Jenn Lavers (Institute for Marine and Antarctic Studies, University of Tasmania, Australia) has published in the ICES Journal of Marine Science on Flesh-footed Shearwaters Puffinus carneipes in South and Western Australia.

The paper’s abstract follows:

“Seabirds are considered reliable indicators of the marine environment due to their reliance on ocean-based resources and position at the top of the marine foodweb.  The status of the world’s bird populations have deteriorated over the past 20 years with seabirds declining faster than any other bird group.  For some seabird species, a lack of data or synthesis of available data limits our ability to detect changes in population trends and gain insight into the condition of the surrounding marine environment.  The Flesh-footed Shearwater (FFSH; Puffinus carneipes) exemplifies this with demographic and count data either absent or outdated for most breeding islands.   Results of a survey of 20 FFSH breeding islands in South and Western Australia during 2011–2014, and a synthesis of all available data indicate the current global population is substantially smaller than previously thought, comprising no more than 74 000 breeding pairs. While much of the reduction in numbers is due to outdated burrow counts which are shown to be a poor measure of population size in this species, there is evidence of a decline in numbers on at least six islands that account for ~ 40% of the world’s population.  A review of novel and existing data on FFSH breeding habits (burrow occupancy and density), concurrent threats, and population size in South and Western Australia are presented here along with priorities for management of this declining marine predator.”

Flesh-footed Shearwater, photograph by Barry Baker

With thanks to Barry Baker.

Reference:

Lavers, J.L. 2014.  Population status and threats to Flesh-footed Shearwaters (Puffinus carneipes) in South and Western Australia.  ICES Journal of Marine Science doi: 10.1093/icesjms/fsu164. (+ supplementary data).

John Cooper, ACAP Information Officer, 09 October 2014

The International Commission for the Conservation of Atlantic Tunas (ICCAT) held an intersessional meeting of its Sub-Committee on Ecosystems last month in Olhão, Portugal.  The Albatross and Petrel Agreement was represented by the Convenor of its Seabird Bycatch Working Group, Anton Wolfaardt.

At the meeting progress was achieved in discussing the review process for the commission’s seabird bycatch mitigation measure (Rec 11-09 Supplemental Recommendation by ICCAT on Reducing Incidental By-Catch of Seabirds in ICCAT Longline Fisheries) as described in its report.

The meeting considered a paper prepared and presented by an ACAP intersessional group identifying the elements that should be incorporated into a review of ICCAT’s current seabird conservation measures. These elements include the extent to which ICCAT’s seabird conservation and management measures reflect best practice for pelagic longline fisheries and has appropriate spatial, temporal and vessel application; the availability and quality of the data available for a review; the degree of implementation by vessels (compliance); and the analysis and monitoring of seabird by-catch levels over time, most likely including reported by-catch rates (birds per 1000 hooks) and the total number of birds killed per tuna RFMO per year.

It was agreed that because Rec 11-09 came fully into force in July 2013 it would be premature to conduct the full assessessment in 2015. However, the Sub-Committee highlighted the importance of initiating work in preparation for the review.  The key elements to be progressed in 2015 include:

• Review the extent to which the by-catch mitigation requirements in Rec 11-09 reflect current best practice for pelagic longline fisheries, and the spatial, temporal and vessel applicability of Rec 11-09;

• Request and review new data on seabird by-catch rates;

• Develop indicators for monitoring Rec 11-09 over time; and

• Update the EFFDIS [Fisheries effort and distribution] database.

The Sub-Committee recognized the trans-oceanic habitat of some seabird species. This necessitates the evaluation of mitigation effects across ocean basins and through collaboration with other tRFMOs, such as the Commission for the Conservation of Southern Bluefin Tuna (CCSBT), which plans to hold a workshop in November 2014 to develop review methods.

Submitted Papers:

ACAP Intersessional Group (C. Small, A. Wolfaardt, G. Tuck, I. Debski, W. Papworth, Mi Ae Kim)  2014.  Preliminary identification of minimum elements to review the effectiveness of seabird bycatch mitigation regulations in tuna RFMOs.  SCRS/2014/121.

Reid, T.A., Wanless, R.M., Hilton, G.M., Phillips, R.A. & Ryan, P.G. 2014.  Foraging range and habitat associations of non-breeding Tristan albatrosses: overlap with fisheries and implications for conservation.  SCRS/2014/122. (Published in 2013 as Endangered Species Research 22: 39-49).

With thanks to Anton Wolfaardt.

John Cooper, ACAP Information Officer, 08 October 2014

Sebastien Jaquemet (Université de La Réunion, Laboratoire ECOMAR, France) and colleagues report on seabirds recorded at sea in the Mozambique Channel in the western Indian Ocean in the journal Deep-Sea Research II.  ACAP-listed species seen were Black-browed Thalassarche melanophris and yellow-nosed T. chlororhynchos (=Atlantic T. carteri?) Albatrosses and White-chinned Petrel Procellaria aequinoctialis.

