Issue No. 4 - Eating while you swim

[ID: the distinctive black and white facial markings of an orca rise up through clear water. The calf’s mouth is open, its lower teeth showing as a brown sea bird escapes its grasp.]

Whales, dolphins, and porpoises aka Cetaceans are part of the group: Marine Mammals. Cetaceans can also be divided into two further types: those with teeth and those without. Some whales, along with all dolphins and porpoises, have teeth which they use to for lots of things, including, biting. Other whales have baleen, keratin based fibers, like a bristle brush, that they use to filter their food (more about them next month).

[ID: Two images in one: An Orca with its mouth open, showing its conical teeth. A Humpback with its mouth open showing dark lines of the baleen plates hanging from the upper jaw. Fish are jumping out of the pool of water in its lower jaw.]

Toothed whales or Ondontoceti, From the Greek odontos meaning “tooth” and ketos meaning “whale”, are a diverse group with over 70 species including Sperm whales, Belugas and Narwhals, and all the dolphins (including the Orcas) and porpoises. Toothed whales can be very small, like the 5 foot long Vacita or as large as Sperm whales who can average 60 feet. They can be found in all our oceans, with a small subgroup known as River dolphins living in fresh or brackish water. Odontocete tend to be very social and travel in groups or pods of as few as two or as many as over 1,000 individuals. These groups are often organized along female kinship lines with notably strong matrilineal bounds within Sperm whale and Orca pods. While most tooth whales will travel between locations for food, only one group of Orcas and most male Sperm whales travel very long distances for food. Meanwhile, the least well known toothed whales: the Beaked whales, are all deep divers who break depth records to feed.

[ID: Six types of toothed whales. top: Sperm whale, Middle: orca and Baird’s beaked whale, Bottom: Pilot whale, Narwhal and Beluga].

As their name suggests, all Odontoceti have teeth, but not all of their teeth are the same shape, size, or number. Sperm whales and Dolphins have conical shaped teeth, while Porpoises have spade shaped teeth. Belugas have ‘peg-like’ teeth and Narwhals have two teeth… sort of. Male Narwhals have two canines in their upper jaw, one of which will grow into their world famous tusk. Yes, the tusk of a Narwhal is actually a tooth. Female Narwhals also have the two canines, but they rarely show come through the gum-line, and only very rarely form a tusk. Beaked whales have teeth that look more like tusks and Narwhals have a tooth that looks like a Unicorn’s horn. They have different numbers of teeth and some, like the Sperm whale, only have teeth on their bottom jaw. Male Beaked whales have two teeth which are more like tusks that appear on their lower jaw when they are sexually mature. Female Beaked whales technically have two as well, but they almost never grow through the gum line where we might see them.

[ID: Black and white Infographic demonstrating the five toothed whales described above. Whales are staked one above the other. On the left are drawings of the type of teeth for each whale. From the top: Sperm whale / food: squid, Bottlenose dolphin / food: fish, squid, Harbor porpoise / food: small fish, Stejneger's beaked / whale food: squid, salmon, Baird's beaked whale / food: squid, small fish.]

While Toothed whales have teeth, they don’t generally use them for chewing, instead, they swallow their prey whole using a form of negative pressure to suck their meal into their mouths. Some species, like the Sperm whale’s seem to use their teeth in displays of aggression between males, as evidenced by tooth marks on their hides. Some Orca pods will tear their meal into smaller chucks that can be shared and swallowed. Toothed whales feed on krill, fish and / or squid, while some groups of Orca feed on other marine mammals, and one group feeds on sharks. They all have the ability to use echolocation, sending out sound waves that bounce off of obstacles, to identify prey and objects in their path. The actual forms of hunting vary between species with some similarities in the use of group hunting to corral and/or isolate prey, then use their size and strength as tools to stun or otherwise incapacitate their prey.

