Blog Tags: Dolphins
Herman Melville’s Moby Dick may paint a picture of the sperm whale as a terrifying, ferocious creature that destroys ships and attacks the sailors on them, but modern research shows that sperm whales are compassionate and social creatures, dangerous only to the fish and squid that the giant whale feasts on for dinner, or to the orca whales that prey on sperm whale calves. A heartwarming and unusual recent discovery does even more to distinguish the sperm whale from its deadly reputation, as a group of sperm whales were observed “adopting” a bottlenose dolphin with a spinal malformation.
Behavioral ecologists Alexander Wilson and Jens Krause discovered this unique phenomenon when they set out to observe sperm whales off the island of Pico in the Azores in 2011. Upon arriving there, they discovered a whale group of adult sperm whales, several whale calves, and an adult male bottlenose dolphin. Over the next eight days, the pair observed the dolphin with the whales six more times, socializing and even nuzzling and rubbing members of the group. At times, the sperm whales seemed merely to tolerate the dolphin’s affection, while at others, they reciprocated. "It really looked like they had accepted the dolphin for whatever reason," Wilson reports to ScienceNOW. "They were being very sociable."
Whale watchers off of Dana Point, California were treated to an exhilarating sight this weekend, witnessing a spectacular if unusual phenomenon: the so-called dolphin stampede.
All at once a massive pod of 1,000 dolphins turned the waters around Capt. Dave's Dolphin and Whale Safari boat white, seemingly engaged in one one observer described as a "race", at times topping 25 mph. While the sight of a dolphin stampede is extremely rare, tours by this operator encountered the phenomenon twice this weekend, once on Saturday and once on Sunday.
It is unknown why the dolphins "stampede" or what prompts the bizarre but breathtaking behavior.
Our team in Chile sent us this stunning picture today from just offshore of Robinson Crusoe Island, part of the remote Juan Fernandez archipelago 400 miles West of mainland Chile. In 1704 Scottish castaway Alexander Selkirk became marooned on the island, serving as the inspiration for Daniel Defoe's fictional Robinson Crusoe character (100 miles west is an another island, Alexander Selkirk Island, named in his honor).
The discovery came as a surprise to our Chilean team as dolphins are somewhat rare to the Juan Fernandez Islands. But marine life is not rare on this volcanic chain of seamounts, where nutrient rich water from the deep comes to the surface, powering a profusion of life.
Last month the Chilean senate voted to ban bottom trawling on all 118 of the country's seamounts, after years of advocacy by Oceana, a move that comes as a special relief to Juan Fernandez and its vulnerable marine inhabitants.
Learn more about about Oceana's work in South America.
An article in today's New York Times science section details an effort by the National Oceanic and Atmospheric Administration to map the effects of human-generated noise in the ocean. Whether it's the drone of commercial shipping or the deafening blasts of seismic air guns, sounds that can travel for hundreds of miles, this noise has been on the rise for decades. For animals that depend on sound as their primary means for communicating or finding prey, this increasingly cacaphonous environment can have devastating consequences
The article articulates well the dangers posed to the ocean's inhabitants by an increasingly noisy ocean:
Sea mammals evolved sharp hearing to take advantage of sound’s reach and to compensate for poor visibility. The heads of whales and dolphins are mazes of resonant chambers and acoustic lenses that give the animals not only extraordinary hearing but complex voices they use to communicate.
In recent decades, humans have added raucous clatter to the primal chorus. Mr. Bahtiarian noted that the noise of a typical cargo vessel could rival that of a jet. Even louder, he added, are air guns fired near the surface from ships used in oil and gas exploration. Their waves radiate downward and penetrate deep into the seabed, helping oil companies locate hidden pockets of hydrocarbons.
Marine biologists have linked the human noises to reductions in mammalian vocalization, which suggests declines in foraging and breeding.
