To recognize and celebrate World Oceans Day, I’d like to take this opportunity to feature the Earth’s largest inhabitant—the blue whale (Balaenoptera musculus). While they are the largest animals that have ever lived on Earth, direct human predation, which has largely been stopped, has reduced their numbers severely. And they still face indirect threats from human activity simply by being co-inhabitants of the Earth with us. Living in Southern California I am privileged to be able to see these magnificent creatures from the shoreline, or out on a boat not far from shore. We are lucky that our coastal waters are productive enough to attract a population of blue whales that come here in the summer to feed on krill—a small shrimp-like animal that occurs in huge numbers.
I can go into all the details and basic facts about the blue whale, which are staggering, but that would detract from the deeper significance of these animals here in California and around the world. You can get the facts in the sources below, but I want to spend the rest of this blog considering the blue whale along other lines.
I cannot adequately describe what it is like to see blue whales swimming and feeding in the waters off the coast of Los Angeles. Standing on shore, or on the deck of a boat we only get small glimpses of them. Flukes raised high in the air to drive them down to the depths to feed, massive jaws breaking the surface as they engulf tons of seawater and krill, a pectoral fin waving in the air as the whale lunges forward on its side, or a pleated throat bloated with seawater and krill as the animal tries to right itself. We never see the whole animal. They live in a world we can only visit for short periods of time, which shrouds in them mystery for us. And perhaps this also makes us more than a bit disconnected from them, and all marine creatures for that matter.
While watching these animals go about their lives off the California coast, I can't help but wonder about what it would mean to the world as a whole, and to us as human beings, if these incredible creatures were to disappear from the Earth. What would it say about us as a species capable of imagining the future, and anticipating the outcomes of our actions that we didn't care enough to prevent a species like the blue whale from becoming extinct? To think that this, or any other species might one day cease to exist on Earth as a result of our action or inaction is unconscionable—we who of all the animals on the Earth can understand our impact or anticipate its result.
The science of ecology, of which I am a practitioner, has clearly shown us that all life on Earth is connected in an intimate web with all other life, and with the planet's atmosphere, oceans, soils and every other habitable space on the planet. Indeed, there is strong evidence that life on Earth has influenced the chemistry of the atmosphere and the oceans, and during the evolution of living things, these large physical systems of the Earth have evolved in lockstep. The conditions that exist on Earth today, do so in part because of the evolution of life as we know it. This system and all of its linkages are required to support life on Earth. By changing balances and overloading parts of the system, we run the risk of creating conditions that are less and less conducive to various forms of life. Can we afford to take this risk, given that we also depend on this system for our survival?
But given the complexity and resilience of the system that sustains life, the removal of a single link, a single species, may not have catastrophic effects. Unfortunately, because of the complexity, we can't know the ultimate consequences of breaking any given link. It is in our own best interests to preserve and restore as much of the Earth's biodiversity, and along with it, the ecosystem services this diversity supplies.
Besides being the most impressive creature that the Earth's systems have ever created, the blue whale is also a wonderful illustration of those systems, and perhaps of how we must approach its protection. Although it is the largest creature on Earth, the blue whale is not its most voracious carnivore. Rather than consuming creatures only slightly smaller than itself, it instead feeds on some of the smaller creatures in the ocean. In a book titled Why Big Fierce Animals Are Rare, Paul Colinvaux describes why this is. By eating lower on the food chain than a species like the orca, or great white shark, blue whales have tapped into a larger energy source than that which can be provided by other whales, in the case of orcas, or pinnipeds for great white sharks. With this approach, blue whales have been able to evolve into the largest animal on Earth. We can see parallels in the development of the largest animals to roam the land. Today's largest land animal is the elephant. Among the dinosaurs, plant eaters were the largest. The lesson to be learned from all of this is quite clear.
It can be easily argued that the human species is the most dominant on planet Earth now. Rather than seeking to be the most voracious, the most consumptive, can we perhaps find a way to live that allows us to coexist with the rest of the species on Earth and preserve the important ecosystem services they all provide? It is the only way we can ensure the long-term survival of ourselves, let alone blue whales, or any other species.
In 1906, William Beebe, a famed naturalist and explorer said "The beauty and genius of a work of art may be reconceived, though its first material expression be destroyed; a vanished harmony may yet again inspire the composer; but when the last individual of a race of living beings breathes no more, another heaven and another earth must pass before such a one can be again." If we can't protect something as grand and magnificent as the blue whale, what hope do we have in protecting the unseen, but equally important species on Earth? I believe we are up to the challenge, though. That we can use our intellect and ingenuity to invent ways to protect the planet, and with it ourselves. That we can find a way to insure for posterity that blue whales will continue to swim the world's ocean, and that all of the unseen creatures on which we and blue whales depend also continue to exist.
Colinvaux, P. (1978). Why big fierce animals are rare: An ecologist's perspective. Princeton, N.J: Princeton University Press.