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Coral Bleaching and the Affect of Temperature Change on Coral Reef Predator-Prey Interactions. Juliann Krupa. Coral Bleaching. Color in coral comes from the photosynthetic symbiotic algae that live with in the tissue of the coral
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Coral Bleaching and the Affect of Temperature Change on Coral Reef Predator-Prey Interactions Juliann Krupa
Coral Bleaching • Color in coral comes from the photosynthetic symbiotic algae that live with in the tissue of the coral • When the sea surface temperature is raised above optimal levels, algae die and are expelled and coral dies soon after • The optimal temperature for corals is a small range (24-29°C) and each coral species has a specific “bleaching threshold”
Coral Predators Damsel Fish Parrotfish Crown of Thorns Sea Star
Lokta-Volterra Predator-Prey Model Modified to include another parameter: Δt, degrees that SST is above bleaching threshold level C(t)= population (size) of coral P(t)=population of parrotfish a=growth rate of coral c=death rate of parrotfish b & d= constant of interaction between coral and fish
Lokta-Volterra Model • Assumptions • Interaction limited to between coral and parrotfish • Without coral, parrotfish populations proportionally decline • At its optimal temperature, coral grows at a steady rate • Temperature proportionally affects coral growth • Temperature proportionally affects parrotfish population
Δt=.5 Δt=1 Δt=1.5 Δt=2
Sources Brown, B. E. “Coral Bleaching: Causes and Consequences”. Coral Reefs. Springer Berlin, Heidelberg. Vol. 16. June, 1997. Glynn, P.W. “Coral reef bleaching: ecological perspectives”. Coral Reefs. Springer Berlin, Heidelberg. Vol. 12. March, 1993. Hixen, Mark. “Predation, Prey Refuges and theStructure of Coral-Reef Fish Assemblages”. Ecological Monographs. Vol. 63. 1993. <http://www.jstor.org/view/00129615/di960508/96p00374/0> Hoegh-Guldberg, Ove. “Curbing Coral Crisis”. University of Queensland, Office of Research and Post Graduate Studies. Sept 2006. <http://www.uq.edu.au/research/index.html?page=51783&pid=0>