You are here: Home / Archives for Marine Science

Test your knowledge: Coral reefs

September 12, 2010 by Leave a Comment
Fishing in the Maldives

Image via Wikipedia

Every once in a while it is fun to test your knowledge and see if you are as smart as you think you are in a certain subject. Today it is time see how well you know coral reefs. Have fun with these ten questions …

  1. It has been found that some coral reefs have been growing since a) 10 million years old b) 50 million years ago c) 1 million years ago.
  2. Single coral organisms, called polyps, can live on their own. true or false?
  3. Coral reefs are typically found in which zone of the ocean? a) the twilight zone b) the sunlight zone c) mid-day zone
  4. Coral reefs are simply coral colonies that have joined together. true or false?
  5. Corals are a) insectivores b) carnivores 3) herbivores.
  6. Corals are a) endangered b) threatened 3) extinct.
  7. What is credited to the diverse colors of coral reefs?
  8. Coral reefs support over a) 10% b) 25% c) 50% of life in the oceans.
  9. Corals are closely related to a) horseshoe crabs and spiders b) sea anemones and jellies c) crabs and shrimp.
  10. Corals will die immediately if they do not feed off the byproducts of photosynthesis of the algae they host. true or false?

Find your answers here.

Filed Under: Coral Reef Ecosystems, Test Your Knowledge

How do fish give birth?

September 10, 2010 by 7 Comments

There are three general ways fish in the sea give birth to a new generation.

I will start off explaining what is most familiar to us, fish that give birth to live young. This is called being viviparous. There is a structure similar to the placenta that connects the embryo to the mother’s blood supply. Some shark species are viviparous. In fact, in some shark species such as the shortfin mako, the embryo has been known to eat other eggs developed by the mother.

Next is something similar called giving birth oviviparously. This is when the embryo develops inside of an egg that is inside the mother. The difference between this and viviparity is that the embryo gets no nourishment from the mother. Nutrients are taken from within the egg. Coelacanths are a type of oviviparious fish.

Lastly, I will go over how 97% of fish species reproduce. These are the fish that lay many, many eggs and hide them in a dark corner so predators can’t get to them. This is called being oviparous. With most oviparous fish species fertilization takes place outside the body. But with many types of skates and rays (pictured right) the male will use his claspers to internally fertilize the female eggs before she lays them.

Image (c) www.gma.org

Filed Under: Bony Fishes, Egg Cases, Fish, Sharks, Skates and Rays Tagged With: , , ,

What would it be like to be a seal pup for a moment?

September 9, 2010 by Leave a Comment

Thanks to the amazing video series called CritterCam produced by National Geographic we can take a sneak peak into the life of a bearded seal pup as he (or she) swims with their mother. The video is shot from the point of view of the seal so don’t expect any sounds other than what the seal would be able to hear. One of my favorite moments from the clip is when mum and pup rubbed their noses together for some gentle affection. Also, don’t miss at 2:30 when you can hear the little one making noises and communicating with his (or her) elder. Technology is just so delightful sometimes!

Filed Under: Marine Mammals Tagged With: , ,

Test your knowledge: What am I?

September 7, 2010 by Leave a Comment

I am a bivalve that grows in the Atlantic Ocean. I do have several species closely related to me that live in freshwater. I am very closely related to clams and oysters. I tend to grow to about 4 inches long. I live in colonies and attach to bulkheads, rope and rocks very easily. To do this I use a sticky protein, called byssus, that forms tough yellow fibers that harden in salt water. My inside is often pearly iridescent and my outside is a blueish black color. I use my gills to filter water to get food and oxygen which  I need to survive. I am very tasty steamed with garlic and butter.

Here are some pictures of me:

Images (c) top: maggiesfarm.anotherdotcom.com, middle and bottom: Beach Chair Scientist.

Filed Under: Bivalves, Mollusks Tagged With:

Visit to the Smithsonian

September 4, 2010 by Leave a Comment

I am excited to bring you a look into the Smithsonian’s American Museum of Natural History. We are taking a sneak peek into the Department of Ichthyology with Research Curator, Melanie Stiassny. Ichthyology is the study of fishes. In this collection you will see the ceolacanth, Latimeria chalumnae, the three lobed caudal finned fish considered to be the missing link between fish and tetrapods (animals with four limbs).

Filed Under: Fish

Why don’t fish freeze in the Arctic Ocean?

September 3, 2010 by Leave a Comment

Fish species that frequent the cold temperatures of the Arctic Ocean (e.g., toothfish, cod, ice fish, etc.) have special ‘antifreeze’ proteins within their blood stream that enables them not to freeze in the cold waters of the northern hemisphere. This discovery was made about 50 years ago.

Recently, scientists from the Ruhr-University Bochum in Germany discovered how these proteins work. In the presence of the proteins, water molecules in the blood stream act in a more uniform fashion and are more particular about the bonds that they create. Whereas without the antifreeze proteins, water molecules just create haphazard bonds. Now we understand why fish can survive in the temperatures of the polar oceans which are below what should freeze fish blood.

