The Beacon

Blog Tags: Sharks

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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Shark Fin Soup Minus the Sharks

Image via Wikimedia Commons.

Every year, tens of millions of sharks are killed for their fins alone. Shark fins are used to make shark fin soup, a popular and expensive dish that is a symbol of wealth and status primarily in Asian cultures.

The demand for fins can lead to cruel and wasteful practices, such as cutting off a shark’s fins at sea and then throwing the rest of the shark, sometimes still alive, back into the water. And shark fin soup can be dangerous to humans. Since sharks are at the top of the food chain, they accumulate toxins like mercury, which is a dangerous neurotoxin.

So are there any alternatives to shark fin soup? Shark fins themselves have no taste and are used only for texture. In traditional shark fin soup recipes, chicken or fish stock is added to give the soup flavor which means that there are a lot of ways to enjoy shark fin soup without using shark fins – like this recipe from the Monterey Bay Aquarium:


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What’s Scarier Than a Shark? Lots of Things.

This stonefish is far scarier than your average shark.

If you think that sharks are the scariest creatures in the sea, this post may surprise you.

As we've discussed in the past, the majority of shark attacks are caused by only three species (white, tiger, and bull), yet there are more than 500 species that swim the world’s oceans. So next time you’re swimming in the sea, you may want to keep an eye out for these other, seemingly harmless ocean-dwellers as well.

Did you know that there are over 1,200 species of venomous fish on Earth? They vary in the level of harm they can cause to a human who comes into contact with them, but the stonefish is the deadliest of them all. This fish is found in reef habitats in the Indo-Pacific region, and is called a stonefish because it is able to camouflage itself perfectly among the corals, where it lies in wait for an unsuspecting passing fish. Stonefish have 13 venomous spines that, if stepped on by a human, could be deadly.

There are other marine animals besides fish that can be dangerous as well. The sea wasp, also known as the box jellyfish, is one of the most dangerous jellies, and can be found in the Pacific Ocean around Hawaii, the Philippines, and Australia. Their tentacles can grow up to 10 feet long, and each one has about half a million stinging cells!

Sea wasps use their stinging tentacles to paralyze fish prey, but if they make contact with a human, they can cause paralysis and even death in a matter of minutes. Surprisingly, even a dead sea wasp washed up on a beach can be harmful, because their cells are still able to sting. If you are ever stung by a sea wasp, pour vinegar on the affected area to lessen the effects of the venom.

And remember, terrestrial animals can be just as dangerous as marine ones. The Centers for Disease Control and Prevention and International Shark Attack File reported that between 2003 and 2008, 108 people in the U.S. were killed by cows. That is 27 times higher than the four people killed by sharks during the same period, according to the International Shark Attack File.

This blog post is not meant to scare you from ever going outside again, but rather to draw attention to the fact that there are other potentially dangerous animals in the ocean (and on land), but that sharks always get a bad rap in the media ever since the movie Jaws.

What do you think is scarier than a shark? Tell us in the comments.


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Maryland Introduces Shark Fin Trade Ban

shark fins

Shark fins drying in the sun. © Oceana/LX

The West Coast shark fin trade bans we celebrated last year may be catching on here on the East Coast.

Maryland lawmakers introduced bills Tuesday in both the House and Senate that would outlaw the sale, trade, distribution or possession of shark fins, with violations punishable by fines ranging from $5,000 to $50,000.

As Oceana's Campaign Director Beth Lowell told the Baltimore Sun’s Green blog, there's been no dried shark fin shipped into or out of the port of Baltimore, but U.S. Customs data show exports of shark products, mainly dogfish, exported from Washington and Norfolk.

Each year, tens of millions of sharks are killed for their fins, mostly to make shark fin soup. In this wasteful and cruel practice, a shark’s fins are sliced off while at sea and the remainder of the animal is thrown back into the water to die. Without fins, sharks bleed to death, drown, or are eaten by other species.

Shark finning is illegal in the U.S., but fins are imported from countries with weak or nonexistent protections. In recent decades some shark populations have declined by as much as 99%.  

We’ll be keeping a close eye on this legislation and we’ll be sure to keep you posted!


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Marine Monday: Tasseled Wobbegong

tasseled wobbegong

Image via Wikimedia Commons.

Some sharks are fearsome predators, all sharp teeth and angular fins. These are the sharks that inspire epic monster movies and give the word “shark” its fearsome connotations.

And then there are sharks that look like a pile of seaweed. The tasseled wobbegong is a flat reef-dwelling shark with leafy tentacles and a name that’s just as ridiculous as its appearance.

But appearances can be deceiving. The tasseled wobbegong settles down on a rock or reef, blending in perfectly with the sand and seaweed. When a tasty fish swims by, the shark comes to life, opening its jaws full of sharp, respectable teeth and snapping the poor swimmer up. Its tasseled face may look rather silly, but this shark is just as efficient a predator as its more fearsome brethren.

Sadly, we don’t know much about the tasseled wobbegong, but we do know that this sneaky hunter is in trouble thanks to overfishing and the destruction of the reefs it depends on.

