Mathew Schwaller (Department of Ecology & Evolution, Stony Brook University, New York, U.S.A.) and colleagues have published in the journal Remote Sensing of Environment, reporting on discovering unknown Antarctic Petrel Thalassoica antarctica colonies on the Antarctic Continent using remote sensing by satellites. This finding goes quite some way to solving the anomaly previously pointed out by Jan van Franeker and colleagues who found that there are not enough known colonies to support the numbers of Antarctic Petrels they had counted at sea.

The paper’s abstract follows:

“The Antarctic petrel (Thalassoica antarctica) has been identified as a key species for monitoring the status and health of the Southern Ocean and Antarctic ecosystems. Breeding colonies of the Antarctic petrel are often found on isolated nunataks far from inhabited stations, some up to hundreds of kilometers from the shoreline. It is difficult therefore to monitor and census known colonies, and it is believed that undiscovered breeding locations remain to be found. We developed an algorithm that can detect Antarctic petrel colonies and used it to complete a continent-wide survey using Landsat-8 Operational Line Imager (OLI) imagery in Antarctica up to the southernmost extent of Landsat's orbital view at 82.68°S. Our survey successfully identified 8 known Antarctic petrel colonies containing 86% of the known population of Antarctic petrels. The survey also identified what appears to be a significant population of breeding birds in areas not known to host breeding Antarctic petrel colonies. Our survey suggests that the breeding population at Mt. Biscoe (66°13′S 51°21′E), currently reported to be in the 1000s, may actually be on the order of 400,000 breeding pairs, which would make it the largest known Antarctic petrel breeding colony in the world. The algorithm represents a first-ever attempt to apply satellite remote sensing to assess the distribution and abundance of the Antarctic petrel on a continent-wide basis. As such, we note several algorithm shortcomings and identify research topics for algorithm improvement. Even with these caveats, our algorithm for identifying Antarctic petrel colonies with Landsat imagery demonstrates the feasibility of monitoring their populations using satellite remote sensing and identifies breeding locations, including Mt. Biscoe, that [sic] should be considered high priorities for validation with directed field surveys.”

Antarctic Petrel

References:

Schwaller, M.R., Lynch, H.J., Tarroux, A. & Brandon Prehn, B. 2018.  A continent-wide search for Antarctic petrel breeding sites with satellite remote sensing. Remote Sensing of Environment 210: 444-451.

van Franeker, J.A., Gavrilo, M., Mehlum, F., Veit, R.R. & Woehler, E.J. 1999. Distribution and abundance of the Antarctic Petrel.  Waterbirds: The International Journal of Waterbird Biology 22: 14-8.

Editorial note:  ACAP Latest News normally restricts its posts to news items on or related to the biology and conservation of the 31 species of ACAP-listed albatrosses, petrels and shearwaters, as well as on non-listed species of shearwaters, of which a number are also at risk to longline fisheries (Cooper & Baker 2008).  News, including of scientific publications, on other species of procellariiforms may be followed on ACAP’s Facebook page.  Occasionally, however, an exception is made, such as this posting, deemed to be of high interest, covering a technique potentially of significance to the study of surface-nesting ACAP-listed species.

Cooper, J. & Baker, G.B. 2008. Identifying candidate species for inclusion within the Agreement on the Conservation of Albatrosses and Petrels. Marine Ornithology 36: 1-8.

John Cooper, ACAP Information Officer, 12 April 2018

Tangi le Bot (Centre d’ Écologie Fonctionnelle et Évolutive, Université de Montpellier, France) and colleagues have published open access in the ICES Journal of Marine Scienceon compiling a “methodological toolkit” from 501 scientific publications on seabird–fishery interactions.

The paper’s abstract follows:

“Seabirds and fisheries have been interacting from ancient times, sometimes with mutual benefits: Seabirds provided fishermen with visual cues of fish aggregations, and also fed upon food subsids [sic] generated by fishing activities. Yet fisheries and seabirds may also compete for the same resources, and their interactions can lead to additional seabird mortality through accidental bycatch and diminishing fishing efficiency, threatening vulnerable seabird populations. Understanding these complex relationships is essential for conservation strategies, also because it could enhance and ease discussion between stakeholders, towards a common vision for marine ecosystem management. As an aid in this process, we reviewed 510 scientific publications dedicated to seabirds–fisheries interactions, and compiled a methodological toolkit. Methods employed therein serve four main purposes: (i) Implementing distribution overlap analyses, to highlight areas of encounter between seabirds and fisheries (ii) Analysing movement and behavioural patterns using finer-scale information, to characterize interaction types (iii) Investigating individual-scale feeding ecology, to assess fisheries impacts at the scale of bird populations, and (iv) Quantifying the impacts of seabird–fishery interactions on seabird demography and population trends. This latter step allows determining thresholds and tipping points with respect to ecological sustainability. Overall, we stress that forthcoming studies should integrate those multiple approaches, in order to identify and promote best practices towards ecosystem-based fisheries management and ecologically sound marine spatial planning.”

