Leigh Gurney (Department of Earth, Ocean and Atmospheric Sciences, University of British Columbia, Vancouver, Canada) has been awarded a PhD for her research on the marine ecosystem of South Africa’s Prince Edward Islands in the southern Indian Ocean.  Marion and Prince Edward Islands that form the group support nine regularly-breeding species of albatrosses and petrels that are listed within ACAP.

The thesis abstract follows:

“This study brings together the wealth of data available for the Prince Edward Islands marine ecosystem and consolidates it into a network, mass-balanced model (using Ecopath).  Biomass estimates for the land based top predators show penguins dominate the system for all three time periods assessed (1960s, 1980s and 2000s).  The islands appear to have a carrying capacity which may be declining.  A consumption model shows a change in prey for the land based top predators from one in which both crustaceans and myctophid fish were of equal importance in the 1960s, to one dominated by myctophids for the 2000s period.  The contribution of the sources of primary production were assessed through the ecosystem model with open ocean productivity dominating at all but the smallest scale (shelf region), where the macrophyte production was important.  The model describes the marine ecosystem for each of the above mentioned time periods at the scale of the Exclusive Economic Zone and, when compared to other subantarctic and Antarctic systems for which there are ecosystem models, the system was most similar to the neighbouring Kerguelen Islands.  An investigation into the ecosystem boundary size was conducted, with all constituents able to satisfy their energetic requirements if considered at the scale of the EEZ.  Using the dynamic temporal simulation approach (Ecosim), the model was able to successfully hindcast three past events: the fur seal exploitation, Patagonian toothfish fishery, and the effect of cat predation on small flying birds. In each instance the model performed well for the directly impacted groups.  Potential ecosystem effects of climate change were explored through simulations of increasing and decreasing productivity.  No single scenario was able to replicate observed patterns and a suite of drivers needs to be considered to reproduce observed patterns.  The inclusion of energetic density of prey led to improvements in consumption rate estimates for the static models and should be incorporated into estimates to improve ecosystem model parameterization.  The work constitutes the first ecosystem model for the PEIs that can be used as a tool for an ecosystem approach to marine resource management.”

Albatross Valley on Prince Edward Island: home of Wandering Albatrosses

Photograph by Bruce Dyer

Click here to read of a publication by Leigh Gurney from her thesis.

With thanks to Leigh Gurney for information.

References:

Gurney, L.J. 2013.  An ecosystem study of the Prince Edward Archipelago (Southern Ocean).  PhD thesis, University of British Columbia, Vancouver, Canada.  320 pp.

Gurney, L.J., Pakhomov, E.A. & Christensen, V. 2014.  An ecosystem model of the Prince Edward Island archipelago.  Ecological Modelling 294: 117-136.

John Cooper, ACAP Information Officer, 18 November 2014

John Parkes (Kurahaupo Consulting, Christchurch, New Zealand) and colleagues have published open access in the New Zealand Journal of Ecology on successes achieved in eradicating feral Domestic Cats Felis catus from islands.  Of the six largest islands where success has been achieved three support breeding populations of ACAP-listed species: Little Barrier (New Zealand, 2817 ha), Macquarie (Australia, 12 780 ha) and the largest, Marion (South Africa, 29 000 ha).

The paper’s abstract follows:

“Feral cats (Felis catus) are predators and competitors of native species on many islands and are therefore the target of control efforts.  Cat eradication has been achieved on 83 islands worldwide. Six of these successes have been from large islands (over 2000 ha) and have reported sufficient data to examine how the eradication was achieved through combinations of aerial and ground-based poison baiting, fumigation in rabbit burrows used by cats, cage and leghold trapping, day and night shooting, and hunting with dogs.  No common sequence of tactics was deployed although leghold traps were used in the latter phases of most projects.  It took a mean reported effort of 543 ± 341 person-days per 1000 ha of island over 5.2 ± 1.6 years to completely remove cats and validate success from the six islands.  These precedents may assist in planning future proposals to eradicate cats from other large islands.”

Marion Island with its scientific base - cat free since 1991

Reference:

Parkes, J., Fisher, P., Robinson, S. & Aguirre-Muñoz, A. 2014. Eradication of feral cats from large islands: an assessment of the effort required for success.  New Zealand Journal of Ecology 38: 307-314.

John Cooper, ACAP Information Officer, 17 November 2014

David Latham (Landcare Research, Lincoln, New Zealand) and colleagues have pre-published in next year’s New Zealand Journal of Ecology on matters to consider when planning the tracking of wildlife by satellite or GPS.  ACAP-listed species considered in the paper are the Northern Royal Albatross Diomedea sanfordi, White-capped Albatross Thalassarche steadi and Black Petrel Procellaria parkinsoni.

The paper’s abstract follows:

“GPS and satellite technology for studies on wildlife have improved substantially over the past decade.  It is now possible to collect fine-scale location data from migratory animals, animals that have previously been too small to deploy GPS devices on, and other difficult-to-study species. Often researchers and managers have formatted well-defined ecological or conservation questions prior to deploying GPS on animals, whereas other times it is arguably done simply because the technology is now available to do so.  We review and discuss six important interrelated questions that should be addressed when planning a study requiring location data.  Answers will clarify whether GPS technology is required and whether its use would increase efficiency of data collection and learning from location data. Specifically, what are the required: (1) ecological question(s); (2) frequency and duration of data collection; (3) sample size; (4) hardware (VHF or GPS or satellite) and accessories; (5) environmental data; and (6) data-management and analysis procedures?  This approach increases the chance that the appropriate technology will be deployed, budgets will be realistic, and data will be sufficient (but not excessive) to answer the ecological questions of interest.   The expected results are important advances in ecological science and evidence-based management decisions.”

A Northern Royal Albatross chick approaches fledging on New Zealand's Taiaroa Head

Reference:

Latham, A.D.M., Latham, M.C., Anderson, D.P., Cruz, J., Herries, D. & Hebblewhite, M. 2015.  The GPS craze: six questions to address before deciding to deploy GPS technology on wildlife.  New Zealand Journal of Ecology 39.

John Cooper, ACAP Information Officer, 16 November 2014

Marcelo Flores (Departamento de Ecología y Biodiversidad, Universidad Andres Bello, Santiago, Chile) and colleagues have published in the Latin American Journal of Aquatic Research on seabirds occurring on Chilean oceanic islands in the South Pacific Ocean.  ACAP-listed species recorded regularly or occasionally were Black-browed Thalassarche melanophris and Salvin's Albatrosses T. salvini and Northern Macronectes halli and Southern Macronectes giganteus Giant Petrels.

The paper’s abstract follows:

“We reviewed available information on seabirds inhabiting Easter Island, Salas y Gómez Island and Desventuradas Islands and their adjacent waters through an analysis of published and grey literature.  Results obtained indicate that a total of 37 species are present in the study area and that, among the orders represented, the Procellariiformes and Charadriiformes are the dominant taxa (29 species).  Moreover, the family Procellariidae is represented by 13 species and Laridae by 7 species.  There has been an increase in new records over the past six years but no systematic studies have been developed.  The need for further research that focuses on ecological aspects and anthropogenic impacts is critical in order to develop adequate conservation strategies.”

Salvin's Albatross at sea, photograph by Aleks Terauds

Reference:

Flores, M.A., Schlatter, R.P. & Hucke-Gaete, R. 2014.  Seabirds of Easter Island, Salas y Gómez Island and Desventuradas Islands, southeastern Pacific Ocean.  Latin American Journal of Aquatic Research 42: 752-759.

John Cooper, ACAP Information Officer, 15 November 2015