Sunday, December 2, 2007

FORUM TOPIC (Chapter 14, Page 323 - Critical Thinking Q2)

Scientists predict that the ocean will get warmer and the sea level will rise as a result of an intensified greenhouse effect. How might this affect coral reefs?
A prediction of how global warming will affect the marine environment is that the flow of some major ocean currents may change, affecting many marine ecosystems. Already stressed ecosystems such as mangrove forests and estauries will be flooded; coral reefs may not grow fast enough to keep up with rising sea levels.
Marine Biology Sixth Edition - Peter Castro/Michael E. Huber
Living in a Greenhouse: Our Warming Earth, pages 406 & 407

Coral Reefs Assignment - Chapter 14, Part II

1. Fringing reefs are reefs that form along a coastline.
2. Barrier reefs grow parallel to shorelines, but farther out, usually separated from the land by a deep lagoon.
3. Coral Atolls are rings of coral that grow on top of old, sunken volcanoes in the ocean.
4. Fringing reefs grow on the continental shelf in shallow water.
5. Coral Atolls begin as fringe reefs surrounding a volcanic island; then, as the volcano sinks, the reef continues to grow, and eventually only the reef remains.

1. Spur-and-groove formations develop primarily on reef slopes that are exposed to consistent strong winds which are found on atolls and some fringing reefs as well as barrier reefs.
2. All grow different types of corals
3. All consist of a reef flat and a reef slope
4. All are home to many different types of fishes
5. All are type of coral reefs


Coral Reefs Assignment - Chapter 14, Part I



1. How is each reef structure formed? “Coral” is a general term for several different groups of cnidarians, only some of which help build reefs. In reef-building, or hermatypic, corals the polyps produce calcium carbonate skeletons. Billions of these tiny skeletons form a massive reef. The most important reef builders are a group known as scleractinian corals, sometimes called the stony or “true” corals. Nearly all reef-building corals contain symbiotic zooxanthellae that help the corals make their calcium carbonate skeletons. It is the zooxanthellae as much as the corals themselves that construct the reef framework, and without zooxanthellae there would be no reefs.

2. Where is each reef structure found? There are three basic types of coral reefs; fringing, barrier and atoll. Fringing reefs are located very close to shore, and because of water run off they are typically high in nutrients and the water has a high turbidity. Barrier reefs are further from shore, with a lagoon between the reef and the shore. And finally atolls are a circular reef with a central lagoon and possibly small islands formed on the reef.

3. What is the trophic structure of a reef? The trophic structure of a reef is the recycling of nutrients. Coral reefs have among the highest rate of nitrogen fixation of any natural community. Coral reefs are very productive even though the surrounding ocean water lacks nutrients because nutrients are recycled extensively, nitrogen is fixed on the reef, and the zooplankton and nutrients that occur in the water are used efficiently. The reef is able to provide some of its own nutrients.

4. How does the location and type of reef influence the trophic structure? It is theorised that each of these types of reefs corresponds to a differing age of the entire reef structure. The youngest is the fringing reef, with the corals colonising a shallow water area close to the land. If the sea levels then rise or the land subsides, then the reef structure keeps up with this changing depth by growing upward. Eventually a shallow area with no coral growth will form behind the main reef, called a lagoon, giving a barrier reef. If the sea level or land subsides so much as to cause the land to disappear below the water surface, then an atoll is formed. The overall type of the reef whether it is a turbid, high nutrient reef where the stony corals are less common and algae abounds or crystal clear, low nutrient reef where the stony corals can dominate, is dependent of several factors. These include the proximity to land (therefore water run off which will be high in nutrients), proximity to river mouths (for the same reason as land proximity), and location of deep sea currents (which typically bring nutrient rich water. Each type of reef is also divided into various zones within each reef.

5. Give examples of the types of corals found on reefs. Corals are divided into two kinds and both are stationary on the ocean bottom. Hard corals such as brain, star, staghorn, elkhorn and pillar corals have rigid exoskeletons, or corallites, that protect their soft delicate bodies. Gorgonians, or soft corals, such as sea fans, sea whips, and sea rods, sway with the currents and lack an exoskeleton.

6. Give examples of competition, predation, and grazing. Competition – Sessile coral reef organisms must compete for space. Corals and seaweeds compete for light as well. The two main ways in which corals compete for space are by overgrowing their neighbors and by directly attacking them. NOTES FOR STUDENT ONLY: Competition – The interaction that results when a resource is in short supply and one organism uses the resource at the expense of another. Predation – Predation on corals occur when a variety of animals eat corals, but instead of killing the coral and eating it entirely, most coral predators eat individual polyps or bite off pieces here and there. The coral colony as a whole survives and can grow back the portion that was eaten. NOTES FOR STUDENT ONLY: Predation – The act of an animal, or predator, eating another organism, or prey. A top predator is one that feeds at the top of the food chain. Grazing – Grazing is the process of transplantation, removal and caging. An example of the effects of grazing on reefs are damselfishes. Many damselfishes graze on seaweeds inside territories that they vigorously defend, chasing away other fishes that happen to venture inside. Many such damselfishes has actually “farm” their territories. NOTE FOR STUDENT ONLY: Grazer – An organism that feeds primarily on plants.

