Endangered Caribbean Coral Reefs By: Yvette Armenta
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The Caribbean Coral Reef endangered ecosystems interested me because I never thought human activities could effect systems that are below the ocean so dramatically. The strange changes occurring in the world are drastically changing the coral reefs which indicates there is something terribly wrong going on. In an article by Beth " 5 Of the worlds most endangered Coral Reefs" on August 4, 2013, she talks about how nearly two-thirds of coral reefs in the Caribbean are threatened by human activities, such as coastal development, sediment and pollution, marine based threats and overfishing. As a popular tourist destination, the Caribbean reefs are also greatly threatened by waste from cruise ships, tankers and yachts that is discharged directly into the water. “In addition, coral bleaching episodes-the most direct evidence of stress from global climate change on Caribbean marine biodiversity-are on the rise. Another example of the dramatic change of corals would be from an article from Conservation International on June 11, 2007.
Which stated that Caribbean coral species are dying off, indicating dramatic shifts in the ecological balance under the sea, a new scientific study of Caribbean marine life shows. The study found that 10 percent of the Caribbean's 62 reef-building corals were under threat, including staghorn and elkhorn corals. These used to be the most prominent species but are now candidates to be listed as Critically Endangered on the IUCN Red List of Threatened Species.
Caribbean coral reefs account for only 7% of the world total coral reef area but play a vital role in the economy of the region and the livelihoods of millions of people who depend upon the reefs for income and employment.
Coral cover has declined from 50% in the 1970s to less than 20% today, potentially reducing the ability of the reefs to provide the ecosystem services that many people rely upon, including habitat for reef sheries, tourism appeal and coastal defense from storms. Coral loss has been accompanied by an increase in seaweed across. Many impacts have contributed to this shift from coral to seaweed reefs including disease, coral bleaching, hurricanes.
Human impacts on reefs in the Caribbean predate the arrival of European settlers in the 15th century, but it is only since the 1970s that large declines in coral cover across the region have occurred. These declines were in part due to outbreaks of disease which wiped-out much of the branching acroporid corals and long-spined sea urchins during the late 70s and early 80s. Over shing and land-based run-o due to human development fundamentally weakened the ability of the reefs to recover from these impacts. Since the 1980s, many reefs have declined further because of hurricanes, major bleaching events in 1995, 1998, 2005 and 2010, and coral diseases. While climate change is already impacting coral reefs, reef management is by no means futile and more important than ever.
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Two major groups of animals inhabit coral reefs: animals with backbones (called vertebrates) and those without these structures (called invertebrates). Vertebrate Coral Reef Animals are Fishes, Sea Snake, Sea Turtle, Dugongs, and Manatees. Invertebrate Coral Reef Animals are Sponges, Echinoderms, Mollusks, Crustaceans, Polychaetes.
Sea Snakes, there are between 55-65 recognized species of sea snakes, but of these only a relative few are commonly found in coral reef areas. Sea Turtles, only three regularly visit corals... Green sea turtle, HawksBill turtle, and the Flatback turtle.Due to loss of nesting habitat and over-harvesting, all three species are now considered either threatened or endangered. Dugongs and Manatees Dugongs were once plentiful in coral reef lagoons. These peaceful giants eat seagrasses, and were well needed herbivores in coral reef lagoons but to recent levels of human interference with these ecosystems they are beginning to retreat from reefs.
As for invertebrates Sponges are primitive, sedentary animals that filter feed on tiny food particles carried in the water sweeping over them. Echinoderms, of the five distinct types that can be found on and around coral reefs, there are two that are generally the most common and that have the greatest influence on reef ecosystems; sea stars and sea urchins. Sea stars, also known as "starfish", are often found in sand and seagrass habitat around coral reefs as well as upon the hard reef. Sea Urchins, are active grazing herbivores and are among the most common of all coral reef echinoderms. Gastropods are mostly herbivorous marine snails - slow-moving. Bivalves have a shell composed of more or less equal halves. These are active filter feeders, pumping water through strainers to remove food. Cephalopods (squid, cuttlefish, octopus)... These swift, intelligent predators have well-developed nervous systems complete with relatively large brains and eyes very much like our own. Coral reef crustaceans include the large, more familiar animals such as shrimps, lobsters, and crabs, as well as many smaller or cryptic types like amphipods, stomatopods, and copepods.
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The term "coral reef plants" has been traditionally used to refer to all photosynthetic life forms. Such organisms have also been traditionally divided into two major "plant" sub-divisions: "flowering plants" and "algae".
