Drugs and pesticides released into the environment have reached levels that are toxic to the health of the birds that nest in the Venice Lagoon. This was revealed by a new study conducted by the Italian research team coordinated by scholars from the Ca ‘Foscari University of Venice which, as part of the AWExPharma project for monitoring the exposure of wild birds to pharmaceutical products, found the presence of high concentrations of some contaminants in the feathers of the “sandwich tern” pullets (Thalasseus sandvicensis) and coral gull (Ichthyaetus melanocephalus), located respectively in the Barena Celestia area and in the North Lagoon.

The results of the analyzes, publications on Total environmental science and Environmental researchindicated that in the feathers taken from the pullets of these two species, 87% of the 47 samples analyzed contains the active ingredient diclofenac, a non-steroidal anti-inflammatory drug, as well as ibuprofen, nimesulide, naproxen and the antidepressants citalopram, fluvoxamine and sertraline. The 91% of the samples they also contain quantifiable traces of neonicotinoids, a class of pesticides chemically similar to nicotine.

The project, coordinated by ecotoxicologist Marco Picone of the Ca ‘Foscari University of Venice, is the first to consider the use of feathers to monitor the exposure of water birds to pharmaceutical products. In addition, it is the first to testify to the presence of non-steroidal anti-inflammatory drugs (NSAIDs) and selective serotonin reabsorption inhibitors (SSRIs) in pulp tissues. “We studied non-flying sandwich terns and coral gulls because they were totally fed by the parents – Picone explained in one Note -. These birds provide food for their offspring in an area of ​​a few square kilometers around the nesting colonies. As a result, contaminants present in the chicks result totally attributable to localization nesting area“.

The feathers taken from the dorsal tract of the pullets without any consequences for the young birds, in fact act as “archive of contaminants“During the formation of the feather – like ours, who want to acquire the drugs and drugs -, the exposure precisely the period to which they are indicated are subject to the individuals studied.

The feathers of the sandwich terns, in particular, were collected in June 2019 while the samples taken from the pullets of coral gulls dated back to June 2018, two relevant dates since in 2018 the European Union has banned its use in outdoor crops of products containing three neonicotinoids considered by the research: imidacloprid, thiamethoxam and clothianidin.

“We found imidacloprid and clothianidin in all gulls and most sandwich terns – Picone added -. This confirms that the 2018 ban, not (it only concerned outdoor crops), did not eliminate the inputs of these pesticides and that seabirds are exposed to these contaminants. to learn from their eating habits. In fact, coral gulls are omnivores and both aquatic species and insects sprayed with pesticides can enter them. The sandwich terns, on the other hand, feed on small fish (sardines, sprats and anchovies), confirming how neonicotinoids can reach anywhere in the ecosystem.“.

Although the presence of these contaminants in feathers is necessarily indicative of toxic effects, scholars agree that the harmful neonicotinoids for the reproductive health of birds. “Toxicants induce a delay in migration which could, in turn, lead to the specimens stopping in places that are not optimal for the selection of mates and delays in nesting. – concluded Picone -. Knock-on effects that can endanger already vulnerable species“.