Robin Thomson and colleagues (Oceans and Atmospheres Flagship, CSIRO Marine and Atmospheric Research, Hobart, Tasmania, Australia) write online in the open-access journal PLOS ONE on the effects of climate change and fisheries bycatch on Shy Albatrosses Thalassarche cauta.

The paper’s abstract follows:

“The impacts of climate change on marine species are often compounded by other stressors that make direct attribution and prediction difficult.  Shy albatrosses (Thalassarche cauta) breeding on Albatross Island, Tasmania, show an unusually restricted foraging range, allowing easier discrimination between the influence of non-climate stressors (fisheries bycatch) and environmental variation.  Local environmental conditions (rainfall, air temperature, and sea-surface height, an indicator of upwelling) during the vulnerable chick-rearing stage, have been correlated with breeding success of shy albatrosses.  We use an age-, stage- and sex-structured population model to explore potential relationships between local environmental factors and albatross breeding success while accounting for fisheries bycatch by trawl and longline fisheries.  The model uses time-series of observed breeding population counts, breeding success, adult and juvenile survival rates and a bycatch mortality observation for trawl fishing to estimate fisheries catchability, environmental influence, natural mortality rate, density dependence, and productivity.  Observed at-sea distributions for adult and juvenile birds were coupled with reported fishing effort to estimate vulnerability to incidental bycatch.  The inclusion of rainfall, temperature and sea-surface height as explanatory variables for annual chick mortality rate was statistically significant.  Global climate models predict little change in future local average rainfall, however, increases are forecast in both temperatures and upwelling, which are predicted to have detrimental and beneficial effects, respectively, on breeding success.  The model shows that mitigation of at least 50% of present bycatch is required to offset losses due to future temperature changes, even if upwelling increases substantially.  Our results highlight the benefits of using an integrated modeling approach, which uses available demographic as well as environmental data within a single estimation framework, to provide future predictions.  Such predictions inform the development of management options in the face of climate change.”

Shy Albatross, photograph by Drew Lee

Reference:

Thomson, R.B., Alderman, R.L., Tuck, G.N. & Hobday, A.J. 2015.  Effects of climate change and fisheries bycatch on Shy Albatross (Thalassarche cauta) in Southern Australia.  PLOS ONE  DOI: 10.1371/journal.pone.0127006.

John Cooper, ACAP Information Officer, 02 July 2015

There is increasing evidence of a die-off of Great Shearwaters Puffinus gravis along the Atlantic coast of the Bahamas.  The shearwater die-off is a phenomenon that happens every five to ten years.  In the Bahamas it last occurred in 2007.

According to the late Dave Lee these are young Great Shearwaters migrating from their natal home in the South Atlantic to their feeding grounds off the US and Canada.  The combination of poor food supply and wind conditions in the doldrums that make the passage unusually strenuous leads to the birds expending all their energy and expiring.  It is a normal event for this species and has been recorded many times.

Great Shearwater

Information taken from Seabirds.Net.

References:

Lee, D.S. 2009.  Mass die-offs of Greater Shearwater in the Western North Atlantic: Effects of weather patterns on mortality of a trans-equatorial migrant. Chat 73: 37-47.

Watson, G. 1970.  A shearwater mortality on the Atlantic coast.  Atlantic Naturalist 25: 75-80.

John Cooper, ACAP Information Officer, 01 July 2015

The International Commission for the Conservation of Atlantic Tunas (ICCAT) held an intersessional meeting of its Sub-Committee on Ecosystems from 08 to 12 June 2015 in Madrid, Spain (click here).

At the meeting progress was achieved in preparing for the formal review of the Commission’s seabird bycatch mitigation measure (Recommendation 11.09 Supplemental Recommendation by ICCAT on Reducing Incidental Bycatch of Seabirds in ICCAT Longline Fisheries).  The review of Rec 11-09 was originally scheduled to take place in 2015.  However, at the 2014 meeting of ICCAT’s Sub-Committee on Ecosystems it was agreed that a longer time series of data was required, and so it was recommended that the review be delayed by a year.  Consequently, the 2015 meeting of the Sub-Committee on Ecosystems was earmarked for preparatory work to inform and help facilitate the review in 2016.  The meeting considered a number of seabird-related papers, three of which were submitted by the Albatross and Petrel Agreement.

On the basis of the papers presented and discussions at the meeting, the Sub-Committee agreed to use as the two main indicators for the 2016 review trends in seabird bycatch rates and estimated total numbers of seabirds killed from 2010 to 2014, a period which spans the adoption of seabird bycatch mitigation measures as set out in Rec 11-09.  A draft work plan was prepared, and the information that Contracting Parties (CPCs) will be required to submit for the review was identified.  The ICCAT Secretariat has also recently contracted work to update EFFDIS (the Fisheries Effort and Distribution Database), which is an important source of information for the seabird review.  It is anticipated that the update will be ready well in advance of the 2016 review.

ACAP was represented by the Convenor of its Seabird Bycatch Working Group, Anton Wolfaardt.

Submitted papers relevant to seabirds:

ACAP Secretariat 2015.  ACAP summary advice for reducing impact of pelagic longlines on seabirds.  SCRS/2015/114.

Angel, A., Wanless, R. & Small, C. 2015.  ICCAT process for national reporting on bycatch: an assessment of need from a seabird bycatch perspective.  SCRS/2015/119.

Crawford, R. 2015.  Seabird bycatch mitigation factsheets.  SCRS/2015/117.

Inoue, Y., Yokawa, K. & Minami, H. 2015.  Preliminary analyses; evaluation of the effects of the newly employed seabird bycatch regulation for longline fisheries in ICCAT conventional area with using current observer data.  SCRS/2015/130.

Wanless, R. & Small, C. 2015.  New opportunities to improve reporting and develop approaches for better understanding seabird bycatch in tuna longline fisheries.  SCRS/2015/118.

Wolfaardt, A. 2015.  Data collection requirements for observer programmes to improve knowledge of fishery impacts on seabirds.  SCRS/2015/115.

Wolfaardt, A. & Debski, I. 2015.  Estimation of seabird bycatch rates and numbers. SCRS/2015/116.

Anton Wolfaardt, Convenor, ACAP Seabird Bycatch Working Group, 30 June 2015

Hadoram Shirihai (Shoham, Israel) and colleagues have published in the journal Dutch Birding on the endemic gadfly petrels of Chile’s Juan Fernández Islands.

“This paper details the special avifauna of Juan Fernández archipelago, off Chile.  We visited the archipelago from 3 to 15 March 2013, mainly to study the local gadfly petrels Pterodroma at sea, namely Juan Fernández Petrel P. externa, Stejneger’s Petrel P. longirostris and De Filippi’s Petrel P. defilippiana.”

Reference:

Shirihai, H., Díaz, H.A., Huichalaf, J.E. & Bretagnolle, V. 2015.  Endemic breeding birds of Juan Fernández archipelago, Chile.  Dutch Birding 37: 1-20.

John Cooper, ACAP Information Officer, 29 June 2015