The sorts of air gun tests described above are currently being proposed for waters spanning from Delaware to Florida to search for oil and gas deposits. The Department of the Interior which is reviewing the proposal and will issue its decision sometime next year, estimates that those tests would injure 138,500 whales and dolphins.
In this case “injuring” often means literally deafening the animals. For whales and dolphins that use sound as the primary means to find mates, find food, and communicate, such as the North Atlantic right whale (of which there are an estimated 361 left on the planet) going deaf is equivalent to a death sentence.
The tests could also wreak havoc on the area's $12 billion fishing industry. Similar tests elsewhere have resulted in drops in catches of cod and haddock from 40 to 80 percent after the use of just a single airgun array.
Editor’s note: This blog by actress and environmentalist Victoria Principal was originally posted at NRDC’s OnEarth blog.
I’ve been fascinated with marine life like whales and dolphins since I was a kid. Their grace and power, their beauty and intelligence, their joy and their song -- they are truly special creatures.
Now, as an adult, I feel a responsibility to do all I can to help protect ocean wildlife from environmental risks … like the latest threat posed by oil companies dead set on seismic testing in the Atlantic Ocean.
In case you haven’t heard, for the first time in 30 years the U.S. government plans to open up the Atlantic Ocean from Florida to Delaware to high-intensity seismic exploration for offshore oil and gas.
It's a disaster waiting to happen. After the BP oil spill I teamed up with NRDC and Oceana to help protect the ocean from further tragedy. In an effort to stop these seismic testing plans from happening, we’ve created a Facebook photo petition urging the Secretary of Interior to abandon this plan. Please “sign” the petition by adding your Facebook profile photo!
Add your picture to our Facebook photo petition urging the Department of the Interior to abandon the proposal to allow seismic testing in the Atlantic that could injure hundreds of thousands of whales and dolphins!
Not only is seismic testing the gateway to drilling off our coasts, it represents in itself a major assault on our oceans, with widespread harm to ocean wildlife like whales, dolphins and fish. Seismic testing in the Atlantic would expose ocean wildlife to constant dynamite-like blasts about every 10 seconds, 24-hours a day, for weeks and months on end. Even the government admits it could injure up to 138,500 marine mammals and disrupt marine mammal feeding, calving, breeding, and other vital activities more than 13.5 million times.
And because of the enormous distance sound can travel in the ocean, the noise from seismic testing can stretch many hundreds of miles and drive whales to abandon their habitats, go silent, and cease foraging over vast areas of ocean. At shorter distances, it can cause permanent hearing loss, injury, and death.
It would also harm our multi-billion dollar fishing, tourism, and recreational industries that support hundreds of thousands of American jobs. All of this just to make it easier for oil companies to find new sites in our oceans for offshore drilling.
And that just breaks my heart.
The upside though is that we can do something about it. If enough people add their photo to the petition, the Secretary of the Interior will have to take notice. It’s not too late to turn this thing around.
If you’re not on Facebook, you can also sign our traditional-style petition here. Every signature counts!
Yesterday Oceana and its supporters braved foul weather to protest a truly foul idea. Armed with airhorns and megaphones they gave the Department of the Interior (DOI) a tiny preview of what is in store for the ocean’s inhabitants should the Department allow seismic airgun testing to go forward in the Atlantic Ocean.
The DOI is currently reviewing a proposal to use seismic airguns to search for pockets of oil and gas in a huge expanse of ocean from Delaware to Florida. The effects of these round-the-clock tests, which will run for days on end with dynamite-like blasts firing at 10 second intervals, will be devastating to marine mammals and fish alike.
As Oceana marine scientist Matthew Huelsenbeck said at the event:
“There is only one word that I can use that sums up this proposal: unacceptable. The levels of impacts to protected dolphins and whales, including critically endangered species like the North Atlantic right whale are simply unacceptable.”
What will happen to marine life if the government allows seismic testing, using loud airgun blasts, to search for oil and gas deep beneath the seabed along the U.S. Atlantic coast in the next few years?