The paper’s abstract follows:

“The Mozambique Channel (western Indian Ocean) is a dynamic environment characterised by strong mesoscale features, which influence all biological components of the pelagic ecosystem.  We investigated the distribution, abundance and feeding behaviour of seabirds in the Mozambique Channel in relation to physical and biological environmental variables, with a specific interest in mesoscale features.  Seabird censuses were conducted in summer and winter during 7 cruises in the southern and northern Mozambique Channel. Tropical species accounted for 49% of the 37 species identified and 97% of the individuals, and species from the sub-Antarctic region constituted 30% of the identifications.  The typically tropical sooty tern (Onychoprion fuscata) was the dominant species during all cruises, and overall accounted for 74% of the species observations and 85% of counted birds.  Outputs of Generalised Linear Models at the scale of the Mozambique Channel suggested that higher densities of flying and feeding birds occurred in areas with lower sea surface temperatures and lower surface chlorophyll a concentrations.  Most of the flocks of feeding birds did not associate with surface schools of fish or marine mammals, but when they did, these flocks were larger, especially when associated with tuna.  While tropical species seemed to favour cyclonic eddies, frontal and divergence zones, non-tropical species were more frequently recorded over shelf waters.  Sooty terns foraged preferentially in cyclonic eddies where zooplankton, micronekton and tuna schools were abundant.  Among other major tropical species, frigatebirds (Fregata spp.) predominated in frontal zones between eddies, where tuna schools also frequently occurred and where geostrophic currents were the strongest.  Red-footed boobies (Sula sula) concentrated in divergence zones characterised by low sea level anomalies, low geostrophic currents, and high zooplankton biomass close to the surface.  Our results highlight the importance of mescoscale features in structuring the tropical seabird community in the Mozambique Channel, in addition to segregating tropical and non-tropical species.  The mechanisms underlying the segregation of tropical seabirds seem to partially differ from that of other tropical regions, and this may be a consequence of the strong local mesoscale activity, affecting prey size and availability schemes.  Beyond characterising the foraging habitats of the seabird community of the Mozambique Channel, this study highlights the importance of this region as a hot spot for seabirds; especially the southern part, where several endangered sub-Antarctic species over-winter.”

Black-browed Albatross, photograph by John Larsen

Reference:

Jaquemet, S., Ternon, J.F., Kaehler, S., Thiebot, J.B., Dyer, B., Bemanaja, E., Marteau, C. & Le Corre, M. 2014.  Contrasted structuring effects of mesoscale features on the seabird community in the Mozambique Channel.  Deep-Sea Research II 100: 200-211.

John Cooper, ACAP Information Officer, 07 October 2014

Martina Müller (Graduate School of Environmental Studies, Nagoya University, Japan) and colleagues have published in the Chinese journal Current Zoology on migration patterns of Scopoli’s Shearwaters Calonectris diomedea from Linosa Island, near Sicily, Italy.

The paper’s abstract follows:

“Recently-developed capabilities for tracking the movements of individual birds over the course of a year or longer has provided increasing evidence for consistent individual differences in migration schedules and destinations.  This raises questions about the relative importance of individual consistency versus flexibility in the evolution of migration strategies, and has implications for the ability of populations to respond to climatic change.  Using geolocators, we tracked the migrations of Scopoli’s shearwaters Calonectris diomedea breeding in Linosa (Italy) across three years, and analysed timing and spatial aspects of their movements.  Birds showed remarkable variation in their main wintering destination along the western coast of Africa.  We found significant individual consistency in the total distance traveled, time spent in transit, and time that individuals spent in the wintering areas.  We found extensive sex differences in scheduling, duration, distances and destinations of migratory journeys.  We also found sex differences in the degree of individual consistency in aspects of migration behaviour.  Despite strong evidence for individual consistency, which indicates that migration journeys from the same bird tended to be more similar than those of different birds, there remained substantial intra-individual variation between years.  Indeed, we also found clear annual differences in departure dates, return dates, wintering period, the total distance traveled and return routes from wintering grounds back to the colony.  These findings show that this population flexibly shifts migration schedules as well as routes between years in response to direct or indirect effects of heterogeneity in the environment, while maintaining consistent individual migration strategies.”

Cory's/Scopoli's Shearwater off South Africa, photograph by John Graham 

Reference:

Müller, M.S., Massa, B., Phillips, R.A. & Dell’Omo, G. 2014.  Individual consistency and sex differences in migration strat.egies of Scopoli's shearwaters Calonectris diomedea despite year differences.  Current Zoology 60: 631-641.

John Cooper, ACAP Information Officer, 06 October 2014