Peter Puskic (Institute for Marine and Antarctic Studies, University of Tasmania, Newnham, Tasmania, Australia) and colleagues have published in the journal Conservation Physiology finding that fatty-acid levels in two shearwater species were not related to the amount of plastic items ingested.

The paper’s abstract follows:

“Marine plastic pollution is increasing exponentially, impacting an expanding number of taxa each year across all trophic levels. Of all bird groups, seabirds display the highest plastic ingestion rates and are regarded as sentinels of pollution within their foraging regions. The consumption of plastic contributes to sub-lethal impacts (i.e. morbidity, starvation) in a handful of species. Additional data on these sub-lethal effects are needed urgently to better understand the scope and severity of the plastics issue. Here we explore the application of fatty acid (FA) analysis as a novel tool to investigate sub-lethal impacts of plastic ingestion on seabird body condition and health. Using gas chromatography-mass spectrometry, we identified 37 individual FAs within the adipose, breast muscle and liver of flesh-footed (Ardenna carneipes) and short-tailed (Ardenna tenuirostris) shearwaters. We found high amounts of FA 16:0, 18:0, 20:5n3 (eicosapentaenoic acid), 22:6n3 (docosahexaenoic acid) and 18:1n9 in both species; however, the overall FA composition of the two species differed significantly. In flesh-footed shearwaters, high amounts of saturated and mono-unsaturated FAs (needed for fast and slow release energy, respectively) in the adipose and muscle tissues were related to greater bird body mass. While total FAs were not related to the amount of plastic ingested in either species, these data are a valuable contribution to the limited literature on FAs in seabirds. We encourage studies to explore other analytical tools to detect these sub-lethal impacts of plastic.”

Flesh-footed Shearwater, photograph by Barry Baker

Reference:

Puskic, P.S., Lavers, J.L., Adams, L.R., Grünenwald, M., Hutton, I. & Bond, A.L. 2019.  Uncovering the sub-lethal impacts of plastic ingestion by shearwaters using fatty acid analysis.  Conservation Physiology 7(1).  doi:10.1093/conphys/coz017.

John Cooper, ACAP Information Officer, 08 July 2019

Helen Booker (South West Regional Office, Royal Society for the Protection of Birds, Exeter, UK) and colleagues have published in the April 2019 issue of the journal British Birds on the recovery of seabirds on the UK island of Lundy after the eradication of rats in 2004.  The population of Manx Shearwaters Puffinus puffinus has risen from 297 to 5504 pairs since then.

The paper’s abstract follows:

“Lundy once supported large numbers of breeding seabirds, but declines during the twentieth century left the island with only remnants of its former colonies.  One major concern during this time was the impact of rat predation on eggs and chicks, especially of burrow-nesting Manx Shearwaters Puffinus puffinus and Puffins Fratercula arctica.  A major project to eradicate rats from Lundy was completed in the spring of 2004.  This paper examines the latest Manx Shearwater survey and how the species has responded since rats were eradicated, and sets this into the context of how the overall status of seabirds on Lundy has changed over the last 15 years.”

A Manx Shearwater chick at its burrow mouth, photograph by Jaclyn Pearson

Read popular accounts here and here.

Reference:

Booker, H., Price, D., Slader, P., Frayling, T., Williams, T. & Bolton, M. 2019.  Seabird recovery on Lundy: population change in Manx Shearwaters and other seabirds in response to the eradication of rats.  British Birds  April issue.

John Cooper, ACAP information Officer, 05 July 2019

ACAP Latest News has previously reported on development of the Kellian Line Setter, which is designed to deliver baited longline hooks underwater at a depth safe from albatrosses scavenging on or near the sea surface and shallow-diving petrels (click here).

New Zealand Minister of Conservation Eugenie Sage

New Zealand Minister of Conservation Eugenie Sage and Minister of Fisheries Stuart Nash in a government press release have announced funding of NZ$350 000 to test the Kellian Line Setter’s ability to eliminate seabird bycatch on a commercial tuna longliner.  “The device will be installed on a Nelson-based fishing vessel owned by Altair Fishing and put through its paces for six weeks during normal fishing.  A specially trained engineer will be on the vessel for the whole trial”.

Dave Kellian demonstrates his line setter

“New Zealand is home to more species of seabird than any other country with more albatross, petrel, shag and penguin species breeding here than anywhere else in the world. Many seabirds are at risk of bycatch in fisheries including the … Endangered Antipodean Albatross [Diomedea antipodensis] and the Near Threatened … Buller’s Albatross [Thalassarche bulleri]” said Conservation Minister Eugenie Sage in the release.

