Issue No. 5: Eating while you swim Pt 2

^{[ID: Illustration of a Baleen whale, on the left, and Toothed whale, on the right. Each is show with the skull evident inside the head cavity, illustrating the placement of the baleen in the long jaw of a Gray whale and the sharp teeth in the much smaller skull of an Orca. Labels for both Baleen and Teeth are linked to the whales’ jaws with white lines. ]}

Whales have been around for about 55 million years, though the earliest ones looked less like the elegant whales we know today and more like enormous swimming amphibians. When the evolutionary process settled on something close to ‘whales’ they all had teeth. Teeth worked well for them till about 23 million years ago when a group of whales split off from their toothed relatives to feed on the availability of very small fish and krill. Since it was more profitable to eat a lot at once, their teeth were eventually replaced them with a way of filtering food from gulps of water. The new tool was a keratin based fiber (like our fingernails) that forms plates of long bristles, called Baleen, which grows down from upper jaw. These baleen plates are smooth on the outside while the edges og baleen on the inside ends up fraying and spreading out like a very bristly comb. The coarseness of the baleen traps and holds the fish, crustaceans, and krill inside while the whale uses their tongue, and abdominal muscles to force the water out pasted the baleen. Once all the water’s gone, the whale swallows dinner and repeats the process as many times as needed, which is often, given how large most of them are. The baleen plates vary in length and thickness depending on the type of whale and their feeding strategies. The color of the baleen ranges from pale straw to black. Some the coloration is genetics, some is aging, and some builds up over the years [1].

^{[ID: Color illustration showing a cutaway of baleen plates attached to the top of a whale’s jaw with small crustaceans trapped inside the mouth. Green arrows flow through the plates toward the words: “The baleen bristles filter out plankton as water flows through”. Below this is a drawing of a Right whale: charcoal colored body, wider at the head with a narrow tail ending in flukes. The large jaw open showing some of the baleen plates. A green arrow leads from the top of the whale to the inside of the baleen plates above. Beside it are the words: “With its tongue the whale pushes water out through the baleen”.]}

Because of their baleen, this group of filter feeders are called Baleen whales. Their scientific name is Mysticeti, from the Greek for moustashe because with their mouths open the Baleen whales kind of look like they have bushy hair on their upper jaw. This group includes sixteen species from the Pygmy Right Whale, who, at only 20 feet is the smallest of the ‘large whales’, to the largest mammal to ever exist: the Blue whale averaging 100 feet. Baleen whales are further divided into three groups based on the way they feed. While they are all filter feeders, the types approach their feeding rather differently. These differences are reflected in the length and quantity of their baleen.

^{[ID: The docent, in an orange coat, holds a piece of Blue whale baleen. The baleen is dark gray rougly the shape of a right triangle. One side is smooth and flat, the other, slopping side, is rippled and light gray at the edge, the baleen frayed.]}

^{[ID: Close up of the cart with a tan colored bit of baleen from a Gray whale, and a piece of black baleen about four feet long, from a Humpback whale. Both are roughly right triangle shaped with the sloping side curving out a bit, narrowing at the bottom. The slopped side is frayed about 1/3 of the way down, the individual fibers separating. The other side is smooth and mostly straight.}

The three types of Baleen whale feeding are Bottom feeding: where the whales use the side of their nose to push into the bottom silt in shallow areas and suction up food. Skim feeding: where the whales glide through a patch of food, with their mouths ajar, letting food come to them. Lunge feeding: where the whales will propel themselves through a patch of food and engulf it as they swim through, closing their mouths as they go.

