The spring season of whale watching on Stellwagen Bank was eventful, and a team of observative naturalists, captains, and interns was tasked with locating and identifying one animal from another in the midst of highly active surface activity. The month of May is usually exceptional every year, but there is always renewed anticipation in discovering new calves.
Humpback whales migrating from southern breeding grounds arrive at different points in the season, so finding calves and identifying their mothers was important for determining family lineage. Mothers and their single offspring travel in pairs or dyads, which are the only long term associations of baleen whales, and after one year whale juveniles become independent.
We focus particularly on the patterns of humpback whale flukes to identify them, and the patterns of calves can sometimes change drastically throughout the first five years of life. Their tails document their travels and tribulations, and at any time they can arrive with scars from orca pods and injuries inflicted by fishing gear and vessels.
Top: Fluke of Canopy’s 2014 calf on July 20, 2014. Photo by Hannah Pittore, BHC naturalist.
Bottom: Photo of same fluke on November 15, 2014. Photo by Tasia Blough, BHC naturalist.
While observing whales in their feeding grounds on we witnessed a wide display of behavior. Sightings recorded in the months of May and September were notably bountiful, and the humpbacks revealed a repertoire that continued throughout the year.
The captains and naturalists of BHC are always thoughtful of the safety and comfort of whales and keep an appropriate distance from these animals, but on occasion a few bold creatures granted passengers memorable views.
The captains and naturalists of BHC are always thoughtful of the safety and comfort of whales and keep an appropriate distance from these animals, but on occasion a few bold creatures granted passengers memorable views.
Mogul breaching off bow of Asteria on June 21, 2014. Photo by Haylee Herman- Haase, NEAQ summer intern.
Follicle parallel to boat on August 31, 2014. Photo by Tasia Blough, BHC naturalist.
Nile is one particular humpback of interest who has remained faithful to her feeding grounds. She garnished special attention this year when she returned with a new calf.
Some passengers were surprised to learn that a humpback whale can weigh and measure 15 feet long when born! They can gain up to 100 lbs. per day just from nursing, as humpback whale milk has a fat content of about 40%.
Some passengers were surprised to learn that a humpback whale can weigh and measure 15 feet long when born! They can gain up to 100 lbs. per day just from nursing, as humpback whale milk has a fat content of about 40%.
Nile’s 2014 calf flipper slapping on September 27, 2014. Photo taken by Tasia Blough, BHC naturalist.
Giving live birth to very large young increases the odds of survival, but this tactic only enables mothers to sustain one calf at a time. While this reproduction rate is common in whales (and species of large sharks), female humpbacks can have a new calf every two to three years!
Milkweed's 2014 calf. Spy-hopping is a sign of curiosity and is seen often by calves. Photo by Tasia Blough, BHC naturalist.
The summer season of 2014 was a great year to observe a diversity of species that frequent Stellwagen Bank to feed from its wealth of nutrients, planktonic organisms, and plentiful schools of fish.
One remarkable visitor to the region is the ocean sunfish, or Mola mola. The species is found in temperate and tropical waters worldwide, and are also found in Massachusetts Bay when hunting jellyfish. The ocean sunfish weighs up to 2,200lbs (1,000 kg) and is the heaviest bony fish in the ocean. Specimens have been found to exceed 10 feet in diameter!
Mola mola sighted on September 27, 2014. Note the abundance of jellyfish and larvae at the water’s surface. Apparent scarring also visible on dorsal side. Photo by Laura Cupicha, BHC naturalist.
The ocean sunfish is related to the pufferfish and also has a beak formed by the fusion of its four front teeth. The species is typically found “basking” at the surface in a horizontal orientation, enabling our passengers to appreciate their enormity.
It lacks a caudal fin (or tail fin) but instead has a clavus, a fin created by the conversion of the dorsal fin and anal fin. The clavus is strong enough to propel the behemoth out of the water’s surface by a height of three or more body lengths! Scientists speculate that the fish breaches to rid its body of parasites.
It lacks a caudal fin (or tail fin) but instead has a clavus, a fin created by the conversion of the dorsal fin and anal fin. The clavus is strong enough to propel the behemoth out of the water’s surface by a height of three or more body lengths! Scientists speculate that the fish breaches to rid its body of parasites.
Mola mola sighted on September 27 2014. Photo by Tasia Blough, BHC naturalist.
Another exciting fish sighted on several trips in August was the blue shark, a pelagic species that is typically found in cool waters. They are usually no longer than 12 feet long and weigh under 450lbs., and are usually mistaken as juveniles of larger shark species. Due to their small size, passengers had to be alert and scan for their dorsal fins penetrating the water’s surface.
They also demonstrate a clear example of countershading, as their dorsal side is blue in contrast with their white underside. Countershading is a trait found in sharks that makes it hard for predators and prey to see them from above and below in deep, blue water.
They also demonstrate a clear example of countershading, as their dorsal side is blue in contrast with their white underside. Countershading is a trait found in sharks that makes it hard for predators and prey to see them from above and below in deep, blue water.
Blue shark on Stellwagen Bank. Photo by Tasia Blough, BHC naturalist.
They are one the few sharks that have their own hierarchy or social structure, traveling in groups organized by gender and size. The blue shark is truly an oceanic wander, traversing thousands of miles in little time.
