Sunday, August 12, 2012

Day 3: Pilot whales (again and again) and a rare sighting

Pilot whales
(Photo: M. Kaplan, NMFS permit #15530 to CRC)
Today was the longest day on the water yet. We covered around 160 km and had 4 sightings, 3 of which were of pilot whales. In fact, we've seen so many pilot whales over the last couple days that tonight over dinner none of us could actually remember our second encounter of the day, which was, of course, more pilot whales. Memory starts to go and events blend together when you spend long consecutive days on the water, which is why recording sightings and all of the associated data right at the time is so important.

Aran (l) and Daniel (r) photograph pilot whales while Robin (center) manoevers the boat and Jeff (bottom) records sighting data (Photo: M. Kaplan)
Our third sighting of the day was of Risso's dolphins (Grampus griseus), which are infrequently seen around Hawaii and very rarely seen in the numbers we encountered today (around 40 individuals). We got around 15 minutes of good acoustic recordings from the towfish - lots of clicks. Unfortunately, this species isn't the most cooperative so attempts to satellite tag an individual were unsuccessful. Even though we haven't yet seen our two main focal species - false killer whales and melon-headed whales - we've still been collecting some good acoustic recordings. And hopefully, if the weather cooperates, in the next few days we will be able to head north out of the harbour on the leeward side of Hawaii, where these species are more frequently encountered. To prepare for that, we have finally got the drifter buoy working.
Two Risso's dolphins with characteristic white scarring on the body
(Photo: T. A. Mooney, NMFS permit #15530 to CRC)

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