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Blog Tags: Sharks

Top 5 Myths About Sharks

Basking sharks are gentle giants, nothing to fear here (unless you're plankton). ©NOAA

Happy Shark Week!

Sharks are the center of a lot of stories and urban legends, but you might be surprised by the truth behind some of the most common myths about sharks. In honor of Shark Week, we’re going to dispel some of the major myths surrounding sharks and shark behavior.

MYTH #1: All sharks are voracious predators, looking to attack anything in sight, including humans.
FACT:
While some shark species do have aggressive tendencies, most hunt only to find food (and humans aren’t on the menu). Just like other top predators, sharks make a meal out of animals lower in the food web, keeping the ocean habitat in balance. Only a few species have been known to attack humans unprovoked, and that’s often because of poor visibility or inquisitive bites. There are even species, like the whale shark and the basking shark, that are filter feeders that eat fish eggs, krill, and other microorganisms in the water.

MYTH #2: Sharks do not attack at midday.
FACT:
It’s true that there are fewer attacks in the middle of the day, but that’s not because sharks aren’t active then—it’s because everybody’s out of the water eating lunch. Sharks are most active at dawn and dusk, but it’s possible to encounter at shark at nearly any time of day.

MYTH #3: Sharks have walnut-sized brains.
FACT:
Sharks are actually pretty smart! They have some of the largest brains in the fish world (along with their close relatives, rays), and their brain-to-body size ratios are similar to birds and mammals. Sharks have been known to exhibit complex social behavior, curiosity, and play in the wild. Many species live in groups and hunt in packs.

MYTH #4: In order to stay alive, a shark must constantly be moving.
FACT:
The movement of swimming allows water to pass over a shark’s gills so that they can breathe, but some species have adaptations that allow them to stay still and breathe at the same time. When resting, some sharks can lie on the sea floor and actively pump water over their gills.

MYTH #5: Sharks have no predators.
FACT:
Yes it’s true that sharks are at the top of the food chain, but they have a very powerful predator: humans. Each year, tens of millions of sharks are killed for their fins, sport, or caught and killed as bycatch. By removing so many of these important predators without allowing them time to restore their populations, we’re disrupting the balance of the marine food web.

The great white shark, the most iconic shark in the ocean, faces serious threats off the West coast of the United States. Only a few hundred are left, and their populations aren’t recovering quickly — unless we do something. Sign today to help improve protections for great white sharks in the Pacific.


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Get Ready for Shark Week 2012

Shark Week turns 25 this year! ©Discovery Channel

You’ve been waiting for it all summer, and now it’s finally here — Shark Week returns this Sunday, August 12th! Oceana is again a conservation partner, and we’ve got some fin-ominal stuff in store this year.

Need some help preparing for the sharkiest week of the year? Have no fear, we’re here to help! Here are some ways you can gear up for Shark Week’s 25th year:

1.    Spread the Shark Week Love
Have your friends over for a watch party. Check out Discovery’s programming schedule and pick out the shows that look the best. ”Great White Highway” follows shark scientists in their effort to solve some of the more mysterious behaviors of the most well-known shark in the world. It’s also narrated by our board member Ted Danson! Check it out on Thursday, August 16th at 9 p.m.

2.    Spend Shark Week with Oceana
We’re so excited about Shark Week that we’re going to be live-tweeting all the new shows! Follow along on our Twitter — we’ll be watching along with you and answering your shark questions. And look out for some fun Shark Week swag give-aways.

You can also share photos and stories with us via Twitter, Facebook, Pinterest, and Instagram.


3.    Protect Sharks
For one week a year, over 30 million Americans are glued to their TV sets, transfixed by incredible stories of amazing, powerful sharks. But the true story is that they can’t save themselves from their top predator: us.

Right now there are only a few hundred adult great white sharks remaining of the U.S. West Coast. They are in danger of extinction, but you can help. Sign today to help great whites off the West Coast get listed under the Endangered Species Act.. [link to action page] You can also help spread the word through social media by signing up at Thunderclap.it/sharkweek.

