Every spring, a silent massacre takes place along the central Tyrrhenian coast, particularly between Lazio and Campania. The victim is the Yelkouan shearwater (Puffinus yelkouan), a protected pelagic seabird that spends almost its entire life on the open sea. The figures are alarming: over 300 individuals washed ashore last year, and at least twenty have already been recorded this year.
The most likely cause of death: bycatch
uring the breeding season, these birds undertake long journeys to feed their young. As they dive to catch fish, they are constantly at risk of becoming entangled in fishing nets or hooks. This phenomenon, known as bycatch, kills around 200,000 seabirds a year in European waters. In Italy, there is an urgent need to implement structural and mitigation measures to halt the decline of the species.
Some carcasses collected during the mass deaths in previous years in Lazio were found entangled in fishing nets. The reports from the Regional Veterinary Services (IZS) of Lazio and Tuscany leave no doubt as to the cause of death of these specific specimens, although it is not scientifically possible to automatically attribute the same cause of death to all individuals found elsewhere or in different seasons.
eyond the emergency: collaboration between IZSM, SZN CRIMAC, CRAS and CRIUV
To tackle this crisis, collaboration between research bodies is essential. The Experimental Zooprophylactic Institute of Southern Italy (IZSM), as well as investigating the direct causes of mortality, has provided the CRIMAC at the Anton Dohrn Zoological Station with samples of the internal organs of lesser shearwaters to launch an in-depth study into microplastics. The contribution of the Wildlife Rescue Centre (CRAS) and the Regional Reference Centre for Urban Veterinary Hygiene (CRIUV) was also crucial; they co-ordinated the identification, recovery and transfer of the carcasses to the IZSM, enabling the timely joint commencement of diagnostic investigations and research activities.
Scientific note: Plastic is not considered to be the immediate cause of seasonal mortality, but analysing it provides crucial ecological information about the species and the environment.
The objectives of microplastics research
The study focuses on three main areas:
• Contamination mapping: Use the Yelkouan shearwater as a ‘bioindicator’ of the health and pollution levels of the Mediterranean.
• Characterisation by organ: To understand how different plastic fragments are distributed and accumulate (by type, shape and polymer) in the various organs of birds.
• Abundance and trends: To assess the amount of microplastics actually ingested by this pelagic species in the open sea.
The scientific community’s aim is clear: to call on the relevant authorities to carry out ongoing monitoring and take concrete measures to protect the Yelkouan shearwater and the entire marine ecosystem.