As a nomadic species they do not return to the same areas often, so passengers lucky enough to make multiple trips were unlikely to see the same shark twice! They are thought to use shallow waters as nurseries for their young, so there may be a correlation to their presence on Stellwagen Bank.
As a nomadic species they do not return to the same areas often, so passengers lucky enough to make multiple trips were unlikely to see the same shark twice! They are thought to use shallow waters as nurseries for their young, so there may be a correlation to their presence on Stellwagen Bank.
Blue shark on Stellwagen Bank. Photo by Tasia Blough, BHC naturalist.
Passengers and crew were also elated to see the world's second largest shark species, the Basking sharks! These enormous sharks typically reach 26 feet long and can weigh approximately 5 tons. They filter feed for the same organisms that sustain humpback whales.
Rather than being equipped with baleen plates they utilize gill rakers, which are bristled, cartilaginous appendages that are suspended on the inside of the gills. While the shark swims slowly with an agape mouth, the gill rakers ensnare small organisms from water passing through the gills.
Rather than being equipped with baleen plates they utilize gill rakers, which are bristled, cartilaginous appendages that are suspended on the inside of the gills. While the shark swims slowly with an agape mouth, the gill rakers ensnare small organisms from water passing through the gills.
Basking shark filter feeding. Photo by Danielle Gendron, BHC naturalist.
A number of the whales identified this year bore reminders of hazards associated with the presence of humans in their feeding ground. The need to breathe, sleep, and filter for food on the ocean’s surface makes baleen whales susceptible to boat strikes. Aside from cataloguing behavior and distribution of whales on a daily basis, naturalists and captains are tasked with reporting any injured whales and documenting their status and recovery.
Northstar made a notable appearance this year with wounds undoubtedly caused by a collision with a large vessel. An interesting pattern we witnessed throughout the season was the pairing of Northstar with a much larger humpback whale named Hippocampus.
Northstar was seen with Hippocampus for many consecutive trips, but it is difficult to determine if this individual was willingly helping him feed. Adult humpback whales are typically solitary mammals that interact through short term associations to feed collaboratively, achieved through making large bubble clouds and trapping confused prey at the water's surface.
Northstar with fresh injuries on July 25, 2014. Photo by Tasia Blough, BHC naturalist.
Scientists have theorized that humpback whales may exhibit kleptoparasitism, when one humpback rushes through a bubble net created by another whale to steal the prey trapped within. The presence of bubble nets and bubble clouds is obvious on the ocean's surface, but scientists can speculate upon the drama that happens below by attaching cameras (Gopros in particular) via temporary tags attached with suction cups.
Northstar healed rather well through the summer, and it is tempting to ponder if shadowing such a productive whale early in the feeding season expedited his recovery.
Northstar healed rather well through the summer, and it is tempting to ponder if shadowing such a productive whale early in the feeding season expedited his recovery.
Northstar with Hippocampus on November 9, 2014. Photo by Tasia Blough, BHC naturalist.
Another anthropogenic threat to baleen whales is entanglement from fishing gear. Towards the end of September, passengers aboard the Cetacea witnessed Milkweed’s newest calf become entangled while playing and feeding around fixed fishing gear!
Milkweed’s 2014 calf entangled in one of two buoy lines on September 24, 2014. Photo by Tasia Blough, BHC naturalist.
Before the captain completed the call to the local disentanglement team, Milkweed’s calf demonstrated a bit of valiant tail thrashing and was able to remove the gear from its tailstock within ten minutes of the initial entanglement. We were relieved to watch as Milkweed joined with a group of 11 other humpback whales who were productively bubblecloud feeding.
Witnessing a whale disentangle itself is as rare as watching an entanglement occur on site, and passengers saw both events within a single trip! Calves are found to be more susceptible to such a threat than adults, due to their inexperience and tendency to panic and thrash when ensnared.
Witnessing a whale disentangle itself is as rare as watching an entanglement occur on site, and passengers saw both events within a single trip! Calves are found to be more susceptible to such a threat than adults, due to their inexperience and tendency to panic and thrash when ensnared.
Humpback whales feeding at surface. Photo by Tasia Blough, BHC naturalist.
Researchers and private entrepreneurs are working to develop gear modifications. Progress has been made from Scott Kraus of the New England Aquarium, who has been studying vision in right whales and found that they respond to lines that are red and orange. Fishing fleets in Massachusetts are now being encouraged to use color patterned lines so they are detectable by whales as well as investigators who can associate gear found on whales to correlating areas or fisheries.
The longevity of large whale populations is dependent on how we conduct ourselves in their world. Disentanglement teams, fishing regulations, and whale-friendly gear are measures taken to ease our impact but are not a means of salvation. Whales will mistake refuse for food, absorbing pollutants with protein. The depths by which we harm our neighbors remain untold.
Photo taken by Annie Goodenough, BHC naturalist.
We are bound to whales through a history of tragedy and reverence. To be a naturalist for one year or a passenger for one day means witnessing the enormity and fragility of these creatures. Are we ostracized from our mammalian relatives because of our differences or our collective indifference? It is the question for which we must answer; our generation will be commemorated as stewards of the natural world or we will confound our descendants.
Photo taken by Laura Cupicha, BHC naturalist.
