More than 90% of birds in the Canary Current have ingested plastic, according to the CSIC

90% of seabirds that feed in the Canary Current end up ingesting plastics in this segment of the great Atlantic gyre, which provides important resources to Spanish and EU fisheries, according to a study led by the National Museum of Natural Sciences (MNCN-CSIC).

The work, published in the journal 'Marine Pollution Bulletin', highlights the role of Cory's shearwaters (Calonectris borealis) as key bioindicators of this environmental problem, after analyzing the stomach contents of 116 chicks of Cory's shearwater on three islands of the archipelago: Tenerife, Gran Canaria and Lanzarote, the MNCN-CSIC reported this Tuesday in a statement.

In total, 1,159 plastic fragments were identified, with a higher prevalence of transparent or white fibers that come off the nets and ropes used in fishing activity.

"Despite the differences in the feeding areas of the adults, which we have determined through isotopic analysis and GPS tracking, the amount and type of plastics ingested by the chicks was similar on all the islands," explained MNCN researcher Airam Rodríguez.

"This indicates that the presence of plastics is uniform along the Canary Current, a region characterized by its high biodiversity and intense fishing activity," he pointed out.

The Canary Current is an upwelling of cold, deep waters rich in nutrients that concentrates great biological productivity and biodiversity, and its presence influences the climate and ecosystem of the Macaronesian islands of Madeira, Cape Verde, the Canary Islands and the Savage Islands.

Cory's shearwaters are seabirds that spend most of the year offshore, visiting the islands only to breed, and feed mainly on squid and fish, which they catch by diving up to 15 meters deep, being a bioindicator of the environmental situation of the ecosystems where it is present.

The chicks analyzed are those that are collected between the end of October and the beginning of November, when they make their first flight, many of them ending up disoriented and colliding with urban structures (antennas, streetlights, buildings, even the ground) due to light pollution.

When the collision is fatal, the team studies the stomach contents of each specimen and, as they have not been able to feed themselves before leaving the nest, it is known with certainty that the ingested plastics have been provided by the parents who fish in the Canary Current.

"The high presence of plastics in birds reflects a serious problem that not only affects the fauna, but also the quality of our marine ecosystems where we fish and from which we feed," Rodríguez warned.

According to the note, the results highlight the importance of standardizing plastic monitoring programs in the marine environment, the usefulness of biomonitoring as an effective tool to assess the health of the marine environment, and the need to strengthen international cooperation to address this growing environmental threat in large ecosystems that transcend political barriers.