Dimas Gianuca (Environment and Sustainability Institute - University of Exeter, Penryn, UK) and colleagues have published a note in the Brazilian Journal of Oceanography on whether fishing lights can make longline hooks sink faster.

The note concludes:

“… our results indicate that the addition of EFL [electric fishing lights] did not improve substantially the sink rate of baited hooks, hence they do not support the hypothesis raised among fishermen that the utilization of EFL would help mitigate seabird mortality.  EFLs should not therefore be interpreted as a measure for mitigating seabird bycatch, and should always be utilized in combination with one of the line-weighting regimes recommended by ACAP and ICCAT best practices guides.”

Reference:

Gianuca, D., Rodrigo Sant'Ana, R. & Neves, T. 2016.  Influence of electric fishing lights on sink rates of baited hooks in Brazilian pelagic longline fisheries: implications for seabird bycatch.  Brazilian Journal of Oceanography 64.  http://dx.doi.org/10.1590/S1679-87592016092306401.

John Cooper, ACAP Information Officer, 15 June 2016

Lesley Thorne (School of Marine and Atmospheric Sciences, Stony Brook University, New York, USA) and colleagues have published open access in the Journal of the Royal Society Interface on Laysan Phoebastria immutabilis and Black-footed P. nigripes Albatrosses.

The paper’s abstract follows:

“Changes to patterns of wind and ocean currents are tightly linked to climate change and have important implications for cost of travel and energy budgets in marine vertebrates.  We evaluated how El Niño-Southern Oscillation (ENSO)-driven wind patterns affected breeding Laysan and black-footed albatross across a decade of study.  Owing to latitudinal variation in wind patterns, wind speed differed between habitat used during incubation and brooding; during La Niña conditions, wind speeds were lower in incubating Laysan (though not black-footed) albatross habitat, but higher in habitats used by brooding albatrosses.  Incubating Laysan albatrosses benefited from increased wind speeds during El Niño conditions, showing increased travel speeds and mass gained during foraging trips.  However, brooding albatrosses did not benefit from stronger winds during La Niña conditions, instead experiencing stronger cumulative headwinds and a smaller proportion of trips in tailwinds. Increased travel costs during brooding may contribute to the lower reproductive success observed in La Niña conditions.  Furthermore, benefits of stronger winds in incubating habitat may explain the higher reproductive success of Laysan albatross during El Niño conditions.  Our findings highlight the importance of considering habitat accessibility and cost of travel when evaluating the impacts of climate-driven habitat change on marine predators.”

Black-footed and Laysan Albatrosses, photograph by Kure Atoll Conservancy

Reference:

Thorne, L.H., Conners, M.G., Hazen, E.L., Bograd, S.J., Antolos, M., Costa, D.P. & Shaffer. S.A. 2016.  Effects of El Niño-driven changes in wind patterns on North Pacific albatrosses.  Journal of the Royal Society Interface 13: 20160196.

John Cooper, ACAP Information Officer, 14 June 2016

Fernanda Colabuono (Universidade de São Paulo, Instituto Oceanográfico, Laboratório de Química Orgânica Marinha, São Paulo, Brazil) and colleagues have published in the journal Environmental Pollution on persistent organic pollutants in Southern Giant Petrel Macronectes giganteus from the South Shetland Islands, Antarctica.

The paper’s abstract follows:

“Seabirds play an important role as top consumers in the food web and can be used as biomonitors of exposure to pollutants.  Contamination studies involving non-destructive sampling methods are of considerable importance, allowing better evaluation of the levels of pollutants and their toxic effects.  In the present study, organohalogen contaminants were analyzed in 113 blood samples from Southern Giant Petrel (Macronectes giganteus) adults and chicks collected in the austral summer of 2011/2012 and 2012/2013 from colonies on Elephant and Livingston Islands, South Shetland, Antarctica.  Polychlorinated biphenyls (PCBs), hexachlorobenzene (HCB), pentachlorobenzene (PeCB), mirex, dichlorodiphenyltrichloroetane and derivatives (DDTs) and chlordanes were detected in all birds, whereas polybrominated diphenyl ethers (PBDEs) were not detected in any blood samples.  No significant differences were found in organochlorine levels between sampling events.  Adults exhibited significantly higher levels than chicks, except for PeCB. PCBs, HCB, mirex and DDTs were statistically similar in males and females from Elephant Island.  Females on Livingston Island exhibited higher HCB values than males, but no sex differences were found regarding other organochlorines.  The similarity in organochlorine levels between sexes in birds with very marked sexual segregation in feeding habits during the breeding season may indicate that significant amounts of contaminants are acquired during migration to lower latitudes, when the diets of males and females are similar. Birds sampled on Livingston Island exhibited significantly lower levels of PCBs, HCB, DDTs, mirex and chlordanes in comparison to those on Elephant Island, which could be the result of distinct foraging patterns between the two colonies.  Organochlorine levels were similar between years in birds captured in two consecutive breeding seasons.  Blood samples from Southern Giant Petrels adults and chicks proved to be useful for the comparison of intraspecific contamination levels and appear to be adequate for the long-term assessment of organohalogen contaminants in antarctic top predators.

Organochlorine contaminants in blood samples of Southern Giant Petrels reflected intra-specific differences and suggested distinct foraging patterns between colonies.”

A white-phase Southern Giant Petrel in Antarctica, photograph by Michael Dunn

Click here for a related paper by Fernanda Colabuono.

Reference:

Colabuono, F.I., Vander Pol, S.S., Huncik, K.H., Taniguchi, S., Petry M.V., Kucklick, J.R. & Montone, R.C.  2016.  Persistent organic pollutants in blood samples of Southern Giant Petrels (Macronectes giganteus) from the South Shetland Islands, Antarctica.  Environmental Pollution 216: 38-45.

John Cooper, ACAP Information Officer, 13 June 2016

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