https://www.treehugger.com/plastic/microplastic-chemicals-hurt-snails-ability-evade-predators.html
Microplastics are hurting snails' ability to evade predators
Katherine Martinko
December 4, 2018
This could have serious implications for the entire food chain.
Microplastic contamination of seawater is affecting predator-prey
interactions. An alarming study from the National Centre for Scientific
Research in northern France, just published in the journal Biology
Letters, has found that periwinkle snails living in microplastic-infused
water fail to respond appropriately when hunted by a crab. It appears
that the toxins in microplastics inhibit the chemical cues that would
normally help a snail to know what to do. Researcher Prof. Laurent
Seront explained,
"The whole set of behaviours are totally inhibited. It is worrying
news. If the periwinkles are not able to sense and escape from the
predator, they are more likely to disappear and then to disturb the
whole food chain."
The common periwinkle is a main food source for crabs, although it is
eaten by many humans too. Usually the snails evade death by withdrawing
into their shells or hiding under rocks. But in the case of this study,
which was conducted using wild snails found on a beach near Calais,
France, the periwinkles were slow to withdraw into their shells and
didn't wait as long as they should have before re-emerging. From the
Guardian,
"The concentration of microplastics used in the experiments was
similar to that on the beach. Microplastics are known to attract heavy
metals and persistent organic pollutants and the researchers believe the
release of this chemical cocktail interferes with the periwinkle's senses."
It is not the first time that scientists have noted plastics' toxic
effects on animals. Mussel larvae have been found to grow abnormally as
a result of microplastic exposure, and there are concerns about the way
in which plastics move up through the food chain, being consumed by
creatures as tiny as plankton and eventually making their into the
seafood that humans eat for dinner. But never before has a study found
that microplastic leachates are affecting an animal's ability to protect
itself from a predator. This is truly alarming, with major implications
for the entire food chain.
All the more reason to ban single-use plastics, mandate better water
filtration systems on household washing machines and wastewater
treatment facilities, and incentivize clothing made from natural fabrics.