Make sure that Shark Week isn’t the only time you care about sharks. They’re great to watch on TV, but we need them in the wild, too!


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This Shark Week, Save Great Whites

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Great whites play an important role in the ocean ecosystem ©Terry Goss

During Shark Week we love watching majestic great whites on TV, but if we don’t act soon to protect them, recordings will be the only place they exist.

In the Pacific, great whites are important predators. As the largest predatory fish on the planet, they can reach lengths over 20 feet and weigh more than 5,000 pounds. They’re shaped like torpedoes and can swim through the water at speeds of up to 15 miles per hour. Great whites can detect electromagnetic currents in the ocean and have such a sharp sense of smell that they can identify blood in the water from up to 3 miles away.  You can’t deny that these are impressive animals.

As fearsome as they might be as predators, they’re not the killing machines that they’re often identified as. They use all those prey-detecting skills to help keep the marine food web intact — without great whites, the ocean’s balance would be thrown off.

But that might be what the future holds, if nothing is done. A recent study found that there may only be a few hundred adults left swimming off the coast of California and Mexico, far fewer than anyone expected. And those that are left face deadly dangers from fishing nets.

Newborn great whites are often killed by commercial fishing gear off of Southern California and Baja California, making it hard for the populations to stabilize.

Sharks have inhabited the oceans for more than 400 million years and now they’re disappearing because of human actions. We’re working to get US great whites the protection they need — sign today to help get great white sharks on the Endangered Species Act.

Shark Week starts on Sunday – stay tuned for lots more sharky updates!


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Victory for Mediterranean Sharks and Rays

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Hammerheads are one of ten species that are now protected ©Wikimedia Commons

Sharks and rays in the Mediterranean have something to be happy about this week—10 species now have special protections under the Barcelona Convention.

These 10 species—including hammerheads and shortfin makos—have suffered significant population losses. Shark and ray numbers have declined and some species are nowhere to be seen in areas where they were once common.

Today’s decision allows the EU to formalize protection for these important predators. It’s a step in the right direction for the EU, which recently delayed measures that would have limited overfishing in European waters.

“These vulnerable sharks and rays have been granted the legal protection that they urgently require,” according to Ricardo Aguilar, Director of Research at Oceana Europe. Now that the legal protections are in place, the next step will depend on locating where the protected species remain in the Mediterranean, and implementing strict protection measures in those areas.

Sharks and rays are some of the oldest fish in the ocean—the oldest shark relative is estimated to be up to 450 million years old. And now some species have lost 99% of their population in just the last century. Overfishing is a huge threat to these living fossils, and if we want them to be around in the future, we have to act now.


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If You Were President...

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We asked our Ocean Heroes finalists: If you were elected President, what would be the first thing on your agenda?

They gave us some pretty great answers, check them out below, and don’t forget to vote for your favorite finalist! Who knows, maybe one of our finalists will be running for President themselves someday.

Adults

Michele Hunter Stop the killing of all marine mammals throughout the entire world.

Hardy Jones Expose levels of pollution.

Kristofor Lofgren I would change our energy policy, because reducing carbon and oil and gas spills, creates a healthier and less acidic ocean.

Dave Rauschkolb End offshore oil drilling.

Rick Steiner An emergency effort in clean, sustainable energy, and energy conservation, to stop climate change and its devastating impacts on marine ecosystems.

Don Voss Appoint Sylvia Earle Secretary of World's Oceans and give her free reins to establish regulations as needed.

Juniors

Sara Brenes Ban all shark finning in US, no shark products to be sold, imported or exported, create an ocean world conservation summit to try and make a plan to end shark finning, whaling and overfishing and try to create peaceful and safe ocean pact.

The Calvineers Reinforce the Endangered Species Act, especially the Marine Mammal Act so that NOAA would be better funded and more efficient at protecting marine mammals from human made dangers.

Sam Harris No killing sharks on this earth ever!!!!

