Latest News

White-chinned Petrels hooked and drowned by a Namibian longliner, photograph by John Paterson

Nina Da Rocha (BirdLife International Marine Programme, Royal Society for the Protection of Birds, Sandy, UK) and colleagues have published in the journal Biological Conservation on how well bycatch mitigation has reduced seabird mortality in Namibian waters.

The paper’s abstract follows:

“Many industrial activities impose a threat on biodiversity, and it is unclear to what extent environmental regulations can reduce the threat of such activities. Bycatch in industrial fisheries is one of the greatest sources of mortality for seabirds, but a threat for which effective mitigation exists. Here we quantify whether the introduction of a new regulation that required the use of bird-scaring lines reduced seabird mortality in two of the most hazardous fisheries in the South Atlantic. The Namibian hake demersal trawl and longline fisheries, estimated to be killing 20,000–30,000 birds/year, have been required to use bird-scaring lines since 2015. We used data from BirdLife International's Albatross Task Force and the Namibian Fisheries Observer Agency to quantify changes in seabird mortality in these fisheries before and after the introduction of these regulations. Our estimated bycatch rates in the longline fleet were 0.468 birds/1000 hooks (95% confidence interval 0.067–1.450) before regulations and 0.004 birds/1000 hooks (0.001–0.013) following their introduction, a 98.4% reduction. Our estimate suggests that 215 (1–751) seabirds were killed across this fleet in 2018 compared to 22,222 (3187–68,786) in 2009. In the trawl fleet, observers recorded seabird mortality resulting from interactions with trawl cables. The average rate of heavy interactions was 1.09 interactions/h (0.81–1.39) before the regulation came into effect, and 0.49 interactions/h (0.23–0.84) since then. Extrapolations based on the number of observed fatal interactions suggest 1452 (0–3865) birds were killed by this fleet in 2017 compared to 7030 (0–16,374) in 2009. The lower mortality reduction in the trawl fleet is likely due to incomplete implementation of regulations and highlights the importance of adequate enforcement for effective bycatch mitigation. Overall, we demonstrate that regulations that mandate that well-tested safeguards are used during industrial operations can have enormous benefits for the conservation of threatened species.”

Read a popular account here.

With thanks to Rory Crawford, Bycatch Programme Manager - BirdLife International Marine Programme.

Reference:

Da Rocha, N., Oppel, S., Prince, S., Matjila, S., Shaanika, T.M., Naoma, C., Paterson, J.B., Shimooshili, K., Kashava, S. & Crawford, R. 2020.  Reduction in seabird mortality in Namibian fisheries following the introduction of bycatch regulation.  Biological Conservation 253. doi.org/10.1016/j.biocon.2020.108915.

John Cooper, ACAP Information Officer, 08 January 2021

Matt Rayner (Tāmaki Paenga Hira Auckland Museum, New Zealand) and colleagues write in the journal Notornis on Northern Buller’s Albatrosses Thalassarche bulleri platei in the Manawatāwhi/Three Kings Islands.  Six occupied nests were found on Rosemary Rock, with four unguarded live and two dead chicks present.  “Compared with previous observations our count suggests a poor breeding season for Buller’s mollymawk on Rosemary Rock in 2019/20.  [F]urther work is clearly required to ascertain the trajectory and threats to New Zealand’s most northern albatross colony.”

Northern Buller's Albatross adults and chicks on Rosemary Rock, photographs by Kevin Parker

Read a popular account of the field trip to Rosemary Rock from the Auckland Museum and also a previous ACAP Latest News post on the visit.

With thanks to Kevin Parker, Matt Rayner, and Roger Sharp of Web Support, Birds New Zealand.

Reference:

Rayner, M.J., Parker, K.A., Neho, T. & Hvid, T. 2020.  Buller’s mollymawk (Thalassarche bulleri platei) count at Rosemary Rock, Manawatāwhi (Three Kings Islands).  Notornis 67: 580-582.

