Blog Tags: Sperm Whales
If you head to the beach without sunscreen, you’ll probably return home with a scarlet, painful sunburn. That’s because you’ve exposed your skin to several hours of UV rays, which damage DNA within your skin cells. But did you know that whales can get sunburned, too?
May 17th is the day to show your love for endangered sea turtles, whales, dolphins, and all sorts of marine creatures. Why? Because it’s Endangered Species Day! Today is the day to learn and share information about your favorite endangered animals and rally support around the creatures that need it most.
We can breathe a momentary sigh of relief. This Monday, the Pacific Fishery Management Council voted unanimously to maintain protections off California and Oregon for the critically endangered population of Pacific leatherback sea turtles. However, in 2014 these federal fishery managers will consider another proposal for allowing driftnets into sea turtle habitat southwest of Monterey, California.
At the meeting a few days ago in Tacoma, Washington, the Council considered a full array of proposals to expand the use of drift gillnets off California and Oregon and into an area currently designated to protect Pacific leatherback sea turtles. But Oceana—with the help of our partners, and support of our avid Wavemakers—successfully thwarted those efforts by presenting new science on the decline of leatherback sea turtles; by revealing scientific data showing massive wasteful bycatch of large whales, dolphins, sharks, and other fish by the drift gillnet fishery; and by bringing forward the public uproar over the proposed expansion of the driftnet fishery into a currently protected area.
Mile-long drift nets hang like invisible curtains in the water column to catch swordfish, but they unselectively entangle other marine life traversing through the open ocean. To numerically paint the portrait of this wasteful fishery, for every five swordfish caught in 2011, one marine mammal was killed and six fish were tossed back dead. When it comes to whales, this fishery takes many species, but one of particular concern is the sperm whale. The largest of the toothed whales, sperm whales have the largest brain of any animal and it is estimated that 16 of these amazing endangered whales were taken in the drift gillnet fishery in 2010 alone.
In this gorgeous new Oceana video Alexandra Cousteau delves into Monterey Bay to illuminate the diversity of life at the bottom of the ocean, a crucial habitat that is under the constant threat of obliteration from bottom trawling. Using an ROV the camera captures an otherworldly scene, as scallops flutter by and curlicued basket stars unfurl. Armies of shrimp and brittle stars scamper by, fed by the organic matter from above that drifts down the water column like snowfall, sustaining a remarkably rich community. In shallower waters, coral gardens that take hundreds of years to blossom shelter rockfish and ingeniously disguised crabs, and serve as a nursery for dozens of species of fish. Here octopuses go camouflage against the rocky shale, out of sight of the hungry sperm whales and sea lions from above. Anemone-covered spires upwell nutrient rich waters that feed shoals of krill, which in turn feed blue whales. It is an intricately connected ecosystem and it can be destroyed in an instant by bottom trawling. That’s why Oceana has pushed for an end to bottom trawling in ecologically sensitive areas. And that work has paid off in concrete victories: in 2006 NOAA protected 140,000 square miles of Pacific seafloor from the destructive practice, but more needs to be done. For the most part this world goes unseen by human eyes and it’s why Oceana is working laboriously to document these precious areas before they disappear.
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.