Matthew Savoca (Graduate Group in Ecology, University of California, Davis, California, USA) and Gabrielle Nevitt write in the Proceedings of the National Academy of Sciences (PNAS) on a mutualistic interaction between procellariiform seabird species using dimethyl sulfide as a foraging cue and primary producers.

“This study demonstrates that dimethyl sulfide, a chemical cue involved in global climate regulation, mediates a tritrophic mutualistic interaction between marine apex predators and primary producers.  Our results imply that marine top predators play a critical role in maintaining both ocean health and global climate.  Our results highlight the need for more collaboration and discussion between micro- and macroscale biologists working on global issues in the Southern Ocean.”

The paper’s abstract follows:

“Tritrophic mutualistic interactions have been best studied in plant–insect systems.  During these interactions, plants release volatiles in response to herbivore damage, which, in turn, facilitates predation on primary consumers or benefits the primary producer by providing nutrients.  Here we explore a similar interaction in the Southern Ocean food web, where soluble iron limits primary productivity.  Dimethyl sulfide has been studied in the context of global climate regulation and is an established foraging cue for marine top predators.  We present evidence that procellariiform seabird species that use dimethyl sulfide as a foraging cue selectively forage on phytoplankton grazers.  Their contribution of beneficial iron recycled to marine phytoplankton via excretion suggests a chemically mediated link between marine top predators and oceanic primary production.”

Black-browed Albatrosses on Saunders Island, photograph by Anton Wolfaardt

Click here for a popular account of the publication in Science Daily.

Reference:

Savoca, M.S. & Nevitt, G.A. 2014.  Evidence that dimethyl sulfide facilitates a tritrophic mutualism between marine primary producers and top predators.  Proceedings of the National Academy of Sciences 111: 4157–4161.

John Cooper, ACAP Information Officer, 16 April 2014

The 12th International Conference of the [United Kingdom] Seabird Group was held over 21-23 March 2014 in Oxford, United Kingdom.

Abstracts of oral and poster presentations made at the conference on ACAP-listed species by senior author and title are listed below.  Click here to read their full authorship and abstracts, as well as a number of presentations on other procellariiform seabirds, including on potential candidate taxa for ACAP listing, such as Calonectris shearwaters.

Oral presentations

Alice Carravieri.  Foraging ecology drives contamination by persistent organic pollutants and mercury in the Wandering Albatross

Filipe Ceia.  Consistency in the foraging niche of seabirds: possible causes and ecological implications [Wandering Albatross]

Hannah Froy.  Age-related variation in reproductive traits in the Wandering Albatross

Rhiannon Meier.  Combining multiple tracking systems reveals at sea behaviour and a pattern of annual variation in breeding season movements of a Critically Endangered seabird [Balearic Shearwater]

Deborah Pardo.  Comparative albatross demography; species-specific responses to changing climate and fishing pressure [Wandering, Grey-headed and Black-browed Albatrosses]

Samantha Patrick.  Senescence rates are strongly influenced by personalities in Wandering Albatross

A Wandering Albatross and its chick at Marion Island

Photograph by John Cooper

Poster Presentations

Thomas Clay.  Population-level differences in the distribution and habitat characteristicsof non-breeding Grey-headed Albatrosses

Lucas Krüger.  The sexual year-round spatial segregation on an Antarctic population of Southern Giant Petrel

John Cooper, ACAP Information Officer, 15 April 2014

Rebecca Lewison (Department of Biology, San Diego State University, California, USA) and colleagues identify taxa-specific hotspots for fisheries bycatch of seabirds, marine mammals and turtles in the Proceedings of the National Academy of Sciences of the United States of America (PNAS).  “This analysis provides an unprecedented global assessment of the distribution and magnitude of air-breathing megafauna bycatch, highlighting its cumulative nature and the urgent need to build on existing mitigation successes.”

