Black-vented Shearwater at sea, photograph by Madeleine Claire

Cecilia Soldatini (Centro de Investigación Científica y de Educación Superior de Ensenada, Unidad La Paz, Mexico) and colleagues have published in the journal Science of The Total Environment on the diving behaviour of the Near Threatened Black-vented Shearwater Puffinus opisthomelas utilizing GPS and accelerometers.

The publication's graphical abstract

The paper’s abstract follows:

“Oceanic mesoscale systems are characterized by inherent variability. Climatic change adds entropy to this system, making it a highly variable environment in which marine species live. Being at the higher levels of the food chain, predators maximize their performance through plastic foraging strategies. Individual variability within a population and the possible repeatability across time and space may provide stability in a population facing environmental changes. Therefore, variability and repeatability of behaviors, particularly diving behavior, could play an important role in understanding the adaptation pathway of a species. This study focuses on characterizing the frequency and timing of different dives (termed simple and complex) and how these are influenced by individual and environmental characteristics (sea surface temperature, chlorophyll a concentration, bathymetry, salinity, and Ekman transport). This study is based on GPS and accelerometer-recorded information from a breeding group of 59 Black-vented Shearwater and examine consistency in diving behavior at both individual and sex levels across four different breeding seasons. The species was found to be the best performing free diver in the Puffinus genus with a maximum dive duration of 88 s. Among the environmental variables assessed, a relationship was found with active upwelling conditions enhancing low energetic cost diving, on the contrary, reduced upwelling and warmer superficial waters induce more energetically demanding diving affecting diving performance and ultimately body conditions. The body conditions of Black-vented Shearwaters in 2016 were worse than in subsequent years, in 2016, deepest and longest complex dives were recorded, while simple dives were longer in 2017–2019. Nevertheless, the species' plasticity allows at least part of the population to breed and feed during warmer events. While carry-over effects have already been reported, the effect of more frequent warm events is still unknown.”

Reference:

Soldatini, C., Rosas Hernandez, M.P., Albores-Barajas, Y.V., Catoni, C., Ramos, A., Dell'Omo. G., Rattenborg, N. & Chimienti, M. 2023. Individual variability in diving behavior of the Black-vented Shearwater in an ever-changing habitat. Science of The Total Environment 883.  https://doi.org/10.1016/j.scitotenv.2023.163286.

19 May 2023

A Black-browed Albatross flies over a stormy sea, by Rodrigo Tapia Jimenez, winner of the World Albatross Day 2020 photography competition “Albatrosses, their World and Threats' (click here)

Juan Gonzalez (Instituto de Biodiversidad Neotropical, Universidad Nacional de Tucumán, Argentina) and colleagues have published in the journal Polar Biology on the fate of Black-browed Albatross Thalassarche melanophris in the face of climate change.

The paper’s abstract follows:

“The Black-browed Albatross (BBA), Thalassarche melanophris, is one of the most abundant and widespread pelagic seabirds in the southern hemisphere, considered an indicator species of climate change in Antarctica. In addition to the known negative interactions with fisheries, other threats may act indirectly on this species whose effects have not yet been evaluated, such as increased sea surface temperature due to climate change. Under the assumption that carbon emissions modify the distribution of BBA, we modeled the environmental suitability and inferred BBA distribution under future climate scenarios for 2050 and 2100. We used 23 years of observation data (1991–2020) from research vessels in the Southwest Atlantic Ocean and Antarctica to estimate habitat suitability and predict change in suitability for the two future time ranges (2040–2050 and 2090–2100) under four representative concentration pathway scenarios: optimistic, intermediate pessimistic. Our projections predict a reduction in the total habitat suitability for BBA by 8% and 31.4% by 2050 and 2100, respectively, in the worst-case scenario compared to the present. Our study enhances understanding of the factors driving distribution dynamics for the species and aid in the development of conservation areas under future global change scenarios.”