The answer may be foreshadowed by the scene in Peru, where earlier this year, hundreds of dolphin carcasses washed ashore along an 85-mile stretch of beach. While the science is not definitive, one expert, Dr. Yaipan-Llanos who has been investigating the cause of the dead dolphins and has conducted 30 necropsies, claims to have seen physiological impacts that resemble what would be expected from seismic testing for oil and gas.
Dr. Yaipan-Llanos found bubbles in the organs and tissues of the dolphin carcasses. These harmful bubbles may have been caused by the disruptive impacts of an intense sound source dislodging bubbles inside the animals or the rapid ascent of the animals toward the surface after being scared.
Alternatively, some have suggested that they could be caused by the natural breakdown of the animal’s body on the beach after death. However, the freshness of some of the carcasses sampled may rule out that theory. Another alarming finding is that the middle ears of 30 of the dolphins had fractures, an injury which could be caused by airgun blasts.
Peruvian government officials have denied that the deaths are due to seismic testing for oil and gas or any other human-related causes, but their methodologies are being questioned by Peruvian scientists. Only two autopsies were conducted by government officials, and those dolphin carcasses were collected late in the process, making the cause of death difficult to identify.
What we do know is that seismic equipment was tested between 50 and 80 miles offshore of Peru from January 31st through February 7th and seismic surveys were conducted offshore between February 7th and April 8th. Dr. Yaipan-Llanos first noticed the carcasses on February 7th and he collected his first samples on February 12th. Carcasses then continued to appear through mid-April. The Peruvian government report ruled out viruses, bacterial infections, pesticides or heavy metals and says that it did not find signs of trauma that would indicate seismic tests or human-related causes. But the report did not identify any cause or causes of the deaths, which remain a mystery.
This incident in Peru is unresolved, and may remain that way, but this unfortunate turn of events gives us a picture of what a mass mortality event in the U.S. could look like if seismic surveying moves forward on the Atlantic coast. Given the impacts on dolphins in the Gulf of Mexico following the Deepwater Horizion oil spill, it would be a shame to further threaten even more dolphins with unnecessary air gun use.
Can you imagine the headline “Hundreds of Dolphin Deaths in Atlantic May be Linked to Airgun Blasts from Seismic Testing for Oil and Gas”?
The U.S. government actually predicts that over the next eight years, 138,000 marine mammal injuries would occur from seismic testing using airguns on the Atlantic coast. Vital activities in marine mammals like feeding, calving, and breeding would be disrupted 13.5 million times. Airguns would also threaten valuable East coast fisheries, marine tourism and endangered species like the North Atlantic right whale and loggerhead sea turtle.
The U.S. Bureau of Ocean Energy Management (BOEM) is currently looking into the Peruvian mass mortality of dolphins, and at the same time they are also reviewing a decision about whether to allow seismic testing for oil and gas off the Atlantic coast from Florida to Delaware. The comment period for this decision ends soon, but you can still tell BOEM to protect whales and dolphins from destructive airgun blasts: submit your comments before Monday July 2!
In the last three months, more than 3,000 dolphins have washed ashore in Peru, most likely due to offshore oil exploration. Oil companies in the region often use sonar or acoustic soundings to detect oil beneath the floor of the sea, and dolphins and whales can be affected because of their sensitivity to sound.
Toothed whales, including dolphins and porpoises, have evolved to be able to echolocate. Instead of having two nostrils like other mammals and baleen whales, toothed whales have only one which is used as their blowhole. A whale emits squeaks and whistles from its blowhole, and the sounds bounce off objects in the water, providing an echo. The other nostril has developed into a fatty tissue known as the melon, which is used to receive and focus the returning echoes.
Hearing is considered to be whales’ most important sense, used not only for navigating but also for feeding, bonding with offspring, and finding mates. Noise pollution cause changes in calling behavior, but can also cause whales to change their diving habits which can result in “the bends,” when nitrogen bubbles get trapped in the body.
