Wednesday, February 29, 2012

Is that an Octopus Walking?

Like a sea monster, the octopus (Octopus aculeatus) walks along the benthic floor while maintaining its camouflage as a piece of algae.  This specimen was captured, along Australia's Great Barrier Reef, and was used in a study carried out at Berkeley.

Could it be possible that octopuses can stroll around on two arms?  An octopus has eight arms total and recent research done at Berkeley has shown that octopuses can use two of those eight arms to run across the ocean floor as a adaption to predation.  Two species of tropical octopuses have developed this trick where they pick up six of their legs and walk or run backwards on two of them to easily escape predators.    

The first report of bipedal behavior in octopuses, was written by University of California, Berkeley, researchers, and will be published in the March 25th issue of Science.

In Indonesia, an example of bipedal movement was found in the coconut octopus, commonly referred to as this because it looks like a coconut.  The coconut octopus can be found tiptoeing along the ocean bottom having six of its arms wrapped around its body, while two are touching the ground.  The octopus is able to use the outer halves of their two back arms like tank treads when walking along.  They alternately lay down a sucker edge, located on their arms, and roll it along the ground to propel themselves forward.

The coconut octopus is found to live on sandy bottoms in water 20-30 meters deep.  They live among sunken coconuts and sometimes even hide in the shells of the coconuts to protect its self from predators.

The other octopus that was studied in the laboratory was able to propel itself backwards.  A graduate student from the University timed the two octopuses to see which was more adapted to this new trick that has evolved.  The coconut octopus moved forward at a rate of two and a half inches per second, while the other octopus moved backwards at five and a half inches per second.  These speeds are faster than they can crawl around, but slower then when they swim (jet) around.

The Indonesian Octopus, Octopus marginatus, scoots along the ocean floor using the tips of its arms and their suckers.

The other type of octopus that can camouflage itself as algae in tropical waters looks like a sea monster walking along the sea floor with two legs, just as the coconut octopus.  This octopus is the one at the beginning of the post, known as Octopus aculeatus.

 Octopus (abdopus) aculeatus, was found to have a head the size of a walnut and it inhabits intertidal zones, with sandy bottoms, living among grasses and hiding out in tide-pools or burrying itself in the sand at low tide so it does not dry out and get stuck on shore.  To camouflage itself, it has been seen to coil its front (2) arms and raise them in a pose to resemble algae.

The researchers at Berkeley believe that the bipedal walking strategy evolved in these two octopuses to backpedal away from predators while remaining camouflaged.  Octopuses can camouflage themselves by changing their color and shape.  Normally, when octopuses are startled they cannot move away and stay camouflaged at the same time, but with this walking behavior they can do both at the same time.

The octopuses can change shape readily because they are basically a water-filled balloon, but their fluid is contained within muscles cells rather than an open cavity.  Octopuses keep their shape due to hydrostatic pressure (hydrostatic skeleton or hydrostat).  They do not contain an external or internal skeleton, that is what the pressure is for.  For movement of octopuses they normally push and pull their suckers on their eight arms or jet backwards through the water (jet propulsion).  These movements are done through the muscles that squeeze and bend the fluid filled arms and body.

In Conclusion:

The two octopuses that are found to walk along the bottom of the sea floor and their ability to camouflage relates to the idea of predation covered in class.  This new evolved trick, can help the octopuses get away from the predators, while still being camouflaged.  These adaptions can help the octopuses to survive and this can lead to zonation and other effects in the food chain and water column.

Monday, February 27, 2012

Ocean sciences on Twitter

If you are not on Twitter you might want to get an account if only to get a virtual tour of scientific conferences (of course there is lots of other stuff going on in the twitterverse).  Cruising around Twitter last week I stumbled upon the hashtag for the 2012 Oceans Sciences Meeting in Salt Lake City, co-organized by three prominent societies of ocean scientists.

By following #oceans2012 you can get a sense of the types of talks going on at the meeting, at least from the perspective of the marine science twitterati, which can be quite expansive.  Some random tweets:

Non-dominant diatom spp matter to vertical carbon flux-form rapidly sinking resting spores. Must know nat hist of your system!

Getting  at these meetings sometimes makes me wonder how many tons of plastic is used for coffee stirrers every year.

Fish can have sublethal neurological effects in high CO2. Decrease olfaction, learning problems. 

Great day of  talks and posters at  !! Excited to hear more tomorrow!

Speaker begins a talk saying that macroalgae are not as sexy as corals. I know some people who would beg to differ. 

Depends on depth, red sometimes masks blue -> dusky blue Why are some copepods red? "Less" visible to fish.

