Fish, Fisheries and Queryomics
Wired reports that a recent paper by British scientists highlights the growing problem of plastic contamination in British waters- indeed, this is a global problem. The paper, by A. Lusher and colleagues reported finding traces of plastic, in the form of small particles, in a third of the fish sampled off the cost of Plymouth.
Lusher and colleagues looked at the presence of plastic in the digestive tracts of ten species of fish found in the English Channel. Of the 504 fish in their samples, 36.5 percent were found to have ingested various plastics. Further, they found no difference in the presence of plastics in bottom-dwelling fish versus those that live in open waters: they found plastics in fish collected everywhere.
The most prevalent plastic? Raylon. As in Aloha shirts.
Interestingly, the proportion of fish that fed on plastics in Lusher’s study (36.5%) is similar to proportion observed in other studies: 35% in 17 marine species (Christiana Boerger and colleagues) and 33% in catfish from estuaries in Brazil (Fernanda Posatto and colleagues).
These studies document the prevalence of plastic consumption, but thus far have failed to report any real hazards to the fish. However, the plastics are unlikely to be doing anything positive for the fish. Just one more thing to deal with.
According to Wired, “The researchers suggest that the accumulation of this plastic in fish could block their digestive system, and even cause the fish the stop eating as it constantly feels full. It is also possible that contaminants attached to the plastics could accumulate in the fish.”
Well, says Beel, a read of the paper does not support these statements. The authors do not claim plastics will stop fish from feeding. Nor would Beel believe such a suggestion. Beel has seen fish feeding on prawns so greedily that the prawns were literally passing through the fishs’ digestive system undigested, dead but undigested. Fullness may affect the aggressiveness of feeding, but it will not shut it down.
Also, it is unlikely that contaminants attached to the plastics are an issue, as the plastics themselves release chemicals that can adversely affect the fish.
Another instance of plastics in the water? Beel says, look what this fellow found in the water in Russia. Maybe this is why they lost the cold war?
Christiana Boerger and colleagues. 2010. Plastic ingestion by planktivorous fishes in the North Pacific Central Gyre. Marine Pollution Bulletin, Volume 60, pages 2275–2278.
A. Lusher and colleagues. 2012. Occurrence of microplastics in the gastrointestinal tract of pelagic and demersal fish from the English Channel. Marine Pollution Bulletin, in press.
Fernanda Possatto and colleagues. 2011. Plastic debris ingestion by marine catfish: an unexpected fisheries impact. Marine Pollution Bulletin, Volume 62, pages 1098–1102.