James Hemphill Ban the chemical BPA from plastics to reduce the human input of toxins in the ocean.

Teakahla WhiteCloud I would ban all long-line fishing and trawler fishing and make sure all ocean laws are strictly enforced and make all reef systems National Parks.

Only a few more days of voting are left, tell us your favorite finalists today at oceana.org/heroes!

Photo Credits (clockwise from top left): Oceana/Juan Cuentos, Oceana/Maria Jose Cortex, Oceana/Carlos Suarez, Kip Evans Photography, Oceana/Carlos Suarez, Oceana/Carlos Suarez, Oceana/LX, Oceana/Juan Cuentos, Oceana/LX, Oceana/Juan Cuentos, Oceana/Enrique Talledo.


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What Motivates You?

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To be an Ocean Hero, you have to have a strong commitment to your work—so what keeps our finalists going when the going gets tough?

The voting is open for our 2012 Ocean Heroes Awards, but if you're having a hard time deciding who your favorite finalist is, here's a chance to get to know them better.

Each of our finalists has their own unique story about just what it is that motivates them to protect the world’s oceans. Here’s what they told us keeps them working hard to achieve their goals:

Adults

Michele Hunter Sometimes it's witnessing the small steps a critical patient will take because of the dutiful care and treatment we provide to our patients.  Knowing that all those hours of care made a difference. Being able to stand on the beach with your team and release an animal that you helped save is motivation enough!

Hardy Jones Frankly, what motivates me is the undeniable need for reform of the way we view and deal with the oceans. There is real danger of a collapse of the ocean ecosystem. Other motivation comes from direct contact with the magnificence of the ocean realm. Finally, I am motivated by the knowledge that I can make a difference if I put out the energy and intention to accomplish important goals.

Kristofor Lofgren I want to live in a healthy and beautiful world.  I also want to do all I can to share that wonderful world with others.  I am motived each and every day to help make the world a better place for everyone I never meet, simply because it is the right thing to do.  We all breathe the same air, drink the same water, and share the same earth.  I choose each day to bring passion to simple, good work...and that is enough.

Dave Rauschkolb The unapologetic grip the dirty fuel and nuclear industries have on our world, and seeing that clean energy and renewables are beginning to break that grip.

Rick Steiner I'm motivated by knowing the desperate state of the oceans, seeing my favorite seas and coasts lost to human ignorance and greed, and facilitating the successes I've been involved with.  There is simply no other option but to ramp up the science-based advocacy for ocean protection -- and that is a powerful motivator.  It is urgent to act, not just talk about the problem.  Knowing we can, and must, succeed.

Don Voss I am motivated by the thousands of kids I talk to each year who are interested and react to this project.  I help at least 25 new divers a year get started and into this sport and debris collection.  I am motivated by the progress in removal and changes in water quality we are finding just this year.  I am motivated when others notice what we do and want to participate and/or learn more.  I am motivated when we continue to release thousands of snagged and trapped aquatic animals.  I am spiritually motivated when I visit our Turtle rescue hospital and visit the critters we have sent there.  Turtles are awesome and send me home an activist.

Juniors

Sara Brenes I am so passionate about my belief and my drive to make a difference. I feel like I breathe, eat, sleep, and dream about sharks and our oceans. I think it is just hard wired in to me to not give up and to fight and fight and fight and reach another person and another person and another one. Just don't stop!

The Calvineers The North Atlantic right whale is the most endangered large whale in the world.  Their population has grown little in the last thirty years (from about 300 to about 450), way below the estimated 2-3,000 needed for recovery.  Until the whales recover, the Calvineers will keep up their work of educating the public.

Sam Harris I do it for the sharks. I love them.

James Hemphill My love of the ocean keeps me going.  This is a problem that will not go away.  As long as there is a large human population, there will be conflicts with the environment that need solutions.  I want to be a part of those solutions.  I have a stubborn determination to see cleaner oceans.  This is where I play, swim, surf, fish, and kayak.  I want my children to experience the same beautiful environment that I have.

