Mysterious giant sharks may be everywhere
They can be as big as great white sharks, but that’s about as far as the comparison goes. Their maximum speed is a lethargic 1.7 miles per hour, many are almost blind, and they are happy to eat rotting carcasses. They may be common throughout the ocean, but you’ve probably never heard of them. Meet the Greenland shark.
Looking like nothing so much as a chunk of weather beaten rock, Greenland sharks (Somniosus microcephalus) can grow up to 7.3 metres (24 feet) long, making them one of the largest of all fish, and the biggest in the Arctic. But they prefer to live in deep, cold water, so humans rarely see them.
Studies in the Arctic have revealed a few canada goose outlet store snippets of information about Greenland sharks, and more data is now starting to come in from elsewhere. It turns out that Greenland sharks are canada goose outlet bizarre, and may be crucially important for the ocean ecosystem.
canada goose jacket outlet toronto View image of (Credit: NOAA OKEANOS Explorer Program, 2013 Northeast US Canyons Expedition, CC by 2.0) canada goose jacket outlet toronto
canada goose outlet kokemuksia Greenland sharks only come close to the surface in places where the shallow water is frigid enough for them primarily in the Arctic. They are most easily seen around Greenland and Iceland. As a result, they were long thought of as purely polar animals, as were the closely related Pacific sleeper shark and southern sleeper shark. canada goose outlet kokemuksia
canada goose outlet online uk But they have been reported on the coasts of Canada, Portugal, France, Scotland and Scandinavia. Some researchers think they live in many other areas too but just haven’t canada goose outlet new york city been spotted in them yet. canada goose outlet online uk
“They may be everywhere that’s cold enough and deep enough,” says Aaron MacNeil of the Australian Institute of Marine Science, canada goose outlet reviews in Townsville, Queensland.
The obvious way to see a Greenland shark in the wild is to dive into the deep sea. canada goose factory outlet For instance, in 2001 a remotely operated vehicle in the Gulf of Mexico captured footage of either a Greenland shark or a sleeper shark in over 2,600 metres (8,530ft) of water.
canada goose jacket outlet store They may be everywhere that’s cold enough canada goose outlet online and deep enough canada goose jacket outlet store
canada goose jacket outlet uk Two years later, a pilot and a scientist from the Harbor Branch Oceanographic Institution in Fort Pierce, Florida, became the first people to come face to face with a Greenland shark in the deep sea. The shark, which was five metres (16ft) long, bumped into their submersible vessel 1,000 metres (3,280ft) down in the Gulf of Maine. canada goose jacket outlet uk
canada goose outlet in chicago But hardly anyone dives that deep. So these rare encounters can’t tell us how widespread and important the Greenland sharks are. canada goose outlet in chicago
View image of Greenland sharks used to be heavily fished (Credit: ARCTIC IMAGES / Alamy)
However, if the history of fishing is any official canada goose outlet guide, Greenland sharks are common as muck. The sharks were fished from the early 20th century until the 1960s; mainly for their liver oil, which was used as lamp fuel and industrial lubricant. In some years, over 30,000 were taken. That suggests a very healthy population.
canada goose outlet london uk In line with that, a recent expedition used 120 hooks on a longline, and caught 59 sharks. “I think they’re fairly common,” says Aaron Fisk of the University of Windsor in Ontario. “When we want to catch them we don’t have any trouble.” canada goose outlet london uk
canada goose outlet belgium So what are all these Greenland sharks eating? To find out, scientists have to get their hands dirty by cutting open the canada goose outlet uk sale sharks’ stomachs and pulling out the remains of their meals. canada goose outlet belgium
It seems the sharks aren’t too concerned about the freshness of their meals
So far this kind of work suggests the menu of the Greenland shark is highly varied. As well as fish, they eat just about anything that might fall off the ice, including reindeer and polar bears.
canada goose parka outlet uk Given a chance it seems they will even try to eat moose. Last November, a man in Newfoundland found a Greenland shark gagging on a piece of moose canada goose jacket outlet hide, which had probably been thrown into the water by a hunter. He and another man decided to save the shark from choking on canada goose outlet black friday the hunk of moose. “A couple yanks and it just came right out,” he told the Canadian Broadcasting Corporation. canada goose parka outlet uk
canada goose outlet online store review It seems the sharks aren’t too concerned about the freshness of their meals. Researchers have found small crustaceans called amphipods in their stomachs. These critters swarm over dead bodies in deep waters, so finding them hints that the sharks sometimes eat carrion. canada goose outlet online store review
canada goose outlet store quebec View image of “My eye! It on my eye!” (Credit: Louise Murray / Science Photo Library) canada goose outlet store quebec
canada goose outlet vancouver That would make sense, because it’s hard to understand how a Greenland shark could ever catch living prey. canada goose outlet vancouver
For one thing they are absurdly slow, moving more sluggishly than any other shark. One satellite tagging study found that they usually meander about at around 0.8mph (1.1kph), accelerating to 1.7mph (2.7kph) when going all out. Others say they can reach 2.2mph (3.5kph). Regardless, many of the things they might want to eat can swim faster.
canada goose clothing uk If that wasn’t enough, many Greenland sharks appear to be almost blind. The culprit is Ommatokoita elongata, a crustacean with the nasty habit of permanently attaching itself to the front of the sharks eyes, damaging their corneas (see the photo above). In some populations, 90% of Greenland sharks carry these parasites. The shark that rammed the Harbor Branch submersible had them dangling from its eyes. canada goose clothing uk
So how do Greenland sharks catch anything? It has been suggested that the parasitic crustaceans might be bioluminescent, and that the light they give off attracts fish for the shark. But that’s “poppycock”, canada goose outlet shop says George Benz at Middle Tennessee State University in Murfreesboro. He says the scientific literature on the sharks is “contaminated” with unsubstantiated claims like this.
View image of A harbour seal (Phoca vitulina), also known as lunch (Credit: imageBROKER / Alamy)
canada goose outlet store near me Benz thinks the sharks are more likely to be ambush predators. For example, Arctic seals sometimes sleep in the water to avoid polar bears, potentially allowing Greenlands to sneak up goose outlet canada on them. canada goose outlet store near me
The seals also have to poke their cheap canada goose heads through ice holes to breathe, giving the sharks an opportunity to catch them unawares. “They can still see light and dark, canada goose outlet nyc and a hole in the ice is like a big flashlight that says where the food comes in,” says MacNeil.
canada goose outlet in canada No one has directly observed Greenland sharks catching seals in this way, but canada goose outlet store uk there is some circumstantial evidence. Large numbers of dead seals with “corkscrew” wounds have been recovered at Sable Island off the coast of Nova Scotia. Some were bitten in half, while others had the skin and blubber stripped from canada goose outlet toronto factory the lower halves of their bodies. “We’re thinking those are Greenland shark bites,” says MacNeil. “When they bite, the seal spins to get away, stripping the blubber away literally as it’s trying to get out.” https://www.canadagoosepark.com canada goose outlet in canada.