A Black-browed Albatross falls victim to a trawler in the South Atlantic, photograph by Graham Parker

With thanks to Anton Wolfaardt.

Reference:

Le Bot, T., Lescroël, A. & Grémillet, D. 2018.  A toolkit to study seabird–fishery interactions. ICES Journal of Marine Science doi:10.1093/icesjms/fsy038.

John Cooper, ACAP Information Officer, 11 April 2018

Katherine Keogan (Institute of Evolutionary Biology, University of Edinburgh, UK) and a suite of colleagues have published a study of no less than 62 seabird species in the journal Nature Climate Change that shows that breeding seasons have not altered in relation to sea temperature rise.

The paper’s abstract follows:

“Reproductive timing in many taxa plays a key role in determining breeding productivity¹, and is often sensitive to climatic conditions². Current climate change may alter the timing of breeding at different rates across trophic levels, potentially resulting in temporal mismatch between the resource requirements of predators and their prey³. This is of particular concern for higher-trophic-level organisms, whose longer generation times confer a lower rate of evolutionary rescue than primary producers or consumers⁴. However, the disconnection between studies of ecological change in marine systems makes it difficult to detect general changes in the timing of reproduction⁵. Here, we use a comprehensive meta-analysis of 209 phenological time series from 145 breeding populations to show that, on average, seabird populations worldwide have not adjusted their breeding seasons over time (−0.020 days yr⁻¹) or in response to sea surface temperature (SST) (−0.272 days °C⁻¹) between 1952 and 2015. However, marked between-year variation in timing observed in resident species and some Pelecaniformes and Suliformes (cormorants, gannets and boobies) may imply that timing, in some cases, is affected by unmeasured environmental conditions. This limited temperature-mediated plasticity of reproductive timing in seabirds potentially makes these top predators highly vulnerable to future mismatch with lower-trophic-level resources.”

An albatross breeding colony, photograph by Rachael Alderman

For popular accounts of the publication click here and here.

With thanks to Susan Mvungi and Richard Phillips.

Reference:

Keogan, K., Daunt, F., Wanless, S., Phillips, R.A. et al. 2018. Global phenological insensitivity to shifting ocean temperatures among seabirds.  Nature Climate Change 8: 313-318.

John Cooper, ACAP Information Officer, 10 April 2018

Dominic Rollinson (FitzPatrick Institute of African Ornithology, University of Cape Town, Rondebosch, South Africa) and colleagues have published in the journal Antarctic Science on at-sea tracking of both breeding and non-breeding White-chinned Petrels Procellaria aequinoctialis.

The paper’s abstract follows:

“White-chinned petrels Procellaria aequinoctialis L. are the most frequently recorded procellariiform species in the bycatch of Southern Hemisphere longline fisheries. Our study investigated the year-round movements of ten adult white-chinned petrels (seven breeders, three non-breeders/suspected pre-breeders) from Marion Island tracked with global location sensor (GLS) loggers for three years. Additionally, 20 global positioning system (GPS) tracks were obtained from breeding white-chinned petrels during incubation (n=9) and chick-rearing (n=11). All GLS-tagged birds remained, year-round, in the area between southern Africa and Antarctica, not making any major east/west movements. Three core areas (50% kernels) were utilized: around the Prince Edward Islands (PEI; incubation and early chick-rearing), c. 1000 km west of PEI (pre-breeding and early incubation) and around South Africa (non-breeding birds). The only area where 50% utilization kernels overlapped with intensive longline fishing effort was off the Agulhas Bank (non-breeding season). Our results confirm the lack of foraging overlap between the two subspecies; nominate birds (South Georgia/south-western Indian Ocean) utilize separate areas to P. a. steadi (New Zealand/sub-Antarctic islands), and thus should be treated as separate management units. Knowledge of the year-round movements of a vagile species, such as the white-chinned petrel, is important for its continued conservation.”

White-chinned Petrels display, photograph by Ben Phalan

With thanks to Susan Mvungi, Niven Librarian, University of Cape Twon.

Reference:

Rollinson, D.P. Dilley, B.J., Davies, D. & Ryan, P.G. 2018. Year-round movements of white-chinned petrels from Marion Island, south-western Indian Ocean.  Antarctic Science doi.org/10.1017/S095410201800005.

John Cooper, ACAP Information Officer, 09 April 2018