Jaime Ramos (MARE–Marine and Environmental Sciences Centre, Department of Life Sciences, University of Coimbra, Portugal) and colleagues have written in the journal Deep Sea Research Part I: Oceanographic Research Papers on foraging changes by Macaronesian shearwaters Puffinus baroli during a North Atlantic Oscillation.

The paper’s abstract follows:

“Changes in oceanographic conditions, shaped by changes in large-scale atmospheric phenomena such as the North Atlantic Oscillation (NAO), alters the structure and functioning of marine ecosystems.  Such signals are readily captured by marine top predators, given that their use of foraging habitats and diets change when the NAO changes.  In this study we assessed sexual, seasonal and annual (2010/11–2012/13) differences in diet, trophic and isotopic niche (usingδ15N andδ13C values of whole blood, 1st primary, 8th secondary and breast feathers), foraging locations and oceanographic variation within foraging areas for Macaronesian shearwaters' (Puffinus baroli) during two years of contrasting NAO values, and between two sub-tropical islands 330 km apart in the North Atlantic Ocean, Cima Islet and Selvagem Grande.  These two locations provide contrasting oceanographic foraging regimes for the birds, because the second colony is much closer to the African coast (375vs650 km), and, therefore, to the upwelling area of the Canary Current.  There was a marked environmental perturbation in 2010/2011, related with a negative NAO Index and lower marine productivity (lower concentration of Chlorophylla).  This event corresponded to the Macaronesian shearwaters feeding farther north and west, which was readily seen in change of both δ15N and δ13C values, and in a higher intake of cephalopods.  Diet and stable isotopes did not differ between sexes.  Regurgitation analysis indicate a dominance of cephalopods in both islands, but prey fish were important for Selvagem Grande in 2012 and cephalopods for Cima Islet in 2011. Bothδ15N andδ13C values were significantly higher for Cima Islet than for Selvagem Grande, irrespective of year, season and tissue sampled.  SIBER analysis showed smaller isotopic niches for the breeding period.  Our study suggests that during years of poor environmental conditions Macaronesian shearwaters shift their foraging location to more pelagic waters, take more cephalopods and overall present a narrower isotopic niche.”

Macaronesian Shearwater, photograph by Luis Ferreira

With thanks to Jaime Ramos.

Reference:

Ramos, J.A., Fagundes, A.I., Xavier, J.C., Fidalgo, V., Ceia, F.R., Medeiros, R. & Paiva, V.H. 2015.  A switch in the Atlantic Oscillation correlates with inter-annual changes in foraging location and food habits of Macaronesian shearwaters (Puffinus baroli) nesting on two islands of the sub-tropical Atlantic Ocean.  Deep Sea Research Part I: Oceanographic Research Papers 104: 60–71.

John Cooper, ACAP Information Officer, 25 July 2015

Joshua Hatch (Integrated Statistics, Inc., Falmouth, Massachusetts, USA) and colleagues have published in the journal Conservation Letters on tracking Great Shearwaters Puffinus gravis in the Gulf of Maine.

The paper’s abstract follows:

“Identifying the overlap of commercial fishing grounds and seabird habitat can suggest areas of high bycatch risk and inform management and mitigation measures.  We used Bayesian state space modeling to describe the movements of 10 satellite-tagged Great Shearwaters and a bivariate kernel density technique to investigate spatial overlap with commercial fishing effort to predict areas of high bycatch in the Gulf of Maine.  We then used contemporaneous fishery observer data to test the validity of our predictions, highlighting an area constituting 1% of the Gulf of Maine as having the highest bycatch risk that accounted for 50% of observed takes.  Fishery observer data also provided insights into characteristics of the seabird-fishery interactions.  Our results indicate that a relatively small number of satellite-tagged seabirds, when combined with fishery-dependent data, can lead to identifying high-bycatch areas, particular fishing practices that might increase risk, and fishing communities that could be targeted for education/mitigation.”

Click here for the unedited version of the manuscript.

Great Shearwater, photograph by John Graham

Reference:

Hatch, J.M., Wiley, D., Murray, K.T.& Welch, L. 2015.  Integrating satellite-tagged seabird and fishery-dependent data: a case study of Great Shearwaters (Puffinus gravis) and the U.S. New England sink gillnet fishery.  Conservation Letters DOI: 10.1111/conl.12178.

John Cooper, ACAP Information Officer, 24 July 2015

Rhiannon Meier (National Oceanography Centre, Southampton, UK) and colleagues have published open-access in the journal Biological Conservation on at-sea movements of the ACAP-listed Balearic Shearwater Puffinus mauretanicus.

The paper’s abstract follows:

“Unprecedented changes to the marine environment and growth of bio-logging science make detailed study of the movement ecology of threatened marine species timely.  Here, we study spatial and temporal patterns of marine space use by a critically endangered seabird: the Balearic shearwater Puffinus mauretanicus.  Using a suite of bio-logging systems, 67 foraging trips were recorded during incubation periods between 2011 and 2014 from one of the species’ largest colonies (Sa Cella, Mallorca).  Most birds followed narrow flight corridors to restricted neritic foraging grounds on the Iberian continental shelf.  Productive foraging areas along the Catalan coast (NE Spain) were consistent across multiple years and between sexes, indicating extensive use of predictable resources.  While our study emphasises the vulnerability of this species to anthropogenic activity in nearshore waters, consisteant commuting corridors and foraging grounds represent tractable habitat for protection and offer hope for developing area-based management approaches.  Preferred foraging areas showed strong overlap with recently declared Special Protection Areas, strengthening the evidence base for targeted management at these sites.”

Balearic Shearwater, photograph by Pep Arcos

Reference:

Meier, R.E., Wynn, R.B., Votier, S.C., McMinn Grivé, M., Rodríguez, A., Maurice, L., van Loon, E.E., Jones, A.R., Suberg, L., Arcos, J.M., Morgan, G., Josey, S.A. & Guilford, T. 2015.  Consistent foraging areas and commuting corridors of the critically endangered Balearic shearwater Puffinus mauretanicus in the northwestern Mediterranean.  Biological Conservation 190: 87–97

John Cooper, ACAP Information Officer, 23 July 2015

Guilherme Frainer (Laboratório de Sistemática e Ecologia de Aves e Mamíferos Marinhos, Departamento de Zoologia, Universidade Federal do Rio Grande do Sul, Porto Alegre, Brazil) and colleagues have published in the journal Marine Biodiversity Records on three aberrantly plumaged White-chinned Petrels Procellaria aequinoctialis.

The paper’s abstract follows:

“We report on three aberrantly plumaged White-chinned Petrels Procellaria aequinoctialis from the Brazilian Economic Exclusive Zone in the south-west Atlantic Ocean – the first reports based upon tangible evidence for the region.  Two of them showed a low degree of colour aberration (some white around the eyes and on the upper-wing coverts), whereas the third exhibited the highest degree of plumage aberration so far reported for the species: a plumage mostly white with brown freckles on the upper- and under-parts, head and nape.  We also commented on problems related to at-sea identification of aberrantly plumaged seabirds.”

Normally-plumaged White-chinned Petrels, photograph by Ben Phalan 

Reference:

Guilherme Frainer, G., Daudt, N.W. & Carlos, C.J. 2015.  Aberrantly plumaged White-chinned Petrels Procellaria aequinoctialis in the Brazilian waters, south-west Atlantic Ocean.  Marine Biodiversity Records 8.  DOI: http://dx.doi.org/10.1017/S1755267215000871.

John Cooper, ACAP Information Officer, 22 July 2015