Blog Tags: Sperm Whales
The spring issue of Oceana magazine is now available online! We are especially excited about the Q&A in this issue, which I did with sperm whale researcher Shane Gero.
Gero, who wrote an incredible guest blog post for us last year, is working on his PhD at Nova Scotia's Dalhousie University, and is the lead researcher for the Dominica Sperm Whale Project.
He has has spent thousands of hours at sea observing families of sperm whales off the coast of the Caribbean island of Dominica. His research marks the first time that scientists have tracked individual sperm whales from birth into maturity, and it provides insights into sperm whale society, diet, genetics, communication and culture. Prepare to be amazed:
How did you become interested in sperm whales?
They are the largest of the toothed whales, among the deepest divers, have the planet’s largest brain, and they can be found in every ocean and most coastal seas and gulfs on the planet, so as a result they are a significant part of the ocean ecosystem. They also live in complex multi-level societies, have a highly sophisticated communication system, and show signs of culture – so there are lots of interesting questions to explore.
During your research have you become attached to any of the individual whales?
I don’t pretend that the animals know who I am, but I have followed some of these whales since birth. I have been there as they have played with their siblings, nursed from their mothers and through the toils and troubles of growing up. As a result, I feel an obligation to them to share their stories in an effort to ensure they have a healthy ocean in which to raise the next generation.
What do you see as the biggest threats facing sperm whales?
While whaling for sperm whales has largely stopped, humans are still the sources of the major threats to sperm whales. Chemical and heavy metals are being found in the tissues of animals from around the world, including those as far away as Antarctica, and animals can become entangled in fishing gear including longline and gill nets. But ocean noise is increasingly being seen as a major threat to cetaceans around the world.
Close your eyes and imagine you’re a sperm whale. Your world is mostly darkness. In order to stay connected with your family you play a constant game of Marco Polo. You see with sound. Now imagine a constant background noise from all around blurring the echoes. As humans it might compare to living in a rock concert your whole life, just asking your neighbor a simple question would be difficult.
Why do you think sperm whale conservation is important?
On an evolutionary timeline, sperm whales are among the oldest of the toothed whales. They have lived in the oceans for longer than modern humans have walked upright. Both the whales and humanity depend on the ocean for survival, so in some ways, I am not asking people to care about sperm whales specifically, I am just asking them to care. If more people feel the shared burden we all have to protect the oceans then I will have done my job.
Anything else you want to share about sperm whales or your research?
Ultimately, what I have learnt from these families of sperm whales thus far is simple. Love your family. Learn from your grandmothers’ experience. Be a good neighbor. Share the burden of your responsibilities by working together. Spend time with your older brother because eventually he moves away. And most importantly, life, it seems, is about the relationships one builds with those around them.
Plastic is one of the most common pollutants that end up in the ocean, but the properties that make it ideal for shopping make it deadly to marine life.
Plastics are durable and do not decompose easily, which means they can stay in the ocean for decades. And because they are so lightweight, plastics can float in the ocean where sea turtles and marine birds can get entangled or even ingest them by mistake. For example, plastic bags in the ocean closely resemble jellyfish, which are a common food for sea turtles.
Plastic can also have serious effects on marine mammals, including sperm whales which are some of the world’s smartest animals – possessing the largest brain of any known species.
Sperm whales typically feed on squid, sometimes diving more than a mile below the ocean’s surface to find food. But plastic trash is becoming more and more a part of the whales’ diets. Each year, sperm whales eat more than 100 million tons of seafood using suction, which makes them more vulnerable to ingesting plastic. And because sperm whales are at the top of the food chain, they are the most likely to be affected by pollution.
Editor’s Note: Guest blogger Shane Gero is a Ph.D. candidate at Dalhousie University in Nova Scotia and a lead researcher for the Dominica Sperm Whale Project.
I met Enigma when he was only a few months old. He was about three meters long and probably weighed over a ton.
That’s about average for a newborn sperm whale. When he reaches full size, in about 25 years, Enigma might be as long as 18 meters and weigh over 50 tons.
