Under the ocean’s surface, an underwater paradise is fading—-vibrant coral reefs, once overflowing with life, are turning ghostly white as climate change tightens its grip. Coral reefs are all around the world, but they are slowly disappearing, affecting our ecosystem and biodiversity worldwide.
What is a coral reef?
Coral reefs are some of the most integral parts of marine ecosystems. Many may not know that coral reefs are animals—-and have many interesting functions and anatomical structures.
Art by Julia Marcos
Just like other living things, coral reefs eat, grow and reproduce. These animals are relatives of jellyfish and anemones, and just like them, coral reefs eat microscopic algae and nutrients that float throughout the water.
According to the National Oceanic and Atmospheric Administration (NOAA), “During feeding, a coral polyp will extend its tentacles out from its body and wave them in the water current where they encounter zooplankton, bacterioplankton or other food particles.”
Where are they?
Coral reefs live in both shallow and deep waters all across the world! The NOAA has a map of the locations of many coral ecosystems:
Credit: NOAA’s Coral Reef Conservation Program
What’s happening to them?
Many of us may have heard the terms “global warming” or “climate change,” but what do they really mean? In simpler terms, when greenhouse gases such as carbon dioxide concentrate in the atmosphere, they trap the heat that comes from the sun and re-radiate it back to the earth as infrared energy and, in turn, heat our planet. Think of it as a big jacket (of harmful gases) being wrapped around our atmosphere.
When this happens, our ocean temperatures begin to rise. This is harmful because coral reefs are sensitive to harsh temperature changes.
“The total heat stored by the oceans rose 187 zettajoules from 1992 through 2019,” wrote Angela Colbert, Ph.D. in her NASA article.
Even small temperature changes can lead to a thing called “coral bleaching.” Coral bleaching is when stressed coral releases microscopic algae—-which gives the coral its color, as well as food, in exchange for shelter—-known as zooxanthellae. When this is expelled, the coral dies and turns white.
Why is this bad?
“Once a coral is bleached, it becomes more vulnerable to any additional stressors, including those from diseases and storms,” wrote Colbert, Ph.D. Now, historically, coral reefs would have a couple of decades to recover in between these events, but climate change has made these events more frequent which gives coral reefs far less time to recover, leading to the loss of a habitat for the thousands of marine species that need it to survive.
Though ocean warming is a major issue affecting these reefs, it is not the only one. Human activities like large fishing boats that use big nets to collect large amounts of fish (which scrape across the ocean floor) break off and damage coral reefs. This completely devastates marine ecosystems, leading to a decline in the populations of the fish that humans are collecting for consumption.
The food chain is also being damaged by these factors—-which affects the whole world, including humans. If we continue to destroy these ecosystems, we will eventually run out of many primary food sources; especially with the human global population rising rapidly.
What can we do?
Although it may feel like total doom, we can still help. Here is a list of things you can do to make a change:
- Be responsible when visiting coral reefs: Don’t touch them or anchor your boat on them.
- Wear reef-safe sunscreen: Avoid chemicals like oxybenzone and octinoxate, which are commonly used in sunscreen, on your next beach trip.
- Volunteer and donate: Go to beach clean-ups or support charities that are helping coral reefs.
- Educate yourself: Do some research (Google is free!) and try to eat sustainably; figure out if the seafood you’re eating is caught sustainably.
- Educate others: Tell your friends and family about it, bring it up the next time your sibling takes too long in the shower, etc.
- Leave no trace: a common phrase among nature lovers that means: clean up after yourself. Don’t leave fishing lines/nets, litter or other pollutants in the water.
Conserve water: especially since we live in California. (FYI: This will make your water bill cheaper.)
