A Black-browed Albatross pair, New Island, South Atlantic, photograph by Ian Strange

Javed Riaz (South Atlantic Environmental Research Institute, Stanley, Falkland Islands) and colleagues have published open access in the journal Ecography on utilizing at-sea tracking of three colonial marine predators in the South Atlantic to identify potential pathways for the spread of highly pathogenic avian influenza (HPAI).

The paper’s abstract follows:

“Animal movement and population connectivity are key areas of uncertainty in efforts to understand and predict the spread of infectious disease. The emergence of highly pathogenic avian influenza (HPAI) in South America poses a significant threat to globally significant populations of colonial breeding marine predators in the South Atlantic. Yet, there is a poor understanding of which species or migratory pathways may facilitate disease spread. Compiling one of the largest available animal tracking datasets in the South Atlantic, we examine connectivity and inter-population mixing for colonial breeding marine predators tagged at the Falkland Islands. We reveal extensive connectivity for three regionally dominant and gregarious species over the Patagonian Shelf. Black-browed albatrosses (BBA), South American fur seals (SAFS) and Magellanic penguins (MAG) used coastal waters along the Atlantic coast of South America (Argentina and Uruguay). These behaviours were recorded at or in close proximity to breeding colonies and haul-out areas with dense aggregations of marine predators. Transit times to and from the Falkland Islands to the continental coast ranged from 0.2–70 days, with 84% of animals making this transit within 4 days - a conservative estimate for HPAI infectious period. Our findings demonstrate BBA, SAFS and MAG connectivity between the Falkland Islands and mainland South America over an expansive spatial network and numerous pathways, which has implications for infectious disease persistence, transmission and spread. This information is vital in supporting HPAI disease surveillance, risk assessment and marine management efforts across the region.”

Reference:

Riaz, J., Orben, R.A., Gamble, A., Catry, P., Granadeiro, J.P., Campioni, L., Tierney, M. & Baylis, A.M.M. 2024.  Coastal connectivity of marine predators over the Patagonian Shelf during the highly pathogenic avian influenza outbreak.  Ecocography doi.org/10.1111/ecog.07415.

30 July 2024

Figure 1 from the paper: Five southern giant petrels (Macronectes giganteus) feed on a dead juvenile Magellanic penguin (Spheniscus magellanicus) in the waters off of Punta Tombo, Argentina, site of a large penguin colony. Note how the two birds actively eating the penguin have their wings outstretched, and the bird on the right further has raised and fanned its tail. Note also the plumage variations among the birds, from wholly brown (likely juvenile or immature) to one with a whitish head (an adult). Photograph by Dee Boersma.

Eric L. Wagner (Center for Ecosystem Sentinels, Department of Biology, University of Washington, USA) and colleagues have published open access in the journal Ecology and Evolution on Southern Giant Petrels’ Macronectes giganteus predation of live Magellanic penguins.

The paper’s abstract follows, 

“Southern giant petrels (Macronectes giganteus) are important consumers that range across the oceans throughout the southern hemisphere. In Argentina, previous studies have shown they eat primarily pinnipeds and penguins, which they are assumed to scavenge, although there are occasional anecdotes of them attacking living penguins. Here we describe a predation attempt by a trio of southern giant petrels on a molting adult Magellanic penguin (Spheniscus magellanicus) at the large colony at Punta Tombo, Argentina. We relate giant petrel attendance patterns at the colony to the penguins' phenology, showing how giant petrel numbers rise with the increasing prevalence of vulnerable penguins. We suggest that living penguins—both fledglings and adults—may constitute a more seasonally significant proportion of the giant petrel diet than previously assumed, and their capture may represent a specialized predation technique.”

Reference:

Wagner, E. L., Rebstock, G. A., & Boersma, P. D. (2024).  A fearful scourge to the penguin colonies: Southern giant petrel (Macronectes giganteus) predation on living Magellanic penguins (Spheniscus magellanicus) may be more common than assumed. Ecology and Evolution. https://doi.org/10.1002/ece3.11258.

29 July 2024

The banded Indian Yellow-nosed Albatross off Terrigal, photograph by Carey Devey

An Endangered Indian Yellow-nosed Albatross Thalassarche carteri with leg band W23 was photographed in “shelf waters” from a Terrigal pelagic tour operating off the central coast of New South Wales, Australia on 19 July.

Based on information from the Australian Australian Bird and Bat Banding Scheme (ABBBS), the albatross was banded as an adult in December 2011 in the Entrecasteaux study colony on France’s Amsterdam Island in the southern Indian Ocean.  It was visually sexed as a female and has been regularly observed at the colony during the breeding season since 2011.

Albatross studies on Amsterdam Island are undertaken in the framework of the project “Seabirds and Marine Mammals as Sentinels of Global Change in the Southern Ocean” (Project: 109 ORNITHO2E), supported by the French Polar Institute Paul Emile Victor (IPEV).

Information from the Seabirds and Pelagics Australia Facebook group. With thanks to Karine Delord.

John Cooper, Emeritus Information Officer, Agreement on the Conservation of Albatrosses and Petrels, 26 July 2024, updated 01 August 2024

Availability of data on estimated total seabird bycatch in different trawl fisheries in FAO Major Fishing Areas (from the publication)

Richard Phillips (British Antarctic Survey, Cambridge, UK) and colleagues have reviewed open access in the journal Biological Conservation seabird mortality caused by trawl fisheries around the world.  “Across the Southern Ocean, species estimated to be caught in their thousands were, in order and as a percentage of the total, Black-browed Albatross Thalassarche melanophris (23,176 birds, 68 %), Southern Giant Petrel Macronectes giganteus (2812 birds, 8 %), Northern Giant Petrel Macronectes halli (1941 birds, 5 %) …”.

The paper’s abstract follows

‘Seabirds are amongst the most threatened taxa in the world, often due to incidental mortality (bycatch) in fisheries. Hundreds of thousands are thought to be killed worldwide in gillnets and longlines each year, but global mortality in trawl fisheries is unknown. Based on our comprehensive review, bycatch totals from cable strikes and net captures were available for only 25 fisheries. Bycatch rates were highly variable, precluding substitution from monitored to unmonitored fisheries to estimate bycatch totals, and total fishing effort was often unknown, which is also a prerequisite for scaling bycatch rates to estimate total birds killed. Ten, seven and one trawl fishery were known to catch of the order of 100s, 1000s and 10,000s of birds, respectively, and total bycatch from all monitored fisheries sums to ∼44,000 birds per year. However, given the scale of cryptic mortality and the many unmonitored or poorly monitored fisheries, the actual global mortality in trawl fisheries will be much higher. The most bycaught species were albatrosses and large petrels (many of which are threatened) in the Southern Hemisphere, and gannets in the Northern Hemisphere. The few long-term studies indicated that mitigation measures (particularly strategic offal management and bird-scaring lines) were effective at reducing bycatch rates. Much improved regulations, and close monitoring of compliance and bycatch rates are essential for ensuring trawl fisheries do not continue to have major impacts on vulnerable seabird populations.”

Black-browed Albatrosses gather en masse behind a trawler in the South Atlantic, photograph by Graham Parker

Read the British Antarctic Survey's press release on the scientific paper.

With thanks to Richard Phillips.

Reference:

Phillips, R.A., Fox, E., Crawford, R., Prince, S. & Yates, O. 2024.  Incidental mortality of seabirds in trawl fisheries: a global review.  Biological Conservation 296.  doi.org/10.1016/j.biocon.2024.110720.

25 July 2024