With thanks to Javier Quiñones.

Reference:

Gonzalez, J.C., Orgeira, J.L., Jimenez, Y.G., Nieto, C., Romero, C., Alegre, A. & Quiñones, J. 2023. Habitat suitability under future climate scenarios in black-browed albatross (Thalassarche melanophris) in Southern South America and Antarctica. Polar Biology doi.org/10.1007/s00300-023-03143-7.

18 May 2023

At risk to longlines in the Pacific: a Laysan Albatross at sea, painted by Flávia Barreto, Artists and Biologists Unite for Nature for World Albatross Day 2022, after a photograph by Kirk Zufelt

Eric Gilman (Fisheries Research Group, The Safina Center, Honolulu, USA) and colleagues have published open access in the journal Scientific Reports showing that setting baited fishing gear deeply and at night resulted in a 99% lower seabird catch rate (70% were albatrosses) than with lines set shallowly during the day in a in a temperate Pacific longline fishery targeting Albacore Tuna Thunnus alalunga.

The paper’s abstract follows:

“Marine megafauna exposed to fisheries bycatch belong to some of the most threatened taxonomic groups and include apex and mesopredators that contribute to ecosystem regulation. Fisheries bycatch is a major threat to the conservation of albatrosses, large petrels and other pelagic seabirds. Using data sourced from a fisheries electronic monitoring system, we assessed the effects of the time-of-day and relative depth of fishing on seabird and target species catch rates for a Pacific Ocean pelagic longline fishery that targets albacore tuna with an apparently high albatross bycatch rate. Using a Bayesian inference workflow with a spatially-explicit generalized additive mixed model for albacore tuna and generalized linear mixed regression models both for combined albatrosses and combined seabirds, we found that time-of-day and fishing depth did not significantly affect the target species catch rate while night-time deep setting had > 99% lower albatross and total seabird catch rates compared to both deep and shallow partial day-time sets. This provides the first evidence that night-time setting in combination with fishing deep reduces seabird catch risk and may be commercially viable in this and similar albacore tuna longline fisheries. Findings support evidence-informed interventions to reduce the mortality of threatened seabird bycatch species in pelagic longline fisheries.”

Read a popular account of the publication here.

Reference:

Gilman, E., Evans, T., Pollard, I. & Chaloupka, M. 2023. Adjusting time-of-day and depth of fishing provides an economically viable solution to seabird bycatch in an albacore tuna longline fishery. Scientific Reports 13, 262. doi.org/10.1038/s41598-023-29616-7.

17 May 2023

Members of the Seabird Bycatch Working Group and Observers seated for the commencement of the meeting.. From left to right sitting at the far facing table: SBWG Vice-convenor, Dimas Gianuca; Seabird Bycatch Working Group Convenor, Igor Debski and SBWG Vice-convenors, Sebastián Jiménez and Juan Pablo Seco Pon.

ACAP’s round of meetings has commenced in Edinburgh with the Seabird Bycatch Data Workshop kicking off proceedings on Sunday 14 May. The aim of the workshop was to understand and find solutions to the challenges experienced in the reporting of ACAP seabird bycatch indicators. Further details on the workshop including the Rationale and Scope can be found in the workshop preparatory document. Conclusions from the workshop will be reported on during the three-day Eleventh Meeting of the Seabird Bycatch Working Group (SBWG11) taking place 15 - 17 May. 

Documentation for each of the meetings taking place over the next two weeks are accessible at the ACAP website:
• The Eleventh Meeting of the Seabird Bycatch Working Group (SBWG11)
• The Joint Eleventh Meeting of the Seabird Bycatch Working Group and Seventh Meeting of the Population and Conservation Status Working Group (Joint SBWG11/PaCSWG7)
• The Seventh Meeting of the Population and Conservation Status Working Group (PaCSWG7)
• The Thirteenth Meeting of the Advisory Committee (AC13)

 16 May 2023