Sooty Shearwater, photograph by John Graham

Alejandro Simeone (Universidad Andres Bello, Departamento de Ciencias Biológicas, Santiago, Chile) and colleagues have published in the journal Biological Conservation on using beached seabirds in Chile to assess mortality from fishing fleets.  Sooty Shearwater Ardenna grisea comprised 70% of all dead birds reported.  Only 16 of the 19 281 birds in the study were positively identified as belonging to ACAP-listed species; ten of these were Pink-footed Shearwaters A. creatopus.

The paper’s abstract follows:

“The Chilean coast holds a high seabird diversity and also extensive fisheries that interact with birds producing bycatch. We used data on beached seabirds reported by news media to depict spatial and temporal patterns of fishery-related seabird mortality and correlated these data with the spatial and temporal fishing effort of the three main purse-seine fleets operating in south-central Chile (33 to 40°S). Between 2005 and 2019 we detected 97 mortality events reporting >19,000 beached seabirds attributed to bycatch. Mortality was recorded between 18 and 53° S (~3800 km of coastline), affecting 16 seabird species, with 90% concentrated between 33 and 40°S (800 km), exactly where purse-seine fleets operate. Sooty shearwater (Ardenna grisea) comprised 70% of all dead birds recorded. Magellanic penguins (Spheniscus magellanicus) and guanay cormorants (Phalacrocorax boungainvillii) were also affected. Mortality events of Sooty shearwaters was highest (P < 0.001) between February and May (54%) and October–November (36%), coinciding with the timing of the species migratory movements; shearwater mortality was particularly high at 36–37°S (50%) and 39–40°S (36%). Sooty shearwater mortality presented a very high spatial overlap (93%) and significant temporal correlation (0.64) with combined industrial and artisanal purse-seine fishing effort targeting on Peruvian anchovy (Engraulis ringens) and Araucanian herring (Strangomera bentincki). Our study shows when and where seabirds are more susceptible to mortality due to interactions with fisheries along the Chilean coast. This information could be used by authorities to regulate the fishing activity and focus conservation efforts to the most affected species at the appropriate spatial and temporal scales.”

With thanks to Janine Dunlop, Niven Librarian, FitzPatrick Institute, University of Cape Town.

Reference:

Simeone, A., Anguita, C., Daigre, M., Arce, P., Vega Guillermo, R., Luna-Jorquera, G., Portflitt-Toro, M., Suazo, C.G., Miranda-Urbina, D. & Ulloa, M. 2021.  Spatial and temporal patterns of beached seabirds along the Chilean coast: linking mortalities with commercial fisheries.  Biological Conservation doi.org/10.1016/j.biocon.2021.109026.

John Cooper, ACAP Information Officer, 23 March 2021

A Laysan Albatross constructed from ingested plastic debris, by Jennifer Urmston

Lauren Roman (CSIRO Oceans and Atmosphere, Hobart, Tasmania, Australia) and colleagues have published open access in the journal Environmental Research Letters on the threats imposed on procellariform seabirds by the ingestion of marine debris.

The paper’s abstract follows:

“Marine debris is a growing threat to hundreds of marine animal species. To understand the consequences of marine debris to wildlife populations, studies must go beyond reporting the incidence of wildlife and debris interactions and aim to quantify the harm resulting from these interactions. Tubenosed seabirds are globally threatened, with a near universal risk of debris ingestion and an unquantified risk of mortality due to eating plastics. In this paper, we explore the mortality risk narrative due to the acute effects of debris ingestion, and quantify behavioural and ecological factors including age, diet and foraging method. We examined ingested debris loads, types and mortality of 972 adult and immature seabirds across 17 albatross, shearwater and prion species in a global seabird biodiversity hotspot. Though age and foraging method interact to influence the incidence and number of items ingested, age and diet were the most important factors influencing mortality. Mortality is influenced by debris load and type of debris ingested and there is selectivity for items that visually resemble a seabird's prey. Immature birds that forage on cephalopods are more likely to ingest and die from eating debris than are adults. Conversely, the risk of death to seabirds that forage on crustaceans is linked to the number of plastic items ingested and is higher in adults. Debris ingestion is an under-recognised cause of tubenose mortality and is likely negatively affecting rare and threatened species.”

Read of related papers by the senior author.

Reference:

Roman^, L., Hardesty^, B.D., Hindell, M.A. & Wilcox, C. 2021.  Disentangling the influence of taxa, behaviour and debris ingestion on seabird mortality.  Environmental Research Letters 15(2) doi.org/10.1088/1748-9326/abcc8e.

