Graham Robertson (Australian Antarctic Division, Kingston, Tasmania) and colleagues write open-access in the Open Journal of Marine Science on the development of an underwater bait setter to deliver pelagic longline hooks to depths out of the reach of albatrosses and petrels.

The paper’s abstract follows:

“Longline fisheries for tunas and tuna-like species present an existential threat to many populations of albatrosses and petrels worldwide.  To prevent this form of mortality we developed a new technology designed to deploy baited hooks underwater beyond the dive depths of seabirds (6 – 10 m for the species most commonly caught).  The underwater bait setter is a stern-mounted, hydraulically-operated and computer-controlled device that catapults baited hooks underwater in a steel capsule connected to hydraulic winches by Spectra® rope.  Baits are flushed from the capsule by water pressure through a spring-loaded bait release door.  The chief engineering challenges in the developmental stages were ensuring: 1) bait delivery to target depths with cycle times (time from release to recovery) that were practical for fishing operations; 2) bait retention in the capsule (no drop-outs) on the descent phase of the cycle; 3) baits, upon release at target depth, were not drawn up the water column on the capsule recovery phase (from possible hook-ups and/or suction); and 4) the retention of baits on hooks post-release from the capsule was not affected by the mechanical release underwater.  Operational trials with the final version of the capsule yielded satisfactory cycle times to depths of 6 - 10 m.  All baits were retained in the capsule on the descent and released as required at target depths (n = 606 deployments).  Bait retention on hooks post release from the capsule and retention on hooks hand-set at the surface (the conventional method) were statistically indistinguishable.  The underwater bait setter is modular in construction and can be fitted to all types of vessel sterns.”

The problem: a White-chinned Petrel caught on a longline hook

Photograph by Nicolas Gasco

With thanks to Barry Baker for information.

Reference:

Robertson, G., Ashworth, P., Ashworth, P., Carlyle, I. & Candy, S.G.  2015.  The development and operational testing of an underwater bait setting system to prevent the mortality of albatrosses and petrels in pelagic longline fisheries.  Open Journal of Marine Science 5: 1-12.

John Cooper, ACAP Information Officer, 07 January 2014

David Gremillet (CEFE-CNRS, Montpellier, France) and colleagues have published in the journal Biological Conservation on movements of Scopoli’s Shearwaters Calonectris diomedea and Northern Gannets Morus bassanus off West Africa.

The paper’s abstract follows:

“Foreign fisheries massively harvest waters off West Africa, plundering local marine economies and threatening African food security.  Here we warn that these fisheries might affect both juvenile and adult European seabirds during their autumn migration and at their wintering grounds.  Using miniaturised GPS, satellite transmitters and geolocators, we tracked the migratory movements of 64 adult and juvenile Northern gannets (Morus bassanus) and Scopoli’s shearwaters (Calonectris diomedea) after their breeding season in the eastern Atlantic and the Mediterranean Sea, respectively.  It was the first time ever that the movements of gannet fledglings were tracked with GPS accuracy.  During winter (October to March) birds made extensive use of marine areas within the exclusive economic zones of Morocco, Western Sahara, Mauritania and Senegal.  These juvenile and adult European seabirds are therefore dependent upon African marine resources and at risk from competition with fisheries, as well as intentional and incidental mortality by fishing gear.  Those threats occur additionally to detrimental seabird–fishery interactions in Europe.  There is an urgent need for improved marine conservation off West Africa, and our data demonstrating connectivity between specific European breeding colonies and African wintering areas are a major step towards stakeholder involvement.”

Cory's Shearwater at sea, photograph by Jacob Gonzalez-Solis

Reference:

Gremillet, D., Peron, C., Provost^, P. & Lescroel, A. 2015.  Adult and juvenile European seabirds at risk from marine plundering off West Africa.  Biological Conservation 182: 143-147.

John Cooper, ACAP Information Officer, 06 January 2015

George Sangster (Department of Bioinformatics and Genetics, Swedish Museum of Natural History, Stockholm, Sweden) and colleagues write in the ornithological journal Ibis on the taxonomic status of the shy albatross complex.  They recognize three species, regarding the Shy Albatross Thalassarche cauta (endemic to Australia) and the White-capped Albatross T. steadi (endemic to New Zealand) as conspecific and separable at the subspecific level.

