Seabird biomonitoring indicates similar plastic pollution throughout the Canary Current

Area of Science:

• Marine Biology
• Environmental Science
• Ecotoxicology

Background:

• Marine plastic pollution poses a significant threat to global biodiversity.
• Petrels, including Cory's shearwater (Calonectris borealis), are particularly vulnerable to plastic ingestion.
• The Canary Current Large Marine Ecosystem (CCLME) is a critical biodiversity hotspot and fishing ground facing pollution challenges.

Purpose of the Study:

• To investigate plastic ingestion by Cory's shearwater fledglings across three islands in the Canarian Archipelago.
• To analyze potential differences in plastic ingestion loads and trophic niches between colonies.
• To assess the link between foraging segregation and plastic ingestion patterns.

Main Methods:

• Analysis of plastic ingestion parameters (number, length, type, color) in Cory's shearwater fledglings.
• Stable isotope analysis (δ13C and δ15N) to determine trophic niche.
• Comparison of data from three colonies on Tenerife, Gran Canaria, and Lanzarote.

Main Results:

• A high incidence of plastic ingestion (>90%) was observed in Cory's shearwater fledglings from all three islands.
• Predominantly white and transparent threadlike fragments, likely from fishing activities, were ingested.
• Despite spatial segregation in foraging areas, no substantial differences in plastic ingestion were found between colonies.

Conclusions:

• Cory's shearwater exhibits high plastic ingestion rates, indicating widespread pollution in the CCLME.
• The species serves as an effective bioindicator for pelagic ecosystem health.
• Standardized monitoring and management measures for fishing activities are crucial to mitigate plastic pollution.