Camera in Wageningen captures coral eating plastic

Amsterdam, 12 June 2019 – Filmed for the first time: coral eating microplastics. And they even seem to enjoy it. A marine biologist from Wageningen University and Research (WUR) has the disturbing primeur.

Coral normally feeds on plankton. In 2015, researchers discovered that stony corals are unable to distinguish between plankton and microplastics when filtering water. Analysis at the time showed that 21% of the corals investigated contained at least one microplastic. Many animals mistake plastic for food, but coral does not have eyes. Other researchers therefore made the assumption in 2017 that corals eat plastic because they like the taste. The phenomenon has now been filmed.

Tasty additives?

Coral turns out to have a preference for clean plastic above plastic that is covered by a layer of bacteria. The plastic, itself, seems to be a treat for the plankton. It seems likely that this is the result of the chemical additives in plastic. The corals ate all of the different kinds of plastic that were tested, but showed no interest in sand. The coral can’t properly process the plastic that is swallowed. It is also clear that, as a result of the growing plastic pollution, corals more regularly come into contact with plastic.

Filmed: coral eating plastic

Tim Wijgerde, a marine biologist from Wageningen University, has been studying coral for years, specifically recovery and conservation of coral riffs. He has successfully filmed coral consuming various pieces of plastic. Wijgerde: “Although we already knew that corals can eat plastic, there were no clear recordings of this behaviour until now. So I set up a high-resolution camera above coral polyps in our coral lab in Wageningen, and fed the coral with pieces of plastic of about 2 millimetres. Within an hour it was evident that our coral also found the plastic very tasty. The next step will be to investigate how harmful microplastic is for the continued existence of coral.”

Watch Tim’s film, A Reef by Night and Day. The film runs for 12 minutes: The fragment alluded to above starts after 10 minutes and 40 seconds.

Also read: Plastic is making coral reefs sick


Plastic Is Making Coral Reefs Sick

Amsterdam, January 30, 2018 — Coral reefs are the most biodiverse ecosystem in the ocean. They brew with life, yet they are extremely vulnerable. It is well-known that fishing nets have a disastrous effect on reefs, and that in the case of heavy currents, the coral is easily broken by abandoned nets. A new scientific study has recently appeared in Science that points to additional negative effects of plastic on coral health; the insights are alarming. 

Corals are living organisms that can become ill. Plastic plays a major role in this process, as has recently been revealed for the first time. Plastic-damaged coral is weakened and therefore vulnerable to illness. These illnesses do not only affect single organisms, but spread throughout entire reefs.

Coral that ensnares plastic has a 20 times greater chance of becoming ill. Plastic can seal light and oxygen, and release toxins. The most alarming thing, however, is that bacteria can piggyback on plastic and colonize it. If pathogenic bacteria attack the coral, nothing can be done. Researchers compare such cases with gangrene, the ongoing process of tissue extinction in humans and animals. 

Between 2011 and 2014, 159 coral reefs were researched in the Southeast-Asian region and in Australia. The chance of coral becoming diseased increases dramatically when plastic lingers in the reefs; 89% of coral in the presence of plastic were found to be ill, as opposed to 4% of the coral in the absence of plastic. There is also a clear relationship between the degree of plastic pollution in reefs near countries with poor waste management, such as Indonesia (25.6 items per 100m2), versus those in the vicinity of countries that have better management, like Australia (0.4 items per 100m2).

Researchers estimate that by now there are more than 11 billion pieces of plastic present in reefs. If action is not taken, the number will rise to15.7 billion pieces by 2025. The food security of millions of people is at stake; when coral reefs die, many species of fish lose their breeding spot, which results in a reduction of species diversity.