John Cooper, ACAP Information Officer, 22 March 2021

Laysan Albatrosses on Sand Island, Midway Atoll

The ongoing COVID-19 pandemic halted plans last year to eradicate albatross-attacking House Mice Mus musculus on two globally important seabird breeding localities, the Gough Island Nature Reserve in the South Atlantic and the Midway Atoll National Wildlife Refuge in the northern Pacific – both of which form parts of World Heritage Natural Sites.  The South Atlantic eradication is going ahead this year with the first team members of the Gough Island Restoration Programme arriving on the island last and this month, but what of Midway’s postponed Seabird Protection Project?  ACAP Latest News reached out to North Pacific colleagues to find out the current situation.  In reply Wes Jolley, Project Manager, Island Conservation, writes to ALN:

“In September of 2020 the Midway project partnership [that includes the environmental NGO Island Conservation] determined that the best course of action was to delay the project and aim for a 2022 implementation.  It was a disappointing decision, but after working for several months to evaluate various scenarios there was strong alignment around this being the right approach.  The timing for the decision was because increased irretrievable resources would be needed starting in Q4 [Fourth Quarter] 2020 in order to ramp up for a 2021 implementation.  The continued uncertainty around COVID-19 was the major underlying factor. We performed scenario and mitigation planning and based on the best information available determined that increased logistical uncertainty and associated costs around a 2021 implementation reduced our confidence that we could implement the project to the highest quality possible. Our best chance at achieving our ultimate goals was to delay.

We remain committed to seeing the project’s successful conclusion and are optimistic about 2022. Due to the advanced stage of planning at time of delay we are well positioned to pick things up, but we have been using the time well to fill in additional knowledge gaps and improve strategies where we can.”

Laysan Albatross attacked by mice on Sand Island, Midway; photograph from Friends of Midway Atoll National Wildlife Refuge

One of the knowledge gaps that now has been filled is a recently completed study of the arthropod communities on Midway’s mouse-ridden Sand Island in comparison to that of adjacent mouse-free Eastern Island by Northern Illinois University postgrad Wieteke Holthuijzen.  In her thesis abstract she concludes “Our study contributes to the body of knowledge of arthropods in the Northwestern Hawaiian Islands, arthropod community ecology, and potential mouse impacts on islands.”

View a recording of Wieteke’s virtual thesis defence.

ACAP Latest News looks forward to reporting further on the Gough and Midway mouse eradication efforts and in time – and with both hard work and luck - lauding their successes.

With thanks to Emily Heber, Communications Manager and Wes Jolley, Project Manager, Island Conservation, and Wieteke Holthuijzen, Friends of Midway Atoll National Wildlife Refuge.

Reference:

Holthuijzen, W. 2021.  Fly on the wall: comparing arthropod communities between islands with and without house mice (Mus musculus).  MSc thesis, Department of Biological Sciences, Northern Illinois University.  127 pp.

John Cooper, ACAP Information Officer, 21 March 2021

A Royal Cam parent feeds its chick

Taiaroa Head/Pukekura on New Zealand’s South Island is one of the very few places where the general public can view breeding albatrosses.  Along with the ‘Royal Cam’ that streams activities at an occupied nest to the world it’s no surprise that the colony of Northern Royal Albatrosses Diomedea sanfordi (globally Endangered) gets headlines in the media, most notably in recent days from a Department of Conservation video clip that has gone viral of an adult tumbling onto its back with its legs flailing in the air after a bad landing.

This breeding season is expected to be a good one.  Back in December last year ACAP Latest News reported that 41 eggs (the second highest number of eggs recorded) had been laid in the mainland colony at the tip of the Otago Peninsula – although this figure does not include any eggs laid by female-female pairs.  After the usual long incubation period all the fertile eggs have now hatched with 33 chicks present in the colony following a few early deaths.  Following a query from ACAP Latest News, the Royal Albatross Centre replied on its Facebook page: “We usually have a few infertile eggs each season and occasionally adults break eggs (big feet get in the way) or embryos die before or not long after hatching.”  In detail, 36 eggs hatched from the 41 laid, giving a hatching success of 87.8%.

An eggshell collected for DNA gender testing, photograph by Sharyn Broni

Following hatching, the fresh eggshells are collected in the intensively managed colony.  These allow for DNA tests of adhering blood vessels by Dunedin’s nearby University of Otago to assign gender.  Of the 33 chicks, 17 are females and 15 males with one unknown due to an inadequate sample.  Followers of the Royal Cam will be interested to know that this season’s featured chick – as yet unnamed - is a female.  The annual Name the Royal Cam Chick Competition is sure to follow soon!

Information from Sharyn Broni, Department of Conservation Biodiversity Ranger.via Facebook pages

John Cooper, ACAP Information Officer, 20 March 2021, updated 22 March 2021