Teakahla WhiteCloud Knowing that I am saving hatchlings so that the ocean will continue to live so that I will have a future to live.

Don’t forget to visit oceana.org/heroes and vote for your favorite adult and junior finalists. There’s less than a week until the voting period is over!

Photo Credits (clockwise from top left): Courtesy Hardy Jones, Oceana/Dustin Cranor, zeroXTE.com, Oceana/Carlos Minguell, Courtesy James Hemphill, Oceana/Eduardo Sorenson, Courtesy Sara Brenes, NOAA, Courtesy Michele Hunter, Courtesy Kristofor Lofgren, Flickr/Nemo’s Great Uncle (middle).


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One Step Closer to a Fin-Free New York

sharkfin

With your help, we can keep this from happening. ©Oceana/LX

New York state is the largest importer of shark fins on the East Coast, but if a new bill passes, this fact could be history.

This trade is driven by a demand for shark fin soup, which can sell for hundreds of dollars. Sadly, shark numbers are dropping worldwide due to relentless fishing for fins, and in many places sharks have their fins cut off while still alive (a cruel practice called “finning”). Finning is illegal in the United States, but the demand for fins in New York and elsewhere in the US add to the pressure. Imported fins can come from countries with less regulations, and many shark populations in the US are dropping dangerously low, with some hammerhead populations falling as much as 98%.

But New York is considering a bill that would ban the trade of shark fins within the state, and we’re so excited to announce that it’s moving forward! After a huge push by Oceana and other shark supporters, which included thousands of your signatures and personal pleas from Leonardo DiCaprio and January Jones, both the Senate and Assembly committees passed the bill. Now it’s up for a vote in the Assembly and Senate. But the New York legislation session ends this week, which means they have to act soon.

We’re still gathering signatures to send to New York legislatures. Please sign today and pass the petition along to your friends. The world’s sharks need you.


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The Shark Finatics are Back

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2010 Junior Ocean Heroes the Shark Finatics are building a shark out of recycled materials. ©ArtsWestchester

Editor’s note: With two days until the launch of the 2012 Ocean Heroes Awards, we have a guest post today from Robin Culler – one of the founders of the Shark Finatics (Junior Award winners, 2010) from the Green Chimneys School in Brewster, NY.

Hello Oceana, it’s been two years since the Shark Finatics were honored to be named Junior Ocean Heroes and now we’re busier than ever. In the past few months, the Finatics have been involved in a few projects:

  • When we heard that two sisters had opened a restaurant in Brooklyn and were serving shark burgers, the kids got fired up. They all wrote letters and drew pictures, pleading them to stop and keep the sharks in the oceans. One boy, totally on his own, got his mom to take him to the restaurant so that he could have a heart-to-heart conversation with one of the sisters! I was thrilled!
  • I took the kids to the aquarium the other month to see the Sand Tigers there. It was really fun as some kids had never even been to an aquarium before. They loved it! One of the reasons we went was that we were invited to submit a project for an art exhibit in White Plains, NY. It is on the fish around Westchester, in the Hudson and the Long Island Sound. Since the Sand Tiger is in the Sound, we created a wonderful portfolio on all aspects of this shark (her name is Shirowani), including text and pictures. We also created a wonderful shark from soda bottles, foil, cardboard, and lots of duct tape and it will all be on display to the public all summer long.
  • I just recently held two workshops at a large conference for educators on the Finatics program. It was so cool having everyone hanging on every word, hearing about how we got started and how we grew. It really is a wonderful story.

As you can tell, we are never without projects to work on! We next have to concentrate, big time, on the shark fin bill in NY. We will be writing letters, getting a petition together, making phone calls, and maybe a trip to legislator offices.

So, long story short, we are thrilled to be staying busy and look forward to seeing who will be the next Ocean Heroes in 2012.

