DOLPHIN FLEET NATURALIST NOTEBOOK 24 AUGUST TO 31 AUGUST

August 25^th began the last week in August, and blue skies and reports of spectacular whale sightings brought thousands of whale watchers to Provincetown to enjoy what was for some the last official week of summer vacation. Today served as a demonstration of how rapidly conditions and sightings can change, even over the course of just a few hours. The morning started off with major excitement as we came across a humpback whale named Buzzard who was kickfeeding. Buzzard was using his tail to generate clouds of bubbles which would trap and scare fish, allowing him to swallow a huge mass of them in one gulp.

Although the activity of one humpback feeding sometimes attracts others to the area, this did not seem to be the case this morning. Habeñero, a humpback whale born in 1990, was observed logging, or resting at the surface, while other humpbacks, including Agassiz, Blackhole and her calf, as well as Conflux and Apex seemed to be on the move, traveling in a linear direction.

By the time we returned to the southern edge of Stellwagen by the second trip, however, everything had changed, and the feeding frenzy had begun! Rapier, Grackle and Trident were using bubble clouds to confuse and ensnare schools of sand lance, lunging through the bubble clouds with open mouths and forcing the salt water back out of their mouths between their baleen plates.

Meanwhile, humpback whales weren’t the only feeding whales. Minke whales charged among the humpbacks, using bursts of speed to charge through schools of fish, also using the filamentous baleen in their mouths as a filter!

By August 26^th, the feeding had subsided, but the humpbacks remained active and abundant. Perseid’s calf provided the clear highlight of the morning’s trip, as it breached, or jumped, and landed with a resounding crash, sending spray flying. Nobody knows exactly why whales breach, but when we see calves breach, most people will suggest that it’s a play behavior. Many young mammals engage in play behavior, so this is certainly a distinct possibility, but generally, play behavior is practice for a behavior that might be critical to survival in adult life. What they are practicing for, we can only offer educated guesses.

Perseid and calf

Throughout the day, we managed to encounter a humpback whale named Pregunta on several occasions, usually traveling with another female named Whisk. Pregunta is the Spanish word for “question”, and she is named for the question mark shaped marking on her flukes.

Pregunta

Naturalists on the evening trips remarked that some of the humpback whales were diving for longer periods of time than usual. Humpback whales are capable of going for 30 to 45 minutes without breathing, although this is hardly the norm. If they are finding food deep in the water column, however, this will be their priority and they might spend more time below the surface, sometimes even using their jaws to stir up fish that have buried themselves in the mud and sand on the ocean floor!

Whales are voluntary breathers, so not breathing is a more natural state for them. Their high concentrations of hemoglobin and myoglobin, which are pigments in their blood and muscle tissue, bind tightly to oxygen molecules, and this oxygen is carefully distributed throughout their bodies. On long dives, their heart rates slow down and blood flow is restricted to only the necessary bodily functions so that long dives are possible.

Another humpback that appeared throughout the day was a whale named Draco. Look carefully and see if you can see the dragon-shaped mark in the very center of Draco’s flukes.

Draco

On August 27^th, the first sighting of the day consisted of two finback whales off of Race Point Beach. Also catching our attention was the high concentration of tuna boats in the area, hoping to catch another frequent visitor to Stellwagen Bank—the bluefin tuna. Dolphin Fleet naturalists often stress ecosystem interactions during their discussions of Stellwagen Bank, often stressing the role of birds in the environment, as birds and baleen whales often feed on the same small fish. Bluefin tuna frequent Stellwagen Bank for the very same reason—this area of the North Atlantic provides a most hospitable environment for their favorite foods, such as sand lance, herring, and mackerel. Therefore, watching tuna splash in the proximity of finback whales is no surprise.

Bluefin tuna are some of the only fishes that are warm blooded. This consistent and warm body temperature allows these fish to swim extremely fast, sometimes at speeds of over fifty miles an hour! The bluefin tuna is also known for its enormous size. One mature tuna can weigh over one thousand pounds, so that even one mature tuna is a prize catch for any fisherman.

Because of the dense boat traffic, we decided to leave the area after catching fleeting glances of the enormous and majestic finback whales. Some of the mainstays from the previous evening, including Whisk, Pregunta, and Draco had stayed in the same general vicinity and were joined later in the day by a female humpback named Springboard, first seen in 1997. Springboard was observed earlier in the season with fishing gear on its body but has since been photographed entanglement-free.

