Almost ideal conditions are required for coral to thrive, allowing for very little change in any environmental factors. Considering this fact, isn’t it fascinating that coral species have survived an estimated 250 million years? Their resiliency is in part due to their ability to reproduce and regenerate. Yet, we would be remiss to assume that corals are invincible. What has allowed coral and coral reefs to survive for millions of years is their incredible ability to adapt and mutate in ways that best aid in species survival.
1. Coral has an amazing ability to survive through adaptation.
For millions of years, coral has demonstrated a remarkable ability to adapt to climate and environmental changes or stressors. One striking example is how certain fluorescent species have, in recent times, developed the ability to protect their zooxanthellae (algae critical to coral survival) from harmful UV rays as they can transform harmful light wavelengths to usable. Nonetheless, scientists are finding coral dying at a frightening rate.
2. Will coral be able to adapt to threats to their food?
The zooxanthellae, on which coral rely as an energy source, is very sensitive to changes in light and temperature, factors that are significantly affected by climate change and ocean temperatures. When temperatures rise, algae begin to overwhelm or provide too many nutrients to the coral. The stressed coral then expels the algae, a process called bleaching, since algae is what gives coral its color. If conditions continue the coral will starve and eventually die.
The brain coral in the foreground has died and the diseased coral next to it will likely suffer the same fate. Credit: Greg McFall/NOAA
3. Will coral be able to adapt to the increased rate of ocean acidification?
Our oceans play a crucial role in balancing the earth’s carbon levels and do this by absorbing carbon dioxide from the air. Increased levels of CO2 in the air have led to increased CO2 being absorbed by the oceans. When this gas reacts with the seawater the carbonic acid by-product makes the water more acidic. The resulting chain reaction affects the ability of coral to thicken the skeletal structures making it significantly more vulnerable to disease and destruction.
Coral colonies affected by stony coral tissue loss disease.
Credit: Nova Southeastern University
4. Will coral be able to adapt faster than the human impact?
The question today is will coral’s ability to adapt and regenerate be able to out-run our harmful effects? We are learning more each year about how our decisions and behaviors contribute to the accelerated rate of climate change which naturally increases the rate at which coral dies. Activities like eco-tourism and aquatic recreation, over-fishing or destructive fishing practices, over-development of coastal regions, and of course marine pollutions have also had negative impacts on coral.
Sewer dumping into a coral reef. Credit: Shutterstock
5. There is hope for coral.
The promising note is that there are many individuals studying these amazing creatures and finding ways to positively impact the future survival of coral reefs. The Virginia Aquarium is a silver partner with Project SECORE, an international organization focusing on the restoration and protection of coral reefs around the world.
Capturing coral (Diploria labyrinthiformis ) spawn with these spawning nets, designed by SECORE.
Projects include collecting and growing threatened species in human care until strong enough to survive in the ocean, repopulating areas free of disease with coral babies (settlers), and even making strides at developing species to be more resilient to the current stressors. Scientists around the globe are collaborating to find solutions.
Scientists attach substrates with coral babies (settlers) on these PVC grids they attach to rocks and are able to closely monitor them.
We know corals have demonstrated a remarkable ability to adapt to environmental change and pressures over millions of years, even adapting to those created by humans. But is our impact increasing at a rate too fast for the corals to adapt and reproduce? If we take an honest look at how our choices impact the natural world and continue supporting the important conservation work being done, perhaps the tide can turn. Perhaps if our species can learn to adapt too, we can actually have a positive effect on the future of coral and coral reefs.
Elkhorn coral re-growing after a majority has died.
Credit: Zach Ransom
If you would like to learn more about the important work being done by the Virginia Aquarium, be sure to visit us. Stay tuned for future announcements regarding the opening of a brand-new coral lab that our guests will be able to observe and learn from. We are cautiously hopeful for the future survival of coral reefs and hope you will partner with us in caring for corals.