The scientists made this discovery by using a technique called terahertz radiation on an Antarctic toothfish, Dissostichus mawsoni.

Journal reference:
Simon Ebbinghaus, Konrad Meister, Benjamin Born, Arthur L. DeVries, Martin Gruebele, Martina Havenith. Antifreeze Glycoprotein Activity Correlates with Long-Range Protein−Water Dynamics. Journal of the American Chemical Society, 2010; : 100816142208022 DOI: 10.1021/ja1051632

Image (c) wikimedia.com

Filed Under: Fish Tagged With: , , ,

I found a great whale watcher

September 2, 2010 by Leave a Comment

I miss my time aboard the Atlantic Star where we would head out to sea in the early morning and Atlantic bottlenose dolphins would be at the surface near the bow of the boat as if leading the way for a great trip. Ah, those were the days. As a substitute I did discover Ms. Monica Wieland who has a great blog about her sightings of killer whales, Orca orca. Her photos and blog descriptions are dynamic and captivating and I enjoy what she has to share. Recently she even wrote about her encounter with Mr. Paul Watson, captain of the Sea Sheperd (the boat that is famous from Discovery Channel’s  Whale Wars).

I hope you find as much enjoyment with the images of Ms. Wieland’s  magnificent neighbors as I have these days!

I love how the motion of the tail slap is captured here:

Image (c) Monika Wieland 2010.

Filed Under: Marine Mammals, People, Random Fun! Tagged With: ,

Where have all the horseshoe crabs gone?

August 31, 2010 by 1 Comment

If you’ve kept on eye on the sandy shores of the Atlantic Ocean or eastern Gulf of Mexico over the past twenty years you’ve noticed a significant decline in the number of horseshoe crabs, Limulus polyphemus, covering the beach. As a marine educator and naturalist in my past life, I always said the decline was due to over harvesting for bait and pharmaceutical needs. This is only half the reason. Recently scientists also noted that climate change, with the sea level rise and temperature fluctuation, may be a cause of the decline.

Tim King, a scientist with the United States Geological  Survey, thinks that what happened during the Ice Age could happen again. With climate change comes a loss of habitat and a loss of diversity. These issues could have severe implications, not only for horseshoe crabs, but also for species that rely on them for sustenance. For instance, along the Delaware Bay the red knot eats the horseshoe crabs eggs at the midpoint of their migration. In the Chesapeake Bay, loggerhead sea turtles are struggling to find one of their favorite food sources, horseshoe crabs, and are retreating elsewhere to find food. Now that the link of a decline in the horseshoe crab population and climate change has been made fisheries managers can take this into consideration.

Images (c) Greg Breese, US Fish and Wildlife Service

Filed Under: Atlantic Horseshoe Crab Tagged With: , ,

What is a fish kill?

August 23, 2010 by 1 Comment

Like it or not sometimes fish kills occur. It is a harshly worded phrase used to define a massive localized die off of a fish population. When there is a fish kill it is a serious matter that environmental agencies use an indicator something may have run a muck in the local ecosystem. Although, fish kills can occur due to natural causes or artificial causes.

For instance, recently in New Jersey the Department of Environmental Protection (DEP) determined that a menhaden fish kill was attributed to a lack of oxygen (hypoxia). It seems as though over one million of the tiny bait fish were swam right into shallow water, perhaps being chased by a predator such as bluefish. All those fish in the shallow water used up the limited oxygen before the tide could take them back out to sea. The water was tested by the DEP and was said to have a very low oxygen level due to very warm air and water temperatures. Fish kills are very prevalent in the warmer months. Other natural causes of fish kills may include drought or underwater earthquakes.

Meanwhile, in Mississippi there was a similar fate for speckled trout that may have been caused by the tar balls and patties that locals have been seeing wash ashore.  Thermal pollution (heated water let off of a nuclear plant), oil, chemical or hazardous waste spills are some of the major causes of man-made fish kills. The use of oil water separators technology can also help in filtering the oil, chemical or hazardous waste spills.

What can you do to prevent a fish kill? Please do not over fertilize your lawn, overstock fish in your pond at home, feed ducks or sport fish, and always try to prevent garbage from entering your local watershed.

Photo (c) http://ian.umces.edu

Do you have another great question? Email info@beachchairscientist.com.

Filed Under: Fish, People Tagged With: , , , ,

How did the loggerhead sea turtle get its name?

August 16, 2010 by 3 Comments

The loggerhead sea turtle, Caretta caretta, was given the common name because it has such a massive head.  On this massive head is an incredibly powerful jaw that aids the turtle in consuming any type of food it can get its mouth on. This can include corals, sponges, crabs, jellies, fish, other sea turtles,  sea urchins, and even octopi. They are true omnivores. This jaw is the most powerful jaw of all the sea turtles. Out of all the turtles in the world it has the second most powerful jaw coming in behind the Alligator snapping turtle.

Image (c) treehugger.com

Filed Under: Sea Turtles Tagged With: , ,