Ocean Creatures II

In a previous post, we looked at the evolution of life in the oceans and then at several of the most fascinating creatures living there today - the "alien intelligences" (the cephalopods - octopus, cuttlefish) and the "living fossils"(horseshoe crab, coelacanth).  In this post, we look at a few more of the amazing beings living in the seas around us - the charismatic giant manta ray; the operatic humpback whale; and the acrobatic bottlenose dolphin.

A truly awesome presence in the ocean, the Giant Manta Ray can have a tip-to-tip width from 22 to 26 feet and can weigh from 3000 to 5300 pounds.  Their natural lifespan is about 45 years.  But it's not just their awesome presence that distinguishes them from other fish. Possessing the largest brain-to-body ratio of any fish species, they are among the most intelligent fish in the sea.  [1]

Csilla Ari, director of the Manta Pacific Research Foundation, studies manta ray brains and behavior. These rays have enlarged brain areas, she said, associated with intelligence, vision and motor coordination.   Mantas also act smart.  They flaunt their intelligence in behavioral tests that use mirrors to check for self-awareness. Only a few species, including great apes and bottlenose dolphins, can recognize their own reflections, rather than attacking or ignoring the mirror.  In a 2016 study, Ari found that captive mantas swam repetitively back and forth in front of a mirror for an unusually long time, while they examined body parts that they otherwise wouldn’t see.  The rays rolled and unrolled the short, horn-shaped fins around their mouths 10 times more often than without the mirror, and blew bubbles while looking at the mirror — unusual repeated behaviors that could imply self-recognition. [2]

As well as being one of the most intelligent creatures in the seas, manta rays are one of the most charismatic. 

Todos Santos Eco Adventures working out of Baja California writes that mantas "move that remarkable bulk with utter grace, using their massive triangular wings (pectoral fins) to fly through the sea, exuding the glide and flow of an eagle in flight. So when you realize that this fish that seems straight out of myth is turning in patterns with you, engaging with you, and – like any good dance partner –  making direct...eye contact with you, it, well, tugs at your heartstrings." [3]

SAIL magazine recounts an up-close-and-personal encounter with a manta in Polynesia:

"I watched in awe as the manta banked sideways like a Jedi spaceship along the underwater wall, flipping a loop to take another pass along the reef. The ray let us keep pace, and Talon dove again to be nearer. My heart swelled to see my son, dwarfed by its massive wingspan, cruising the reef in tandem with a majestic manta. I was mesmerized, oblivious to everything but the flight of the ray and my corresponding kicks. It could have been minutes or hours that we shared space with the manta before she performed an impressive slow-motion barrel-roll, as if waving goodbye before jetting into the deep." [4]

But these charismatic, intelligent creatures are endangered. So much so that, in 2014  the Convention on International Trade in Endangered Species of Wild Fauna and Flora strengthened manta protections, requiring special permits to trade their meat, gills and fins.  In 2018 NOAA Fisheries listed the species as threatened under the Endangered Species Act. [1,2]

NOAA considers the most significant threat to the giant manta ray to be "overutilization for commercial purposes. Giant manta rays are both targeted and caught as bycatch in a number of global fisheries throughout their range, and are most susceptible to small-scale fisheries and commercial fisheries, particularly purse seines, gill nets, longlines, and trawls."   They note also note that the "demand for the gill plates of manta rays in Asian markets. With this expansion of the international gill plate market and increasing demand for manta ray products, estimated harvest of giant manta rays, particularly in many portions of the Indo-Pacific and Eastern Pacific, has led to massive declines in manta ray populations and fishery collapse." [1]

Individual countries are looking out for their rays too. In 2016, Peru approved regulations to stop fishermen from killing its giant oceanic mantas, the largest population in the world. Mexico, the Philippines, Indonesia and Ecuador also restrict fishing. [2]

On December 9 of last year, the conservation status of the giant (or oceanic) manta ray was up-listed to Endangered on the International Union for the Conservation of Nature (IUCN) Red List of Threatened Species. Over the past two decades, the giant manta ray has progressed from Near Threatened to Vulnerable and now to Endangered.  "The announcement marks the end of a devastating two decades for this species. Targeted for their gill plates – which they use to filter feed on small zooplankton from the water column – the unrelenting and increasing demand for their body parts has fueled both existing and emerging target fisheries. The relatively new Asian-based trade seems to be impacting the giant manta more than other species of manta ray, with the unsustainable harvesting decimating their populations across the globe." [5]

If you want to learn more about manta rays, the Todos Santos website has a post with some "fun facts" about these amazing creatures.  If you want to learn more about protecting manta rays, visit the Manta Trust website. 

