Repost from Wired.com: Sea Creatures Hint at Recent Trans-Antarctic Seaway

The discovery of nearly identical sea creatures on either side of a now solid Antarctic ice sheet — 1,500 miles wide and over a mile thick — points to an open ocean passage there as recently as 125,000 years ago.

A schematic of a seaway created by the partial collapse of the West Antarctic Ice Sheet (on left).

The new evidence adds to geologic clues indicating the West Antarctic Ice Sheet has collapsed at least once in the last million years, and could do so again in a warmer climate. The complete collapse of the West Antarctic Ice Sheet would raise global sea level by 11 to 16 feet.

“The West Antarctic Ice Sheet can be considered the Achilles heel of Antarctica,” biologist David Barnes of the West Antarctic Survey, lead author of the study, said in a press release. “Our research provides compelling evidence that a seaway stretching across West Antarctica could have opened up only if the ice sheet has collapsed in the past.”

As part of the Census of Antarctic Marine Life, scientists were looking at the distribution of different species of bryozoans, small filter-feeders that are attached to the sea floor as adults (top image). They found that the populations of bryozoans were remarkably similar in two different seas separated by the ice sheet, the Weddell and the Ross.

“Because the larvae of these animals sink and this stage of their life is short — and the adult form anchors itself to the sea bed — it’s very unlikely that they would have dispersed the long distances carried by ocean currents,” Barnes said. “Our conclusion is that the colonization of both these regions is a signal that both seas were connected by a trans-Antarctic sea way in the recent past.”

“This biological evidence is one of the novel ways that we can look for clues that help us reconstruct Antarctica’s ice sheet history,” Barnes said. The study appears in Global Biological Change.

The West Antarctic Ice Sheet is already considered to be highly vulnerable to climate change, but estimates of when it might collapse vary from a few hundred to a few thousand years.

Read More http://www.wired.com/wiredscience/2010/08/antarctic-passage/#ixzz0yH1cDspW

Repost TampaBay.com: Woman Gets Ride on Back of Shark

A woman swimming in the Atlantic off Behune Beach found herself picked up and carried on the back of a shark, news-journalonline.com reports.

“My first thought was ‘I hope this is a manatee,’ ” Judy Fischman told the Daytona Beach News-Journal. “Then I saw the black tail. … Then I saw other sharks and I thought, ‘My God, how am I going to escape a whole group of sharks?’ ”

She started punching the animal, “then a wave came. All of a sudden they were gone,” she said. “They probably realized I’m not food and let go. Maybe they thought I was a seal. I had on a black bathing suit.”

It Flows Like a River…

some science news this week.

First up, rivers on the seafloor. According to the UK Telegraph, apparently researchers have found channels on the sea bed with water of much different density and salinity than surroundings water coursing through them:

If found on land, scientists estimate it would be the world’s sixth largest river in terms of the amount of water flowing through it.

The discovery could help explain how life manages to survive in the deep ocean far out to sea away from the nutrient rich waters that are found close to land, as the rivers carry sediment and nutrients with them.

The scientists, based at the University of Leeds, used a robotic submarine to study for the first time a deep channel that had been found on the sea bed.

They found a river of highly salty water flowing along the deep channel at the bottom of the Black Sea, creating river banks and flood plains much like a river found on land.

Dr Dan Parsons, from the university’s school of earth and environment, said: “The water in the channels is denser than the surrounding seawater because it has higher salinity and is carrying so much sediment.

“It flows down the sea shelf and out into the abyssal plain much like a river on land. The abyssal plains of our oceans are like the deserts of the marine world, but these channels can deliver nutrients and ingredients needed for life out over these deserts.

“This means they could be vitally important, like arteries providing life to the deep ocean.

Digitial Release of Bjork, Dirty Projectors Collaberation to Benefit Nat Geo’s Ocean Initiatives

Bjork and the Dirty Projectors (a band that’s garnered some buzz  last year with their release Bitter Orca) have re-released a recent collaborative effort of theirs in digital form, this time to benefit Nat Geo’s Ocean Initiatives.

The original work, dubbed Mount Wittenberg Orca, was originally composed and preformed to benefit the homeless and an AIDS advocacy group.It’s fitting however, that the songs are being re-released to provide further assistance to a slightly different cause. According to the nat-geo article on this recent news item, the work was actually inspired by the ocean:

“Together they wrote and performed a new suite of songs called “Mount Wittenberg Orca,” which was inspired by Dirty Projectors’ Amber Coffman sighting of a family of Orcas on the California coast, and features Björk singing the part of the mom whale.”

Purchase and download the EP here.

Shrimp Go Into the Light

A recent study in aquatic toxicology studied the effects of several well prescribed anti-depressants on the behavior of shrimp. One in particular, fluoxetine, better known as Prozac significantly altered the shrimp’s behavior, causing them to move towards rather than away from light right into the awaiting maws of predatory shrimp-eaters. In scientist speak, this movement towards or away from light stimulus is called “phototaxis” (on a complete aside, another more bizarre photo-response is the photic sneeze effect where bright light causes someone to automatically sneeze. I like the mental picture of a mass of little sneezing shrimp…).

These kinds of studies are gaining more import because of the types of chemicals ending up in aquatic systems. Much of what we put into our bodies is never completely absorbed and ends up in the sewer system which consequently often ends up in other water-based ecological systems (sewage is treated for things like excess nutrients but we couldn’t possibly screen for all the possible chemicals sewage may contain). So materials like caffeine, medications we take, etc. are now outside of our superficial human realm and in the larger natural environment, with detrimental if not even bizarre effects on wildlife including sex changes in fish.

