If you've ever gone diving in a coral reef, you know it's like being teleported into a different world. These vibrant underwater cities are bursting with color and teeming with life.

They’re not just beautiful though. Coral reefs are known as the rain forests of the sea, supporting 25% of all marine species. They play a critical role in maintaining ocean health.

Unfortunately , these underwater treasures are under threat, and one of the major culprits is plastic pollution. Let’s explore how marine plastics are impacting coral reefs and what we can do to help.

How Do Plastics End Up in the Ocean?

Plastics in the ocean come in all shapes and sizes, from large discarded fishing nets to microplastics (particles smaller than 5mm). These plastics originate from sources like degraded bottles, synthetic fibers from clothing, and single-use items.

Plastics end up in the ocean primarily due to poor waste management practices on land, which account for about 80% of marine plastic pollution. When plastic waste is not properly disposed of, it can be swept away by rain and storms into rivers, which serve as conduits to the sea.

Additionally, plastics can be blown directly into coastal waters by wind or discarded carelessly on beaches. While most plastics originate from land, marine activities like fishing also contribute significantly, with lost or abandoned fishing gear adding to the ocean's plastic burden. This combination of factors results in millions of tons of plastic entering our oceans each year, posing serious threats to marine ecosystems and wildlife

How Do Plastics Harm Coral Reefs?

Plastic pollution poses a devastating threat to coral reefs, with research revealing alarming impacts.

Studies show that the risk of disease can increase up to 22 times on plastic-polluted reefs compared to pristine ones, with major coral diseases becoming more prevalent in contaminated areas.

In one study, almost all coral reefs surveyed (77 out of 84) contained human-made debris, with 88% being plastic and 73% consisting of fishing gear.

Additionally, microplastics harm corals by blocking their digestive tracts, causing a false sense of fullness, and preventing proper nutrient intake. Corals exposed to microplastics experience reduced growth, impaired feeding, compromised immune systems, and increased susceptibility to bleaching and tissue necrosis.

The physical damage is compounded by the ability of microplastics to transfer toxic chemicals and harmful microorganisms, effectively turning these tiny particles into a chemical weapon against coral reefs.

 

Top Causes for Coral Damage From Plastic Pollution

1. Physical Harm from Plastic Pollution

Corals are natural filter feeders. They stretch out their tentacles to capture tiny food particles like zooplankton floating in the water.

Both large plastic items and microplastics can harm corals.

First of all, large plastic items floating through the ocean can cause tissue damage to corals. There have been many documented cases for example, how corals get entangled in fishing lines, damaging and even killing them.

But even if the direct damage does not kill the coral, large plastic items can be dangerous. Because corals cannot move around the ocean floor, a simple plastic bag can be a death sentence.

If corals get covered in large plastic items like plastic bags, they are not able to free themselves. Being deprived of nutrients and food, they essentially starve and get weaker and weaker.

The same can happen with microplastics.

When corals ingest microplastics, their digestive systems can become clogged, affecting their ability to obtain nutrients. This weakens the corals, making it harder for them to thrive. In the worst case, microplastics can fill up the coral's digestive system, causing the coral to feel satiated, while starving to death.

2. Biological Stress from Plastic Chemicals

Plastics are packed with harmful chemicals like flame retardants and heavy metals. It isn't surprising that the same chemicals that are harmful to humans are just as damaging to corals.

When corals ingest plastics, the toxins can disrupt their immune systems and their symbiotic relationship with algae. This relationship, where algae and corals exchange nutrients is essential for the energy and vibrant colors that corals are known for.

Chemicals in plastic can also disturb other biological processes, for example by harming reproduction, preventing digestion, or hindering development.

Last but not least, ingesting microplastics can cause an immune reaction in the coral, that is similar to what we know from mammals. The coral tries to fight the foreign object, putting it into a constant state of inflammation and irritation.

3. Environmental Degradation

Healthy oceans provide healthy habitats for corals. Plastic pollution compromises reef structure, reducing habitat quality for marine life, including corals.

This leads to a ripple effect, where declining coral health impacts other species that depend on coral reefs. The less healthy coral reefs become, the less food and protection are available for marine wildlife.

At the same time, corals themselves depend on flourishing wildlife for food availability. Over time, if corals are weakened by plastic pollution, the structural integrity of the reef begins to deteriorate. This leads to the collapse of entire ecosystems that countless marine species depend on.

 

What Can We Do to Protect Coral Reefs?

The situation is serious, but there are actions we can take to reduce plastic pollution and protect our beautiful coral reefs:

• Reduce Plastic Use: Choose reusable items over single-use plastics whenever possible.
• Spread Awareness: Share information about the impact of plastics on coral reefs to encourage collective action.
• Minimize Microplastic Shedding: Use laundry bags designed to capture synthetic fibers or switch to clothing made from natural materials.
• Support Legislation: Advocate for policies that limit plastic waste and fund coral reef conservation. Many NGOs fight plastic pollution and support ocean protection. By supporting their fight, you can shift the scale into the right direction.

The Bottom Line

Coral reefs do much more than look stunning. They provide food and livelihoods for millions of people worldwide, protect coastlines from storm surges, and support marine biodiversity. When coral reefs suffer, the entire ocean ecosystem feels the impact, which eventually affects human communities as well.

Plastic pollution is a major challenge for coral reefs, but there is hope. By taking meaningful steps to reduce plastic waste and supporting conservation efforts, we can help protect these essential ecosystems. The health of our oceans depends on the health of coral reefs, and every action counts.

 

We hope you enjoyed this article. Please feel free to leave a comment below if you want to engage in the discussion.

If you want to read more like this, make sure to check out our Blog and follow us on Instagram. If you are interested in truly sustainable products, check out our Shop.