I have been following Enigma’s family since before he was born. I have spent literally thousands of hours at sea following them and about 20 other families of sperm whales which live in the eastern Caribbean Sea.
It has really been the first time that anyone has come to know these leviathans from the deep as individuals with personalities, as brothers and sisters or as mothers and babysitters, and as a community of families each with their own ways of doing things, their own dialects, and their own cultures.
Sperm whale relationships are very much like our social lives -- more so than many might like to admit. The main difference is the most obvious, they live in the ocean. You see, most of the ocean is actually dark. Only a thin layer at the surface gets any light from the sun. For a sperm whale, life is really in the darkness of the deep.
I jokingly call them “surfacers” rather than “divers” because an adult female, like Enigma’s mother Mysterio, will spend over 80 percent of her life in the darkness of the deep ocean feeding. She will only spend about 10 to 15 minutes of every hour in the part of the ocean that sunlight touches and where I can observe her interacting with other members of her family.
As a result, while Mysterio’s eyesight is good both above and below the water, her world is dominated by sound. Just like bats, sperm whales have evolved a system of echolocation to “see” in the dark. Their unique nose, which houses the most powerful natural sonar system, has allowed them to exploit the deepest parts of the ocean that very few other mammals can, and as a result has made them a significant part of the ocean ecosystem. Globally, sperm whales can eat as much squid as all of humanity’s fisheries combined.
On this hump day, a few cetaceous stories for your perusal:
As you've probably heard, the team behind Sunday’s Oscar-winning documentary “The Cove” exposed Santa Monica sushi restaurant The Hump for serving illegal whale meat. The possession or sale of marine mammals -- in this case, the endangered sei whale -- is a violation of the Marine Mammal Protection Act, and can lead to a year in prison and a fine of $20,000.
And on the brighter side, the BBC has a remarkable slideshow of images showing a sperm whale surface feeding off the coast of New Zealand. Surface feeding is uncommon for sperm whales, who usually hunt many meters below the sea’s surface -- this individual must have been pretty hungry.
The researchers have evidence of the whales staying together over several months in the Gulf of Mexico. And their behavior varied with each deep dive, indicating that they alternate roles to spread out the physiological demand of the 1,000-meter dives.
One researcher said that the some whales appeared to guard the bottom of a squid bait ball, while others took advantage of the center of the ball.
Other research has suggested dolphins may exhibit herding behavior, but this is the first evidence in sperm whales; some scientists remain skeptical.
Just remember, whales: there is no "I" in "team."
Don't you hate when you're at a party or restaurant, and even without music on, the room grows louder and louder and louder? Until you can barely hear the person standing right next to you? New research shows that sperm whales have evolved to circumvent this cocktail party conundrum.
According to the scientists, whose work will be presented at the Acoustical Society of America next week, the whales are polite conversationalists -- they make a specific effort to keep their calls from overlapping by changing the intervals between their echolocating clicks.
Perhaps humans can try this. It might go something like this:
"Would you - click - like an hors d'oeuvre - click?"
"Yes, one - click - mushroom puff - click - please."
And in other acoustic findings, researchers have discovered the first known instances of male humpback whales singing to one another, similar to songbirds. Whether the whale songs are macho seduction tunes -- like male birdsongs -- is still unclear.
What is clear is that there's a lot we don't know about what's being said and sung under the sea.
Sperm whales are named for the waxy oil in their head, spermaceti. Used in many industries ranging from cosmetics to automotive, spermaceti drove whalers to target sperm whales and they are now listed as threatened by the International Union for Conservation of Nature and Natural Resources. Due to their size, however, sperm whales have been known to fight back, famously attacking and sinking the whaling ship, Essex, the ship Moby Dick is based upon. Learn more about these large predators and other animals in the Creature Corner.
When I usually read about theft and the sea, I think of overfishing and depleted natural resources. But this time around, it is a hungry predator taking advantage. Check out this video on National Geographic Kids and get ready for a surprise around the 35 second mark. One particularly smart sperm whale has learned how to shake fish free of lines without injury. Perhaps if he had enough food in the open sea, he wouldn’t have to resort to such tactics.
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