UPDATE:  Read a popular article on the publication here.

Ed Melvin (Washington Sea Grant, Seattle, Washington, USA) and colleagues have published in the journal Conservation Biology on reductions in seabird bycatch in longline fisheries in Alaska

The paper’s abstract follows:

“Although bycatch of seabirds and other long‐lived species is a critical conservation issue in world fisheries, case studies documenting significant reductions in the mortality of these low‐productivity species in a fishery are rare. We studied progress toward seabird conservation in the Alaskan longline fisheries, one of the largest and most diverse demersal fisheries. We generated annual seabird bycatch rates in 4 target fisheries and all fisheries combined from 23 years of fisheries observer data. We used 0‐inflated negative binomial models to evaluate variables influencing seabird bycatch per unit effort (BPUE) in 2 target fisheries. Following adoption of streamer lines, at first voluntarily and then mandatorily, seabird BPUE was reduced by 77‐ 90%, preventing mortality of thousands of birds per year. Despite this, BPUE increased significantly in 2 of 4 target fisheries since streamer lines were adopted. Although night setting yielded significant reductions (74‐97%) in seabird BPUE and significant increases (7‐11%) in fish catch per unit effort over daytime setting, nighttime setting increased the BPUE of Northern Fulmar (Fulmarus glacialis) by 40% and nontarget fish species by 5–17%. Thus, best practices to prevent seabird mortalities in longline fisheries varied by species assemblage and fishery. Our results inform global efforts toward fisheries bycatch reduction by illustrating that successful conservation requires fishery‐specific solutions, strong industry support, constant vigilance in analysis and reporting observer data, and ongoing outreach to fleets, especially to vessels with anomalously high BPUE.”

Bird-scaring lines deployed behind Alaskan longliners, photographs by Amanda Gladics & Ed Melvin

See also here.

Reference:

Melvin, E.F., Dietrich, K.S., Suryan, R.M. & Fitzgerald, S.M. 2019.  Lessons from seabird conservation in Alaskan longline fisheries.  Conservation Biology doi.org/10.1111/cobi.13288.

John Cooper, ACAP Information Officer, 15 February 2019, updated 21 February 20219

Thomas Clay (British Antarctic Survey, Madingley Road, Cambridge, UK) and colleagues have published open access in the journal Marine Biology on GPS-tracked foraging trips made during incubation by Henderson Island’s globally Near Threatened Murphy’s Petrels Pterodroma ultima.

The paper’s abstract follows:

“Divergent foraging strategies may emerge within a population due to a combination of physiological and environmental factors; yet to persist, neither strategy should offer a consistent selective advantage over the alternative in the long term. Murphy’s petrels Pterodroma ultima from Henderson Island (24°20′S, 128°20′W) in the South Pacific Ocean are highly vagile, and exhibit two distinct foraging trip types during incubation; similar proportions of birds undertake either looping trips around the South Pacific Gyre to waters off Peru (hereafter “East”) or trips south-west of the colony towards the Subtropical Front (“South”) (mean maximum ranges of c. 3800 or 2000 km from the colony, respectively). However, the relative benefits of the distinct trip types remain unclear. Through tracking birds with GPS and salt-water immersion loggers in 2015, the fine-scale foraging behaviour was examined for East (trip durations: 14.1–19.8 days, maximum ranges 2387–4823 km) and South trips (12.9–25.8 days, 1565–1991 km). Data on behaviour classified from GPS tracks, the number of wet bouts per hour (a proxy for landing rates) and wind speeds, were used to distinguish two distinct foraging modes: birds on East trips spent more time in directed movement, whereas those on South trips spent a greater proportion of time in area-restricted search (ARS) behaviour. East trips were associated with higher overall mass gain, and wet bouts occurred in equal proportions during directed movement and ARS behaviour. This suggests that in unproductive marine environments, it may be more profitable to maximise area covered to increase the chances of encountering prey. Analysis of lower-resolution geolocator data (collected from 2011 to 2014) indicated that individuals were largely consistent in trip type between years.  Since birds that conducted East trips were 19% lighter on departure from the colony and experienced more frequent tailwinds on foraging trips, we speculate that these birds may benefit from reduced movement costs, whilst also experiencing reduced competition for foraging opportunities.”

Murphy's Petrel ashore

Reference:

Clay, T.A., Oppel, S., Lavers, J.L., Phillips, R.A. & Brooke, M.deL. 2019.  Divergent foraging strategies during incubation of an unusually wide‑ranging seabird, the Murphy’s petrel.  Marine Biology doi.org/10.1007/s00227-018-3451-7.

