CAUSE OF THE MONTH
Dwarf sperm whales
EXPLORE THE CAUSE
Raising awareness about dwarf sperm whales
The ocean’s smallest whale
Like their namesake the sperm whale, dwarf sperm whales are a toothed whale named for the waxy substance called spermaceti that’s found in their heads. While sperm whales can grow over 50 feet long, these pint-sized cuties are smaller than some species of dolphin.
Dwarf sperm whales are careful and quite secretive animals. They travel in groups of 10 or fewer and prefer to move at a slow, steady pace. While they spend very little time at the surface, they’re sometimes seen “logging,” or floating motionless as they bask in the sunshine. When they’re ready to submerge, they slowly and quietly sink from view.
The only time you’ll see them diving below the surface is when they feel threatened. When that happens, you might also see them release a cloud of reddish-brown fluid, kind of like a squid will squirt ink. Scientists are unsure whether this is a simple nervous reaction or a defense mechanism, but it is a trait that’s unique to these whales.
Human activity is their biggest threat
Much of what we know about these elusive whales has been discovered during entanglement incidents. Entanglement happens when animals get stuck in ocean plastic or other marine debris. In the case of dwarf sperm whales, this is most often commercial fishing gear like trap lines, pots, and gillnets.
Once entangled, whales may swim for long distances with the debris dragging behind them. Over time, this can cause extreme fatigue, impact their ability to feed and reproduce, and lead to severe injuries and infections. If trapped underwater, it can also prevent them from coming to the surface for a life-saving breath of air. Right now, entanglement is the leading cause of death for whales.
Whales can also ingest marine debris. Dwarf sperm whales have been found stranded and beached with plastic and other debris blocking their digestive tract. Other threats include accidental vessel strikes, noise pollution, and disease.
More research needed
Dwarf sperm whales spend very little time at the ocean’s surface and tend to avoid vessels, planes, and other tools that scientists use to research marine life. They also look very similar to the pygmy sperm whale, which can make them difficult to identify when weather conditions aren’t still and clear. As such, information about these animals is limited and much of their lives remain a mystery; even their population size is unknown at this time.
Ultimately, effective species management and conservation require a detailed understanding of the animal you’re trying to protect. More research is needed to understand the specific biology, behavior, and ecology of dwarf sperm whales; however, we already know enough about the impacts of plastic, chemical, and noise pollution, overfishing, and other human activities to know that we must take drastic and immediate action to protect the ocean and all the animals that call it home from their impacts.