Seagrasses are most often found in shallow, sheltered marine or estuarine waters. They are the only type of true plant to successfully colonize the sub-tidal sea. Seagrass meadows play key roles in the lives of many coral reef animals including fishes, invertebrate animals, and visiting marine reptiles and mammals. Mangroves are a unique group of large shrub-like plants that grow in thick, physically complex "forests" that line many tropical and sub-tropical shores. A variety of algae is always present in coral reef ecosystems; in fact, a few types are essential to the survival of corals and the formation of coral reefs. Large, multicellular forms of marine algae are commonly called "seaweeds". Green algae are most common in shallow reef areas. Most of the biomass of coral reef algae are microscopic forms (microalgae).
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Specialist are those species that are only found on coral reefs, and generalist are those species that are associated with a broader range of habitat types, including less complex habitats such as seagrass beds, gorgonian fields, sponge beds and macroalgal stands. In total, they categorized 81 species from 27 families as habitat-specialists and 80 species from 26 families as habitat-generalists. Fish species in each of the two habitat-use groups were also separated into two sub-groups based on their level of exploitation. Fished species included those that are marketed as food-fish or are heavily targeted by the aquarium trade.
My ecosystem does not show good signs of consist display of species richness or species diversity because the human activities are dramatically effecting it. However, the role of consumer diversity in affecting community structure or ecosystem function is not well understood. Here, we show that herbivore species richness can be critical for maintaining the structure and function of coral reefs.
a.) Both priority effects and habitat complexity have been demonstrated in coral reef fishes and display varying degrees of interspecific competition. Combined effects of priority effects and habitat complexity on the strength of interspecific competition among coral reef fish Thalassoma quinquevittatum. interspecific competition is weak and increases survivorship when competitors arrive simultaneously but when competitors arrive at different times, aggression increases.
b.) Reef fishes exhibit interspecific competition when selecting a habitat, yet habitats can be highly variable in predation which can have varying magnitudes on the importance on habitat selection in reef fishes.
c.) For example, a fish can have parasites and be cleaned by another ... Those cleaning stations near coral reefs where fish go to have parasites.
d.) A mutualism relationship exists between Hermatypic (reef-building) corals and zooxanthellae or coral polyps. The zooxanthellae live inside the Hermatypic coralÕs tissue.
e.) A good example of a relationship that demonstrates commensalism is between the Imperial Shrimp (Periclimenes imperator) and large sea cucumbers. The Imperial Shrimp will ride on the sea cucumbers, receiving transportation.
An example of resource partitioning exists between the Carrier Crab and Urchins. The Carrier Crab is highly creative in locating defenses. This species will carry urchins on their back for protection as it crosses the sea floor. The urchins prefer a solitary existence but are not harmed by this activity.
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R - selected species would be sea snake, green turtle, lobster, crab, snail, coral fish, etc. K - selected species would be algae, moss, seaweed, coral reefs.
A species in my ecosystem that has exceed carrying capacity and has experienced a crash would be caribbean sea coral reef fish because if it's a partially isolated population belonging to the same species, the different populations are able to exchange individuals and recognize sites in which the species has recently become extinct.
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Corals are found across the world’s ocean, in both shallow and deep water, but reef-building corals are only found in shallow tropical and subtropical waters. This is because the algae found in their tissues need light for photosynthesis and they prefer water temperatures between 70-85°F (22-29°C).
There are also deep-sea corals that thrive in cold, dark water at depths of up to 20,000 feet (6,000 m). Both stony corals and soft corals can be found in the deep sea. Deep-sea corals do not have the same algae and do not need sunlight or warm water to survive, but they also grow very slowly. One place to find them is on underwater peaks called seamounts.
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Geologic structure:
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Significant Issues:
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Sources:
http://www.care2.com/causes/5-of-the-worlds-most-endangered-coral-reefs.html
https://www.sciencedaily.com/releases/2007/06/070607070826.htm
http://www.marinespatialecologylab.org/force/Biogeography%20p.10-23.pdf
http://www.coral-reef-info.com/coral-reef-animals.html
http://www.coral-reef-info.com/coral-reef-plants.html
http://www.coral-reef-info.com/caribbean-coral-reefs.html
http://journals.plos.org/plosone/article?id=10.1371/journal.pone.0126004
https://noahflanigan.wordpress.com/2011/12/10/stay-off-my-lawn-habitat-complexity-and-priority-effects-on-interspecific-competition-in-coral-reef-fishes/
http://jrscience.wcp.muohio.edu/fieldcourses06/PapersMarineEcologyArticles/Symbiosisonthecoralreefsf.html
http://www.softschools.com/facts/biomes/coral_reef_biome_facts/168/
http://www.globalissues.org/article/173/coral-reefs
http://coralreef.noaa.gov/conservation/keythreats/
http://www.nature.org/ourinitiatives/habitats/coralreefs/ways-to-help-coral-reefs/index.htm