The Beacon: Meghan Bartels's blog

Thursday Trivia: Japanese Spider Crab

japanese spider crab

Japanese spider crab. [Image via Wikimedia Commons]

The Japanese spider crab is the largest crab in the world thanks to its long legs, which can span up to 13 feet. It is also one of the longest-lived crabs, living as long as 100 years.

The Japanese spider crab lives in the cold deep waters off the Pacific coast of Japan, where it scuttles along the seafloor scavenging for food, typically dead organisms and occasionally living kelp and algae. Japanese spider crabs scavenge alone and are not known to communicate; their sensory systems are less sensitive than those of close relatives since they don’t hunt.

These crabs are dark orange or light tan and most adults do not camouflage beyond occasional sponges, as they are large enough that they have few predators. Because the Japanese spider crab’s legs are long and weakly jointed, they are often lost to predators and fishing gear. But amazingly, these crabs can survive missing up to three legs, plus these limbs regrow when the crab molts.

There is little population data for this species, but reported catches are declining. Japanese spider crabs are protected during their breeding season.

Learn more about other fascinating creatures in our marine life encyclopedia!


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Marine Monday: Blue Buttons

Blue buttons are just one of the many small critters that live in the oceans. They are often mistaken for jellyfish or colored plastic when they wash up on beaches, but they are actually free-floating colonies of hydrozoa.

Blue buttons have two main parts: the central disk, which is about an inch across and yellow brown, is a hard flattened bubble that holds gas to keep the blue button floating. Attached to this disk are a type of bluish stinging polyp, which act as tentacles, although the blue button itself does not have a powerful sting—it can only cause minor skin irritation.

In the center of the disk, a larger central polyp acts as a mouth for food intake and waste removal for the entire blue button colony. Blue buttons eat live and dead small fish, eggs, and zooplankton.

The blue button cannot swim; it relies on drifting on currents and wind to move through the ocean.

Pretty cool, huh?


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Thursday Trivia: Puffins

puffin photo

An Atlantic puffin. © Oceana/Concha Martinez

Puffins are curious and charismatic birds that live in the North Atlantic ocean, where their orange beaks and feet make for a colorful sight.

Atlantic puffins can swim as well as fly. Like a plane taxiing for take-off, a puffin runs along the surface of the water to gather speed for flight.

Puffins spend the summer in clifftop colonies and they winter at sea. Once a year, the puffins moult, and are left temporarily flightless.

Each year, Atlantic puffins return to breeding grounds, where they perform rituals like bill-knocking and marching in front of burrows. Burrows are sometimes re-used between seasons. Each pair of Atlantic puffins incubates a single egg, and when the chick hatches, they bring it small whole fish, which they are able to carry by using their tongues to hold the fish to the roof of the beak. Chicks are fed for six weeks, then abandoned; after several days the chicks leave to hunt for themselves.

Atlantic puffins currently have large and fairly healthy populations. However, they have been targeted by human hunting for meat and feathers, and they are also vulnerable to attacks by gulls, rats, cats, dogs and foxes. One of the most important risks they face is overfishing of species like sand eel and capelin, which Atlantic puffins rely on for food. Puffins are also vulnerable to the effects of oil spills.


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Marine Monday: Mediterranean Monk Seal

mediterranean monk seal

A Mediterrean monk seal. [Image via Wikimedia Commons.]

The Mediterranean monk seal, like its cousin the Hawaiian monk seal, is one of the most endangered mammals in the world.

Estimates suggest that they number around 400 total, with the largest populations in Greece and Morocco. Mediterranean monk seals are larger than their Hawaiian relatives, and unlike most seals, their pups are born with black fur.

Mediterranean monk seals are not migratory and can usually be found in small groups or alone. They eat primarily fish and cephalopods, and they can communicate about dangers using high-pitched noises.

Pregnant seals used to give birth on beaches, but due to habitat loss they now typically do so in sea caves, which are more protected. At about one week old, Mediterranean monk seal pups enter the water for the first time. Only about half of pups survive their first two months.

Among Mediterranean monk seals, both long-term fostering and milk-stealing are common between unrelated mothers and pups. However, mothers and pups remain together for as long as three years.

Mediterranean monk seals have a long history -- they even appeared on coins around 500 BC. Beginning in the 15th century, they were heavily hunted for skin and oil. Now, fishermen often kill Mediterranean monk seals, either in an attempt to eliminate fishing competitors or accidentally, as bycatch.


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Thursday Trivia: Sharksucker

nurse shark with sharksuckers

Sharksuckers hitch a ride with a nurse shark. [Image via Wikimedia Commons.]

Imagine a fish with a suction cup on the top of its head – that’s basically what a sharksucker, or remora, is. This fish isn’t a very strong swimmer, so to get around it hitches a ride with a shark, large fish, whale, sea turtle, stingray, or even a ship.

As an added perk, the sharksucker gets to munch scraps from its host’s meals, in addition to the small fish it catches itself. The shark neither suffers nor benefits from its relationship with the sharksucker (tweet us with the term for this type of relationship, and you could win a cool tote bag!) 

Sharksuckers are found throughout warm waters, either attached to a host or swimming freely over corals, where they help keep reef fish clean. These fish can grow up to about a yard long.

Some fishermen have developed a clever use for sharksuckers: they tie line around the fish’s tail, then release it. The sharksucker looks for an animal to attach itself to, then the fisherman reels the pair back in.

Otherwise, sharksuckers are not popular targets for fishermen. In fact, the main risk they face is shrinking populations of sharks and other large marine animals to host them.

You can learn more about sharksuckers from Oceana’s marine wildlife encyclopedia.


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‘Tis the Season to Adopt for the Oceans

adopt an animal

It’s almost December, and that means it’s time to start thinking about holiday gifts. But don’t panic! No matter how long your list is, we’ve got you covered.

