The Inter-American Tropical Tuna Commission (IATTC) will hold its 90th Meeting in La Jolla, California, USA at the end of this month.  ACAP’s Executive Secretary, Marco Favero will be attending to follow and contribute to discussions on a proposal from the United States to amend Resolution C-11-02 to Mitigate the Impact on Seabirds of Fishing for Species covered by the IATTC.

The proposal aims to replace the existing “two-column” approach to selecting mitigation measures to be utilized by longline vessels to one in line with the Western and Central Pacific Fisheries Commission (WCPFC) measure CMM 2015-03 to be adopted on 01 January 2017 in replacement of CMM 2012-07.  It proposes that in “Southern Areas” (south of 30°S) at least two of the following three mitigation methods, line weighting, night setting, and bird-scaring lines, be used simultaneously to be “generally consistent with current advice from the Agreement on the Conservation of Albatrosses and Petrels (ACAP) regarding seabird mitigation techniques”.

However, in “Northern Areas [north of 23°N], the proposal retains the two column approach to provide for additional options for bycatch mitigation measures and includes blue-dyed bait, side-setting, deep-setting line shooter, night setting with minimum deck lighting, tori [bird-scaring] lines, weighted branch lines, and management of offal discharge.”

Adoption of the US proposal by the IATTC will lead to an increase in consistency in required seabird mitigation measures across the southern Pacific Ocean.

Reference:

United States 2016.  Amendment to Resolution C- 11-02 to Mitigate the Impact on Seabirds of Fishing for Species covered by the IATTC.  Proposal IATTC-90 J-1.  Inter-American Tropical Tuna Commission.  8 pp.

John Cooper, ACAP Information Officer, 10 June 2016

Peter Becker (Institute of Avian Research, “Vogelwarte Helgoland”, Wilhelmshaven, Germany) and colleagues have published online in the journal Environmental Pollution on mercury levels in 25 species of Southern Ocean and Antarctic procellariiforms and penguins.

The paper’s abstract follows:

“We studied mercury contamination in 25 seabird species breeding along a latitudinal gradient across the Southern Ocean, from Gough Island (40°S) through Marion Island (47°S) to Byers Peninsula (63°S).  Total mercury concentrations in body feather samples of adults caught at breeding colonies from 2008 to 2011 were determined. Krill (Euphausia spp.) and other zooplankton consumers had low mercury concentrations (gentoo penguin Pygoscelis papua, chinstrap penguin Pseudomonas Antarctica [sic], common diving petrel Pelecanoides urinatrix, broad-billed prion Pachyptila vittata; mean levels 308–753 ng g−1), whereas seabirds consuming squid or carrion had high mercury concentrations (ascending order: Kerguelen petrel Aphrodroma brevirostris, southern giant petrel Macronectes giganteus, soft-plumaged petrel Pterodroma mollis, sooty albatross Phoebetria fusca, Atlantic petrel Pterodroma incerta, northern giant petrel Macronectes halli, great-winged petrel Pterodroma macroptera; 10,720–28038 ng g−1).  The two species with the highest mercury concentrations, northern giant petrels and great-winged petrels, bred at Marion Island.  Among species investigated at multiple sites, southern giant petrels had higher mercury levels at Marion than at Gough Island and Byers Peninsula.  Mercury levels among Byers Peninsula seabirds were low, in two species even lower than levels measured 10 years before at Bird Island, South Georgia.  Replicate measurements after about 25 years at Gough Island showed much higher mercury levels in feathers of sooty albatrosses (by 187%), soft-plumaged petrels (53%) and Atlantic petrels (49%).  Concentrations similar to the past were detected in southern giant petrels at Gough and Marion islands, and in northern giant petrels at Marion. There were no clear indications that timing of moult or migratory behavior affected mercury contamination patterns among species.  Causes of inter-site or temporal differences in mercury contamination could not be verified due to a lack of long-term data related to species’ diet and trophic levels, which should be collected in future together with data on mercury contamination.”