Oceana is committed to protecting the habitats of tasseled wobbegongs and all the other strange and mysterious creatures of the deep.


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Ocean Victories of 2011: Thank You!

© Oceana/Eduardo Sorensen

Andy Sharpless is the CEO of Oceana.

As we enter the last weeks of 2011, I’d like to thank you again for your support this year. Even as we continue to face global economic insecurity, your support has made it possible for Oceana to win important victories for the oceans.

Here are just a few of the victories you helped us achieve in 2011:

This is a special year for Oceana, because it’s also our 10th anniversary year. In 2001, our founders decided that the world needed a conservation organization that could win real policy changes for the oceans on an international scale.

Since then, Oceana has expanded to six countries, garnered more than half a million supporters and protected 1.2 million square miles of ocean, including innumerable sea turtles, sharks, dolphins and the people who depend upon and enjoy the oceans. Our founders are pleased with the results, and we hope you are as well.

We continue to have ambitious goals, not just for 2012, but the next decade. I hope you’ll continue to join us for the ride. Thank you again.


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Cuba’s Gardens of the Queen on '60 Minutes'

On Sunday "60 Minutes" aired a great piece by Anderson Cooper on one of the most pristine coral reefs in the world, the Gardens of the Queen (or Jardines de la Reina) in Cuba.

Diving in, Cooper is not disappointed – he is surrounded by colorful corals, large sharks and a 200-lb critically endangered goliath grouper.

Oceana’s research vessel, the Ranger, sailed to the Gardens of the Queen in 2008, and documented a wide variety of marine life including sharks and sea turtles.

Check it out:


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Another Gift Idea for the Oceans

cheyne oglesby nautica tee

In addition to our adorable ocean animal adoptions, here’s one more gift idea that is sure to please anyone on your list this holiday season.

When you purchase the new Come Together Tee from Nautica (Modeled here by Cheyne Oglesby, guest blogger, ocean lover and surfer!), 100% of your purchase will be donated by Nautica to Oceana*. Plus, it’s super soft and 100% organic cotton. Who wouldn't want one?

Get your tees today and thanks for your support!

*Purchases from the following states will not benefit Oceana: AL, MA and ME


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EU Proposes Full Ban on Shark Finning at Sea

blue shark

Blue sharks would benefit from an EU shark finning ban. © Karin Leonard/Marine Photobank

It has been a banner year for shark conservation – and the good news just keeps rolling in, this time out of Europe.

Today the EU's executive arm proposed a complete ban on shark finning, the practice of cutting off the fins of sharks, often while they are still alive, and then throwing the wounded animals back into the sea.

We’re proud to report that Oceana played a big part in securing this victory; our colleagues in Europe have been campaigning for a shark finning ban in the EU for years.

If the proposal is adopted by the European Parliament and the Council, all vessels fishing in EU waters and all EU vessels fishing anywhere in the world will have to land sharks with the fins still attached – a boon for vulnerable shark populations around the world.

The EU includes some of the world’s major shark fishing nations – Spain, France, Portugal, and the UK. The largest EU shark fisheries occur on the high seas, where Spanish and Portuguese pelagic longliners that historically targeted mainly tuna and swordfish now increasingly catch sharks, particularly oceanic species such as blue sharks and shortfin mako sharks. More than half of large oceanic shark species are currently considered threatened.

Globally, up to 73 million sharks are killed each year to satisfy the demand of the international shark fin market. EU nations combined catch the second-largest share of sharks – 14% of the world’s reported shark catches.

Today's proposal strengthens the existing EU legislation banning shark finning, which allows shark finning in certain situations. Currently the fins and bodies can be separated on board vessels with special permits, and then landed at different ports. The EU tries to ensure that no bodies have been discarded by making sure the weight of the fins does not exceed 5 percent of the entire weight of the fish landed. The new rule would close this loophole.

"A stronger ban on shark finning will bring significant benefits for shark fisheries management and conservation, not only in Europe, but in all of the oceans where European vessels are catching sharks," said Dr. Allison Perry, marine wildlife scientist with Oceana in Europe. 

Congrats to everyone who helped score this huge win for sharks, and fingers crossed for approval by the EU Council and Parliament!


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CEO Note: Let's Be Thankful for Ocean Victories

This week, we celebrate Thanksgiving in the United States. It’s a time to appreciate and reflect upon the good tidings of the past year.

We’ve had a great year at Oceana, with numerous policy achievements accomplished for the oceans around the world. I’d like to take a moment to express my thanks for some of our more recent news.

  • The two-year anniversary of our office in Belize was Nov. 15. In that short time, our Belizean colleagues have accomplished several historic ocean victories, from banning trawling in the country’s waters to protecting local fishermen from industrial fishing fleets from other countries.
  • We continue to win victories for sharks around the world. This week, Florida approved a new rule that fully protects tiger and hammerhead sharks.
  • Outside Magazine named Oceana as one of 30 nonprofits who deserve your dollars in what they call “The Year of Giving Adventurously.”

Lastly, of course, I am thankful for all the individuals, foundations and companies who have continued to support Oceana over the years. You have made it possible for us to secure meaningful, positive changes for the oceans. Thank you.


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