Bottom Feeding

^{[ID: A Grey whale’s narrow, curved head rises from green-grey water. Pale plates of short baleen hang from its upper lip on either side. The whales’ lower skin is dark grey with white spots.]}

Found in the eastern and western North Pacific, Gray whales have the shortest baleen plates and are the only know bottom feeding baleen whales. Each gray whale has from 130 - 180 light tan colored plates on either side of the jaw, ranging in length from 5 to 50 centimeters / 2 to 19.5 inches. To feed, a gray whale, generally working on its own, or occasional nearby another whale, will swim on its side along the sea floor, in shallow water while sucking a meal plus water and sediment into its mouth. As they head for the surface they filter out the water and sediment, leaving the worms, crustaceans and small fish they’ve dug up. If the water is shallow enough, the whales will be close enough to the surface while they feed that the plumes of sediment can be seen billowing up as they filter out what they don’t want to eat. Groves or plowed rows can even been seen along the bottom of some locations where Grays are or have been known to feed.

^{[ID: color photo of a pale gray Gray whale on its side, with its long nose/jaw pointed toward the silty bottom. A plum of silt billows out from the front of its mostly closed mouth.]}

Gray whale feeding, Morro Bay, CA 2024. Video

Skim Feeding

^{[ID: Image on the Left: the head of a Right whale facing to the right. It has black skin with white and grey bumps on the top of the head. Its mouth is open, the upper part of the head rising out of the water. A multitude of thin baleen plates descend from a thin white band under a thicker, dark section of the jaw. Image on the Right: the head of Bowhead whale faces Left. Its skin is dark gray and smooth with patches of lighter grey. Its mouth is open, showing long rows of brownish-gray baleen that descends for the top of the dark gray jaw into the water. Some of the plates near the nose are spread out a bit showing dark shadows between them.]}

Skim feeding is done primarily by Bowhead and Right whales, who, in the 18th century were thought to be one whale that everyone called Right whales. The reason for the confusion is easy to understand. Both are thick bodied whales with very large jaws to hold the longest baleen plates - up to 5m in Bowheads and 4 m in Right whales and the largest number of plates: up to 360 in Bowheads and 270 in Right whales. Bowheads and Right whales are both Skim feeders who swim slowly through massive patches of copepods and other small zooplankton, taking lunch into their, slightly open, mouths. The whale then filters the water out through those very long, and slender baleen plates. The great length and number of baleen plates helps them filter the large amount of tiny zooplankton they need to sustain their size. They tend to feed in coastal areas where they can feed both at the surface of the water down to the bottom of the water column.

Right whale skim feeding Video

Bowhead whales: BBC One - Frozen Planet II, Series 1, Frozen Ocean, (not skim feeding but great views of their baleen) Video

Lunge Feeding

^{[ID: On the Left: the head of a Blue whale swimming on its side, it mouth nearly closed, angled to the right. The lower portion of its body is light grey. From the jaw long groves curve out and down, stretched out with water. The upper jaw is medium grey an slender. On the Right: a Humpback whale rises from the water, mouth open wide, the inside of its upper jaw visible with its tongue and the edges of light baleen descending from the gum line. Small fish leap from the open mouth and the water around the whale.]}

Lunge feeders make up the largest group and include: Blue, Fin, Minky, Sei, Bryde’s [2], Rice’s, Omurar’s, and Humpback whales. The Blue, Fin and Humpback are probably the best known of this group. The others are all varying degrees of smaller and shyer, making them harder to spot and track on the open water. All of these whales tend to feed solo but will occasional be found feeding cooperatively. The Humpback, while part of the Baleen group, is different enough in physical characteristics and mannerisms that they are literally and scientifically also in a class by themselves. When lunge feeding, whales will swim under water, building up speed with their mouth closed, moving toward a source of fish or krill, either from below or from the side. When they are close enough, they open their mouths, swim through the fish or krill, engulfing a large amount of water and prey before closing their mouth as they swim past.

Two additional adaptations help lunge feeders manage such large gulps of food and water: 1 - expansive grooves that house ventral pleats [3], which run from their chins to their navels and 2 - a special joint at the front of the jaw “where the two mandibles meet which is connected by a flexible cartilage that allows the mandibles to rotate outwards as the jaw opens” . Once the whale has taken in all the water and fish they can manage, they use their abdominal muscles and tongue to push the water out, as the jaw closes, trapping the meal inside against the baleen.