John Cooper, ACAP Information Officer, 14 February 2019

Jaimie Cleeland (Institute for Marine and Antarctic Studies, University of Tasmania, Hobart, Australia) and colleagues have written in the journal Marine Ecology Progress Series on the results of at-sea tracking of the four species of albatrosses that breed at Australia’s sub-Antarctic Macquarie Island.

The paper’s abstract follows:

“Differences in habitat use of sympatric species is influenced by variability in functional morphology and life history trade-offs and is expected to shape species resilience to environmental change.  To determine differences in year-round habitat use and gain insight into how morphological and life history traits influence foraging of an albatross community from subantarctic Macquarie Island (54.6° S, 158.9° E), we quantified the physical features associated with high residence time for 10 black-browed, Thalassarche melanophris; 10 grey-headed, T. chrysostoma; 15 light-mantled, Phoebetria palpebrata; and 12 wandering albatrosses, Diomedea exulans tracked in 1994-2009.  Overlap among the four species was greatest close to the island during the breeding season, extending north into the Tasman Sea.  Nevertheless, black-browed albatrosses ranged more locally than the other species, perhaps because they have a shorter breeding cycle and morphological traits that result in less efficient flight and greater capacity to outcompete other species for prey.  Nonbreeding albatrosses showed high variability in habitat use across wide ocean expanses, but all used productive frontal regions and mesoscale eddies.  Increased residence times during the breeding and nonbreeding periods were associated with moderate wind speeds for all species (excluding breeding black-browed albatrosses), indicating that birds used areas where aerodynamic performance was enhanced.  Given patterns in residence time at sea, and the functional and life history adaptations of each species, we suggest that black-browed albatross breeding on Macquarie Island will be more vulnerable to expected future climate-driven changes to wind patterns in the Southern Ocean, and potential latitudinal shifts in the Subantarctic Front.”

A Wandering Albatross stands over its nest on Macquarie Island, photograph by Kate Lawrence

With thanks to Richard Phillips, British Antarctic Survey.

Reference:

Cleeland, J.B., Alderman, R., Bindoff, A., Lea, M.-A., McMahon, C.R., Phillips, R.A., Raymond, B., Sumner, M.D., Terauds, A., Wotherspoon, S.J. & Hindell, M.A. 2019.  Factors influencing the habitat use of sympatric albatrosses from Macquarie Island.  Marine Ecology Progress Series 609: 221-237.

John Cooper, ACAP Information Officer, 13 February 2019

Lauren Roman (Institute for Marine and Antarctic Studies, University of Tasmania, Hobart, Australia) and colleagues have reviewed open access in the online journal Scientific Reports levels of marine debris found in collected corpses of 51 procellariiform seabird species from the Australasian region, including a number of ACAP-listed albatrosses and petrels.

The paper’s abstract follows:

“Procellariiform seabirds are both the most threatened bird group globally, and the group with the highest incidence of marine debris ingestion. We examined the incidence and ecological factors associated with marine debris ingestion in Procellariiformes by examining seabirds collected at a global seabird hotspot, the Australasian - Southern Ocean boundary. We examined marine debris ingestion trends in 1734 individuals of 51 Procellariform species, finding significant variation in the incidence of marine debris abundance among species. Variation in the incidence of marine debris ingestion between species was influenced by the taxonomy, foraging ecology, diet, and foraging range overlaps with oceanic regions polluted with marine debris.  Among the ecological drivers of marine debris ingestion variability in Procellariiformes, we demonstrate that the combination of taxonomy, foraging method, diet, and exposure to marine debris are the most important determinants of incidence of ingestion. We use these results to develop a global forecast for Procellariiform taxa at the risk of highest incidence of marine debris ingestion. We find seabirds that forage at the surface; especially by surface seizing, diving and filtering, those with a crustacean dominant diet, and those that forage in or near marine debris hotspots are at highest risk of debris ingestion. We predict that family with the highest risk are the storm petrels (Hydrobatidae and Oceanitidae). We demonstrate that the greater the exposure of high-risk groups to marine debris while foraging, the greater the incidence and number of marine debris items will be ingested.”

Plastic fragments are removed from the stomach of a Flesh-footed Shearwater, photograph by Ian Dutton

Reference:

Roman, L., Bell, E., Wilcox, C., Hardesty, B.D. & Hindell, M. 2019.  Ecological drivers of marine debris ingestion in procellariiform seabirds.  Scientific Reports 9: 916.  DOI: 10.1038/s41598-018-37324-w.

John Cooper, ACAP Information Officer, 12 February 2019