A study of rabbitfish (Siganus fuscescens) in four coastal areas in the Philippines shows high levels of microplastics in the fish’s digestive system. The species is a key commodity in the country, prepared both in its dried variety and its guts used as fermented sauce.
Microplastics for breakfast? It might be likely as a newly published study shows concentrates of small plastic particles, or microplastics, inside the digestive systems of rabbitfish (Siganid fuscescens), a popular catch in the Philippines.
The study, published in Marine Pollution Bulletin this month, analysed 120 rabbitfish bought from local fishermen in the cities of Dumaguete and Bais and in the towns of Manjuyod and Ayungon, all part of the Tañon Strait protected seascape, a major fishing area in the province of Negros Oriental.
Through a series of laboratory tests, researchers found that nearly half of the fish samples had microplastics present in their digestive systems. Compared to other neighboring countries like Indonesia where they reported 100 per cent of sampled rabbitfish had microplastics, we only observed 46.7 per cent, lead author Lilibeth Bucol tells Mongabay.
In terms of per fish basis, our data showed an average of 0.6 microplastic particle per fish, Bucol says. We often heard shocking news about whales or turtles with huge number of plastics in their guts and this is probably an equivalent to the fish.
The majority of these plastics were polypropylene, Bucol says. Polyproplene, or PP, is a heat-resistant plastic commonly used in food and beverage packaging. Over time, it breaks down into small plastic particles, typically less than 5 millimeters in size, that settle on sea algae and can be consumed by small fish like the rabbitfish. This makes rabbitfish a good marker to determine the levels of microplastics in a given location.
The Philippines is one of the most prolific consumers of single-use plastics, using roughly 48 million shopping bags and 164 million sachets on a daily basis. With a still-developing waste management system, this plastic waste ends up in the oceans, making the country the third-largest contributor of marine plastic pollution, according to a 2015 study. China and Indonesia were the top two in the study, which calculated land-based plastics entering the oceans based on worldwide data.
The new study is the first to look at microplastics consumption among fish species consumed by humans. While the researchers could not pinpoint the source of the plastic inside the rabbitfish guts, they were able to establish that these microplastics have reached even the most rural and least populated towns in Negros Oriental.
Eco-Business 20092020