assumptions about monsoon behavior. A University of the Sunshine Coast study tagged 10 reef manta rays between 2016 and 2018 and found most remained near their tagging sites, with 75 percent staying within about six miles of Milne Bay. The longest journey exceeded 50 miles.

Depth use shifted seasonally: average dives were about 207 feet during the northwest monsoon and 161 feet during the southeast monsoon, with two rays descending beyond 1,300 feet in December. The findings, published in PLOS One, inform conservation by highlighting localized habitat use around the Samarai Islands.