Springboard near the bow

As always, Pepper’s calf was a pleasure to watch, and passengers on the sunset trip on the Dolphin VIII were thrilled as Pepper’s calf lobtailed, while Pepper and Springboard seemed to forage for food nearby.

Pepper’s 2007 Calf

Even after leaving these whales to go home, passengers were treated to a glorious sunset as well as a look at the rising full moon, and many people eagerly discussed the upcoming lunar eclipse.

August 28^th was a clear, calm day, and the miles of visibility allowed us to locate and approach a large number of species not normally seen on whale watches. In the morning, many of the humpbacks appeared to be resting, or logging. This afforded us the opportunity to get fantastic looks at Firefly and her calf, marveling at the size difference between an adult humpback that is about fifty feet long, and her rapidly growing calf, less than half her length.

Once we had left these animals, however, we started to see a series of small splashes in the distance and headed towards the surface disturbance, where, sure enough, we came across a small pod of Atlantic white-sided dolphins! Atlantic white-sided dolphins might grow to be eight feet in length, weighing several hundred pounds. They are often seen in Stellwagen Bank with their calves at their sides.

Atlantic White Sided Dolphins

Other relatively unusual sightings today included a harbor seal, a basking shark, and a mola mola, or ocean sunfish. Mola molas are without a doubt one of the most bizarre-looking creatures observed from a whale watch boat, with their nearly spherical shape, tall pointed dorsal fin, and their distinctive mouth. These mola molas frequently bask near the surface, feeding on jellies and squid. They are considered by some to be the largest type of zooplankton, weighing around 600 pounds but frequently drifting with the currents.

Mola Mola

On August 29^th, like many trips, we began the day by watching finback whales feed off of Race Point Beach. We were soon distracted by whitewater on the horizon, and went to investigate what looked to be a breaching humpback whale. By the time we arrived, the breaching had subsided, but Pepper and calf stayed near the surface, and we watched them fluke and surface in unison.

Pepper and her calf

The excitement continued and after leaving Pepper and the calf, Alphorn, another humpback began rolling on his back, slapping his long, white flipper on the surface of the water while rolling over on his back. Naturalists on the Dolphin Fleet always stress that it’s possible to see anything at anytime, but we certainly weren’t expecting to see a finback whale as we rounded Long Point, at the very tip of Cape Cod, just a 5 minute trip from the pier!

On August 30^th, the stunning late-summer weather held up and we had another spectacular day of whale watching. Not only was Anchor’s calf breaching, but this curious calf even approached the boat, rolling and frolicking under the bow while Anchor supervised nearby.

Anchor’s calf breaching

A close boat approach from Anchor’s calf

Pepper and her calf, seemingly ubiquitous this week, surprised us again by swimming among a pod of Atlantic white-sided dolphins. This juxtaposition provided a valuable opportunity to highlight some of the differences between baleen whales, like the humpbacks, and toothed whales, like the dolphins.

Pepper, Calf, and Atlantic white sided dolphins

Baleen whales are, with few exceptions, significantly larger than toothed whales. Baleen is thought to be an adaptation that allowed whales that were reaching increasingly large sizes to reap the energetic benefits of smaller creatures lower on the food chain. Toothed whales, however, have the added advantage of being able to locate their food using echolocation or sound waves. However, these two types of whales are frequently found in close proximity when productivity is high. Seeing the dolphins leap and play between Pepper and her calf was certainly a highlight of the trip.

Atlantic white-sided dolphin

On August 31^st we woke up to find that the fog had rolled in, but the seas were still flat and calm. Pepper had finally located a patch of food and was lunging at the surface while the calf lingered nearby. Meanwhile, Ventisca, a humpback with a bright white dorsal fin, breached as Apex rolled and basked at the surface. The old mainstays of the week, Springboard, Whisk, and Pregunta were also seen east of Stellwagen Bank, with Springboard and Ravine not far away.

Though this trip marked the last day of August, we still have two more months of whale watching ahead, and fall is an ideal time to experience Stellwagen Bank in a time of seasonal changes, as migrating birds, whales, and fish stop along their migration routes to take advantage of the rich productivity mere miles from bustling Provincetown Harbor!