What is the rarest shark species?

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

Guess who’s coming to dinner?

Socially responsible fish!

So, it is the end of a long day on the beach and now you want some seafood. Completely understandable. And, I applaud this question and the quest to be socially responsible. Your choices will make a difference.

It is a tough question to always have a correct up-to-date answer, especially since it varies for regions.

What I can do is recommend a fantastic site that always provides these up-to-date answer – and – for each region. The Monterey Bay Aquarium will even provide you with a seafood pocket guide that you can fit in your wallet.

The guide is broken down into best choices, good alternatives, and fish you should avoid. These valuations are based on fisheries (or fish farms) that are healthier for long term sustainability of the oceans.

Currently, the best farmed choices for the northeast US are char, barracmundi, catfish, oysters, mussels , clams, bay scallops, strugeon (cavier), tilapia, and rainbow trout. The best wild choices for the northeast US are clams, dungeness crabs, atlantic croacker, spiny lobster, pollock, salmon, longfin squid, swordfish, albacore (troll/pole caught) and skipjack tuna (troll/pole caught).

Species labeled as avoidable according to the Monterey Bay Aquarium’s Seafood Watch are: chilean seabass, atlantic cod, imported king crab, Atlantic dogfish, sole, haddock, white hake, imported mahi mahi, marlin, monkfish, orange roughy, farmed salmon, shark, skates, imported or wild shrimp, red snapper, imported wild strugeon (cavier), imported swordfish, tilefish, albacore, bigeye, yellowfin tunas (caught on longline), bluefin tuna, and farmed yellowtail.

Whew.

sfw_map

Don’t forget to download the guide according to your region.

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!

What is the difference between a summer and winter flounder?

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.

what type of flounder is this?

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!

How do sandbars get started?

The current closest to the ocean floor is moving offshore and dumps small piles of sand right at the wave break area. The sand accumulates to various degrees, and regardless it makes the water much shallower where you stand. Now, the sandbars that I am thinking of are very long and are parallel to the coastline. But, the same type of accumulation occurs in the open water, these are known as shoals. A sandbar is a type of shoal.

 

Do sharks have bones?

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?

English: Various types shown. Taken at Mote Ma...

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!

Where are the highest tides found?

The highest tides are found at the Bay of Fundy (Atlantic Ocean) off the coast of Nova Scotia and New Brunswick in Canada, as well as Maine in the United States.

The tides are typically 5 to 10 times higher than other coasts!

Why is being near saltwater good for your health?

I can not believe I am answering this question since I am not a doctor or a beautician on any level.

However, I will happily give you my opinion as a person that has grown up near the ocean. Salt water is amazing for skin – it really moisturizes and tones. That being said, my theory is that once the skin is feeling healthy and strong – circulation increases and eases joint pain and other muscle tensions.

How does coral bleaching result?

Coral bleaching is due to the fact that the algae part of the coral reef ecosystem can no longer photosynthesize properly – therfore, losing the “reef” structure and the corals remain white – since the zooxannthellea are not around (that’s the algae – and responsible for the color of the coral). This occurs due to a lack of sunlight – mostly from a build up of substances (usually, man made – on the surface of the ocean).

What is the second largest reef in the world?

Interesting question.

The top three largest coral reef ecosystems in the world are:

1) Great Barrier Reef off the coast of Australia

2) Belize Barrier Reef

3) Florida Keys Reef Ecosystem

A coral reef ecosystem relies on teamwork between the coral animal (a type of cnidarians) and an algae called zooxannthellea.