By Ashna Kadambi
Remember Finding Nemo? The animated movie, set in Sydney Harbor and the Great Barrier
Reef, captivated a worldwide audience by illustrating the beauty of marine life, particularly coral reefs. Today, reality paints a bleak picture, as climate change is causing irreversible damage to sea life. Rising sea temperatures, ocean acidification, and over 150 million tonnes of plastic harm marine life and bleach vibrant coloured corals to a ghostly, lifeless shade of white.
How is climate change affecting coral reefs?
Coral reefs are sensitive to both thermal and pH changes. With climate change, an increased amount of carbon dioxide (CO2) is released into the atmosphere due to human activity. Such CO2 contributes to excess heat being absorbed and increases the frequency of oceanic heat waves. Furthermore, the ocean absorbs CO2 which in turn creates carbonic acid, making the ocean more acidic.
Coral populations easily undergo “bleaching” due to minor changes in pH and temperature. This is because corals have a symbiotic relationship with an organism known as zooxanthellae. Zooxanthellae provide the corals with nutrients and in turn, the coral provides shelter. However, with minor changes in acidity and temperature, the coral expels the zooxanthellae, turning into a ghostly white color and eventually dying.
An example in which a marine ecosystem was devastated due to coral bleaching was Australia’s Great Barrier Reef. Due to global warming, Australia’s hot summers became warmer which put immense stress on the delicate coral, leading it to bleach and perish. One of the most catastrophic heatwaves was in 2002 when 54% of the reefs were affected by bleaching. Furthermore, recently in 2016, another 30% of coral was lost. Unfortunately, 93% of the whole reef shows some evidence of bleaching.
What is the effect of pollution and marine life?
Pollution, especially plastic debris, has the ability to wreak havoc on marine ecosystems. For example, the Great Barrier Reef has been immensely affected by marine debris. Over 14 billion pieces of plastic in Australia will make it into the sea annually. Yet, knowing where the trash ends up, people still go and buy one-time-use plastic water bottles and plastic straws. Trash and pollution are killing marine creatures, who deserve love and life.
What can we do to help?
We must try our best to mitigate the effects of climate change and reduce our plastic consumption. Small efforts such as riding public transportation to school or bringing reusable bags to grocery stores can make a meaningful difference. Trying to make a change in unsustainable habits is what can protect our future marine life for generations.