Introduction
In preparation for Sea Otter Awareness Week, sea otter enthusiast, Cory Dalton, offered to share his reasons for being so fascinated with the genus Enhydra, including all three subspecies of sea otter that exist today. Cory shares his thoughts concerning their uniqueness in the animal kingdom, their importance within ocean ecology and shares several excerpts from his favorite authors who know and have experienced these animals up close. For things that are more subjective, he emphasizes when things are only his opinion. Ideally, he hopes everyone will experience and respect these wonderful animals the same way he does – as ambassadors for all living things.
In Dalton’s voice:
A knife’s edge existence as described by Dr. Victor B. Scheffer
“Where billow meets billow, then soft be thy pillow,
Ah, weary wee flipperling, curl at thy ease!
The storm shall not wake thee, nor shark overtake thee,
Asleep in the arms of the slow-swinging seas!”
This poem is an excerpt from one of my favorite childhood books called The White Seal by Rudyard Kipling. The story centers around a group of fur seals facing threats of clubbing by the Aleut natives under the thumb of the Russian empire who sold furs to the West and China. The book never gained much popularity and rightfully so, as it described Alaskan natives in poor light. However, the indulgent personification of seals is interesting, and the illustrations are very enjoyable. Interestingly, fur seals were historically not the primary targets for those seeking fur in the North Pacific. Below is a table summarizing a list of hunting expeditions in the North Pacific from 1742-1800 along with some descriptive statistics. This info was compiled from a most interesting read by Ryan Tucker Jones called Empire of Extinction – Russians & the North Pacific’s Strange Beasts of the Sea, 1741-1867. The book discusses “paradoxes provoked by the violence necessary to civilization” and goes into great detail about the resulting extinction of the most mysterious Stellar’s Sea Cow, which was described as “the paradigm of anthropogenic extinction…as one of the only three known megafaunal extinctions to occur in the modern era before 1800.” The sea otter was not far behind. Fortunately, their robust drive for survival overcame complete eradication, but still, their genetic diversity was damaged, and they are now left with issues due to a lacking genetic makeup required to thrive in a world facing accelerating anthropogenic change. As the ecologist, Victor B. Scheffer said (as was quoted in the book), “The wisdom, goodness, and greatness of Man will be measured not wholly by his technical power over the wild things of the Earth but also by his moral strength in letting them be.” This quote is one of my favorites and has been part of my email digital signature for at least five years now. So, the sea otter having survived what the Stellar’s Sea Cow could not, genetically less diverse, and now facing threats from above (birds of prey and climate), from below (sharks and orca killer whales pressured to hunt things outside of their historic or usual diets), from land via humans and other diseases, from fishing and a restricted range, from oil spills, recreation, a high caloric requirement, the list goes on and on, they really do lead, as Dr. Scheffer put it in his book The Amazing Sea Otter, “A knife’s edge existence.”
Credit: Empire of Extinction by Ryan Tucker Jones, Oxford University Press, 2014
A most recent repatriate
Something that has always fascinated me is both scale and perspective. Our perspective of both space and time is limited to our senses. We know of things and can describe things of certain size, but rarely do we ever get to experience them. Deep time is one such scale that is hard to grasp due to our limited perspective, but one that can be valuable in hypothesizing why things are the way that they are.
This may sound abstract.
So, how does this relate to the sea otter? Enhydra is said to be 3 to 5 million years old (herein referred to as mya) and is described as “the most recent repatriate to the sea.” What does this mean? Well, all ocean-going mammals at one point or another in their evolutionary past inhabited dry land before venturing back into the sea to further evolve.
Whales for instance took the form of an unusual cow-like creature (see image; courtesy https://eartharchives.org/articles/the-evolution-of-whales/index.html) whose closest living relatives are the group of hoofed mammals that includes deer, cows, sheep, pigs, giraffes, camels and hippos. What separates Enhydra from these is that 3-5 mya is much more recent than 50 mya, around the time when whales took their first steps back to a fully aquatic life. Or 28 to 30 mya when seals did. This perspective adds context to why sea otters lead such a meticulous lifestyle of constant grooming, feeding, and resting. Enhydra is without the insulation (i.e. blubber) afforded to other mammals of the sea and is dependent on their luxurious coats of fur to keep them protected; this being the very thing that nearly led to their extinction in the relatively recent past, and in more ways than one (fur trade and oil spills included). What most people fail to realize is that our own genus, Homo, is even younger (Homo erectus being around 1.8 mya) and developed in the same global conditions as Enhydra, along with several other fellow mammalian species. In a way, we are one of the same, at least in my mind, and equally remarkable. Sea otters are social, nurturing, intelligent, learning and can behave in ways that occasionally make people respond with joy and delight, and at the other end, make people cringe. It is interesting how we sometimes hold them accountable as if they were not animals. So, from an evolutionary standpoint, Enhydra and Homo are much akin to one another in that they adapted to great change, by drastically changing themselves, in and around the early Pleistocene.
A keystone for climate
Authors and biologists James A. Estes and Sean B. Carroll published some recent writings that followed the ideas of biologist Robert Paine concerning the “Green World Hypothesis” which labels keystone predators as significant drivers in ecological stability in both local and global environments. Two suggested readings are Serendipity by Dr. James Estes and The Serengeti Rules by Dr. Sean Carroll. The basis of a large portion of the reading can be summarized by a quote that was borrowed and slightly altered from George Orwell’s Animal Farm by the ecologist, Robert Paine. This hypothesis postulates that “all species are created equal, but some are more equal than others.” In The Serengeti Rules, the first rule states:
“Some species exert effects on the stability and diversity of their communities that are disproportionate to their numbers or biomass. The importance of keystone species is the magnitude of their influence, not their rung on the food chain.”
