Consistent concentrations of critically endangered Balearic shearwaters in UK waters revealed by at-sea surveys

Allbwn ymchwil: Cyfraniad at gyfnodolynErthygladolygiad gan gymheiriaid

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Dangosydd eitem ddigidol (DOI)

  • Jessica Phillips
    Oxford University
  • Alex Banks
    NATURAL ENGLAND
  • Mark Bolton
    RSPB
  • Tom Brereton
    Marinelife
  • Pierre Cazenave
    Plymouth Marine Laboratory
  • Natasha Gillies
    Oxford University
  • Oliver Padget
    Oxford University
  • Jeroen van der Kooij
    CEFAS
  • James Waggitt
  • Tim Guilford
    Oxford University
Aim

Europe's only globally critically endangered seabird, the Balearic shearwater (Puffinus mauretanicus), is thought to have expanded its postbreeding range northwards into UK waters, though its at sea distribution there is not yet well understood. This study aims to identify environmental factors associated with the species’ presence, map the probability of presence of the species across the western English Channel and southern Celtic Sea, and estimate the number of individuals in this area.

Location

The western English Channel and southern Celtic Sea.

Methods

This study analyses strip transect data collected between 2013 and 2017 from vessel-based surveys in the western English Channel and southern Celtic Sea during the Balearic shearwater's postbreeding period. Using environmental data collected directly and from remote sensors both Generalized Additive Models and the Random Forest machine learning model were used to determine shearwater presence at different locations. Abundance was estimated separately using a density multiplication approach.

Results

Both models indicated that oceanographic features were better predictors of shearwater presence than fish abundance. Seafloor aspect, sea surface temperature, depth, salinity, and maximum current speed were the most important predictors. The estimated number of Balearic shearwaters in the prediction area ranged from 652 birds in 2017 to 6,904 birds in 2014.

Main conclusions

Areas with consistently high probabilities of shearwater presence were identified at the Celtic Sea front. Our estimates suggest that the study area in southwest Britain supports between 2% and 23% of the global population of Balearic shearwaters. Based on the timing of the surveys (mainly in October), it is probable that most of the sighted shearwaters were immatures. This study provides the most complete understanding of Balearic shearwater distribution in UK waters available to date, information that will help inform any future conservation actions concerning this endangered species.

Allweddeiriau

Iaith wreiddiolSaesneg
Tudalennau (o-i)1544-1557
Nifer y tudalennau14
CyfnodolynEcology and Evolution
Cyfrol11
Rhif y cyfnodolyn4
Dyddiad ar-lein cynnar26 Ion 2021
Dynodwyr Gwrthrych Digidol (DOIs)
StatwsCyhoeddwyd - Chwef 2021

Cyfanswm lawlrlwytho

Nid oes data ar gael
Gweld graff cysylltiadau