The paper’s abstract follows:

“Recent research on ocean health has found large predator abundance to be a key element of ocean condition.  Fisheries can impact large predator abundance directly through targeted capture and indirectly through incidental capture of nontarget species or bycatch.  However, measures of the global nature of bycatch are lacking for air-breathing megafauna.  We fill this knowledge gap and present a synoptic global assessment of the distribution and intensity of bycatch of seabirds, marine mammals, and sea turtles based on empirical data from the three most commonly used types of fishing gears worldwide.  We identify taxa-specific hotspots of bycatch intensity and find evidence of cumulative impacts across fishing fleets and gears. This global map of bycatch illustrates where data are particularly scarce—in coastal and small-scale fisheries and ocean regions that support developed industrial fisheries and millions of small-scale fishers—and identifies fishing areas where, given the evidence of cumulative hotspots across gear and taxa, traditional species or gear-specific bycatch management and mitigation efforts may be necessary but not sufficient.  Given the global distribution of bycatch and the mitigation success achieved by some fleets, the reduction of air-breathing megafauna bycatch is both an urgent and achievable conservation priority.”

Black-browed Albatrosses gather behind a trawler in the South Atlantic

Photograph by Graham Parker

Reference:

Lewison, R.L., Crowder, L.B., Wallace, B.P., Moore, J.E., Cox, T., Zydelis, R., McDonald, S., Di Matteo, A., Dunn, D.C., Kot, C.Y., Bjorkland, R., Kelez, S., Soykan, C., Stewart, K.R., Sims, M., Boustany, A., Read, A.J., Halpin, P., Nichols, W.J. & Safina, C. 2014.  Global patterns of marine mammal, seabird, and sea turtle bycatch reveal taxa-specific and cumulative megafauna hotspots.  Proceedings of the National Academy of Sciences of the United States of America.  doi/10.1073/pnas.1318960111.

John Cooper, ACAP Information Officer, 14 April 2014

Caio Cipro (Littoral Environnement et Sociétés, Université de La Rochelle, France) and colleagues have published in the journal Polar Biology on trace elements in tissues of White-chinned Petrels Procellaria aequinoctialis in the southern Indian Ocean.

The paper’s abstract follows:

“The use of seabirds to assess marine contamination by trace elements in areas remote from pollutant emission points has already been done at various latitudes. Nevertheless, little information is available concerning the Southern Indian Ocean. Determining the contaminants levels, there appears necessary not only due to several deleterious effects reported in literature, but also as previous studies have highlighted elevated concentrations of cadmium (Cd) and mercury (Hg) in mollusks, crustaceans and fish.  Within this context, the white-chinned petrel appears as a key species due to its lifespan, diet and trophic position.  Thirty-three accidentally killed (collision with lights/bycatch in longline vessels) individuals collected in Kerguelen waters were analysed for Cd, copper (Cu), Hg, selenium (Se) and zinc (Zn) in liver, kidney, pectoral muscle, feathers and for mature males, testis. Elevated Hg concentrations (average 58.4 μg g⁻¹ dw in liver) are likely due to the presence of mesopelagic prey in the diet of Procellaria aequinoctialis.  Cd concentrations (average of 65.7 μg g⁻¹ dw in kidney) can be attributed to a high level of fisheries offal consumption, as well as crustacean and squid ingestion. Correlation of Hg with Se indicates its detoxification by co-precipitation, and correlation of Cd with Zn suggests its displacement by Cd on metallothioneins binding sites.  This work also indirectly confirms ecological data (range and diet composition) from the wintering period of the species, which is [sic] rather scarce. Seasonal diet change and moulting accounted more for the obtained results than sex of the birds.”

A White-chinned Petrel falls the victim of a longline hook

Photograph by Nicolas Gasco

Reference:

Cipro, C.V.Z., Cherel, Y., Caurant, F., Miramand, P., Méndez-Fernandez, P. & Bustamante, P. 2014.  Trace elements in tissues of white-chinned petrels (Procellaria aequinoctialis) from Kerguelen waters, Southern Indian Ocean.  Polar Biology DOI 10.1007/s00300-014-1476-z.

John Cooper, ACAP Information Officer, 13 April 2014