The last ten days have been very productive for us. During our daytime operations, we have heard sperm whales every day but one. Sometimes we have encountered clusters of them, watching the acoustic tracks as we pass six animals or more. A few days ago, we passed right next to two sperm whales, and their echolocation clicks were so loud they overloaded our recordings! We also got some really nice recordings this past week of Atlantic spotted dolphins and Risso’s dolphins. We’ve had good success matching our acoustic localizations with the visual team, particularly for discrete groups of animals.
The highlight of the week was our trackline yesterday, when we passed through an area with a high density of beaked whales and dwarf/pygmy sperm whales. We were able to take a little extra time to try to get recordings and species IDs from nearby groups of Mesoplodon beaked whales, some of which were very close to the trackline. We definitely recorded echolocation clicks from multiple groups of beaked whales, including some click trains that might be associated with a large group of Gervais’ beaked whales that we passed by, so that was very exciting!
When we’ve had the opportunity, we’ve also towed the hydrophone array at night. We had three nights offshore where we were able to tow the array for a few hours each night where heard a lot of dolphin activity. Tonight we are pairing the oceanography and towing with the hydrophone array for about an hour and a half across Lydonia Canyon. So far we’ve had nonstop sperm whales and several dolphin groups. It will be interesting to compare with the data we recorded earlier today as we crossed the same canyon on our daytime trackline. Stay tuned for more information once we have a chance to go through the data!