On Thursday we headed out on the R/V Barber with the intention of deploying satellite tags on beaked and pilot whales. This is a continuation of the satellite tagging effort we conducted earlier in the summer with Daniel Webster and Robin Baird from the Cascadia Research Collective. We headed offshore approximately 40nm east of Cape Hatteras, NC to the ziphiid ‘hot spot’ and immediately saw a beaked whale. It surfaced several times then dove but, despite staying in the area for 30 minutes and scanning in all directions, we did not resight it.
Short-finned pilot whale equipped with a satellite transmitter off Cape Hatteras
We decided to look for other animals and quickly came across a group of 15 pilot whales. We tagged one of the pilot whales with a Spot satellite tag that will provide data on the whale’s location over the next couple of months and continued surveying offshore, in hopes of running across beaked whales in the deeper waters. We didn’t find any more beaked whales, so we decided to head back inshore and look for pilot whales and soon found another group of about 30 animals. They were scattered in small subgroups and we worked our way from one group to the next, successfully deploying two more Spot satellite tags and two Mark-10 tags that will record information on dive depth as well as location. We focused on pilot whales with distinctive dorsal fins, which will allow us to identify the animals even after the satellite tags have been shed. The wind picked up in the afternoon and continued to blow throughout the evening and into Saturday.
Pelagic bottlenose dolphin swimming on its back at the surface – there is another dolphin just below this one…
On Sunday we had another productive day satellite tagging despite poor tagging conditions in the morning. The seas flattened out by mid-morning and we managed to locate several scattered groups of pilot whales as we worked our way north along the shelf break. We deployed three more Spot satellite tags on pilot whales and then decided to head farther offshore to look for beaked whales. We soon came across a small group of about 20 offshore bottlenose dolphins that came to check out the boat and bow ride for a few minutes. The group was fairly cooperative so we deployed a Spot satellite tag on one of the animals.
And that’s why pilot whales are sometimes referred to as potheads…
As we were tracking the tagged individual to take photos of the tag placement, we saw a large animal breeching in the distance. We immediately switched into tagging mode and made a run for the breaching animal in the hoped that it was a beaked whale. As we closed on the animal we realized it was not a beaked whale but a sperm whale! We are not permitted to tag sperm whales this year, but we hoped to get close enough to collect a biopsy sample for genetic analysis. The whale remained subsurface and just out of reach, so we decided to abort the sample collection. But as often happens, one sighting will lead us to another interesting sighting, a beaked whale no more than 500m from us! We ended up sighting 5-6 Cuvier’s beaked whales before we had to head in due to fading daylight. We weren’t able to deploy a tag but were encouraged that we were able to track the animals for over two hours and make several very close approaches. We have two more days of field work before we wrap up satellite tagging efforts for the season. Check back with us again soon to see where some of the tagged pilot whales and bottlenose dolphins move over the next few months.
Spring and fall pelagic field work always yields a few wayward migrants like this southbound warbler..