Help Save the World’s Best Marine Reserve: Cabo Pulmo
Established in 1995, Mexico’s Cabo Pulmo Marine National Park is slightly more than 7,000 hectares of coastal waters in the Gulf of California, offshore from the small village of Cabo Pulmo. The park’s establishment followed a period of determined lobbying by the village’s 100 or so residents, who had become alarmed at overfishing and declines in the area’s marine life. The reserve is no more than 5 kilometers (3 miles) wide and measures just 14 kilometers (almost 9 miles) north to south. And yet its impact on the marine life within it, such as these Devil Rays, has been profound – so much so that researchers have dubbed it “the most successful marine reserve in the world.”…
You can help save one of the oldest living coral reefs in the world with a click of your mouse: http://bit.ly/178KBhG
For 20,000 years, the reef of Cabo Pulmo has provided sanctuary for whale sharks, Pacific manta rays, humpback whales, dolphins and sea turtles, but today this marine reserve and the thriving sea that surrounds it is still under threat from overdevelopment.
Urge North America’s environmental authorities to support strong enforcement and protect the coral reef. Send your message!
A whale shark (Rhincodon typus) opens its huge mouth as fish hitch a ride on its back in Azores, Portugal. As you probably already know, the whale shark is the largest species of “fish” currently in existence.
Vying for position under a bagan, a fishing net in the waters of Indonesia, male whale sharks—two of about twenty that visit this spot—scramble for a snack. Typically an adult shark might cruise night and day at a sedate one to three miles an hour, sucking in enough seawater to feed itself. This group likely spends a lot of time in Papua’s Cenderawasih Bay, making it one of a few places where the species gathers year-round. In a surprising interaction at sea, colossal whale sharks home in on fishing nets near the island of New Guinea—and fishermen dole out snacks to the pilfering beasts. Scientists hope to cooperate with locals to launch studies of the giants.
Whale sharks that make lengthy dives into the cold ocean depths to forage tend to spend a lot of time at the surface warming up afterward, a new study suggests. Researchers tagged four whale sharks with devices that recorded water depth and temperature, among other factors, at least once every minute.
Typically these immense creatures, the world’s largest fish, traveled directly to and from the surface and spent very little time at the deepest portion of their dives. But in about one dive of every six, the animals dove deep—on average, to depths of about 340 m—and spent about 145 minutes there, presumably foraging.
What is the Biggest Shark? A Chart Shows the Diversity of Shark Sizes
Sharks come in all sizes. The largest is the whale shark, which has been known to get as large as 18 meters (60 feet). The smallest fits in your hand. Find out how these modern sharks stack up against the ancient Carcharodon megalodon. And if you’re a fan of great white sharks, you can download a shark-themed board game, track a shark named Omoo, and listen to a podcast about the species on our Great White Shark section.
What Does a Whale Shark’s Brain Look Like and why Should We Care?
by Jason G. Goldman
The largest fish in the ocean is the whale shark (Rhincodon typus). This massive, migratory fish can grow up to twelve meters in length, but its enormous mouth is designed to eat the smallest of critters: plankton. While the biggest, the whale shark isn’t the only gigantic filter-feeding shark out there: the basking shark and the megamouth shark also sieve enormous amounts of the tiny organisms from the sea in order to survive.
But they weren’t just interested in imaging the brains of the whale sharks. What they wanted to know was how the organization of whale shark brains compared to the brains of other shark species for which scientists had previously obtained neuroanatomical data…
(read more: Scientific American)
(images: T - Dr. Al Love; B - Yopak KE, & Frank LR )
Reference: Yopak KE, & Frank LR (2009). Brain size and brain organization of the whale shark, Rhincodon typus, using magnetic resonance imaging.Brain, behavior and evolution, 74 (2), 121-42 PMID: 19729899
On a recent expedition to Indonesia’s Cendrawasih Bay, Conservation International’s Mark Erdmann learned how whale sharks often congregate around bagan (lift net) fishing platforms to eat the small silverside baitfish that the fishers are targeting. The sharks have also learned how to “suck” the fish out of holes in the nets!
This can be dangerous — but the local fishers like the sharks, considering them good luck, and are working to modify the net designs to prevent sharks from entering.
Learn more about Conservation International’s work:
nitlon: Smallest Whale Shark Discovered — On a Leash
A local whale shark “interaction officer” cradles what is likely the smallest known wild example of the world’s biggest fish on Saturday in San Antonio, Philippines.
The discovery of the baby whale shark could help protect these rare giants by shedding light on where whale sharks are born.
Early on March 7 a project leader from the international conservation organization WWF and others in the town of Donsol heard that a live whale shark was being offered for sale at a nearby beach. Expecting a stranded giant, the rescuers found instead a 15-inch (38-centimeter) shark leashed to a stake in the mud like a neglected puppy.
By the end of the day, after photos and measurements had been taken, the young whale shark was free again, released into deeper waters.
Harmless to humans, whale sharks feed mainly on plankton and can grow to at least 40 feet (12 meters) long. They are listed as vulnerable by the International Union for Conservation of Nature, meaning they “face a high risk of extinction in the medium-term future.”
Video highlights from a recent paper by Gleiss et al published in Functional Ecology. This important new work shows how the majestic whale shark uses basic geometry to minimize energy expenditure during swimming.