HOMESTEAD, FL - This past week, while diving to collect data for our ongoing lionfish study, Fish Ecology Lab members noticed that the reefs of South Florida are a lot less vibrant than usual. It appears that reefs along the edge of Biscayne National Park are currently experiencing a “bleaching” event.
Coral bleaching occurs when the algal cells that live within corals tissues, tiny dinoflagellates called zooxanthellae, become stressed and are expelled by the coral polyps. These algae give corals their bright colors, so corals without zooxanthellae appear white, or bleached.
What causes these stressors is not fully understood, but it has historically been linked to increases in water temperature. Our divers can attest it is HOT, with some sites registering 87 digress F in 65 feet of water! Check out this paper for more information about this connection: ftp://ftp.unc.edu/pub/marine/brunoj/Bleaching%20papers%20for%20NCEAS%202/Glynn%201993_coral%20bleaching.pdf
Why does bleaching matter?
These microscopic algae are symbionts, living inside the coral for protection and in-turn providing energy to the coral via photosynthesis. Corals use this energy to drive their basic life functions. Without the algae, corals must rely on direct feeding to provide all of their energy needs. This method is less efficient and over time the corals will begin to die as they struggle to keep up with their energy demand.
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