Meet the Tank: Sea Stars



Science Museum of Virginia sea stars



By Meghan West

Gallery Educator

Science Museum of Virginia

In our “Beach Science: It’s a Shore Thing” exhibit we have a saltwater tank housing some sea creatures that can be found off the coast of Virginia. For those of you who have been to “Beach Science: It’s a Shore Thing” you may have already seen or even touched one of our sea stars. For those of you who have not, let me introduce you.

Sea stars, formally known as starfish, were renamed because they don’t look like a fish, don’t swim like a fish, and are not a fish. Because of this they dropped the name fish and added sea (same thing happened to sea jellies, formerly known as jellyfish). They are in the phylum echinodermata, which means spiny skin and anyone who has touched one or even handled a dead one can feel the bumpy, spiny skin. They are in the same phylum as sea urchins and sand dollars, even though they don’t look a lot alike.

Strange creatures are our sea stars; they have no blood, no brains, and if we chop them up, as long as there is a fifth left, they will grow everything back. As for the no brains thing, anyone who has seen “SpongeBob SquarePants” can attest that Patrick Star, SpongeBob’s best friend, is not the sharpest knife in the drawer. Comedy is not the only reason Patrick is a little slow on the uptake. The creator of SpongeBob, Stephen Hillenburg, taught marine biology at Orange County Ocean Institute in California and puts weird facts like that into the story and characters. Sea stars actually have something going on upstairs, but it’s just a nerve ring instead of a brain.

Breathing is another thing that our dear sea stars don’t do like most of the creatures we come in contact with. They absorb sea water through a small dot normally located somewhere on the top facing side of the sea star; this is called a madreporite. The water they absorb is used in their circulatory system (yes, you read that right, sea water being used for blood). While they have the water they might as well make the most of it and absorb the oxygen out of it.

For vision the sea star uses a tiny dot on the end of each arm to see. If you find a sea star large enough you may notice the tiny dot (it looks like someone put the point of a highlighter on the very tip of the arm). Their vision is not like ours and is more like dark and light (sun’s out - sun’s not out).

To get around, the sea star uses its arms with hundreds of little, tiny tube feet on each arm. None of the arms are dominant. Our Forbes Sea Stars have 5 arms each and have been clocked at a whopping five inches a minute! That is a sea star run! Full speed, petal to the metal, run! (That’s .005 mph.) When you don’t have to run down your food and most things don’t want to eat you or will only take a bite that you will grow back, speed is not a major concern. Their favorite food is most bivalves (animals with 2 shells) like oysters, mussels, and clams. The creatures that they are most concerned about avoiding are crabs, bottom dwelling fish, sea gulls, sea urchins, lobsters and (be surprised) humans.

To eat, the sea star wraps its arms with tube feet around a bivalve. The bivalve slams shut; it doesn’t want to get eaten. After roughly 10 hours the amount of pressure the sea star exerts on the bivalve forces it open, just a little bit. Then the sea star takes its stomach out through its mouth and begins to eat the squishy inside of the bivalve. When the sea star finally removes itself from the bivalve all that is left is shell (licked clean!). Mussels are easily the favorite food of the sea stars in our tank. I am not sure if it’s because they are easier to open or if it’s the fact that they prefer the taste. Our sea stars go through about a pound of mussels in a week. With some of the larger clams in the tank, our sea stars appear to attack them in a group, which amazes me since they have no brain. So I wonder - can they organize? Is it instinct? Communication beyond our understanding? We may never know.

Mysteries of the ocean are being unfolded every day. Remember we know more about the planet Venus than we do about our own oceans. Till the next “Meet the Tank”, take care.

Dive into Deep Sea

By Ben Remo
Science Museum of Virginia intern

Deep under the surface of the world’s oceans is a whole other dimension of life that one has to see to believe. Humans have always been fascinated with the ocean and creatures of the seas. The new IMAX movie, Deep Sea delivers to that curiosity by giving audiences an up-close look at the most bizarre and intriguing sea creatures in existence.