A Sooty Albatross family on Gough Island, photograph by Kalinka Rexer-Huber

Reference:

Becker, P.H., Goutner, V., Ryan, P.G. & González-Solís, J. 2016.  Feather mercury concentrations in Southern Ocean seabirds: variation by species, site and time.  Environmental Pollution 216: 253-263.

John Cooper, ACAP Information Officer, 09 June 2016

Joanna Alfaro-Shigueto (Pro Delphinus, Lima, Perú) and colleagues have published in the Pan-American Journal of Aquatic Sciences on the reasons given for the intentional killing of Waved Albatrosses Phoebastria irrorata by Peruvian artisinal fishers.

The paper's abstract follows:

“The waved albatross Phoebastria irrorata is classified by the IUCN as “critically endangered” because of its geographically restricted breeding range and evidence of a substantial decline in adult survival during the 1990s and early 2000s.  This decline has been proposed to be a consequence of incidental mortality in the Peruvian small-scale fisheries but also of direct hunting for human consumption by fishermen.  This paper uses a trans-disciplinary approach to describe and analyse the intentional capture of waved albatrosses in northern Peru by offshore small-scale fishermen.  During 2008, 36 interviews were conducted in the port of Salaverry to understand the extent and reasons for the intentional capture.  Sixty-nine precent [sic] of the interviewees mentioned occasionally harvesting albatrosses.  Considering two to three vessels capture albatrosses regularly in Salaverry, we estimate a total annual mortality between 16 and 24 individuals since 2006.  Reasons for capturing albatrosses included insufficient food supplies onboard during long fishing trips, collection of rings from ringed birds, the development of a taste for the bird’s meat and even boredom. Interviews with fishermen showed a lack of awareness of the conservation status of albatrosses.  We recommend strengthening the role of existing local governmental and non-governmental organizations involved with monitoring and surveillance, education and conservation.”

At risk in Peru: Waved Albatross at sea

Reference:

Alfaro-Shigueto, J., Mangel, J. C., Valenzuel, K. & Arias-Schreiber, M. 2016.  The intentional harvest of waved albatrosses Phoebastria irrorata by small-scale offshore fishermen from Salaverry port, Peru.  Pan-American Journal of Aquatic Sciences 11: 70-77.

John Cooper, ACAP Information Officer, 08 June 2016

Charlotte Curéa (Cerema—DTer Est, Acoustics Group, Strasbourg, France) and colleagues have published in the journal Behavioural Processes on vocal recognition of mates by Scopoli’s Shearwater Calonectris diomedea.

The paper’s abstract follows:

“Vocal recognition is an important process allowing partners’ reunion in most seabirds.  Although the acoustic basis of this recognition has been explored in several species, only a few studies have experimentally tested the acoustic coding-decoding strategy used for mate identification.  Here, we investigated mate recognition in the Scopoli’s shearwater (Calonectris diomedea) by conducting playbacks of calls with modified acoustic features.  We showed that females and males in a seabird species with a moderate vocal dimorphism are likely to share the same coding-decoding rule for vocal mate identification.  Specifically, a disruption of call temporal structure prevented mate recognition in both sexes, in line with the parameters previously identified as supporting an individual signature.  Modifications of spectral cues and envelope structure also impaired recognition, but at a lesser extent: almost half of the tested males and females were still able to recognise their partner. It is likely that this equal ability of female and male Scopoli’s shearwaters to vocally recognise their partner could be found in other seabirds.”

Click here for a related paper by Charlotte.

Reference:

Curéa, C., Mathevon, N. & Aubinc, T. 2016.  Mate vocal recognition in the Scopoli’s shearwater Calonectris diomedea: do females and males share the same acoustic code?  Behavioural Processes 128: 96-102.

John Cooper, ACAP Information Officer, 07 June 2016