Skip to main content

Advertisement

Log in

Anthropogenic food resources, sardine decline and environmental conditions have triggered a dietary shift of an opportunistic seabird over the last 30 years on the northwest coast of Spain

  • Original Article
  • Published:
Regional Environmental Change Aims and scope Submit manuscript

A Correction to this article was published on 12 March 2020

This article has been updated

Abstract

Human activities and environmental conditions are the main drivers of ecosystem change. One major alteration near the western Iberian coast has been the collapse of the Atlanto-Iberian sardine Sardina pilchardus stock, with important cascading effects on marine top predators. We investigated the effect of long-term changes in fishery landings, sardine availability and environmental conditions on the diet of the yellow-legged gull Larus michahellis in the northwest coast of Spain, over the last 30 years (1987–2017). Dietary trends of gulls were investigated through the analysis of 5010 pellets that revealed a sharp decline of fish and refuse and a shift to a crustacean-based diet. General additive mixed models showed that both total fish and sardine occurrences in gull pellets were negatively associated with total fishery landings and positively associated with sardine landings, suggesting fish depletion and higher fishing efficiency (i.e. reduced discards) during the study period. The winter North Atlantic Oscillation (NAO) index was also positively related with sardine occurrence in gull pellets, possibly due to low sardine abundance and rough conditions in years with very low NAO values. The refuse decline was most probably caused by the closure of open-air landfills, implemented under the European Union Landfill Directive. Our results suggest that changes in fishing practices and waste disposal were the main factors responsible for the sharp decline of fish and refuse in yellow-legged gull diet.

This is a preview of subscription content, log in via an institution to check access.

Access this article

Price excludes VAT (USA)
Tax calculation will be finalised during checkout.

Instant access to the full article PDF.

Fig. 1
Fig. 2
Fig. 3
Fig. 4

Similar content being viewed by others

Change history

  • 12 March 2020

    The article which was recently published contained error in Table 1.

References

Download references

Acknowledgements

Dr. Jose Guitián and the staff of the National Park of the Atlantic Islands of Galicia are acknowledged for the help and support during fieldwork all over these years.

Funding

We received the support of Portuguese national funds provided by ‘Fundação para a Ciência e a Tecnologia, I.P.’ (FCT), through the strategic project UIDB/04292/2020 granted to MARE and the fellowships PD/BD/127991/2016 and SFRH/BPD/85024/2012 granted to JGC and VHP, respectively.

Author information

Authors and Affiliations

Authors

Corresponding author

Correspondence to Joana G. Calado.

Additional information

Communicated by Anne Bousquet-Melou

Publisher’s note

Springer Nature remains neutral with regard to jurisdictional claims in published maps and institutional affiliations.

Electronic supplementary material

ESM 1

(DOCX 46 kb)

Rights and permissions

Reprints and permissions

About this article

Check for updates. Verify currency and authenticity via CrossMark

Cite this article

Calado, J.G., Paiva, V.H., Ramos, J.A. et al. Anthropogenic food resources, sardine decline and environmental conditions have triggered a dietary shift of an opportunistic seabird over the last 30 years on the northwest coast of Spain. Reg Environ Change 20, 10 (2020). https://doi.org/10.1007/s10113-020-01609-6

Download citation

  • Received:

  • Accepted:

  • Published:

  • DOI: https://doi.org/10.1007/s10113-020-01609-6

Keywords

Navigation