Blue whales Lunge feeding. San Diego, CA May 2024: Video

Fin whale Lunge Feeding. Monterey Bay, CA 2020: Video

Humpbacks have gotten a reputation for being rather showy, particularly when it comes to feeding. Their version of lunge feeding involves corralling fish or krill underwater, sometimes with the help of a group of sea lions, and then swimming up through the mass of food, mouths wide, breaking the surface with a splash of water and wildlife before closing their mouths and pushing the water out through their baleen. While some Humpbacks will lunge feed solo, they are known to gather in cooperative groups which makes for one hell of a show. Between the whales, the sea lions, and the inevitable birds who hover for stray fish, it’s loud and energetic.

Humpbacks lunge feeding, Monterey CA, 2019: Video 

Humpbacks have a variation on Lunge feeding that involves bubbles. Known as “Bubble Net feeding”, it is a cooperative feeding strategy that can involve as many as ten to fifteen whales. In versions documented around Alaska a lead whale will swim to the bottom of a school of fish and blow bubbles through its blowhole while swimming in a spiral pattern. While the bubbles confuse the fish, another whale will send out a loud, trumpeting, call that stuns the fish, and other whales are swimming around the outside of the net, keeping stray fish inside. At a signal from the leader, the whales will begin swimming through the corralled fish, engulfing water and fish as they lunge toward the surface. Bubble Net feeding in Antarctica has mostly been documented as several whales blowing bubble spirals in tandem before swimming up through their meal.

Humpbacks Bubble Net feedings. Southeast Alaska 2019: Video

Humpback Bubble net feeding with cameras attached to the whales - for their view mixed wiht arial drone footage. Akaska 2019: Video

New Methodology

^{[ID: Two Bryde’s whales, both light gray, their mouths open wide with the top jaw pointed straight up to the sky, the lower jaw horizontal to the water’s surface. Very short light grey baleen can be seen on the upper jaws.]}

Two types of the Baleen whales have been seen doing a new feeding technique dubbed Tread-water feeding for Bryde’s whales and Trap feeding for Humpbacks. In both cases the technique appears, so far, location specific. In the case of a specific population of Bryde’s whales, the process may have come about because of pollution in the Gulf of Thailand where they feed. Oxygen levels in the water are very low, reducing the amount of fish and forcing the those that remain to spend more time near the more oxygenated surface. This is turn has led the Bryde’s whales to use a low energy technique where they open their mouths, lower jaw nearly vertical to the surface and tread water with the tail flukes. The fish swim in to what looks like a pool of water. After enough time, the whale closes its mouth, filters, and eats, repeating the process as often as needed.

Bryde’s Whale’s Tread-water Feeding: Video

A variation of this method, dubbed Trap Feeding, turned up in a group of Humpback whales in 2011 off of Vancouver Island, Canada. In this case the adaptation appears to be more about conservation of energy compared to the amount of food one can collect at a time. In Trap feeding a Humpback whale will hover near the water’s surface with its mouth open. Often the whale will turn in place and/or use its pectoral fins to move fish toward its mouth.

Humpbacks Trap feeding: Video

Recommendations

Whale Nation by Heathcote Williams. This long form poem by “English poet, actor, political activist and dramatist” Heathcote Williams was published in 1988 as both a book, with an abundance of photos, and an audio CD with Williams doing a dramatic reading interwoven with music. It was one of the first books about whales that I remember owning. Listening to the audio today I realize that teenage me skipped a lot of the book and just focused on the photos. Partly this was because the photos were amazing. What I skipped where the descriptions of whale hunting and processing which are rough, but important. The book and its CD were part of the effort to grab public attention and make people understand why whales needed saving. The poem reflects the information we had at time, and was an ad for WHALES! so it leans into the fanciful for things we still didn’t know much about. Also be aware that the descriptions of industrial whale harvesting are very hard to listen to / read about but are also an important part of our history, which we will get into more in later issues.