[ID: Left: a small gray, torpedo-shaped porpoise leaps part way out of the water. It has a very small triangular dorsal fin on its back. Its head is rounded and comes to a soft point at the front. Right: two gray dolphins leap part way out of the water, they both have a wide white stripe along their sides, medium sized triangular dorsal fins and long, pointed, beak-like noses.]

[ID: Info-graphic Top right is a Harbor Porpoise skull with flat or spade-like teeth Lower left is a Bottlenose Dolphin skull with star, pointed teeth.]

When it comes to hunting techniques, Dolphins have come up with some interesting ones. Several communities of Bottlenose Dolphins have developed a technique dubbed “Mud Ringing” where a dolphin will swim in a circle, near shore, rucking up the sand and sediment to create a circle of mud around a group of fish, corralling them in what the fish think is an impenetrable wall. The fish panic, and try to jump away only to get caught by the rest of the pod who were waiting for lunch. Video In a variation of this technique, called “fish-kicking” or “fish-whacking”, the dolphins may work in groups or on their own, hearing the fish, squid, or even octopuses and then using their tail to kick or whack a fish or other prey with their tail stunning it and allowing the dolphin to eat their meal with less fuss. In another technique, used by some Dolphins and some Orca (see below) individuals will purposely strand or beach themselves in shallow water, or even on a beach to get at their prey. This can occasionally lead to the Dolphin getting stranded themselves.

[A large orca at the surface of the water. The majority of its body, and its tall, straight, dorsal fin is black. There is a white patch near its eye on the right, and a light gray patch at the base of the tail.]

Orca / Killer whale (both terms are correct and in use in varying degrees depending on who you talk too) have three distinct ecotypes or groups, each with their own prey type, which in turn changes how their conical shaped teeth end up looking. The Fish eaters, referred to as Resident Killer Whales (most eat lots of types of fish but one group only eats salmon) show the least amount of wear on their teeth. The Offshore Killer Whales are shark eaters. Because shark skin is very rough and abrasive, their teeth wear down much faster, losing their sharpness and sometimes breaking or falling out. The Mammal eaters spend the most time traveling and are called Transient or Biggs Killer Whales. These Orca hunt seals, sea lions, and the other types of whales. Transients show some wear on their teeth from the tough hides of their prey and tend to be larger than the other two types.

[ID: Three types of Orca and Orca lower jaws are shown stacked one on the other. On the left are the jaws, on the right are orca torsos showing some size and shape differences. At the top is Resident Killer Whales who eat salmon. The teeth are conical shaped. The whale is average size, black and white body. Middle row are Offshore Killer whales who eat sharks. The teeth are very worn down. Body type of the whale is similar to the fist. Bottom row are Biggs Killer whales who mammals. The teeth are slightly worn down. Body shape is noticeably larger that the first two.]

Of the world wide Killer whale populations some of the best documented are the three types found in the waters off of Canada, down along the Pacific coast as far as California, in what is referred to as the coastal waters of the northeastern Pacific Ocean. The different types of Orca have a variety of techniques for hunting prey, one of their main techniques is to use the power of numbers, along with their size, and a wide variety of calls, for coordinated hunts. All three types of Orca also appear to participate in food sharing, allowing large prey to be broken into smaller portions through cooperation and to ensure the whole pod has a chance to feed.

Offshore Killer (OFK) whales, a group of between 180 and 300 individuals that are seen mainly in the deeper, offshore waters of the northeastern Pacific Ocean between Alaska and California. Most encounters unplanned and unexpected and most often happen when researchers were studying one or the other type of Killer whale. OFK’s have been see in groups ranging from just five individuals to groups of over 100 but we still know very little about the pod structures. Their primary prey are sharks of a variety of species which they hunt in groups using a large variety of calls to coordinate their attacks.

Many of the mammal eating Transient Killer Whales can been seen traveling along the coast of the northeastern Pacific Ocean, stopping in at Monterey Bay multiple times a year. The pods will hunt in near silence, using stealth to find and track their prey. They will single out an individual, surround them, then use the pod’s strength and speed to overwhelm their prey.

