9/4/13

#12: A Dance with Dolphins

During our six days offshore in August, we surveyed the Grand Manan Banks, Lurcher Shoal, Roseway Basin, and part of Brown's Bank. That's a lot of ocean, and we certainly had plenty of sightings to keep us on our toes! Over the course of those six days, we counted 27 ocean sunfish, 6 basking sharks, and 36 leatherback turtles! Personally, I was very excited to see leatherbacks. I've watched these huge turtles haul themselves out of the Caribbean Sea to lay their eggs at Sandy Point Refuge, located on the island of St. Croix, USVI. The mortality rate of hatchlings and juveniles is very high, but even the small possibility that one of the leatherbacks I was seeing on Roseway had been born from one of the clutches laid on St. Croix was very exciting to me.


A leatherback surfaces for a breath. Photo: Kelsey Howe

Aside from our four right whales, other large whales did make an appearance. We counted 4 fin whales, 11 sei whales, 15 humpback whales, and 19 minke whales. We tried to photograph as many humpback whales as we could, as we submit them to a humpback whale catalog for identification.


A humpback goes down for a dive. Photo: Marianna Hagbloom

Another exciting sighting was a small group of about 7-10 pilot whales (commonly known as "blackfish") that passed right by the Shelagh. Their large, broad dorsal fins and bulbous heads were what initially distinguished them, but another unique identifying feature were their flukes, which were raised before disappearing on a long dive. Their flukes looked so small and dainty in comparison to the rest of their bodies!



A typical pilot whale dive depth is 30-60 m, but they are capable of diving to at least 600 m! Photos: Amy Knowlton

We had our fair share of dolphins and porpoise as well; approximately 122 white-sided dolphins, 151 common dolphins, and 310 harbor porpoise! The most thrilling dolphin interaction I've ever had occurred on this trip- three common dolphins bow riding the Shelagh, right under our feet as we stood on the bowsprit!



Common dolphins bow riding. Photos: Marianna Hagbloom

At some moments, they chose to coordinate their movements, and they would dance back and forth across the bow of the boat, zigging and zagging in sync with each other. Other times, they expressed their individuality by swimming away to leap out of the water, or (my favorite) swimming upside down. It was exhilarating to watch how effortlessly they moved, and to see these wild animals having fun!


Oh, you know. Just swimming upside down. Photo: Marianna Hagbloom

We were able to document this behavior on film (courtesy of Philip Hamilton):



While observing these dolphins swimming below us, we noticed that they would occasionally turn on their sides. In this position, they seemed to be purposefully looking at us. Could they recognize us as living beings, separate from the vessel? I like to think so.


What are you thinking?? Photo: Marianna Hagbloom

After a good 15-20 minutes, the three dolphins started swimming further away from the boat, and before we knew it, they were gone. Right before they disappeared, I heard a high-pitched whistle from one of the dolphins. I had never heard dolphins communicating unless there was a hydrophone involved, so I wasn't sure if I was just imagining things, but I later read that it is possible to hear common dolphins above the surface (listen to two examples here!)! The next morning while I was laying in my bunk, I even heard some whistles through the hull of the boat! So while we didn't have the right whale sightings we were hoping for, we all came away with a greater sense of awe and curiosity about the ocean, both of which researchers in our line of work can never have too much of.

-Marianna


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