Monitoring the melon-heads

Melon-headed whales, rough-toothed dolphins and bottlenose dolphins have all crossed the path of the Cascadia Research Collective boat that’s currently cruising through Kauai’s western waters.

Last Monday was day one of the cruise and by Tuesday afternoon, the three species had surfaced in the vicinity of the boat, allowing for a chance to tag two of the melon- headed whales with depth- transmitting Fastloc GPS tags and get biopsy samples.

Rough-toothed dolphins and bottlenose dolphins were also encountered Tuesday.

“Successful,” confirmed Daniel Webster, research associate who deployed the tags while the 24-foot boat was bobbing around in around a 2-foot swell between Kauai’s Westside and Niihau.

The tags will tell researchers about diving habits and give clues to the paths of the melon-headed whales and their deployment is part of the Cascadia Research Collective’s 15-day project.

“That’s the first time we’ve deployed tags on melon-headed whales,” said Robin Baird, who is heading the project, which is funded by the U.S. Pacific Fleet through the Marine Species Monitoring Program and a grant from the Pacific Islands Fisheries Science Center.

It’s the third time the research collective has encountered melon-headed whales off the coast of Kauai.

There were about 150 individuals in the melon-headed whale group, with a few babies in their midst. Researchers initially passed within a couple miles of them on the way out on Tuesday.

It was the captain from a Seasport Divers vessel who connected the researchers with one of their top priority species after encountering the melon-headed whales while out on a morning tour.

The researchers were pursuing some activity that surfaced on the Navy’s hydrophone facility off the coast of the Pacific Missile Range Facility when Seasport Divers’ report came in, and abandoned that chase to find the melon-headed whales instead.

That’s because the animals vocalizing across the hydrophones on the range were in rough water — which makes for difficult and often unproductive work — and were likely dolphins, not on the list of target species.

That list of species the collective is hoping to tag includes false killer whales, short-finned pilot whales, melon-headed whales, pygmy killer whales, bottlenose dolphins, rough-toothed dolphins, sperm whales, Cuvier’s beaked whales and Blainville’s beaked whales.

“I did the math and the probability is that we’ll most likely encounter our target species only four times during this project,” Baird said. “This is one of those times.”

Cooperation between the research collective and the Marine Mammal Monitoring on Navy Ranges (M3R) program using the hydrophone range helps increase the chances of encountering these target species, as does the coconut wireless.

“We passed right by these animals the first time, that shows you how difficult it is to encounter them out here,” Baird said.

The Seasport vessel stayed with the melon- headed whales until Cascadia researchers were able to see them and then meandered off as the boat approached the group, which surfed the bow for a while.

Baird powered down the boat and the animals started milling about, some logging — resting at the surface — some passing back and forth under the boat, and others breaking into smaller groups and maintaining a distance from the vessel.

Around six rough-toothed dolphins were mixed into the group, which were all photographed by Webster, Baird and the rest of the research team and volunteers on the boat.

The photos will be added to databases of individual animals and will help with tracking and understanding the species’ movements, relationships and patterns.

This is Cascadia Research Collective’s 16^th project working off Kauai with the goal of gathering information on movements and behavior of target species, as well as learning more about the endangered main Hawaiian Islands insular population of false killer whales.

Researchers will be on Kauai waters through the next two weeks.

People on the water on Kauai’s Westside should text or call Baird at (425) 879-0360 if they see any whales or dolphins other than spinner dolphins, rough-toothed dolphins or bottlenose dolphins.