In July of 2015 I embarked on a journey to Eleuthera, Bahamas at the Cape Eleuthera Institute through the Earthwatch Reefs and Fish Behavior Research Program. Here, I learned about the coral reefs, their current health, how they were being affected by pollution, the fish that inhabit them, and their behaviors.
One of the many projects we took part in was a fun one for us all: snorkeling around and taking GoPro pictures of what we saw. I was assigned to take pictures of the coral reefs in a few different areas of the island so we could look at the differences between areas and study why that could be. It was quite shocking at how the elk horn coral and stag horn coral had been bleached and drastically decreased in numbers. This led to the important question: why?
You guessed it: humans kinda messed up again. A huge issue with coral bleaching stems from the ocean acidification from the influx of CO2 levels in the ocean.
To understand why this is a problem, we have to go back to the beginning. Coral is an environment for many organisms, including the nutrient zooxanthellae. Zooxanthellae and coral have an important mutualistic relationship in which the coral is a protected habitat and the photosynthesizing zooxanthellae produces oxygen and allows the coral to be healthy and remove wastes. Also, corals are made up of calcium carbonate.
Now, back to the acidification. Burning fossil fuels, chemical runoff, toxins from plastics and other pollutants, and other issues are all components of this acidification as it effects the warmth of the water and PH. The new temperatures and acidity slow the rate that the coral can calcify. Also, the zooxanthellae dies off and allows the coral to pick of diseases and slowly die off.
For this reason, we must take the initiative to limit the CO2 emissions. This can start by simply using less fertilizers on our lawns, driving our cars less, and using less materials that contain toxins. I could see the difference between locations, but sadly each location had shockingly small amounts of coral and the coloring was nothing compared to just a few years ago when I had traveled to Fiji, and Hawaii. Of course these were different locations, but this island of Eleuthera is a pretty remote place specific to research, so this just goes to show the severity of the problem and how connected the oceans truly are.