Corals within the Great Barrier Reef are starting to eat plastic, causing concern among marine biologists.
The corals live in waters off the coast of Australia, and consume nearly anything that is available in the water. When tiny fragments called microplastics are present in the ocean, they can be consumed by the lifeforms. The danger comes from the fact that these materials can not be processed by the corals, and the substance can collect within their digestive systems.
"If microplastic pollution increases on the Great Barrier Reef, corals could be negatively affected as their tiny stomach-cavities become full of indigestible plastic," Mia Hoogenboom from the ARC Centre of Excellence for Coral Reef Studies at James Cook University, said.
Microplastics are common throughout many regions of the global ocean. Negative environmental impacts of contamination by these fragments can be severe, particularly in regions occupied by inshore coral reefs, researchers report. Despite their effects on marine lifeforms, little is known about the effect of microplastics on the ocean environment.
Waters surrounding the Great Barrier Reef were studied, and found to contain various forms of plastics, including polystyrene and polyethylene, although their concentrations were limited.
In order to test how these tiny pieces of plastic can affect lifeforms in the Great Barrier Reef, researchers placed corals from the feature into a tank laced with microplastics. Investigators found the corals started to eat the pollution within just two days.
"Corals get energy from photosynthesis by symbiotic algae living within their tissues, but they also feed on a variety of other food including zooplankton, sediment and other microscopic organisms that live in seawater. We found that the corals ate plastic at rates only slightly lower than their normal rate of feeding on marine plankton," Nora Hall, a James Cook University graduate, said.
In fact, the researchers discovered that the corals consumed microplastics at nearly the same rate as they do plankton. When researchers examined the corals, they found plastic stuck inside digestive tissue within the polyp of the marine organisms. This could suggest that the pollution could impede the ability of corals to properly digest food.
Future research will examine the effect these microplastics could have on the health of corals, as well as other marine species. Part of this study will determine if fish around coral reefs also consume plastics, and how the pollution could alter their digestive processes.
Study of how microplastics are consumed by corals in the Great Barrier Reef was detailed in the journal Marine Biology.
