From far away you can probably only see the fin, right? The Atlantic bottlenose dolphin will have a dorsal fin that is hooked while the Atlantic Harbor Porpoise will have a triangular dorsal fin. If you are closer you will see other differences. For instance, the dolphin is about 7-12 feet as an adult while the porpoise gets to be about six feet. Also, the porpoise has a rather blunt nose while the dolphin has a much more pronounced, almost bottle-shaped, nose. Lastly, the porpoise is usually darker in color than the dolphin. 
Do you have another great question? Check out www.beachchairscientist.com and let us know what you always ponder while digging your toes in the sand!
How can you tell if that fin bobbing up and down in the distance belongs to a dolphin or a porpoise?
April 20, 2009 by Leave a Comment
What do you do if you see a marine mammal stranded?
April 12, 2009 by Leave a Comment
Keep calm. Also, remain at least 100 feet back so as not to scare the animal back into the ocean. If the animal is injured you want to be sure to get experts there immediately to investigate. If you are on the Atlantic coast call one of the following members of the Northeast Stranding Center.
Maine:
College of the Atlantic (207) 288-5015
University of New England-Hot Line (207) 580-0447
Massachusetts, New Hampshire & Maine:
New England Aquarium (617) 973-5247
Connecticut & Rhode Island:
Mystic Marinelife Aquarium (860) 572-5955
New York:
Riverhead Foundation (631) 369-9829
New Jersey:
Marine Mammal Stranding Center (609) 266-0538
Delaware:
Marine Education, Research and Rehabilitation Inst.(302) 228-5029
Maryland:
Cooperative Oxford Laboratory (800) 628-9944
National Aquarium in Baltimore (410) 408-6633
Washington, DC:
Smithsonian Institute (202) 357-1923
Virginia:
Virginia Institute of Marine Science (866) 493-1085
Virginia Aquarium and Marine Science Center (757) 437-6159
Typically you can volunteer at a stranding center. This would involve being available for crowd control and keeping the animal damp with towels during the interim time when an animal is spotted until experts can show up to diagnosis the animal. You must be properly trained before you become a proper marine mammal stranding volunteer.
For more information check out the place I volunteered during my old undergraduate days: http://www.marinemammalstrandingcenter.org/main.htm
Do you have another great question? Check out www.beachchairscientist.com and let us know what you always ponder while digging your toes in the sand!
Where do fish sleep?
March 6, 2009 by 2 Comments
Well, most fish are just like us and simply want to find a place away from all the chaos of the day to day rat race to take a nap and rest – slowing down their busy lives – gaining energy for the next day.
These places could be under logs, coral crevices, or other sorts of reefs spots – basically out of the way of predators.
Here is an interesting adaptation – the parrotfish uses its spit to create a translucent “sleeping bag bubble” around its body while it sleeps. The bubble helps to hide the parrotfish’s scent so other fish will not find it. If another animal bumps into it – the parrotfish will be warned of the other animal nearby and make a quick get away. Parrotfish are found on the coral reef.
But we’ve only scratched the surface here. Check back often at http://www.beachchairscientist.com for more insight about your favorite beach discoveries.
What do sand sharks eat?
February 17, 2009 by 5 Comments
“Sand shark” can be a bit of a catch-all term, but it seems to most commonly refer to the sand tiger shark, Charcharius taurus. Sand tigers are an interesting case study in form following function in shark teeth. Sand tigers have long, narrow, prong-shaped teeth—like the tines of a fork. Their teeth are perfectly shaped for spearing slippery prey like fish and squid. But while slippery swimmers make up the bulk of their diet, it is worth pointing out that sharks are always opportunistic. Sand tigers are not above snapping up a wayward crab or lobster.
Jim Wharton
Vice President, Education Division, Director, Center for School and Public Programs, Mote Marine Laboratory
What is the rarest shark species?
February 13, 2009 by 2 Comments
There are plenty of candidates. The deep-diving, plankton-feeding megamouth shark was discovered as recently as 1976 and is only known from 40 or so specimens. A group of species called “river sharks” seem pretty rare. Some have been described from just a single collected specimen. There are many deep sea sharks that have only been caught a handful of times. Does that make them rare? Maybe we’re just lousy at finding them?
What is clear is that many species are much rarer than they used to be. One study finds shark populations in the Mediterranean Sea down 97%. Another found oceanic whitetips in the Gulf of Mexico down 99% since the 1950s. Large predators are naturally uncommon as it is. It takes a lot of energy in an ecosystem to support them. It’s up to us to make smart decisions when it comes to seafood and coastal development to keep them from becoming even rarer.