Hard copy book with photos at Abe Books 

CD at Abe Books 

Spotlight: Dr. Sylvia Earle, Oceanographer

^{[ID: Dr. Sylvia Earle, a white woman with brown hair, stands inside a white, hard sided dive suite. Dials and tubes can be seen inside, near her head. Two men assist her from outside.]}

Known by many as “Her Deepness”, Oceanographer, diver, and Algae researcher, Dr. Sylvia Earle is still championing the oceans at 89. Her list of accomplishments is long. Among them she holds the record for the deepest untethered dive in a JIM suit (one of the early, successful versions of an Atmospheric Diving Suit) at 381 meters / 1250 feet. She was the first woman to lead the National Oceanic and Atmospheric Administration as its Chief Scientist. And her 1966 doctoral thesis on marine algae became a lifetime passion which amassed a treasure trove of data that now lives at the Smithsonian’s National Museum of Natural History and includes over 20,000 specimens that serves as a resource for scholars looking at the past and future of seaweed and algae, which in turn gives us a look at the on going health of the oceans.

Dr. Earle was born in 1935 and grew up in New Jersey and Florida exploring ponds and the ocean shoreline and keeping a notebook filled with observations about the marine life she saw. At 19 she became a certified SCUBA diver when the gear was still early development. A year later she got her master’s degree in botany and would use her SCUBA skills to study aquatic plants in the ocean, rather than as samples dredged up in poor condition. In 1970Dr. Earle led an all women team of researchers on a two week stay in the Tektite II Project underwater habitat to study living full time underwater and studying the marine ecology around the habitat. In addition to a multitude of dives at varying depths, in oceans around the world, Dr. Earle co-designed and built underwater vehicles that could be used by scientists to do research greater depths. She received Time magazine’s first Hero for the Planet award in 1988 and the 2009 TED Prize. She is also the founder and President of the ocean advocacy group Mission Blue which aids to build a “global network of Marine Protected Areas”.

Exploring the Ocean for Sixty Years | Best Job Ever: Video 

Books by Dr. Sylvia Earle at Abe Books 

And Glitter!

“The opposite of doom isn’t hope. The opposite of doom is curiosity because doom implies a fixed mindset, but curiosity implies exploration, action and change.” - Pattie Gonia

I’m generally a positive person and glitter has always been part of making life fun and shiny. But holy-crap holding onto hope is hard these days, which is why this quote from Pattie Gonia caught my attention. While she’s not specifically talking about glitter, I’ve come to see that “glitter” can be an idea as much as a craft supply, and reframing hope like this was glitter for my soul. Hope is part of why I started this newsletter. My curiosity about whales (I can’t tell you how many times I watched the video of blue whales lunge feeding) and the world brings me joy and keeps me fighting in these crappy days. If your hope is feeling a little tarnished of late, maybe follow your curiosity and let it lead you to your hope. - I might need that on a t-shirt. In glitter letters of course.

Pattie Gonia’s Ted Talk 

Survey Time!

I have a spreadsheet full of ideas that I’m interested in exploring when it comes to whales. Before I start planning new issues though, I’d love to hear from all of you. What you’d like to know more about? I’ve put together a survey, I hope you’ll take a minute or two to fill it out. Thanks!

Survey 

As always, thank you all for coming along on this marine voyage with me!

Kate

Notes

[1]You may also see ‘cleaned’ baleen in exhibits which are lighter than they would be in the living whale, depending on the cleaning process used.

[2] - There is a smaller type Bryde’s whale that is often referred to as Edan’s whale, for simplicity, I’m using Bryde’s for all individuals of this type.

[3]- The ventral pleats are also known as rorquals. The term is derived from a Norwegian word meaning “tubed” or “furrow-bellied”. All of the Lunge feeding whales have these furrows and so are often referred to as Rorqual whales.