Plastic waste in water could prevent or interrupt the reproduction of some shrimp-like creatures.

In a unique study, published in the journal Environmental pollutionthe ability of the “shrimp-like” creatures to reproduce successfully has been found to be compromised by chemicals found in common plastics.

Research has shown that small creatures, known as the marine amphipod Echinogammarus marinus, changed their sexual behavior when exposed to toxic plastic additives.

Until now, most research on plastic pollution has focused on visual plastics; what can get trapped in plastics and the dangers of ingesting large particles. Scientists from the University of Portsmouth took a different approach and studied the chemicals used as ingredients in plastics.

Professor Alex Ford, from the Institute of Marine Science at the University of Portsmouth, said: “This unsuccessful mating behavior has serious implications, not only for the species tested, but potentially for the population as a whole. These animals form pairs to reproduce. Once exposed to a chemical, they separated from their partners and took much longer – in some cases several days – to readjust, and sometimes not at all.

“These creatures are commonly found on European coasts, where they make up an important part of the diet of fish and birds. If they are compromised, it will have an effect on the entire food chain.”

More than 350,000 chemicals are used in everyday products around the world. Ten thousand of them are used to recycle plastics. Chemicals can be used to make plastics more flexible, add color, protect from the sun, or make plastic flame retardant. About a third of these chemicals are known to be toxic to the human immune, nervous, or reproductive systems.

The study tested four widely used chemicals found in plastics. These plastic additives are used in a variety of common products, for example phthalates (DEHP and DBP) found in medical supplies, food packaging and toys. Triphenyl phosphate (TPHP) is mainly used as a flame retardant in products such as nail polish and electronic equipment including cables, and N-butyl benzenesulfonamide (NBBS) is used in nylon, medical devices, kitchen utensils and films.

Bidemi Green-Ojo, lead author and Ph.D. An environmental toxicology researcher at the University of Portsmouth says: “We chose these four additives because the suspected danger they pose to human health is well documented. Two of the chemicals we studied (DHP and DEHP) are regulated and their use is prohibited. ”

The shrimp-like creatures are known to pair up and typically lock up for two days while mating. Pairs of them were exposed to each chemical and the researchers monitored their behavior for four days, measuring how long it took for the creatures to mate. They found that at best it took the creatures much longer to reconnect and at worst they did not reconnect. A video of the experiment shows the problem.

The experiment found that all plastic additives had the ability to reduce the overall percentage of animals forming pairs. Those who formed pairs took longer to make contact and form a pair again.

Two of the chemicals caused a concentration-dependent effect on the shrimp’s sperm, leading to up to a 60% drop in sperm counts in people exposed to high levels of the chemicals.

“Although the animals we tested were exposed to much higher concentrations than would normally be found in the environment, the results indicate that these chemicals can affect sperm counts,” says Professor Ford .

“It is conceivable that if we did the experiment on shrimp exposed for a longer period of time or at critical stages of their life, it would affect their sperm levels and quality.”

Bidemi Green-Ojo adds: “We need to better understand these chemicals and how they affect behavior. Many types of behavior, such as feeding, fight-or-flight, and reproduction, are essential in an animal’s life, and any abnormal behavior can reduce the chances of survival.

“We urge environmental agencies around the world to pay more attention to behavioral data, because sometimes it tells us things that normal toxicity tests don’t. Studies like this give a different perspective on potential harm caused by a specific pollutant.”