To find out more, read the sciencedaily feature here.

So do YOU have a psychic octopus?

Paul the psychic octopus,currently residing at a German zoo, apparently has a thing for the footie. He’s correctly predicted wins and losses in the current soccer world cup. He is not consulting his magic eight-ball (although, he might be thrilled if someone were to offer one. Octopuses are notoriously smart and love new objects to check out.), but rather choosing mussels between two containers upon which the zoo staff has pasted the flags of teams playing in the cup. He’s drawn the ire of some who are blaming the cephlapod for the losses, but mind you it’s nary a stable person who gets mad at an octopus… Check out an article with more information including the fact Octopi have nine brains (they must be sitting in their tanks laughing at us).

Check him out in video form:

Nat Geo Repost: New Leviathan Whale Attacks

Illustration by C. Letenneur, Muséum National d’Histoire Naturelle, Paris, France

Evoking the poster for the original summer blockbuster, a new species of killer sperm whale attacks a baleen whale in an illustration.

Dubbed Leviathan melvillei—an homage to Moby-Dick author Herman Melville—the recently unearthed fossil sea monster lived about 13 million years ago in waters atop what’s now a Peruvian desert, according to a study published by the journal Nature on Wednesday.

Living alongside the largest sharks ever known, the raptorial—meaning actively hunting—whale measured about 60 feet (18 meters) in length, about as big as a modern male sperm whale.

But whereas modern sperm whales feed primarily on squid, Leviathan’s large teeth—some of which measured more than a foot (36 centimeters) long—suggest the whale hunted more challenging prey, including perhaps its close whale relatives.

“It was probably a very powerful and frightening animal, so it fits well with the description Melville made of Moby-Dick,” said lead study author Olivier Lambert, a paleontologist at the National Museum of Natural History in Paris.

(Related picture: “Whale Found in Egypt Desert.”)

—Ker Than

Published June 30, 2010

Octopi- Unlikely Geniuses

I’ve long been interested in octopi (the plural of octopus, as octopuses doesn’t quite work). I’ve recalled prior stories on their mimicing ability and tales originating from aquariums about their resident octopi crawling out of their tanks, into others nearby, and snacking on the exhibit fish. Or perhaps this story about an octopus who escaped a tank in an Australia aquarium and bided his time in a drain waiting for an opportunity to escape. They’re incredibly smart animals which has suprised researchers as they expect these traits in longer-lived organisms. Most species of octopus will lives less than five years. Nevertheless, according to a fascinating article in Discover Magazine:

“Anatomy confirms what behavior reveals: Octopuses and cuttlefish have larger brains, relative to body weight, than most fish and reptiles, larger on average than any animals save birds and mammals. Although an octopus brain differs from a typical vertebrate’s brain—it wraps around the esophagus instead of resting in a cranium—it also shares key features such as folded lobes, a hallmark of complexity, and distinct visual and tactile memory centers. It even generates similar electrical patterns.”

 The latest in a series of reports about octopi doing a little marine yoga and arranging their bodies in shapes reminiscent of other ocean life is a video of an octopus in the Caribbean mimicing a flounder (in some senses, he almost looks like a skate to me):

This is the first Atlantic species discovered to do this, but scientists have known about the Indonesian mimic octopus for quite some time:

Not only, are these creatures masters of mimicry, but it appears they also join the list or organisms observed using tools. Another indonesian species, the veined octopus has been spotted carrying around coconut shells that they can use to form a shelter when predators threaten. Read more here.

New Dolphin Feeding Strategy – Mud Rings

This has been posted multiple other places but seemed interesting enough to post here. The clip is from the new Attenborough series “Life”:

This is yet another case of clever animals quickly adapting their behavior in beneficial, clever ways (see my earlier post on orcas to see another example).

Check out the Florida Keys National Marine Sanctuary newsletter from spring of 2002 that first reports this behavior.

Elysia chlorotica – Proving It May Actually Be Easy Being Green

This conniving little sea slug, Elysia chlorotica, may be a unique “hybrid” of plant and animal.

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a little background: skip to below the next set of asterisks for the “punch-line” concerning these sea slugs…

There is no lack of organisms forming unusual symbiotic relationships, especially those occurring between animal and plant.

The idea is generally that an animal, or more specifically a heterotrophic (can’t rely on sun energy, needs to consume other things for food and nutrients) organism might form a relationship with something autotrophic  (can easily produce its own energy via sunlight or chemical means).

The relationship works because both organisms tend to gain in some manner. The heterotrophic organism gains a more-readily available source of food produced by its symbiotic partner, the autotroph, which itself is likely gaining things like shelter and predator protection.

In the marine world, this is seen in corals polyps, which house tiny zooxanthellae, which are tiny little photosynthetic protozoa. Another fascinating example are the jellyfish like the ones found in Palau, that follow the sun everyday in order to fuel energy production in the symbiotic algae they host.

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E. chlorotica is different from these standard symbiotic relationship because they are not simply keeping the algal cells they consume in working order as usually happens in standard symbiotic relationships. It was previously known that the slugs would acquire photosynthetic organelles and genes from their algea food but it appears  they may be able to incorporate these “stolen goods” into internal chemical pathways to make their own chlorophyll, allowing them to photosynthesize their own food.  The results of the study supporting this find will be published in an upcoming issue of Symbiosis and may need to be scrutinized and further confirmed. But if the findings turn out to be true, there’s a whole lot of sneaky going around, folks.

Resources:

Read the original ScienceNews article

Check out Elysia chlorotica‘s wikipedia page

Visit the slick looking site- SymBio: A Look Into the Life of Solar-Powered Sea Slug