Take care,
Robin 

-You can support Oceana’s and the Finatics’ effort to ban the trade of shark fins in New York state by signing our petition: http://act.oceana.org/letter/l-ny-shark/

-To learn more about the Green Chimney’s School, please go to http://www.greenchimneys.org/

-Don’t forget to come back to Oceana's website on June 6 to nominate a 2012 Ocean Hero


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Tuna Still Feeling the Effects of Fukushima

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Bluefin tuna are carrying radiation from Japan to California. ©Oceana/Keith Ellenbogen

It might seem straight out of science fiction, but this story is real – radioactive tuna could be swimming in an ocean near you.

new study found that after last spring’s Fukushima nuclear accident, Pacific Bluefin tuna caught off of San Diego appear to have been contaminated by radioactive materials from last spring’s nuclear accident in Japan.

The March 2011 earthquake and subsequent tsunami led to the meltdown of the Fukushima nuclear plant in central Japan. Even now, the only way to enter the zone 20 kilometers around the plant is with special government permission. After the accident, tests showed that concentrations of radioactive Cesium in coastal waters increased up to 10,000-fold.

This study, published in the Proceedings of the National Academy of Sciences, found the same radioactive Cesium in 15 Bluefin tuna specimens caught outside of San Diego. The fish tested showed a 10-fold increase from normal Cesium concentrations, well below the safety limit established by Japanese Ministry of Agriculture, Forestry, and Fishes.

Bluefin are a highly migratory species – they spawn in the West Pacific near Japan, then, once they have matured, may travel more than 9,000 miles to the East Pacific and the California coast. They’re such strong swimmers that the trip only takes a few months.

During the course of this trip, the radioactive concentration fell as the fish grew and the Cesium decayed. If they had tested tuna from Japan, the radiation would be expected to be up to 15 times more concentrated, according to Daniel Madigan, Zofia Baumann, and Nicholas Fisher, the co-authors of the study.

Monterey Bay Aquarium’s Seafood Watch already lists bluefin as a species to avoid due to severe overfishing and high mercury levels. They’re highly valued as sushi fish, which has led to a steep decline in their populations in both the Atlantic and Pacific oceans. Bluefin tuna are slow to mature, and are often caught before they have a chance to reproduce. Oceana is currently working to protect bluefin tuna from overfishing.


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Could a Shark Live in a Lake?

A lemon shark at Governors River Walk, Palm Beach, FL. [Image via Wikimedia Commons]

Last year’s horror flick, Shark Night 3D, tells the tale of a group of college friends who are attacked by sharks while vacationing near a lake. While the premise of the movies is that evildoers intentionally put sharks in the lake to make money, it made me wonder whether a shark could ever actually make its way inland to a lake.

First of all, the lake would need to be somehow connected to the ocean via a river or other body of water deep and wide enough to accommodate the large animal as it travels upstream. Secondly, most sharks can only tolerate saltwater, or at the very minimum, brackish water, so freshwater rivers and lakes are generally out of the question for species such as great white sharks, tiger sharks, and hammerhead sharks.

Bull sharks are the exception to this rule – they can tolerate brackish and even freshwater conditions because of their advanced ability to osmoregulate, or maintain a constant concentration of water in their bodies despite changing salinity levels in the water. This species is known to travel 60 miles upstream in warm rivers like the Mississippi and the Amazon.

North Carolina’s Neuse River has long been thought to harbor bull sharks, and Duke University graduate student Meagan Dunphy-Daly has proven it by tagging several of them there this summer. On one of her research trips, she encountered a 2.5 meter male bull shark swimming in water with a salinity of only 21 ppt (seawater is usually around 35 ppt). Why would a bull shark journey up the Neuse River? Perhaps in pursuit of the dolphins also swimming there, or maybe because the river provides a good nursery area for their pups.

Other than the bull shark, there are at least five species of “river sharks” in the genus Glyphis which have been observed in freshwater rivers in South and Southeast Asia and Australia, but they are extremely rare due to habitat degradation and little is known about them. These are the only purely freshwater sharks that have been discovered.

So, although it seems unlikely that you will ever encounter a shark in a freshwater lake, you might want to keep an eye out next time you're on a river.


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