The sea otter seems to be an excellent example of a species being “more equal than the others”, especially man, in my opinion. Proof of this can be found in two recently published papers. One called “Do Trophic cascades affect the storage and flux of atmospheric carbon? An analysis of sea otters and kelp forests – 2012” and the other called “Cascading social-ecological costs and benefits triggered by a recovering keystone predator – 2020.” The first publication concluded that the carbon storage potential that healthy kelp forests offer, as driven by the presence of sea otters, is valued between 205 and 408 million dollars annually in 2012 dollars. The second concluded that “sea otter presence yields 37% more total ecosystem biomass annually, increasing the values of finfish, carbon sequestration, and ecotourism. To the extent that these benefits are realized, they will exceed the annual loss to invertebrate fisheries. Recovery of keystone predators thus not only restores ecosystems but can also affect a range of social, economic, and ecological benefits for associated communities.”
An ambassador and an indicator
To continue and give further thoughts on sea otters being an ambassador to all wildlife and as a valuable indicator for human health, something worth mentioning about the species is the reproduction rate. Sea otters breed year-round and typically give birth every 1 to 2 years and their gestation period is significantly longer than other species of otter, lasting between 4 and 12 months. It is to the benefit of the mother that delayed implantation can occur, with development being suspended for several months. After the birth, the mother must commit a significant amount of her energy budget toward training, feeding and grooming her one and only survivable pup. Occasionally, a mother will have to abandon her pup, choosing survival over successful rearing and even more rarely, a mother will give birth to twin pups (around 2% of the time). There is nothing quite so melancholic as seeing a mother attempt to care for two pups knowing that one will have to go soon after birth for the other to survive. Even more saddening is that the survival rate of a sea otter pup is usually around only 60%; just enough to keep populations from dwindling in certain areas. Newborn sea otters are helpless for two to three months and float like corks on the ocean surface due to the buoyancy of their fur. The pups travel and learn with the mother for approximately eight months. Because of the fragile dynamic, sea otters make excellent ambassadors for the entire animal kingdom and are an excellent indicator of coastal health, which in turn affects the health of ocean ecologies, and ultimately all life. I have always had a somewhat utopian dream of vast kelp forests with enormous buffer zones and immensely biodiverse seas which help regulate climate and extend humanity’s reach into the future.
A term of endearment?
Often in the vein of oppositional defiance and the preservation of short-term monetary objectives people will try to put a negative spin on sea otter presence for one reason or another. I would, however, like to discuss both the negative and positive consequences of animals such as these being labeled as “cute”. While I personally think they are quite cute, I often wonder how this affects the – particularly southern – population’s wellbeing. You may find proof for the negative from the presence of a condition referred to as end-lactation syndrome in which the mother otter cannot obtain the calories needed to support her individual pup and often dies of emaciation or a weakened immune system. What I fear is that if a population of predators, having the caloric demand that they do, are negatively impacted by individuals not allowing for the management required to keep numbers within carrying capacity that the “knife’s edge” will be further sharpened. In other words, are they too “cute” for their own good?
Ideally, if these animals are to continue benefitting their environment, I hope that they have access to the calories they demand and an environment that keeps them healthy – quality of life over quantity, that is.
In conclusion
While I think every species on the planet can be considered just as valuable as the next, the sea otter is the animal I have chosen to read about and study as a proxy for all other life, which is becoming less diverse and thereby diminished. Sea otters are a reminder of what was in place prior to our civilization’s development. They exist just beyond dry land and float at the surface of depths just within light’s reach. There, they were left relatively undisturbed until we learned of how we could take advantage of what they had to offer. At that point, we invaded and reigned an unrelenting terror among all the strange beasts of the North Pacific.
Now scarred, the sea otter still serves as an excellent indicator of ecological health and provides some hope for our own future. If such an energy-intensive and unique animal can survive, despite all the challenges they face, perhaps there is hope for our own future. When I see them in the wild, getting along, with a few calories to spare, it warms my heart providing some relief from the anxieties I have regarding the planet and our recent tendency to waste it away. We once depended on them for their luxurious coats. Perhaps now, if we give them a little space, they can help us once more by accelerating the restoration of what is left. In addition, if we allow them to act as a solid and unfractured keystone species, perhaps they can help us “sea-quester” some of our carbon dioxide wastes as well; while looking good doing it. I have never had any inclination to concern myself too much about what might be beyond the natural world, but I sometimes wonder if the reason we find animals such as these so charismatic is that something divine within us is trying to save them, and in turn save ourselves.
About Cory Dalton
Cory was born and raised in Virginia, spent time in California while serving in the Navy and was fortunate to have first seen sea otters in Whaler’s Cove and at the Monterey Bay Aquarium in California. Since becoming aware of sea otters, Dalton has obsessively followed them and devoted much of his social media toward educating people regarding the remarkable sea otter. After finishing some school and exiting the Navy, he now resides in Sterling, AK where he makes trips to Seward and Homer in the hopes that he can further understand these mysterious and charismatic animals.