“Twenty years ago, New Zealand tuna fisherman, Dave Kellian, carried out a simple experiment on his boat and worked out that if baited hooks were released at ten metres, seabirds would be safe from being hooked. He used this knowledge to come up with the original prototype device that set baited hooks underwater.”

Dave Kellian has been quoted: “"I was fishing off Whakatane for yellowfin tuna, using live bait.  I started experimenting by lowering a raincoat full of pilchards into the water on a string. When I pulled the string, it released the pilchards.  At eight metres the birds didn't bother diving; between five and eight metres they'd dive for some; but above five they'd get every piece. The light went on - if we could get the bait to 10 metres, the problem of birds being killed by baited hooks was solved" (click here).

This trial is a collaborative effort and is being funded by the Department of Conservation, Fisheries New Zealand, Fisheries Inshore New Zealand and the Auckland Zoo Charitable Trust through the Southern Seabird Solutions Trust.

“This project is an excellent example of industry and conservation agencies collaborating to achieve better results for our unique seabirds,” conclude the Ministers.

See also a news report on the planned trial.

Reference:

Baker, G.B., Goad, D., Kiddie, B. & Frost, R. 2014.  Kellian Line Setter Sea Trials Initial Performance Testing.  Report prepared for Department of Conservation Contract 4529.  [Kettering]: Latitude 42 Environmental Consultants Pty Ltd.  7 pp.

John Cooper, ACAP Information Officer, 04 July 2019

Alistair Baylis (Department of Biological Sciences, Macquarie University, Sydney, Australia) and colleagues have published in the online journal Scientific Reports on at-sea movements of tracked Black-browed Albatrosses Thalassarche melanophris and Sooty Shearwaters Ardenna grisea (and other marine predators) breeding in the Falkland Islands (Islas Malvinas)*.

The paper’s abstract follows:

“The Patagonian Shelf Large Marine Ecosystem supports high levels of biodiversity and endemism and is one of the most productive marine ecosystems in the world.  Despite the important role marine predators play in structuring the ecosystems, areas of high diversity where multiple predators congregate remains poorly known on the Patagonian Shelf. Here, we used biotelemetry and biologging tags to track the movements of six seabird species and three pinniped species breeding at the Falkland Islands.  Using Generalized Additive Models, we then modelled these animals’ use of space as functions of dynamic and static environmental indices that described their habitat. Based on these models, we mapped the predicted distribution of animals from both sampled and unsampled colonies and thereby identified areas where multiple species were likely to overlap at sea. Maximum foraging trip distance ranged from 79 to 1,325 km. However, most of the 1,891 foraging trips by 686 animals were restricted to the Patagonian Shelf and shelf slope, which highlighted a preference for these habitats. Of the seven candidate explanatory covariates used to predict distribution, distance from the colony was retained in models for all species and negatively affected the probability of occurrence.  Predicted overlap among species was highest on the Patagonian Shelf around the Falkland Islands and the Burdwood Bank.  The predicted area of overlap is consistent with areas that are also important habitat for marine predators migrating from distant breeding locations.  Our findings provide comprehensive multi-species predictions for some of the largest marine predator populations on the Patagonian Shelf, which will contribute to future marine spatial planning initiatives. Crucially, our findings highlight that spatially explicit conservation measures are likely to benefit multiple species, while threats are likely to impact multiple species.”

Panel (A) = locations of the 21 tracked breeding colonies (blue dots) at the Falkland Islands (Islas Malvinas)*

Panel (B) = important areas identified by overlap of 50% utilization distributions.
(adapted from the publication)

With thanks to Megan Tierney.

Reference:

Baylis, A.M.M., Tierney, M.,Orben, R.A., Warwick-Evans, V., Wakefield, E., Grecian, W.J., Trathan, P., Reisinger, R.R., Ratcliffe, N., Croxall, J.P., Campioni, L., Catry, P., Crofts, S., Boersma, P.D., Galimberti, F., Granadeiro, J., Handley, J., Hayes, S., Hedd, A., Masello, J.F., Montevecchi, W.A., Pütz, K., Quillfeldt, P., Rebstock, G.A. Sanvito, S. & Brickle, P. 2019.  Important at-sea areas of colonial breeding marine predators on the Southern Patagonian Shelf.  Scientific Reports 9. 8517. 10.1038/s41598-019-44695-1.

John Cooper, ACAP Information Officer, 03 July 2019

*A dispute exists between the Governments of Argentina and the United Kingdom of Great Britain and Northern Ireland concerning sovereignty over the Falkland Islands (Islas Malvinas), South Georgia and the South Sandwich Islands (Islas Georgias del Sur y Islas Sandwich del Sur) and the surrounding maritime areas.