Sources: [1] fisheries.noaa.gov  [2] oceana.org [3] Todos Santos Eco Adventures  [4] sailmagazine.com [5] marinemegafauna.org

Image Credit: Giant manta ray in Flower Garden Banks National Marine Sanctuary. Credit: NOAA/George Schmahl 

Videos [below clockwise from the top]: an underwater video from a 2024 Manta Ray tagging expedition off the South African coast that includes a discussion of their intelligence and self-awareness; a manta ray encounter in the Maldives; and an incredible one-on-on encounter between a diver and a manta ray.

If the Giant Manta Ray is on a troubling path to possible  extinction, the Humpback Whale is a species-survival success story.  

By 1970, commercial whaling had reduced many humpback populations by more than 90%, prompting urgent conservation action. The International Whaling Commission had already banned commercial humpback whaling in 1966, but populations were still critically low.

In June 1970, humpback whales were formally listed as “endangered” under the Endangered Species Conservation Act (ESCA), the main U.S. endangered‑species law before the modern ESA. When the Endangered Species Act (ESA) replaced the ESCA in 1973, humpbacks remained listed as endangered.  The ESA provided much stronger protections than the ESCA: a prohibition on killing, harming, or harassing whales, habitat protections, and Federal recovery planning. This is also when the U.S. began pushing harder for global whaling restrictions.

Since that time, the humpback whale has made a remarkable recovery.  The single most important regulatory action was the 1982  moratorium on commercial whaling by the International Whaling Commission, which went into effect globally in 1986.  Many countries stopped whaling entirely; a few continued under “scientific” or objection clauses, but humpbacks were largely spared.

So what happened to cause this dramatic turnaround in world opinion?  After all, whaling was a major global industry for nearly 300 years, flourishing from the late 1600s through the mid-19th century, and then had a resurgence* in the 1960s with whale populations dropping by as much as 90% by the end of the decade.

Pivotal to the swing in public opinion was the pioneering American biologist and conservationist Roger Payne -  one of the most influential figures in whale research and protection. Payne became famous for his 1967 co-discovery, with the naturalist Scott McVay, of humpback whale song. This was the first time anyone realized whales produced long, structured, repeating vocal patterns—essentially “songs.” His work fundamentally changed how the world understands and feels about whales.

In 1970, the same year that humpback whales were listed as endangered, Roger Payne released Songs of the Humpback Whale.  This album played an important role in shifting public opinion and building the political momentum that ultimately led to the protections that enabled humpbacks to recover. 

In 1971, Payne and McVay published a foundational paper, "Songs of the humpback whales"  in the respected, peer-reviewed journal Science.  In it they demonstrated that humpback whale songs have hierarchical structure— short units combining into phrases combining into themes combining in to songs.  This displayed a level of a level of organization that, at the time, had been seriously discussed almost exclusively in relation to human language and music.**  Songs of the Humpback Whale is thus one of those rare cases where an artistic‑scientific intervention helped change the trajectory of a species.

Humpback whale songs are one of the most intriguing windows we have into non‑human intelligence  and point to a mind that is far more complex, intentional, and culturally rich than we once imagined.   Studies have also seen evidence of altruistic behavior in humpback whales, an advanced social behavior with no obvious evolutionary benefit, which we once thought only humans possessed.  

Decades of research following Payne-McVay have led to a consensus that humpbacks possess complex cognition, cultural learning, sophisticated communication, long-term memory, social awareness, and behavior shaped by intention rather than instinct alone. 

In 2016, the Endangered Species Act broke humpbacks into 14 distinct population segments.  Of these 14 segments, nine were removed from the endangered list.

To think that we humans nearly hunted these amazing creatures to extinction is a mark of our hubris and ignorance.  

The rebound in humpback whale populations is a species-survival success story.  But as the baseball-philosopher Yogi Berra once said, "It ain't over 'til it's over." Unfortunately, this progress is now coming under threat from warming oceans.  Inside Climate News reports that new research reveals how rising ocean temperatures are slowing birth rates and shrinking feeding grounds, pushing some whales closer to shore and into greater risk of entanglements.  

Notes: 

*Two primary reasons of this resurgence in whaling and the decline in whale populations in the 1960s included Soviet Union production quotas for whaling fleets and "technological overkill" by large industrial factory ships.   Industrial factory ships could cruise for months and strip a whale to its bones in an hour.  Every part of the whale was utilized for items ranging from margarine and soap to pet food and fertilizer.  