John Cooper, ACAP Information Officer, 07 January 2020

A Grey-headed Albatross guards its chick on Bird Island in the South Atlantic, photograph by Stephanie Prince

William Mills (British Antarctic Survey, Cambridge, UK) and colleagues have published open access in the Proceedings of the Royal Society B Biological Sciences on mercury levels in Grey-headed Albatrosses Thalassarche chrysostoma.

The paper’s abstract follows:

“Mercury (Hg) is an environmental contaminant which, at high concentrations, can negatively influence avian physiology and demography. Albatrosses (Diomedeidae) have higher Hg burdens than all other avian families. Here, we measure total Hg (THg) concentrations of body feathers from adult grey-headed albatrosses (Thalassarche chrysostoma) at South Georgia. Specifically, we (i) analyse temporal trends at South Georgia (1989–2013) and make comparisons with other breeding populations; (ii) identify factors driving variation in THg concentrations and (iii) examine relationships with breeding success. Mean ± s.d. feather THg concentrations were 13.0 ± 8.0 µg g⁻¹ dw, which represents a threefold increase over the past 25 years at South Georgia and is the highest recorded in the Thalassarche genus. Foraging habitat, inferred from stable isotope ratios of carbon (δ¹³C), significantly influenced THg concentrations—feathers moulted in Antarctic waters had far lower THg concentrations than those moulted in subantarctic or subtropical waters. THg concentrations also increased with trophic level (δ¹⁵N), reflecting the biomagnification process. There was limited support for the influence of sex, age and previous breeding outcome on feather THg concentrations. However, in males, Hg exposure was correlated with breeding outcome—failed birds had significantly higher feather THg concentrations than successful birds. These results provide key insights into the drivers and consequences of Hg exposure in this globally important albatross population.”

With thanks to Richard Phillips.

Reference:

Mills, W.F., Bustamante, P., McGill, R.A.R., Anderson, O.R.J., Bearhop, S., Cherel, Y., Votier, S.C. & Phillips, R.A. 2020.  Mercury exposure in an endangered seabird: long-term changes and relationships with trophic ecology and breeding success.  Proceedings of the Royal Society B Biological Sciences doi.org/10.1098/rspb.2020.2683.

John Cooper, ACAP Information Officer, 06 January 2021

Westland Petrel fallout victim near Greymouth

New Zealand’s endemic globally Endangered and ACAP-listed Westland Petrel Procellaria westlandica breeds only in a single locality near the community of Punakaiki on the west coast of South Island.  Fledglings heading for sea at night become disoriented by the street lights in Punakaiki and crash-land on the roads, where they are often severely injured, struck by cars or eaten by predators.  To reduce this a trial project has led to bright LED lights being switched off along a 3.4-km section of the state highway for two months from 8 November to 8 January during which time fledging occurs (click here).

The Westland Petrel Conservation Trust reports that “turning off the street lights this fledgling season has proven to be a great success for the Westland petrels. This year was proposed as a pilot run, but with such positive results we're optimistic that it can become a permanent solution.”  With the street lighting turned off in Punakaiki, 10 of the birds had crash landed there, instead of the usual 15 to 25, according to one report.

However, the trust also says that although the problem has been lessened in Punakaiki, it was now worse 44 km farther south in the town of Greymouth where highway lights have not been switched off.  The Department of Conservation (DOC) has so far found 22 downed petrels in Greymouth of which “17 were able to be released, four were found dead and one was euthanised”.  This is about twice the usual number picked up “10 being the highest number previously, and for the first time they were found in the centre of town”.

Most downings in Greymouth are considered linked to lighting, including lights on businesses and other private properties.  “Where petrels have come down … we have talked with property owners and others with lights in the area to ask about lights being turned off, where possible.”  LED streetlights were introduced in Greymouth last year.  A spokesperson for the district council said it was looking into whether it was possible to turn the lights down or change the colour tone to orange (click here).

A Westland Petrel in its burrow

Photographs by Bruce Stuart-Menteath, Chair, Westland Petrel Conservation Trust

John Cooper, ACAP Information Officer, 05 January 2021