GEO 602 INTRODUCTION TO OCEANOGRAPHY PRESENTATION GROUP MEMBERS JOANA VOSAYACO CAROLINE DOUGHTY

TOPIC : CORAL BLEACHING

INTRODUCTION Tropical coral reefs are the most biologically diverse of marine ecosystems “equaling in beauty and excelling in grandeur the most favorite parterre of the curious florist” (Matthew Flinders, October 1802). Gorgeous, delicate coral reefs are home to millions of fish and fundamental to our own survival. Aside from their natural beauty, many millions of people depend on healthy coral reefs for their livelihoods. Coral bleaching is a global crisis, caused by increased ocean temperatures driven by carbon pollution. Direct local impacts of human activities on many of the world’s coral reefs have already generated the “coral reef crisis”. Human activities, through increased greenhouse gases, are now imposing a compounding threat to maintenance of these charismatic ecosystems -- mass coral bleaching events (where the coral--algal symbiosis breaks down) due to thermal stress. Climate change is the biggest threat to our Reef. The Reef needs our help while there’s still time.

WHAT IS CORAL BLEACHING? The stunning colors in corals come from a marine algae called zooxanthellae, which live inside their tissues. This algae provides the corals with an easy food supply thanks to photosynthesis, which gives the corals energy, allowing them to grow and reproduce. When corals get stressed, from things such as heat or pollution, they react by expelling this algae, leaving a ghostly, transparent skeleton behind. This is known as ‘coral bleaching’. Some corals can feed themselves, but without the zooxanthellae most corals starve. When corals are stressed by changes in conditions such as temperature, light, or nutrients, they expel the symbiotic algae living in their tissues, causing them to turn completely white. When a coral bleaches, it is not dead. Corals can survive a bleaching event, but they are under more stress and are subject to mortality.

HEALTHY CORALS CORAL BLEACHING

CAUSES OF CORAL BLEACHING 1.Change in Temperature 2.Runoff and Pollution 3.Overexposure to Sunlight 4.Extreme Low Tide

1. CHANGE IN TEMPERATURE  Increased ocean temperature caused by climate change is the leading cause of coral bleaching.

2. RUNOFF AND POLLUTION  Storm generated precipitation can rapidly dilute ocean water and runoff can carry pollutants.  These can bleach near shore corals.

3. OVEREXPOSURE TO SUNLIGHT  When temperatures are high, high solar irradiance contributes to bleaching in shallow water corals.

4. EXTREME LOW TIDES  Exposure the air during extreme low tides can cause bleaching in shallow coral.

EFFECTS OF CORAL BLEACHING: Migration of small fishes to seek new home. Since their ocean marine’s habitat is dying. If coral reefs were to vanish then the food cycle will be disturbed. Decrease in number of tourist travelers. Thus leads to decrease in foreign currency. Tropical fish population will decrease. Nearly half of the fish that the world depend on comes from coral reefs. Coral bleaching can affect the formation of reefs.

WAYS TO REDUCE CORAL BLEACHING: Some scientists are studying types of coral that can adapt to warmer ocean temperatures and survive bleaching, and using that information to “train” corals to adjust to warmer acidic water. Their goal is to eventually transplant these more resilient corals into the reefs.scientists are studying People living in the coastal areas should be educated on how important the coral reefs are. Government should create awareness based on Coral Bleaching. Stop polluting the Sea. Especially with plastics.

CONCLUSION: Coral bleaching is a very pressing issue and it ties in with many environmental problems, like global warming and pollution Even though coral bleaching are very easily stressed, there ARE ways that we can help stop this issue and WE would encourage you to.

REFERENCES: Volumes 1 and 2. AUSTRALIAN INSTITUTE FOR MARINE SCIENCES. Townsville, Australia. WILKINSON, C. R. (2008): Status of coral reefs of the world: GLOBAL CORAL REEF MONITORING NETWORK AND REEF AND RAINFOREST RESEARCH CENTRE. https//:googleimages.com. Shultz, D. (2019), The effect of coral bleaching events in the Great Barrier Reef, Eos, 100, Published on 31 May