But we’ve only scratched the surface here. Check back often at http://www.beachchairscientist.com for more insight about your favorite beach discoveries.
Jim Wharton
Vice President, Education Division, Director, Center for School and Public Programs, Mote Marine Laboratory
What is the difference between a summer and winter flounder?
February 13, 2009 by 2 Comments
I would suggest laying it flat on a surface with the head facing your left hand. A summer flounder will have their eyes swiveled to the top of their heads and their mouth will be under their eyes. Their mouth will actually also extend behind their eyes. A winter flounder will have their eyes closer to you while their mouth would then be above their eyes. Also, their mouth is considerably smaller and doesn’t go past their eyes.
Flounder are born with a body type in balanced symmetry, in other words , looking like normal fish. As they continue to grow, their bodies morph to the left or right so their eyes and mouth are on one side. Then they rest on the bottom of the ocean floor on the other side.
That explains that flounder are flat fish with their eyes and mouth on one side of their head. Now, whether the eyes and mouth morphed left or right will be the answer to the question.
OK, quite simply if you were to catch a flat fish and think of only these two options (summer or winter flounder) I would suggest laying it flat on a surface with the head to your left a summer flounder will have their eyes swiveled to the top of their heads and their mouth will be under their eyes. Their mouth will actually also extend behind their eyes. A winter flounder will have their eyes closer to you while their mouth would then be above their eyes. Also, their mouth is considerably smaller and doesn’t go past their eyes.
Please keep in mind that there are Gulf flounder and bunch of others, but we will keep it simple.
Summer flounder are generally darker. But, that type of answer doesn’t help when you have nothing to compare.
So, test your knowledge and leave a comment to answer this question: What type of flounder is pictured above? (And it is facing right to throw you off base.)
Do you have another great question? Email info@beachchairscientist.com and share!
Do sharks have bones?
January 2, 2009 by 6 Comments
No sharks do not have bones.
Sharks do have skeletons, but they’re made of cartilage rather than bone. Cartilage is the flexible stuff in the tip of your nose. A cartilage skeleton has its advantages. It’s light, flexible, and it heals faster than bone. In some spots though, sharks need a little extra strength. Their skulls, jaws, and spine are fortified with calcium salts, making them much thicker and stronger. Can you think of why a shark would need strong jaws, skulls, and spines?
by Jim Wharton
Vice President, Education Division, Director, Center for School and Public Programs, Mote Marine Laboratory
Do you have another great question? Email info@beachchairscientist.com.
Are stingrays related to sharks?
January 2, 2009 by 7 Comments
Image via Wikipedia
Stingrays and sharks are very closely related. They belong to a group of fishes called the elasmobranchs. All elasmobranchs have 1) skeletons made of cartilage (the flexible material that makes up the tip of our nose and ears) and 2) 5-7 gill slits. Elasmobrachs includes sharks, rays, and skates.
It’s not entirely incorrect to think of stingrays as flattened sharks. On the inside, they’re just about the same. There are some animals that blur the lines between the two. Angel sharks and wobbegongs are flat, but they’re not rays. Then there are sawfish (which are rays) and sawsharks (which are sharks). Sharkrays are just plain confused. As a general rule, if the gill slits are on the bottom, it’s a ray. If they’re on the side, it’s a shark.
Jim Wharton
Vice President, Education Division, Director, Center for School and Public Programs, Mote Marine Laboratory
Do you have another great question? Email info@beachchairscientist.com!
How do fish float?
November 21, 2008 by 1 Comment
There are a few different answers – depending on what type of fish we are asking about.
The most sophisticated types of fishes – bony fishes – have a swim bladder. These fish can inflate their swim bladder with gas from a special gas gland. The gas is basically oxygen from the fish’s blood. Bony fishes that spend most of their lives on the bottom of the ocean floor (e.g., flounder) don’t have a strong swim bladder – therefore, don’t float.
Sharks, skates, and rays are all types of fish. However, these fishes are more primitive – lacking bones. They stay afloat with a liver filled with oil. They use long pectoral fins for balance in mid-waters while maintaining a light framework. The ‘light framework’ is made up of cartilage (the same material found in our nose and ears).
Image (c) wiki-fish.com. (Yellow Tang – a true bony fish)
Do you have another great question? Email info@beachchairscientist.com.
Where do seagulls nest?
November 21, 2008 by 2 Comments
It is interesting to think that seagulls may want to rest at some point, but they tend to want to re-energize somewhere safe inland (i.e., old boat yards, rock jetties, water towers, etc.) – not necessarily near the dunes or on the beach. Seagulls are full-grown when they leave the nest. They have to be able to survive outside of the nest and as we know, it’s a cruel, cruel world.
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