Thursday, February 23, 2012

Do The Fish

Humans have the ability to go anywhere they want. Humans can dig in the ground, fly in the air, climb the tallest of mountains, and swim in the oceans. However, there is only so far humans can go while in the ocean. For my first blog post I thought I would focus on a problem marine biologists have studying creatures at great depths. Decompression sickness aka the bends is a major problem for scuba divers going below a certain depth. Due to the human lungs inability to handle the compression/ decompression most scuba divers never go below 70meters. In fact, more people have walked on the moon than have dived below 240meters. The deepest dive ever completed by a human is 701m set by Nuno Gomes and took 14mins to get down there, but 12 hrs to get back up.
As unlikely as it sounds the key to diving deeper than ever before may lie in a 1989 Science Fiction film in James Cameron’s “The Abyss”. The problem of diving deep in the gas in our lungs, therefore, eliminate the gas. Well an inventor in the United States says he has the solution. Arnold Lande, a retired American heart and lung surgeon, has patented a scuba suit that would allow a human to breathe “liquid air”, a special solution that has been highly enriched with oxygen molecules. Lande envisages a scuba suit that would allow divers to inhale highly-oxygenated perfluorocarbons (PFCs) – a type of liquid that can dissolve enormous quantities of gas. The liquid would be contained in an enclosed helmet that would replace all the air in the lungs, nose and ear cavities. The CO2 that would normally exit our body when we breathe out would be taken from our blood by attaching a mechanical gill to the femoral vein in the leg.
The ability to breathe liquid is already in use, but not in a way you might expect. Premature babies have trouble adjusting because their lungs are under developed and cannot handle breathing air. Instead they are used to the liquid breathing inside the womb. So using PFCs these premature babies can breathe easier and have the ability to develop their lungs further until they can breathe air. “A lot of the children I see have less than a 5% survival rate,” he explains. “But when we get them on to liquid breathing we see close to 60% going on to lead fully healthy lives.” Says Professor Thomas Shaffer.
“The first trick you would have to learn is overcoming the gag reflex,” explains Lande, a 79-year-old inventor from St Louis, Missouri. “But once that oxygenated liquid is inside your lungs it would feel just like breathing air.” When a person drowns its not the water that kills them, instead it’s the lack of oxygen. While drowning there is an instinct that overrides holding your breath, and instead tries to get one last breath. When this happens the PFCs provide the oxygen and save the person. The only side effect is hurt ribs from the pressure of breathing the liquid in and out.
With this new technique humans may be able to finally conquer the oceans at all of its depths. What new things that could be discovered is potentially limitless, but first, we need a way to find it. For more info on the story click the diver picture at the top!

Fishing for Hammerheads


Sharks are among the most majestic, feared, and amazing creatures on earth. They are the biggest fish in the sea, with some, like the whale shark reaching lengths of an entire school bus. And some look truly breathtaking, like the hammerhead shark. Sharks have remained virtually unchanged for hundreds of millions of years and have been able to thrive. However, with modern mans invasions on them they are in great danger. Especially one of the most fascinating sharks, the great hammerhead shark. Hammerhead sharks have suffered an estimated 80% decrease in the past 25 years. Many states have put regulations on the catching, handling, and keeping of hammerhead sharks by fishermen; Florida being one of those states. Just recently, as on January 1st 2012, they have added the hammerhead shark to the list of protected and endangered species. According to the International Union for Conservation of Nature (IUCN) and under The Florida code it indicates that

“(1) No person shall harvest, possess, land, purchase, sell, or exchange any or any part of these species:
…(k) Great hammerhead – Sphyrna mokarran.
…(3) “Harvest” means the catching or taking of a marine organism by any means whatsoever, followed by a reduction of such organism to possession. Marine organisms that are caught but immediately returned to the water free, alive, and unharmed are not harvested”
…(5) “Land,” when used in connection with the harvest of marine organisms, means the physical act of bringing the harvested organism ashore”  Florida code section 68B-44  (Emphasis mine)

However, there was a fisherman in Florida that hooked a 14 foot long hammerhead shark, reeled it in for an hour, landed it, measured it quickly, took pictures, and then spent the next hour reviving the shark back to it’s normal conditions in order to swim off to sea in what seemed to be a healthy condition. This article is posted by a graduate student in Florida studying the conservation of sharks who argues that this is not just a normal case of catch and release, but was actually in violation of the endangered species code. The author states that this incidence is in violation of the Florida code because the anglers attempted to weigh the shark, but it was to heavy; and also did not release the fish immediately because they were taking pictures of it. According to Florida law, it is not legal to even hold a fish that is not legal to harvest. Therefore, in this definition of the law the anglers seem to be in violation of the Florida code.
On the other hand, another expert in shark conservation Chuck Bangley says that there must be some leniency in this case. Although, they did not release the shark at the exact moment they saw it was a hammerhead shark, they did follow the best release practices and showed both care and respect for the animal ultimately releasing it alive without noticeable harm. The author of the article agrees with Chuck Bangley and says this example should be used as a teaching experience. I completely agree. In my opinion, I do not think that angler did anything wrong to purposely harm the fish. As someone who grew up in Florida, fishing my entire life I understand where the angler is coming from. Until the fish is actually landed it is somewhat hard to tell what species it actually is, especially in shore fishing. You can have a good idea, but you cannot know for sure it could have been one of many species of shark. In addition, I know if I caught a once in a lifetime magnificent creature like that I would like to snap a quick photograph to remember the beauty of the fish. It seemed that the angler had the upmost respect for the fish; it is not like the angler started kicking the shark in the face for no reason or anything. The author also states that the fish most likely died later on. I have caught many fish in Florida, including sharks, and once the fish swims away it seems to me that they are energetic and will live healthy if the proper care is taken; I do not believe the author can say with confidence that the shark likely died. I understand that the upmost care and respect needs to be taken in order to preserve these magnificent animals and his concern, but, I dont think the angler did anything wrong. What do you guys think? There is also an interesting response from the angler that is worth reading at the end of the article. 

Tuesday, February 21, 2012

Mussel Beach

Excellent video recapping zonation and tides: BBC -- Mussel Beach