**A longer description of the significance of the Payne-McVay findings, condensed from an AI summary of the Payne-McVay paper, can be found here. 

Sources: ourworldindata.org, Wikipedia, nhpr.org, oceanbites.org

You can find a YouTube video featuring a vinyl restoration of Roger Payne's original Songs of the Humpback here.

Below left is a link to a video explaining the work of scientists conducting research into humpback whale song on the leeward side of Maui, inside the Hawaiian Islands Humpback Whale National Marine Sanctuary. 

Below right is a link to a brief description of a study of altruism in humpback whales.

An Evolutionary Tale

Before moving on to the acrobatic, intelligent, and socially complex bottlenose dolphin, we take a look at their evolutionary path.  

Both whales and dolphins are mammals that returned to the sea.  They both trace their return to the ocean to the same evolutionary story: a lineage of land‑dwelling hoofed mammals that began moving back into aquatic life about 50 million years ago.  Whales, dolphions, and porpoises are all members of the cetacean family.  One of their land-dwelling ancestors was the pakicetus, a wolf‑sized, long‑legged mammal that spent most of its time on land but hunted along riverbanks.  It looked something like this:

Pakicetus was fully land-dwelling and is considered the first cetacean.  By ~45 mya, it had evolved into a line of fully amphibious whales and by 30-35 mya, into fully aquatic whales.  These fully aquatic whales had no ability to walk on land  - the lineage is entirely marine.  Tail flukes and streamlined bodies appeared.  One such fully aquatic whale was the basilosaurus, a serpentine giant measuring 50-60 feet long and weighing between 10 and 20 metric tons.

Around this time (~34 mya) whales split into toothed species and baleen* species.  Many millions of years later, dolphins and porpoises branched off from the toothed whales - with dolphins starting to evolve 20-15 mya and porpoises, 15-11 mya.

An ancient toothed whale that stands out as a direct predecessor to modern dolphins is Olympicetus thalassodon, a newly discovered species of toothed whale who swam the seas from about 30.5 to 26.5 million years ago.   Here is what that early dolphin‑like toothed whale may have looked like.

Note: *Baleen whales are whales that do not have teeth, relying instead on finger-nail-like (keratin) baleen plates. 

Sources: science-resources.co.uk, earth.com

Playful and intelligent, social and curious, the acrobatic bottlenose dolphin is one of the most well-known and beloved of any sea creature.  There are are records of interaction with this friendly cetacean going all the way back to the ancient Greeks.  

Like the humpback whale, the bottlenose dolphin is a mammal that lives in the sea.  The bottlenose dolphin weighs an average of 300 kg (660 lb), but can range from 150 and 650 kg (330 and 1,430 lb). It can reach a length of just over 4 m (13 ft).  Social creatures, they travel in groups (pods) of 10-15. They are superb swimmers (18 mph vs. humans' 6 mph) and use echolocation to help them navigate and find food.  

Bottlenose dolphins became one of the most widespread marine mammals (see map below) because of a suite of biological, behavioral, and ecological advantages that let them thrive in almost every ocean basin.  Among these advantages: their physiological tolerance to temperature and salinity, their high intelligence which allows them to rapidly adapt to local conditions, and their swimming ability (up to 18 mph) which allows them to disperse rapidly across entire ocean basins. 

Besides being one of the most beloved of creatures, the bottlenose dolphin is one of the most studied. What’s emerged over decades of research is a picture of a highly intelligent, socially complex, culturally rich species whose behavior rivals that of primates in many ways.  Among the marine scientists findings:

• Bottlenose dolphins can recognize themselves in mirrors, a capacity shared only with humans, great apes, and as we've seen earlier, in the giant manta ray. This demonstrates a level of self-awareness and cognitive sophistication once thought uniquely primate.

• Their ability to learn new tasks, understand symbolic cues, and adapt behaviorally in changing environments supports the view that dolphins possess high-level mental skills.

• Dolphins employ complex vocalizations - using whistles, clicks, burst pulses, and combinations of these sounds.  Acoustic analyses show they adjust vocal behavior depending on daily activities, suggesting context-dependent communication strategies.

• Dolphins are socially complex.  They don’t just live in groups — they build multi‑layered, politically sophisticated societies with cooperation, alliances, communication systems, and cultural traditions that rival primates. These alliances can last decades and require memory, negotiation, and long-term reciprocity. Researchers describe this as the most complex alliance structure outside humans.

