Field work for the 2025 Atlantic Behavioral Response Study (BRS) is underway. Our field team was on the water Saturday and Sunday, June 21-22, to deploy satellite-linked transmitters on goose-beaked whales Ziphius cavirostris. Our first scheduled Controlled Exposure Experiment (CEE) trial is a month away, so our task this weekend was to deploy satellite-linked transmitters on a few whales so that we can relocate them prior to the CEE. This will allow us to deploy more sophisticated data collecting tags, including satellite-linked dive recorders and Digital Acoustic Tags, just prior to the CEE.
We were very fortunate to have excellent field conditions on both days – although it was hot. We need calm seas to find these cryptic whales and to safely deploy our tags. On Saturday we deployed a satellite tag on a female whale accompanied by a small calf. We are hopeful that we will be able to follow this mom to see when the calf is weaned – the timing of these important life events is still largely unknown for this species – we still have much basic information to collect.
On Sunday afternoon we encountered a very large and active group of goose-beaked whales. We estimate that there were about a dozen whales present, including an animal that we tagged last year – although we are still poring over hundreds of photographs to make sure. We deployed a second satellite tag on one of the animals in this group.
We conduct our field work 40 nautical miles northeast of Cape Hatteras. Sometimes it can appear to us that the ocean is a featureless, monotonous habitat, but that is, of course, not true. The bottom topography of our study area, where the whales feed at depths of around 1500 meters (or about a mile deep), is very rugged, with many canyons and escarpments. And the sea water above it is extremely dynamic – on Sunday we just edged into the Gulf Stream, which features mats of floating Sargassum, and a completely different assemblage of birds and fish. These factors combine to make this such an important habitat for goose-beaked whales, and we feel very fortunate to be able to share it with them on such pretty days.
