Blog #1 Coral Reefs ~ Birth rates, Death rates, Emigration, Immigration of populations ~ By Sydney M.

            Coral reefs are not just warm climates with colorful fishes and clear waters.  They are actually one of the main parts to a larger ecosystem.  They are often known as the “rainforests of the oceans,” because of their diverse environments and biological communities.  Since a Coral reef is like a miniature ecosystem, it has many different aspects to it that need to be kept in order for it to be a successful environment (“What Are Coral Reefs?”).

            The Coral reefs environment and population size is kept balanced through the heavy influence made by input and output.  The input is birth and immigration while the output is death and emigration (Brunton).  Recently, there have been many issues surrounding the Coral reefs, due to the fact that corals are beginning to die.  People are trying to help this situation by creating artificial reefs.  This has been affecting the Coral reef’s immigration of population because the fish population is increasing and creating new habitats.  The Coral reef’s emigration of population has also been affected though, because it does not actually increase the fish population.  Instead, it just moves the fish to other locations farther away from their natural habitats.  This is causing the fish population’s death rate to increase because they are easier to catch (“An Introduction to Coral Reefs”). 

            Coral reef fishes go through a process known as recruitment, which is when they add new individuals to the population in order to make it more successful.  The species that shows the most recruitment is usually the one that is highly productive.  For a closed population, the birthrate and death rate rely on the population density, with a small amount of emigration and immigration taking place between local populations.  For an open population, replenishment is dependent on an exterior supply of juveniles.  Overall, birth rates, death rates, emigration, and immigration of populations are all affected by Coral reefs, creating a balanced ecosystem and environment (Jones). 

Works Cited

“An Introduction to Coral Reefs.” NmeaWeb.Org. 7 April 2011. Web. 13 April 2011.

Brunton, Benjamin, and David Booth. “Density- and size-dependent mortality of a setting coral-

reef damselfish.” JSTOR. Web. 13 April 2011.  

Jones, Martha, and Iain McGaw. “Recruitment in Coral Reef Fish Populations.” Regional

Perspectives in Marine Biology. The McGaw-Hill Companies. 2001. Web. 13 April 2011. 

“What Are Coral Reefs?” EPA. United States Environmental Protection Agency. 6 April 2011.

Web. 13 April 2011.