- Research & Education
- Cape Cod
* Whales and Seals and Sharks, Oh My. June 20, was a day of variety. In addition to the three species of whales spotted today, there were also two species of seals and two species of sharks. The day began with feeding humpback whales, most notably, Measles.
* Whalewatchers today also saw Mogul, Hancock, and two mother and calf pairs; Vulture, Tongs, and their calves.
* Numerous finback whales were also sighted today, as were quite a few minke whales. Both of these species offered up some incredible views, especially one of the finback whales sighted on the morning adventure. There were also several gray seals and several harbor seals, both of which are frequently sighted in the nearby waters and on the oceanside beaches. There was also a very close look at a basking shark.
* The highlight of the day, however, was the sighting of this shark, thought to be a porbeagle, swimming alongside the Dolphin 9 for quite a while.
* Though small compared to other mackerel sharks like the great white, the porbeagle shark can be as long as twelve feet and weigh as much as five-hundred pounds. It will feed on cod, hake, flounder, and other bottom-swelling fish, as well as mackerel and squid when it is in open water. Though thought to be common, they are rarely seen by divers. They inhabit cold waters over the continental shelf to depths of twelve-hundred feet.
* Notice the five gill-slits. These are part of a highly advanced respiratory/circulatory system that utilizes a complicated array of tiny arteries and veins to collect the heat produced in the muscles by swimming and uses that heat to warm the blood. The warmed blood is then distributed throughout the tissues and organs of the body allowing greater response speed and strength from both muscular and nervous systems. This system allows the body of a mackerel shark, like the porbeagle, to be elevated as much as twenty degrees above the temperature of the surrounding water, making these cold-blooded fishes functionally warm-blooded.
* Notice the torpedo-like shape of the body. This is a very fast-swimming shark. Though not visible in the photo, the upper and lower lobes of its tail are nearly equal in size, indicating that it needs to continue swimming constantly in order to maintain its oxygen supply, quite odd for a shark that spends most of its time near the bottom. Also no discernible in the photo is the secondary keel located near the base of its tail that cuts easily through the water as the tail swings back and forth during swimming.
* Also not visible are the pair of claspers between the pelvic fins. The presence of claspers would indicate this shark to be a male and the absence of them would indicate a female. It is unclear whether the claspers are not present or are just being concealled by the body. Porbeagles are viviparous, giving birth to live young that develope inside the uterus. Not having a placental connection to the mother, the larger embryos often eat smaller ones while in the womb.
* June 21 was a clear and sunny day, a beautiful day to be on the water. Again, today, three species of whale were spotted, beginning with the large finback whale near Race Point. This animal treated whalewatchers to amazing looks at both sides of its body, allowing them to appreciate the asymmetric pigmentation that is unique to finwhales (among mammals). The other finbacks and the minkes and humpbacks were scattered a bit more today, but that did not prevent the passengers from seeing several of each species. Throughout the day, Measles and Hancock observed blowing spirals of bubble columns, but most of the feeding lunges took place beneath the surface. Again, today, both harbor and gray seals were spotted, both on the beaches and in the water. The highlight of today was, again, not a whale. A very large basking shark was observed feeding very near the surface and, at least on one trip, spent nearly ten minutes swimming with its mouth open very near the Dolphin 9.
* Basking sharks were also seen on June 22. Today, though, was about finback whales. Spread out between the Seashore Ranger Station at the Race and the area known as the triangle, nearly half a dozen were seen, several of which allowed good, close looks at their different dorsal fins and chevrons. The one closest to the triange, was spending its time lunging repeatedly through a huge school of some type of small fish, feeding. Its efforts were also aiding a large group of gulls and shearwaters. At one point, another finwhale (this one identified as Rila) rolled onto its side while swimming along beside the Dolphin 9. Its rorqual pleats were beautifully defined, thanks to the sunny skies and calm waters.
* There were a number of humpbacks sighted early in the day as well. Mostly, they were engaged in bubble feeding deep beneath the surface but, just once, one of them did “a spectacular roll showing us her pleats inflated with food and water.”
* June 23 was another clear day with bright sunshine and fluffy, white clouds against a blue backdrop. One of the finback whales seen today was a female named Skeg. If you will remember from the last two years, she is the one that quite frequently (for a finwhale) lifts her flukes above the surface when going deep beneath the surface. She did it again today! It happened just one time as the morning trip was carefully approaching the whale. If you have never seen the flukes of a finback, they all look very much the same, with a dark outline and a white interior. Smaller than those of a humpback or right whale, the trailing edge is generally smooth (like that of the right whale). She was also seen swimming rather slowly, nearly logging, by the Dolphin 9.
* On the way to Stellwagen, the passengers of the Dolphin 8 spotted a V-shaped spout. It was that of a juvenile right whale on its way toward Provincetown. Its flukes were seen as it swam away.
* And there were humpback whales too. Mogul and Orbit were blowing bubble clouds and feeding beneath the surface. And Diablo appeared again, appearing to be a bit curious about the large vessel she had encountered.
* And, as you can see, she had other things going on too.
* The other thing that was noted by the naturalists on all four trips was the natural result of all of the feeding behavior witnessed over the past several weeks. Defecation. And lots of it.
* The morning action on June 24 was on the SouthWest Corner of Stellwagen Bank. That’s where there were a number of both humpback whales and finback whales. The humpbacks were feeding on short, deep-bodied fish, likely herring. Bubble clouds were being used to corral the fish and push it toward the surface, where three species of shearwaters joined the humpback whales for breakfast.
* Orbit was seen throughout the day, expelling partially digested food in the natural way. And Hancock spent a little time in the afternoon thrilling passengers and crew alike with spirited flipper-slapping.
* June 25 was bright, but hazy. The SW breeze of the morning grew throughout the day, kicking up the seas and making the days adventures like being on nature’s roller-coaster. Whales don’t care about that, though. In fact, the weather patterns that influence our lives so much have very little effect on the lives of whales. Humpback whales continued to feed on the SouthWest Corner. Finback whales continued to move around unconcerned with the presence of the vessels.
* One of which was Skeg. Notice how petite the flukes appear compared to those of a humpack.
* It was foggy and raining on June 26. The Dolphin 10 zig-zagged its way to the SouthWest Corner, hoping to find some of the whales that were feeding there yesterday. Even from a distance, the passengers could see that greater and sooty shearwaters were there in abundance. And when they arrived, a look down, into the water revealled huge schools of small fish. But were the whales still there? Fog can be tricky on a whalewatch. Rain complicates that. Just like on a bright, sunny day, you have to hope for the best.
* As it turns out, there were whales. Humpback whales, a finback whale, and a minke whale. Measles continued to feed and defecate, unconcerned about the weather. And Orbit was making non-fluking dives, likely feeding subsurface.