At our adoption center, you can find gifts that will bring smiles to the faces of your friends and loved ones. Each adoption supports our work to protect the oceans, from fighting destructive fishing techniques and offshore drilling to protecting vulnerable species and habitats.

When you symbolically adopt a shark, sea turtle, dolphin, or any other adorable marine creature, that special someone will receive a cookie cutter or plush to remind them of you and the ocean they love. Or, you can make your gift greener by choosing to send an electronic certificate.

Even better, we’ll take care of all the details. Gifts ship free to the US, and for just $5 extra we’ll take care of the wrapping. Best of all, to thank you for your support this year, take 15% off with discount code HOLIDAY2011!

Check out all our gift options at our online adoption center, and thanks for your support as always!


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Marine Monday: Stalked Jellyfish

A stalked jellyfish. [Image via Wikimedia Commons.]

You’ve probably seen pictures of jellyfish floating gently through the water, but did you know that some jellyfish spend most of their lives in one spot?

Stalked jellyfish, which are funnel shaped, with eight legs joined by membranes surrounding a mouth, are one example. Only an inch or two tall, they live in cold shallow water in the North Pacific.

When stalked jellyfish mature, they attach themselves to a piece of seaweed or eelgrass with an adhesive disk. Scientists believe they might be able to basically cartwheel short distances, but for the most part, they are sessile – meaning they stay in the same place.

Because stalked jellyfish can’t follow prey, they use their tentacles to catch small fish and shellfish, although they have to spit out shells, as they’re too difficult to digest.

Although adult stalked jellyfish cannot eat large prey, immature jellyfish, called planula, have developed a collaborative approach to offer more dining options. At this point in their lives, the jellyfish are mobile, so while they can’t kill by themselves, they can gang up on rotifers, nematodes, copepods, and other ocean snacks.

Stalked jellyfish are also notable for having relatively developed nervous systems compared to their relatives.

You can learn more about stalked jellyfish from Oceana’s marine wildlife encyclopedia.


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Marine Monday: Giant Tube Worms

Image via Wikimedia Commons.

When giant tube worms were discovered in the 1970s, they were like nothing that had ever been seen before, and scientists still find them fascinating.

That’s because they live in some of the harshest environments and, unlike almost all kinds of life on Earth, do not rely on the sun for energy. Most life on the planet relies on energy from the sun, mediated by phytoplankton and plants that convert carbon dioxide into sugars. But not in deep-sea vent communities.

Giant tube worms live in the Eastern Pacific Ocean more than a mile underwater. The ocean floor here is geologically quite active, and vents are forming and closing regularly. When a new vent forms, giant tube worms are among the first species to colonize the area, and their population can reach several thousand adult worms in a couple years. The worms form long tubes out of chitin, the same material that makes up the exoskeletons of insects, crabs, and lobsters

Larval worms will float through the ocean until they find an area that is chemically appropriate to settle down in. As larvae, the worms have mouths and digestive tracts, but these are lost once they settle down and develop. Instead, adults have a large sack that holds symbiotic chemosynthetic bacteria. These bacteria oxidize sulfur produced by the vents, providing energy for the worm.

You can learn more about amazing giant tube worms from Oceana’s marine wildlife encyclopedia.


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Thursday Trivia: West Indian Manatee

manatee

A manatee takes a rest from its exhausting feeding routine. © Oceana/Carlos Minguell

When Christopher Columbus first saw a West Indian manatee, he thought it was a mermaid – you can decide for yourself if the comparison is apt.

November is Manatee Awareness Month in Florida, so this week we’re checking in with the charismatic sea cows – and if you tweet us what makes the manatee’s teeth unique among mammals, you could win a prize.

The West Indian manatee is found in two distinct populations in the Caribbean and Florida, where they live in warm, shallow water, migrating somewhat with the seasons. They are tolerant of a range of saltiness, although they need occasional access to freshwater to keep from being dehydrated.

Manatees are about 10 feet long and can live to be about 50 years old. Despite their massive size, they are surprisingly agile, even though they swim and steer with just their tails. They are usually pale grey, although calves are darker. Their skin is constantly flaking off, likely to reduce algae. For the most part, manatees live alone, spending about six to eight hours a day eating.

Eating takes up so much of their day because their diet consists primarily of seagrass, which has a very low caloric value. Although manatees have developed a low metabolic rate to help conserve energy, they still need to eat a lot of seagrass – about 10-15% of their body weight each day (!) In addition to seagrass, manatees use their flippers to dig up roots, and will occasionally eat invertebrates or fish.


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Oceana Unveils New Oil Spill Map

Have you ever wondered just how common oil spills are? Prepare to have your socks knocked off.

Oceana and SkyTruth have partnered to launch a new online oil spill tracking tool, which maps oil spill reports from the National Response Center. Considering there are a couple dozen reports from just the past week, you may find this new map disheartening – but that isn’t the worst of it. Many of the reports come from the oil industry itself, as well as the public and the government, so the map may actually underestimate the number and size of spills.

Clicking on any incident offers details about the spill. Although many reports are of unknown sheens in the water, the effects of incidents like these add up quickly as the oceans deal with this sort of pollution. By drawing attention to even minor spills, this map highlights the repetitive damage done to our environment by offshore drilling and other oil pollution.

Moreover, some of the incidents marked on this map may be still more serious. For example, a spill near a rig operated by Transocean off the coast of Brazil, reported on Thursday, is currently being attributed by Chevron to “oil seeps.” This spill may contain as much as 628,000 gallons of oil.

“This new Web tool will help people visualize the magnitude of the oil industry’s damage to our natural environment and our economy,” said Oceana senior campaign director Jacqueline Savitz.


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