You will be introduced to odd creatures like the mantis shrimp and the Humboldt squid. Usually when you see any ecosystem based documentary, you recognize some of the animals. However, in this film I rarely saw an animal that I recognized. The tiger shark was the only animal in Deep Sea that I could easily identify. Every other animal in the film was new to my eyes. I was fascinated throughout the movie because most of the material was new to me. Your eyes will be glued to the screen as you watch a sun starfish navigate the ocean floor trying to catch sea scallops and you will wonder how the star ever gets to enjoy a solid meal. This and other interesting sea creature stories make the educational film irresistible.

Most IMAX movies can take us to a different place or time. This IMAX movie takes the audience to a different environment all together. Narrated by well known actors Johnny Depp and Kate Winslet, the film showcases beautiful views of the most unique fish in the sea. Depp and Winslet give a play by play on predator and prey relationships as well as how marine life helps one another survive. For example, sea turtles will swim for miles to get a “shell wash” from the reef fish. The fish swim with the turtle eating the algae off its enormous shell. The narrators excel working together to explain the unique relationships and rivalries of the sea.

While there are literally thousands of underwater documentaries out there, and believe me I feel like I have seen them all after my high school oceanography class, this is the most interesting underwater video I have ever seen. It introduces education to entertainment in a way I have never seen before. The clear video and interesting situations will reach out and grab anybody, child or adult, and make them pay attention throughout the 45 minute film.

The star powered narration certainly helps out but the sights are really what set this one apart from the rest. The colorful and at times intense scenes make it hard to pull your eyes away. Throughout the movie, we visit a fried egg jellyfish with a 30 foot tentacle span, an eel with a fishing pole type contraption on its forehead, millions of plankton, and a coral reef built around a sunken ship. This is not just another fish documentary; it takes the audience so much deeper, literally and figuratively.

Words do not do it justice; you really have to see some of these things to believe them.

Mastering the Science of Surfing

By Ben Remo

Science Museum of Virginia Intern

One of the coolest sports during the hot months of summer may look like nothing more than a balancing act. However, there is a lot more to surfing than just staying up. To surf is to master the waves and motion of the water. Here, we explain the science behind one of the most popular summer sports.
The first thing any good surfer must know is how waves are formed. As wind gushes over the surface of the water, friction causes the water to ripple. How big the ripples become is dependent on the strength of the wind, the distance the wind blows (also known as the fetch), and the length or duration of the gust. Waves are broken up into many parts, necessary knowledge for any good surfer. The crest is the very top of the wave while the trough makes up the valley in between two waves or the lowest point. Wavelength is the distance between two waves and wave height is the distance between a wave’s crest and trough.
Not all waves are good for surfing. It takes a little bit of science to make regular waves into surfer friendly ones. Surfers need waves that have a swell, or a smooth peak. These swells drag against the ocean floor, creating friction. This friction causes a wave to get taller and eventually break when they get close enough to shore. The best surfing waves are caused by a sand bank or reef on the ocean floor and by wind that blows from the beach out to the water. Winds that blow from the water to the beach cause choppy waves, the worst kind of waves for surfers.
To catch a wave, the surfer must paddle to gain momentum, hopefully enough so that the wave accelerates him/her forward. Ideally, surfers should catch the waves just as they are breaking. At this point, the waves are at maximum velocity. To catch a wave, the surfer’s velocity and the wave’s velocity must be the same. When the board is being carried along by the wave, the surfer can stand up. Once the surfer has caught the wave, staying on the board becomes the problem.
Balance is the number one skill any good surfer can have. To stay up, one must find the center of gravity. On a surfboard, the center of gravity is usually towards the back. The surfer must straddle the center of gravity. It is important that the person’s weight be more towards the back or the front of the board will dip into the water and eventually flip. The surfer controls the motion and direction of the surfboard by shifting weight from one side to the other. The sport is both challenging and fun when done properly. We leave you with a couple of tips for safe surfing. First, never let the board get between you and an on coming wave. Always wear a leg rope connected to the board because a loose board is always dangerous. Wear something to protect your chest and stomach from board rashes. When you come up to the surface of the water, locate your board immediately. Always surf with a buddy or make sure somebody has your back. Lastly, have fun and be safe. Also, check out the film The Ultimate Wave Tahiti in the IMAX®Dome featuring professional surfer Kelly Slater.