Two groups of mammal eating Orca in the Valdes Peninsula, Argentina, and the Crozet Islands in the Indian Ocean, have been seeing doing the potentially hazardous technique some of their smaller cousins have tried: Stranding or Beaching. In strand hunting Orca will swim toward the shore after seals and appear to intentionally beach themselves to catch their prey. Often the prey is successfully caught in the shallows, but beaching can happen and can be dangerous for the individual in question.



[ID: Left: A dark gray sperm whale swims toward the camera. Its head is almost squared off at the front end. Its mouth open showing pale gums and a row of conical teeth. Right Top: A Beaked whale’s dark gray head its small eye near the hinge of the jaw. The jaw bone can be seen, x-ray like here and in the bottom of the drawing. It’s long, with a pointed front end that slopes up to a notch in which sits the tooth. The rest of the ja is straight and thick. Between these images is the tooth on its on with a sharp point at the top, spreading out and down to a ragged lower rim.]

Sperm Whales and Beaked whales are primarily squid hunters. The squid in turn hunt fish and zooplankton that can live anywhere from 300 to 3,000 feet deep. Booth Sperm Whales and Beaked whales use echolocation to find and track their prey through deep, dark, water. To get enough food to power their dives, and their bodies, Sperm and Beaked whales make multiple deep dives every day, with many of the dives lasting over a half and hour or more at a time. The Cuvier’s Beaked whale holds the record for the deepest dive of all: 9,816 feet (nearly 2 miles) as well as the longest known dive which lasted 222 minutes. They are reclusive whales and not easy to distinguish from the surface of the water, which is one reason we know so little about them. For the ones we do know, we’ve mostly learned about them from individuals who have washed ashore.

[ID: Title in white: Record breaking whale dives. Depth markers are posted along the sides. In Feet on the right: from 5000 ft to 10,000 ft. In Meters on the right: 1500m to 3000 m. Between the measures are five toothed whales, placed near their deepest known dive: Blainville’s Beaked whale, Baird’s Beaked whale, Sperm Whale, Northern Bottlenose whale, and Cuvier’s Beaked whale at the bottom.]

[ID: Left: Nine torpedo shaped, white, Belugas float in a dark sea with a few small, white chunks of ice. Right: Two torpedo shaped, brown speckled Narwhals float in mid-blue water. One whale has its long, slender tusk across the other’s back almost forming and X. There is a shadow of a third whale below them.]

Belugas and Narwhals are a subgroup of Toothed whales called Monodontidae and are related to each other. They live in Arctic and Sub-Arctic environments where they eat different kinds of fish, squid and crustaceans. While Belugas have about 40 teeth, Narwhals have just two canine teeth. In male Narwhals, one tooth grows horizontally out from the maxillary / jaw bone into a spiral tusk that can be up to nine feet long. The other tooth, also actually a tusk, generally never pushes through the gum line. Once in a while, the second tooth will follow the first and the Narwhal will have two tusks. In most Narwhal females neither tooth ever emerges and they appear to have no teeth. Like other Odontoceti, Belugas and Narwhals use echolocation to hunt for their prey and find their way under the arctic ice flows. They are also less well known members of the Deep Dive club. Narwhals have been recorded making dives as deep as 4,500 feet while Belugas have been recorded diving to up to 3,200 feet. Both are hunting squid and crustaceans at such depths. When not diving, Belugas hunt for prey near the bottom of shallow coastal areas. They work in small pods to corral fish into easily managed balls, then swim through and pick out a meal. And in 2017 it was discovered that Male Narwhals use their tusk to stun fish and then slurp the fish into their mouths. In this video, you have to look closes as the cod the Narwhal is stunning is very small in comparison.

Recommendations

Toothed whales don’t group well into a single book or movie to recommend but I did find a fun playlist of 21 short videos with information about different types of toothed whales: Youtube And, for those who didn’t have time to watch it on first recommendation, there’s Disney+: “Secrets of the Whales”. This is a four part show on Disney+ / Hulu, focusing on four of the most well known types of whales: Orcas, Humpbacks, Belugas, and Sperm whales. You can watch a preview of the film on Youtube.

