Blog Tags: Whale Shark
Warning: This post discusses a graphic subject, and some photos might be upsetting to readers.
Sharks are still in danger, not just in the U.S. but around the world. WildLifeRisk, a Hong Kong-based conservation group, has recently revealed the world’s largest shark slaughterhouse, which processes hundreds of shark carcasses every year to provide oil for health and cosmetic products, meat and fins for restaurants, and skins for handbags.
Today is International Whale Shark Day, so what better time to celebrate these magnificent creatures? Here are 10 facts to dazzle your friends with:
1. We know you’re wondering: whale shark – whale, or shark? The whale shark is a shark, and as a shark (and thus a fish), it is the largest fish in the sea. It breathes via its gills, and has cartilage instead of bone, making it a true shark. The name “whale shark” comes from the shark’s large size, which rivals some species of whales, and also because the shark is a filter feeder, like baleen whales.
Kudos to a team of divers off the coast of Mexico who rescued a pregnant whale shark from near-certain death after the gentle giant became entangled and trapped in a thick rope some 90 feet underwater.
The divers were accompanying a group of tourists off of Roca Partida, a remote volcanic outcrop that is part of the Revillagigedo Islands 250 miles Southwest of Cabo San Lucas, when they discovered the 33-foot 15-ton animal. After the animal was cut loose it showed deep scars where the rope had cut into its back and fins.
Despite their massive size (they are the world’s biggest fish and their mouths are large enough to fit a human inside) whale sharks are docile filter feeders, gulping down huge quantities of plankton, small fish and krill.
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.
The whale shark is the largest fish in the world and can fit a human inside its mouth. But don’t be afraid: this huge fish eats only plankton and small fish, which it gathers by pumping water over its gills.
The whale shark is one of three sharks that filter feeds, and the only one that does so actively rather than relying on simply swimming forward with its mouth open. Despite this, the whale shark has about 300 very small teeth, the purpose of which is unknown.
In addition to being the largest species of fish on the planet, whale sharks also have the thickest skin of any animal – about four inches thick. This skin is decorated with a pattern of yellowish white dots that is unique to each shark.
Whale sharks are usually solitary, but they can feed in groups. One particularly striking example of this behavior occurs around April off Australia, when immature males gather to feast on particularly plentiful plankton. Throughout their travels, whale sharks often cross entire oceans.
Whale sharks are considered vulnerable. One of the most important threats they face is shark finning – although their fins are not very popular to eat, because they are so large, they are highly prized for displays. In 1999, just one whale shark fin sold for around £11,000. Other threats include hunting for liver oil and meat and being caught accidentally as bycatch. It’s not all bad news, though! Some areas are protecting whale sharks in order to foster ecotourism.
Oceana’s shark campaign focuses on reducing shark bycatch, establishing shark finning bans, and implementing species-specific shark management.
Emily went up in a spotter plane last weekend to look for whale sharks, while senior campaign communications manager Dustin Cranor was on the Latitude waiting for word of the sharks' location so the scientists on board could follow them in order to tag the animals. Unfortunately, the sharks proved elusive. Here's Dustin's report:
The whale sharks in the Gulf of Mexico spent the weekend hiding from the Oceana Latitude.
The crew spent two days searching for these sharks off the coast of southeastern Louisiana. Our hope was to tag some of them so that we could monitor their movements and contribute to scientists' understanding of the effects of the Deepwater Horizon disaster on their survival. Whale sharks were observed swimming in surface oil near the gushing wellhead earlier this year.
The two spotter planes did have one sighting, but the four whale sharks dove too quickly for us to track them.
Oceana and the University of Southern Mississippi have not given up and will continue the search Tuesday.
Here’s Oceana marine scientist Elizabeth Wilson:
It wasn’t until we reached Grand Isle to drop off the shark experts that we saw a school of what appeared to be silky sharks.
During transit, the experts spent time talking with Associated Press reporter Rich Matthews. One thing is clear, no matter what direction you look in the Gulf of Mexico, there are always oil rigs in the landscape.
We often tell you about the threats facing sharks globally -- finning, bycatch, overfishing -- but we don’t regularly shine a spotlight on the individual species affected.
To continue our ongoing shark-themed posts in honor of Shark Week, here are 10 of the most threatened shark species in the world:
1. Basking sharks are the second largest shark, easily distinguished by their huge, filter-feeding mouths. Basking sharks are caught in target fisheries around the world for their oil, meat and fins, and they are also caught as bycatch in other fisheries.
2. Blue sharks are one of the most previously abundant shark species. Now they are the most heavily fished shark in the world. An estimated 10-20 million individuals are killed by fisheries annually, mostly as bycatch. Blue shark meat is beginning to replace swordfish in many Mediterranean countries and the fins are commonly used in shark fin soup.
3. Deep-sea sharks have huge livers that contain high amounts of oil to regulate their buoyancy at depths. As a result, they are caught by deep-sea trawls, gillnets and longlines for an oily substance found in their livers called squalene. Squalene, or its derivative squalane, is found in many cosmetic products.
- A Big Day for Little Fish Posted Fri, April 11, 2014
- Reducing Bycatch Casualties, One Whale at a Time Posted Mon, April 14, 2014
- New York, the New Windy City? Posted Mon, April 14, 2014
- Drill, Spill, Repeat: Shining a Light on the BP Gulf Disaster 4 Years Later Posted Tue, April 15, 2014
- Hands Across the Sand Posted Wed, April 16, 2014