Peru

Oil Exploration Noise May Lead to Dolphin Strandings

Posted Fri, Apr 13, 2012 by Piper Wallingford to dolphin strandings, dolphins, echolocation, oil drilling, Peru, seismic testing, SONAR, sound sensitivity, the bends

© Oceana/Carlos Minguell

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.


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New Study Measures Nations’ ‘SeafoodPrint’

Posted Wed, Sep 22, 2010 by Emily Fisher to anchoveta, china, daniel pauly, overfishing, Peru, salmon, seafood, seafoodprint, tuna, united states fishing footprint

You knew the U.S. had a massive carbon footprint, but did you know we also have the world’s third largest “SeafoodPrint?”

That’s according to a study published today in National Geographic led by Oceana board member and fisheries expert Dr. Daniel Pauly and National Geographic fellow Enric Sala.

How do you measure the "SeafoodPrint" of a country, you ask? By factoring in the type of fish and the total amount hauled in. The researchers used a unit of measurement based on "primary production," the microscopic organisms at the bottom of the marine food web that are required to make a pound of a given type of fish.

China comes in at the number one spot because of its sheer population size, while Peru is ranked second because its anchoveta becomes fish meal for farm-raised pigs, chickens and fish (such as salmon) around the world, even though Peruvians themselves don’t consume a lot of fish. Meanwhile, the U.S. is ranked third because of the type of fish we generally prefer -- top-of-the-food-chain fish, such as tuna and salmon.


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A Whale of a... Whale

Posted Fri, Jul 2, 2010 by MollyH to great white shark, killer whale, Leviathan melvillei, Paleontology, Peru, toothed whales

Happy Friday! Time for a brief break from the oil spill. And what better reason than for a really freakin' cool prehistoric whale.

The great white shark is often considered one of the world’s greatest predators. At between 15-20 feet long it is no slouch, but it pales in comparison to the Leviathan melville, a recently discovered predatory whale that lived 13 million years ago.

Named after the mythical sea monster Leviathan and Moby Dick author Herman Melville, the Leviathan melvillei was probably close to 60 feet long. According to the fossils found in a Peruvian desert, which was once part of a great ocean, the teeth of the beast were over a foot long and almost half a foot wide.


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