Spotlight: Dr. Joan Murrell Owens, Teacher and Coral Biologist 

[ID: Black and white photo of a Black woman with short, curly, dark hair seated at a microscope in a lab. She wears a floral blouse and a long sting of pearls. In her right hand she holds a button coral: a circle of white with faint striation radiating from the center.]

From a young age Dr. Owens had a deep love of the oceans. Her parents would take her and her two sisters fishing on the weekends and both encouraged their daughters to pursue higher education. Reading about both Jacques Cousteau and Eugenie Clark (the Shark Lady) added fuel to her dream of becoming a Marine Biologist and kept her going when the road got complicated. She attended the historically Black school Fisk University even though they did not have a Marine Biology program. Being Black and female in the 1950s meant taking more acceptable courses of study. With a voracious appetite for knowledge, Dr. Owen’s first degrees were in Fine Arts, Math, Psychology and Guidance Counseling. After a successful care as a teacher at both the University of Michigan's Children's Psychiatric Hospital and Howard University, and creating a program to teach English to disadvantaged Children which would influence the US’s Upward Bound program, Dr. Owens started over again, going back to school in 1970, at the age of 37. She studied geology and zoology at George Washington University, receiving a Bachelor of Science in 1973 and a Masters of Science in 1976 and in 1984 earned her PhD, in Geology. While working on her degrees she worked at the Smithsonian Institution’s National Museum of Natural History cataloging specimens in the paleontology department’s collection.

Having been born with sickle cell anemia traits, which limited the amount of oxygen in her blood cells, Dr. Owen’s was unable to dive to do research and collect samples herself. This could have limited her ability to study and work in her field but her connection to the Smithsonian allowed her to work on an existing collection of button corals, the eventual subject of her doctoral dissertation. Through her meticulous work Dr. Owens described and catalogued each button coral in the collection and made several lasting contributions to her field. She discovered a new genus of button coral called Rhombopsammia, three new species, once of which she named after her husband Frank, and her hypothesis that deep water coral were more mobil than shallow water coral due to the availability of calcium carbonate during the Cretaceous period.

“It’s important because of its contributions to our understanding of the life of the sea and some of the ways in which ecology and evolution interact. Also, it is important to others working with deep-water organisms because of some of the relationships I think I indicated—if not proved—between water depth and availability of calcium carbonate that influenced the physical evolution of some organisms.” - Quote from Joan Murrell Owens, 1996.  

Links:

Joan Murrell Ownes and Her Button Coral, The Smithsonian

Dr. Joan Murrell Owens: Call of the Coral

And Glitter

When I found out how problematic plastic glitter is for our world, I went looking for alternatives. Thankfully some chemists had done the same and come up with biodegradable glitter! Biodegradable glitter is made from cellulose aka plants, usually eucalyptus. “In order to be considered biodegradable, glitter must be plastic free, break down on its own, and pass  “the fresh water test," meaning it needs to totally disintegrate in fresh water.” At this time there is only one company that I have which makes certified biodegradable glitter is UK based: Bioglitter. They make and distribute craft, technical, and cosmetic grade glitters to a number of retailers in the UK, EU, US, and CA. you can find their list of retailers here.

Two notes: One: a number of the small retailers have gone out of business in the last 5+ years, so I can’t give your recommendations at this time (though I have test samples coming) and not all of the listed websites are still active. Two: Always check the labels. Some places that are licensed to sell Bioglitter also sell plastic plastic glitter, so be sure to read the ingredient lists.

As always, thank you for joining me on this journey. I hope you are having as much fun as I am. In the next month or two I’m going to set up a poll to get feedback from you about what topics you’re interested in. Before that goes out, feel free to leave your thoughts in the comments (they should actually behave now!)

Kate