ACAP currently recognizes these two taxa as full species, as does BirdLife International/IUCN, with both being categorized as Near Threatened.

The 10th Report of the Taxonomic Sub-Committee of the BOU Records Committee writes of the shy albatross taxon as follows:

“A phylogeographical analysis based on mitochondrial DNA sequences indicates that Shy Albatross comprises three major groups: eremita, salvini and cauta/steadi (Abbott & Double 2003a).  Of these, eremita and salvini are sister taxa, and cauta/steadi their closest relatives (Nunn & Stanley 1998, Chambers et al. 2009).  These three groups differ in plumage and bare-parts coloration.  Adult eremita has dark grey plumage on the head and neck and a bright yellow bill, while salvini has noticeably lighter grey head and neck plumage and a grey bill with a contrasting pale yellow upper ridge, and adult cauta/steadi has white head, neck and upper mantle, and a pale grey bill with a pale yellow upper ridge (Marchant & Higgins 1990, Tickell 2000, Brooke 2004).

The taxa cauta and steadi show a single fixed nucleotide difference, minor plumage differences and mean differences in morphometrics but do not form reciprocally monophyletic groups (Abbott & Double 2003a,b, Double et al. 2003).  Current evidence provides insufficient support for recognizing cauta and steadi as full species.  Based on the combination of morphological and molecular data, recognition of three species is warranted:

Shy Albatross Thalassarche cauta (polytypic, with subspecies cauta, steadi)

Chatham Albatross Thalassarche eremita (monotypic)

Salvin's Albatross Thalassarche salvini (monotypic)

Shy Albatross is on the Western Palaearctic list based on a single record in Egypt and Israel (February–March 1981, Shirihai 1996, see also Cole 2000).”

A White-capped Albatross stands over its chick, photograph by David Thompson

Reference:

Sangster, G., Collinson, J.M., Crochet, P.-A., Kirwan, G.M., Knox, A.G., Parkin, D.T. & Votier, S.C. 2014.  Taxonomic recommendations for Western Palaearctic birds: 10th Report.  Ibis 157: 193-200.

John Cooper, ACAP Information Officer, 05 January 2015

Sabrina Tartu (Centre d'études biologiques de Chizé, Villiers-en-bois, France) and colleagues have published in the journal Environmental Pollution on polychlorinated biphenyl exposure and corticosterone levels in ACAP-listed Wandering Albatrosses Diomedea exulans and in Snow Pagodroma nivea and Cape or Pintado Daption capense Petrels.

The paper’s abstract follows:

“The role of polychlorinated biphenyls (PCBs) on exposure-related endocrine effects has been poorly investigated in wild birds.  This is the case for stress hormones including corticosterone (CORT).  Some studies have suggested that environmental exposure to PCBs and altered CORT secretion might be associated.  Here we investigated the relationships between blood PCB concentrations and circulating CORT levels in seven free-ranging polar seabird species occupying different trophic positions, and hence covering a wide range of PCB exposure.  Blood ∑₇PCB concentrations (range: 61–115,632 ng/g lw) were positively associated to baseline or stress-induced CORT levels in three species and negatively associated to stress-induced CORT levels in one species.  Global analysis suggests that in males, baseline CORT levels generally increase with increasing blood ∑₇PCB concentrations, whereas stress-induced CORT levels decrease when reaching high blood ∑₇PCB concentrations.  This study suggests that the nature of the PCB-CORT relationships may depend on the level of PCB exposure.”

Wandering Albatross and chick, photograph by John Cooper

With thanks to Margaret Koopman for information.

Reference:

Tartu, S., Angelier, F., Bustnes, J.O., Moe, B., Hanssen, S.A., Herzke, D., Gabrielsen, G.W., Verboven, N., Verreault, J., Labadie, P., Budzinski, H., Wingfield, J.C. & Chastel. O. 2015.  Polychlorinated biphenyl exposure and corticosterone levels in seven polar seabird species.  Environmental Pollution 197:173-180.

John Cooper, ACAP Information Officer, 04 January 2014