Coral Reef Chemistry Flashcards
What organism do corals have a symbiotic relationship with ?
Photosynthetic Algae
Coral Bleaching
Caused by the symbiotic relationship of coral and algae becoming stressed due to increased ocean temp or pollution, causing the algae to leave the coral tissue. The coral loses its food source and becomes susceptible to disease
Daily Cycle of chemistry on a coral Reef
- Photosynthesis occurring during daylight
- Calcification of corals and algae greatest during daylight
- Calcification continues into the night but at a lower rate
pH of water rises during the day
Photosynthesis removes CO2 from the water
Saturation state rises during the day
Higher pH raises the proportion of DIC that is CO32-
pH drops (acidification) during the night
Production of CaCO3 removes CO32- from the water
Effect of low pH on organisms
Affects their ability to produce CaCO3
Effects of low pH on coral reef:
- Reduced calcification rates
- Increased rates of coral bleaching
- Reduced productivity (photosynthesis)
Increased atmospheric CO2
Adding to the ocean and acidifying it
Common coral diseases (more susceptible due to increased nutrients)
- Black band disease
- White plague
- White band
- Yellow blotch syndrome
Zooxanthellae
Can increase in density and biochemistry depending on amount of N and N:P ratio of nutrients
High nutrient concentrations promote algal growth
- Leads to lower light levels
- Algae can out compete corals for benthic space
- Algae can produce toxins to deter herbivores that damage corals
Algal dominated systems
Tend to have higher concentrations of pathogenic microbes
Local stressors on corals
- Nutrients
- Sediments
- Over fishing
- Anthropogenic pollutants
Global stressors on corals
- Temperature
-CO2 driven ocean acidification
