Anton Wolfaardt, Convenor of ACAP’s Seabird Bycatch Working Group will be attending the 11th Annual Scientific Committee Meeting of the South East Atlantic Fishery Organization (SEAFO) from 30 September to 9 October in Windhoek, Namibia.  This will be the first time that ACAP has attended a meeting of SEAFO, which came into force in 2003.

SEAFO is an intergovernmental fisheries science and management body whose primary purpose is to ensure the long-term conservation and sustainable use of all living marine resources in the South East Atlantic Ocean, and to safeguard the environment and marine ecosystems in which the resources occur.  The Convention Area excludes the Exclusive Economic Zones of the coastal states in the region (Angola, Namibia, South Africa and South Atlantic islands which are Overseas Territories of the United Kingdom).  Currently SEAFO has seven Contracting Parties (click here).

Paired bird-scaring lines deployed behind a southern African trawler, painting by Bruce Pearson

In 2012 SEAFO adopted Conservation Measure 25/12: On Reducing Incidental By-catch of Seabirds in the SEAFO Convention Area which replaced a similar CM 15/09, which itself replaced a 2006 measure (click here).

CM 25/12 requires all longline vessels fishing south of 30°S to carry and use bird-scaring lines to an agreed design and to set longlines only at night under minimum deck lighting.  In addition offal is not to be discarded during line setting and hooks are to be retained on board.  However, if adequate line-sinking rates are achieved by line weighting then day setting is allowed providing not more than three seabirds are killed on hooks per fishing trip.

For trawling operations bird-scaring lines are to be deployed and offal is not to be dumped during setting and avoided during hauling.

Under Agenda Item 19 for this year’s meeting it is noted that the Commission requested the Scientific Committee “to follow up on the by-catch of seabirds by longline fisheries.  The SC should establish whether other birds were caught, the status of the birds and if more could be done to protect seabirds during fishing operations.”

ACAP Latest News will report on outcomes from the meeting relevant to the conservation of ACAP-listed albatrosses and petrels once information becomes available.

John Cooper, ACAP Information Officer, 23 September 2015

A report by R. Francis and colleagues to New Zealand’s Ministry for Primary Industries considers the risks imposed by fisheries on ACAP-listed and Vulnerable Antipodean Albatrosses Diomedea antipodensis gibsoni which breed on Adams Island in the Auckland Island Group.

The report’s executive summary follows:

“This report attempts to assess fisheries risks to the population viability of Gibson’s wandering albatross (Diomedea gibsoni), which is endemic to the Auckland Islands and classified as Nationally Critical under the New Zealand Threat Classification System.   Three data sets covering a 21-year period (1991– 2011) were analysed: mark-recapture, nest-based, and counts of breeders. There is cause for concern about the status of this population.  Since 2005, the adult population has been declining at a rate of 5.7%/yr, because of sudden and substantial reductions in three demographic rates: adult survival (from 0.95 to 0.89), proportion breeding (from 0.53 to 0.37), and the proportion of breeding attempts that are successful (from 0.60 to 0.25).  It is now about two-thirds of its estimated size in 1991.  The breeding population dropped sharply in 2005, to 59% of its 1991 level, but has been increasing since 2005 at about 4.2% per year because of slow increases in adult survival and proportion breeding.  The current (2011) breeding population is estimated to be only 54% of the average of 5831 pairs estimated by Walker & Elliott (1999) for 1991–97.  It is difficult to assess the effect of fisheries mortality on the viability of this population.  There is some information about bycatch of Gibson’s in New Zealand waters, and of wandering albatrosses (species unknown) in Australian waters, but little is known about the effect of fisheries in international waters.  Three conclusions are possible from the available data: most fisheries mortality of this species is caused by surface longlines; mortality from fishing is now probably lower than it was; and there is no indication in the data that the sudden and substantial drops in the three above-mentioned demographic rates were caused primarily by fishing.  Forward projections showed that, of these three demographic rates, the most important to the future status of this population is adult survival.  The extent to which this species exhibits philopatry (i.e., breeds where it was born) is not known, and this compromised our ability to estimate juvenile survival.  Assuming full philopatry, the annual rate of juvenile survival was estimated to be 0.88; this will be an under-estimate if philopatry is partial.  The mean age of first breeding was estimated to be 12.4 y.”

Antipodean Albatrosses on Adams Island, photograph by Colon O'Donnell

Reference:

Francis, R.I.C.C., Elliott, G. & Walker, K. 2015.  Fisheries risk to the viability of Gibson’s wandering albatross Diomedea gibsoni.  New Zealand Aquatic Environment and Biodiversity Report No. 152.  48 pp.

John Cooper, ACAP Information Officer, 22 September 2015

Kath Walker and Graeme Elliott of Albatross Research have produced a report for the New Zealand Department of Conservation’s Conservation Services Programme that analyses the suitability of various census methods, including both ground counts and aerial photography, to estimate the total number of breeding pairs of ACAP-listed and Vulnerable Gibson's Antipodean Albatrosses Diomedea antipodensis gibsoni on Adams Island in the Auckland Island Group.

The “report summarizes our investigations into the problems and potential solutions to the difficulties of obtaining an accurate count of this particular species, and provides some suggestions on the most suitable technique to use in a new estimation of total breeding population size.”

A Gibson's Antipodean Albatross pair on Adams Island, photograph by Colin O'Donnell

Click here to access a related report on surveying Gibson's Antipodean Albatrosses by aerial photography on Adams Island.

The assessment of census techniques is informing a proposed survey to estimate the population size of Gibson's Antipodean Albatrosses and collect data to estimate adult survival and other demographic parameters on Adams Island during 2015/16 (click here).

Reference:

Walker, K. & Elliott, G. 2015.  Gibson’s wandering albatross: analysis of census techniques.  Report prepared for Department of Conservation.  [Nelson]: Albatross Research.  10 pp.

John Cooper, ACAP Information Officer, 21 September 2015

Barry Baker and colleagues (Latitude 42 Environmental Consultants) have produced a report for the New Zealand Department of Conservation’s Conservation Services Programme that assesses aerial census methods to estimate the population size of ACAP-listed and Vulnerable Antipodean Albatrosses Diomedea antipodensis gibsoni on Adams Island in the Auckland Island Group.

The assessment is based on a literature review and on the analysis of exploratory aerial census work conducted at the Auckland Islands.  The report recommends use of helicopters and standard digital photography, followed by manual stitching and overlaying stitched images on satellite photos using GIS software.  Ground-truthing should be used to develop meaningful correction factors.  Lastly, aerial surveys should not be conducted until egg laying is complete.

Antipodean Albatross on Adams Island, photograph by Colin O'Donnell

Reference:

Baker, G.B., Jensz, K. & Hamilton, S. 2015. Assessment of aerial census techniques to robustly estimate the total population size of Gibson’s albatross on Adams Island.  Report prepared for New Zealand Department of Conservation.  [Kettering]: Latitude 42 Environmental Consultants Pty Ltd.  18 pp.

John Cooper, ACAP Information Officer, 20 September 2015