How Does Marine Debris Impact Corals?
A tire sits on coral reefs.
Tires and other heavy marine debris can damage coral reefs.

Coral reefs are often called the "rainforests of the sea." These beautiful and vibrant animals are more than just a pretty aesthetic - they have real value. An incredible amount of marine life depends on healthy coral reef ecosystems, from algae to apex-predator sharks. Humans need them, too, for a variety of reasons:

"Healthy coral reefs are among the most biologically diverse and economically valuable ecosystems on earth, providing valuable and vital ecosystem services. Coral ecosystems are a source of food for millions; protect coastlines from storms and erosion; provide habitat, spawning and nursery grounds for economically important fish species; provide jobs and income to local economies from fishing, recreation, and tourism; are a source of new medicines, and are hotspots of marine biodiversity. They also are of great cultural importance in many regions around the world, particularly Polynesia."

Marine debris, especially large and heavy debris, can crush and damage coral. In the Northwestern Hawaiian Islands, which has one of the healthiest and least disturbed coral reef ecosystems in the United States, an estimated 52 tons of derelict fishing nets accumulate every year. The nets that drift there can be enormous, and when tangled together, weigh hundreds of pounds. These net conglomerates are sometimes described as giant “purses” – they roll across the large reef structures, snagging on corals, breaking them, and collecting them within the tangle. The added coral heads can make the nets heavier than when they started. Once the nets settle, they smother and scour the substrate underneath, impeding growth.

It's not just nets that are a problem for coral. Other larger items such as tires, shipping containers, and derelict fishing traps are also the culprits behind coral damage. Even smaller, everyday litter items can make their way there and degrade the habitat.

Commercial or recreational fishers can help corals out by disposing of unwanted fishing gear through programs such as Fishing for Energy. Everyone can refocus on proper waste disposal, too. If we reuse more, recycle more, and waste less, the amount of our trash making it to precious coral reefs will also decrease. Trash isn't limited to just bottles and cans - bigger items such as tires and laundry baskets need careful consideration for disposal when we are through with them.

Take a moment to appreciate all the beauty and value these incredible corals have to offer, and make sure your waste ends up in the right place - not on coral reefs.