Could the oil spill reach Virginia?

As officials make another attempt to cap the well spilling oil into the Gulf of Mexico, Virginians might be asking, “Could oil show up here?” As of now, it appears a large oil slick on Virginia waterways is unlikely, but oil residue in the form of tar balls could wash up on local beaches. How could oil that’s currently in the Gulf of Mexico end up in Virginia?
The Earth’s oceans are always on the move, their motion influenced by atmospheric circulation patterns, water temperature and salinity, ocean floor topography, and the Earth’s rotation. These ocean currents can occur both at the surface and deep in the ocean; they often travel great distances and have an enormous effect on regional climates.
As far as the oil spill goes, the Loop Current is the first culprit that could carry oil toward the East Coast. This current flows north between the Yucatan Peninsula and Cuba into the Gulf of Mexico, loops east and then south along the west coast of Florida. The Florida Current would take up where the Loop Current left off, carrying the oil around Florida. Then the Gulf Stream would take over and carry it up the southeast coast.
The Gulf Stream is an enormous river of warm water averaging 60 miles in width and 3000 feet in depth. At Cape Hatteras, the current’s flow rate is an incredible 85 million cubic meters per second, equivalent to over 1 billion fire hoses! (By comparison, the Mississippi River moves water at roughly 0.6 million cubic meters per second.) A major influence on East Coast weather, the Gulf Stream sometimes breeds Nor’easters in the winter and intensifies hurricanes in the summer, as happened with Hurricane Hugo off the coast of South Carolina in 1989.
At present, disruptions in the Loop Current appear to be keeping oil away from Florida and the Gulf Stream. Eddies often form and then break off from the main body of the current; the majority of the oil that had drifted into the Loop Current in recent weeks appears to be caught in an eddy and cut off from the main body of the current. Satellite pictures even suggest that the current itself may soon sever entirely, lessening the imminent threat of oil coming ashore in Florida and beyond.
This afternoon BP began an attempt to plug the leak with a method called top kill, an ambitious procedure intended to clog the well with thousands of pounds of heavy fluids pumped through extremely long pipes. This procedure has never been attempted so far beneath the surface; it could take several days to determine if it was successful. For everyone’s sake, let’s hope they succeed.

Satellite image courtesy of NASA. Colors indicate water temperature: darker colors = cooler temperatures, lighter colors = warmer temperatures.

Inspiration From Exploration: Notes From the Field
Céline Cousteau
Thursday, June 25, 2009, 7 p.m.

Céline Cousteau tells captivating stories and shares personal photographs from her many incredible voyages into the world's oceans.

Advance tickets required: $20; $10 for museum members. Available online now or by calling (804) 864-1400 or 800-659-1727. Museum members, please call so that we can include your discount.

About Céline Cousteau

Whether she’s free-diving, horseback riding, leading an expedition to the peaks of the Andes, or swimming amid a school of sharks in the South Pacific, Céline Cousteau seeks to educate through adventure and exploration.Daughter of ocean explorer and filmmaker Jean-Michel Cousteau and granddaughter of the legendary Jacques Cousteau, Céline Cousteau is featured in PBS’ most successful new television series, "Jean-Michel Cousteau: Ocean Adventures."

Fluent in three languages, Cousteau has collaborated with her father's Ocean Futures Society promoting the educational program, "Ambassadors of the Environment," throughout her travels. She has worked on the preparation of expeditions, field production and as an on-camera presenter. Recently, Cousteau has worked on an upcoming documentary for Discovery Channel, aiding scientists conducting research on the many shark species of the Great Barrier Reef. She is also an international spokeswoman for La Prairie cosmetic company, representing their new line of Advanced Marine Biology creams and is ambassador to the Clean Up the World Campaign.

Passionate about intercultural relations, Cousteau received her master's degree in international and intercultural management from the School for International Training. She has worked for a number of prestigious organizations, from the University for Peace of United Nations to the Earth Council’s Earth Charter Project. Her most recent project is trying to bring medical attention to the indigenous people of the Vale do Javari reserve in Brazil.