Sonar can be extremely loud (imagine the sound of 2,000 jet planes), with sound waves travelling hundreds of miles through the ocean. Noise levels this high can cause fatal injuries, similar to those seen in many strandings around the world. As the world’s oceans become noisier, they also become more dangerous for whales and dolphins.
Even more sad news from the Gulf of Mexico, but this time it runs a mile deep. A new study confirms that the oil that likely caused deepwater coral sickness indeed came from the largest accidental oil spill in history, the Deepwater Horizon.
Back in June 2010, deep-sea coral communities showed signs of severe stress and tissue damage after being covered with heavy mucous and brown flocculent material which was believed to be caused by the spill. This type of ill-health in deep sea corals had never before been documented during deep sea research.
The lead author, Helen White from Haverford College, stated, “We would not expect deep-water corals to be impacted from a typical oil spill, but the sheer magnitude of the Deepwater Horizon oil spill and its release at depth makes it very different than a tanker running aground and spilling its contents.”
Deepwater corals can live hundreds of years, and they serve as hot beds for marine biodiversity. The deepwater coral communities are habitat for crabs, shrimp, brittlestars and commercially important fish species like red snapper and grouper. These corals can take a long time to recover from damage and in comparison this would be similar to clear cutting patches of ancient redwood forests in California.
These results are startling in that they show for the first time how harmful deepwater oil drilling is to distant ecosystems even though they are separated from humans by more than 4,000 feet of water. These ancient deepwater corals were likely already living long before the first oil rigs entered the Gulf of Mexico. If we protect them from more drilling and more spilling they could thrive in a world that moves away from oil to smarter and safer sources of energy, like offshore wind.
Oceana is doing its part by filing a legal challenge against new lease sales in the Gulf of Mexico. We do not believe that the government has adequately studied the potential impacts of new drilling or the true extent of the biological impacts from the Deepwater Horizon oil spill. These include the deepwater corals and so many other species that live in the Gulf.
It is also clear that safety measures have not improved to an adequate level. We need your support to continue our efforts to stop offshore drilling and protect important deep sea habitats, dolphins and the thousands of species that are still struggling from oil pollution in the Gulf of Mexico. Go to stopthedrill.org to get involved.
More than 100 dolphins have beached themselves in Cape Cod, Massachusetts this winter, and no one knows why.
In the northeastern United States, it’s normal for about 230 animals to beach themselves over the course of a year. But this year, 129 common dolphins have been found on Cape Cod beaches in the past month.
Examinations of the dolphins haven’t found any sign of illness or injury, adding to the mystery. Beaching or “stranding” happens when an animal gets trapped in shallow water and can’t swim back out to the ocean. This can be caused by disorientation from an unfamiliar landscape, loud noises, illness, or more. Because dolphins form strong bonds, they may follow each other and become stranded in groups.
One factor in Cape Cod might be an unseasonably warm winter, which kept the harbor free from ice and open to wandering dolphins. Combined with the geography of the Cape Cod harbor area—much shallower and confined than the open ocean—and dolphins’ habits of sticking close to their family members, these dolphins could easily find themselves in trouble.
The International Fund for Animal Welfare has been working to save the stranded dolphins and discover the cause of the mass stranding. To date they have been able to release 37 of the stranded dolphins back into the water.
Mass strandings are mysterious events. We may never know the cause, but we hope it comes to an end soon.
- Ocean Roundup: Western Australia Recommended to Halt Shark Cull, Orca Pod Saves Member from Fishing Gear, and More Posted Fri, September 12, 2014
- Oceana Provides Common Hake Recovery Plan to Chilean Government Posted Wed, September 17, 2014
- Offshore Drilling Risks Highlighted in Myrtle Beach Billboards Posted Fri, September 12, 2014
- Sharks and Rays Gain International Protection under CITES Listing Posted Sun, September 14, 2014
- Ocean Roundup: Healthy Corals Mean More Sharks, Extinct Dolphin Found in Peruvian Desert, and More Posted Thu, September 11, 2014