Dolphins helping humans in distress is a persistent theme throughout marine history. The pattern appears across cultures and centuries and is bolstered by modern documented cases. Ancient Greek and Roman literature contains numerous stories of dolphins rescuing sailors, children, and shipwreck victims. Modern accounts echo the same themes, suggesting a long‑standing pattern of human interpretation of dolphin behavior. 

Modern documented examples of bottlenose dolphins aiding humans include protecting a person from sharks, leading rescuers to missing or unconscious people, guiding lost people to safety, and direct physical assistance to help a person stay afloat.   Across all categories, there are  common threads- approach behavior toward distressed humans, protective circling, and guiding or alerting actions. These behaviors align with dolphins’ known tendencies to protect calves, injured pod members, and even other species.

Why do dolphins behave this way?  Researchers do not fully understand this, but a couple of theories are that dolphins may be responding to distress cues similar to those of their own young and that their strong prosocial tendencies within pods may generalize to humans.  Dolphin rescues emerge from advanced social cognition, empathy-like neural systems, cooperative social structures, curiosity, learned behavior, and anti-predator instincts.  These traits make dolphins capable of behaviors that humans interpret as rescue—even if the underlying motivations differ from our own.

Sources:  dolphins-world.com, seaworld.org, Wikipedia, natgeokids.com, Reiss and Marino, Mirror self-recognition in the bottlenose dolphin (Proceedings of the National Academy of Sciences, May 8, 2001), journals.plos.org, dolphinallianceproject.org, americanoceans.org, revlox.com, iere.org

This concludes the posts on ocean creatures.  I hope you've enjoyed reading about these amazing beings as much as I've enjoyed writing about them.  If there is one theme running through these stories, it is that they share much with us.  Intelligence, empathy, creativity, playfulness, community - these are traits not solely present in the human race.  

These reflections on real marine life find several unexpected echoes in the realm of fiction as well.  

In Richard Powers' novel Playground, the aging French diver Évelyne watches the intricate dance of a giant manta ray.  As she observes the ray’s sweeping, deliberate movements, she realizes it is not performing for her but inhabiting its own expressive, self‑possessed life — an observation that requires humility, stillness, and a relaxing of the classifications that shape our perceptions.  In that moment, the ray becomes a quiet corrective to the anthropocentric belief that meaning exists only when it is meant for us, revealing instead a planet alive with other ways of knowing. The manta ray’s lesson in Playground crystallizes Richard Powers’ larger argument that the living world is full of intelligence and intention that humans routinely overlook. 

Witi Ihimaera's The Whale Rider follows Kahu, a young Māori girl destined to inherit the leadership of her tribe even though her grandfather refuses to see her as the rightful heir.  The novel intertwines her story with that of an ancient pod of whales whose leader once carried the legendary ancestor Paikea. As the whales lose their way and beach themselves, the novel reveals their inner world. Rich with memory, emotion, and communal bonds, it implies that whales possess deep intelligence, cultural continuity, and empathy that parallel human experience. Kahu’s ability to communicate with the great bull whale and lead the pod back to sea restores harmony between people and nature, underscoring the idea that nonhuman minds are capable of profound understanding and connection. 

In another example, science‑fiction writer and humorist Douglas Adams, with his characteristic wit, uses dolphins to explore many of the same themes through a charmingly skewed lens.  In his Hitchhiker’s series, Adams uses dolphins as a comic yet pointed reversal of human assumptions about intelligence, turning them into a mirror that reflects our own limitations. In Adams’s universe, dolphins are revealed to be the second most intelligent species on Earth—surpassed only by mice !—while humans rank a distant third. This inversion underscores his recurring theme that we consistently misread the world around us, especially when confronted with minds that do not resemble our own. The dolphins, fully aware of Earth’s impending destruction, attempt to warn humanity, but their signals are dismissed as playful tricks. Their final act—a double‑backward somersault while whistling the Star‑Spangled Banner—is cheerfully misinterpreted as a stunt, though it is in fact their farewell: “So long, and thanks for all the fish.”

Seen from Adams’ vantage point, the humor strikes home because it exposes a deeper truth: for all our pride in our vaunted intelligence, humans remain capable of staggering folly, from waging horrific wars against one another to altering the planet’s climate in ways that threaten all life on Earth.  Maybe some of these "lower forms of life" have something important to teach us.