Marine Biology Sixth Edition, Peter Castro/Michael E. Huber - Chapter 14

Fish Resources - The Fate of the Ocean

The article on The Fate of the Ocean is 12 pages long and I would like more people to read it because it explains the importance of marine organisms in our daily lives as well as the abuse that we humans create for ourselves in the upcoming years. It is an informative article that is easy to understand. It also provides a lot of detailed explanation of how science works around us and how our actions affect marine life.
In this article, Scientists stated that, "From a scientific perspective, we now know enough to improve dramatically the conservation and management of marine systems through the implementation of ecosystem-based approaches." This statement is self explanatory to all but the problem is getting full cooperation from everyone. "Change" has always been close to impossible for many, which is why by the time people understand the importance of marine organisms, it is already to late. SAD, but TRUE!
I love the ending of this article which read, "AT NO TIME IN HUMAN HISTORY has so much scientific inquiry been focused so intensively in one direction: on the anthropogenic changes in our world. As a result, we are learning more, and more quickly then ever before, about the life-support systems of earth work. Science now recognizes that the ocean is not just a pretty vista or a distant horizon but the vital circulatory, respiratory, and reproductive organs of our planet, and that these biological systems are suffering. Much effective treatment is suggested by computer-modeling studies, which the Bush administration, with its fear of science, negates-even though computer models are the same powerful tools that enable us to put men into space, to run wars, and to forecast financial trends." In comparison of this statement, the Marianas, a perfect example of how powerful politicians can be, is the act of our former Governor, Governor Babauta, making the stateless individuals U.S. citizens. If only our politicians would concentrate on the more important matters, EDUCATION and HEALTH, anything can be accomplished!
While reading this article, I kept thinking, what if we completely stop the exporting of wild seafood around the world? Could this be a possible solution to some of the problems? My thoughts continued and came up with, no more exporting wild seafood = more tourists visiting places where wild seafood is overflowing = revenue = growth in wild seafood production. For example, if I am a wild seafood lover and one way to indulge in seafood is to visit a place where seafood is served daily, then I will definitely go there. I wish it was this simple!
The Last Days of the Ocean
News: We're Pushing Our Seas to the Brink. Can They be Saved? A Mother Jones special report.
March/April 2006 Issue

Fish Resources - "Only 50 Years Left" For Sea Fish

I think the article on “Only 50 Years Left” For Sea Fish make a whole lot of sense to me. One reason why I agree with the article is that my father was a fisherman his whole life and today I have three brothers that not only enjoys fishing as a sport but catches fish for food. The catch that my brothers have today even when combined does not even come close to the amount of fish that my father caught 25 years ago. One of the wonderful memories I have of my father when I was as young as 10 years old is when he goes out fishing from night until dawn and returns home with a truck load of fish. Not a cooler full of fish, but, a truck load of fish. Growing up I remembered that people were very generous and neighbors always help each other. When my father returns home from fishing, we already have all our neighbors waiting for their share of the catch, free of charge. With this type of generosity, all our neighbors would also share either their vegetables or animals (pigs, chickens, ducks, cows, goats) with us.

As stated by Steve Palumbi, Scientist from Stanford University, “Unless we fundamentally change the way we manage all the ocean species together, as working ecosystems, then this century is the last century of wild seafood.” I totally agree with his statement because without the cooperation of everyone, the abuse with fishing will continue not forever but rather only until all the wild seafood are gone which is not long from today.

For the Marianas, I will have to say that it will be very sad when the fish population do decline as predicted. Why? Well, one, because some of our people were born fishermen and they fish today for profit as their only way of making ends meet. Two, fish has always been a delicacy for our people and we could not imagine not having fish as part of our diet. An example would be, every year, during lent, we eat only seafood, mainly fish, everyday for 45 days until Easter Sunday. This has always been the practice for my family as part of our religion, Roman Catholics. Therefore, I believe that if people here in the Marianas were educated on the importance of our marine environment as well as to establish strict laws when dealing with our marine organisms, then wild seafood may still be saved and 50 years from today, everyone will enjoy what has always been enjoyed in the past, FISHING!
By Richard Black
Environment correspondent, BBC News website
Last Updated: Thursday, 2 November 2006, 19:01 GMT