12 noon whale watch - Krill We headed out of Plymouth Harbor with clear skies and low seas. What a beautiful October day to be whale watching offshore! As we crossed over Stellwagen Bank and through the waters of the Stellwagen Bank National Marine Sanctuary, we started seeing large flocks of searbirds and sea ducks in the area.
We had great sightings of Northern gannets, greater shearwaters and manx shearwaters. We were also treated to view of common eiders as a number of large flocks passed close by our boat. These sea ducks are preparing for their southerly migrations to warmer wintering areas. The females are a beautiful rich brown while the adult males have a striking black & white pattern.
As we continued offshore, we picked up a small pod of harbor porpoise that were milling at the surface. Milling is often a sign that the animals are feeding just beneath the water's surface.
Harbor porpoise are the smallest of all the cetacean species and are classified as Odontocetes or toothed whales. Adults are between 4 to 5 feet in length with a distinctively triangular dorsal fin . Harbor porpoise are often seen in our waters each spring and fall as they move into the southern Gulf of Maine to feed on herring, their favorite prey.
As we watched this group, we estimated that there were between 5 to 8 individuals making up this family grouping. Most toothed whales have a tight social structure as they travel in tight social units called pods. Strong bonds are formed within these units with some family members remaining in the same pod their entire lives.
We left this group of harbor porpoise and continued our journey east. Earlier in the day, Capt. Dave Niemi and crew aboard the Capt. John and Son had seen a few large baleen whales another 13 miles to our east. Although these sightings were a few hours old, we wanted to try and find these animals for our passengers on today's trip.
As we continued east, we saw quite a lot of splashing off our bow. As we approached this area, we realized that we had porpoises or dolphins traveling very fast at the surface. At first we thought we must have some type or species of dolphin given the very fast nature of their travel. But as we continued to watch this small pod, we realized that we had a very fast moving group of harbor porpoise. In all my years of whale watching and whale research offshore, I have never seen harbor porpoise move so quickly. Wow!
After watching these very active porpoises surface all around the boat, we decided to keep moving. Before long, we saw a number of blows off our bow. Large whales ahead! This pair of endangered whales appeared to be feeding just beneath the water's surface. And the style of feeding that they were exhibiting made us think that they were feeding on large zooplankton, like krill, instead of their usual meal of American sandlance.
As we slowed down our approach, the humpback whales surfaced off our starboard side. Our captain, Capt. Russ Burgess, did an excellent job of maneuvering our boat around this pair giving all of us onboard great looks at feeding whales. Being able to maneuver a boat around whales is an art form with a lot of experience thrown in for good measure. And Capt. Russ did an excellent job around the animals and expertly predicted where and when they would surface to take a breath of air.
Both animals had hooked dorsal fins (fins on the back of the animal), but only one individual lifted its flukes out of the water. Even though the flukes were not raised as high as we would like, we were able to identify this individual as Pixar. We were hoping that Pixar's friend and companion would also fluke out, but our waiting was in vane.
As we held position for Pixar and friend, we saw something pushing the water off our starboard side. As Capt. Russ moved the boat slowly in that direction, a back with a sharp, hooked dorsal fin cut through the water. We watched in amazement as a small sei whale surfaced right next to the boat!
We don't see sei whales very often since this species is typically found in more southern waters. But they do feed on large zooplankton and can sometimes be seen very east of Stellwagen Bank. We watched in amazement as this animal lunged mouth open on its side, taking in hundreds of gallons of water as it slowly swam must beneath the water's surface. Then the whale would make a tight turn and lunge again in the plankton bloom.
As the whale rolled on its side to feed, it brought its pectoral fin (front flipper) out of the water. This gave us a chance to see some type of ectoparasite dangling from the tip of the flipper. Like other mammals, sei whales and other types of whales have a normal parasite load that they live with their entire lives. But it is unusual to see parasites hanging from the flipper of any whale.
Sei whales look like small finback whales, but they have a very falcate or sickle-shaped dorsal fin. And this sei whale's dorsal fin was textbook perfect, in both color and shape. As we left this individual, we couldn't believe our luck for we picked up a second sei whale who was also feeding just beneath the water's surface. This sei whale was bigger in length and size than the first animal, and it was
But this sei whale's dorsal fin was very different in size and shape to the first animal we had watched. This dorsal fin was more erect and larger in size. In fact, this second sei whale was significantly larger than the first. Researchers who study sei whales use the size and the shape of the dorsal fin for photo-identification of individuals within the population. It takes a lot of energy and time, but identifying individuals based on natural body markings and pigmentation patterns is an excellent way to track individuals over the course of their lifetime.
An incredible day of whale watching for all onboard. Although I work 5 to 6 days a week from the beginning of April to the end of October, this is my first sighting of sei whales this season!
