Juan Pablo Seco Pon (Laboratorio de Vertebrados, Instituto de Investigaciones Marinas y Costeras, Facultad de Ciencias Exactas y Naturales, Universidad Nacional de Mar del Plata, Argentina) and ACAP South American News Correspondent has been awarded his PhD with distinction by the National University of Mar del Plata this month for his study of the interactions between pelagic seabirds and Argentinian trawlers.

The English abstract of his thesis follows:

“This thesis addresses various aspects of the interaction between pelagic seabirds and the commercial ice trawl fishery targeting hake Merluccius hubbsi in Argentine waters.  The information was collected at sea on board trawlers pertaining to this fleet.  The results presented here clearly highlight the importance of fishery discard triggering the attendance of seabirds and the effect it has on the abundance and composition of the assemblages, as well as on the level of interactions.  We quantified in detail the interactions with different sections of the fishing gear and showed the importance of the net-sonde cable in seabird contact rate.  We also assessed the ecosystem value from the use of fish by-catch reduction devices, particularly focusing on its effect on seabird abundance and interaction levels.  The ice trawl fleet produces large quantities of discards (unwanted species and sizes) which are taken by seabirds.  Although such use of discards can be considered as a trophic “subside” [subsidy] from the fishery, it is clear that for species with history traits like albatrosses and petrels the negative impact in terms of incidental mortality largely overwhelms any positive effect of such subside.  The strategic management of discards in this fishing fleet (as in other fishing gears and fleets) should be the priority to be deepened in the national agenda to solve the problem of incidental mortality of seabirds.”

Juan Pablo aboard a longliner in the South Atlantic 

Juan Pablo works within the Vertebrate Research Group at the National University of Mar del Plata which is headed by Marco Favero, who has been Chair of ACAP’s Advisory Committee since 2007.

The ACAP Secretariat extends its congratulations to Juan Pablo and looks forward to a continued collaboration.

With thanks to Marco Favero for information.

Reference:

Seco Pon, J.P. 2014.  Asociacion de aves marinas pelagicas a la flota de arrastre de altura: characterizacion integral de las interacciones y desarrollo de una estrategia de conservacion para especies amenazadas.  [Seabirds attending the high-seas trawl fleet: comprehensive characterisation of interactions and development of a conservation strategy for threatened species].  PhD Thesis, Universidad Nacional de Mar del Plata, Argentina.  161 pp.

John Cooper, ACAP Information Officer, 16 March 2014

José Báez and colleagues (Centro Oceanográfico de Málaga, Instituto Español de Oceanografía, Málaga, Spain) have published in the journal Biodiversity and Conservation on how to avoid Scopoli’s Shearwaters Calonectris diomedea (a potential ACAP candidate species) being caught by Spanish longliners in the Mediterranean.

The paper’s abstract follows:

“Cory’s shearwater Calonectris diomedea is the main seabird species by-caught by the Spanish longline fleet operating in the western Mediterranean Sea.  Identification of the principal factors that determine this by-catch and understanding how they could be controlled is fundamental for improving the management of fisheries and so carry out a better conservation of Cory’s shearwater populations in the Mediterranean.  The aim of this paper was to model the longline by-catch of Mediterranean Cory’s shearwater in the Spanish Mediterranean longline fishery as a function of time of the year, technical characteristics of the fishing operation, and geographical location.  We used data recorded by an onboard observer program monitoring commercial longline fisheries. During the 10 years covered in this study, 80 birds were captured in 30 fishing operations out of a total of 2,587 observed fishing sets.  We used favourability functions and Random Forest analyses to relate the presence of Cory’s shearwater in the by-catch with the explanatory factors.  The most explanatory factor in relation to incidence of by-catch was the geographical location (longitude and fishing over the continental shelf) and then the technical characteristics of the fishing operation (number of hooks and fishing during non-working days).  Our conclusion is clear, because seabirds are more likely to approach longline vessels when trawlers are not allowed to operate (i.e. non-working days), activity of longliners should be limited to working days, and closing longliners activity during the month of October could reduce greatly reducing [sic] seabird bycatch.”

Cory's/Scopoli's Shearwater Calonectris borealis/diomedea at sea

Photograph by John Graham

With thanks to Richard Phillips for information.

Reference:

Báez, J.C., García-Barcelona, S.,  Mendoza, M., Ortiz de Urbina, J.M., Real, R. & Macías, D. 2014.  Cory’s shearwater by-catch in the Mediterranean Spanish commercial longline fishery: implications for management.  Biodiversity and Conservation 23: 661-681.

John Cooper, ACAP Information Officer, 15 March 2014

The Bishop and Clerk Islets lie approximately 33 km south of Australia’s Macquarie Island.  They consist of Bishop Islet, a rocky platform with some shallow patches of soil c. 3 ha in area with a highest point of c. 45 m, surrounded by 24 smaller islets, rocks and reefs, all of which are likely be wave-washed at times.

Bishop and Clerk Islets from the south...

 ...and from the east in 1993

Only three landings are known to have been made on the islets, all by ship-assisted helicopter, on 25 February 1965, 7 February 1976 and 23 December 1993.  The first landing was on a wave-washed rock close (c. 50 m) to Bishop Islet, the following two on the islet itself.  These visits ranged from less than an hour (in 1965) to three hours (in 1993 when seven personnel went ashore, some of whom are visible in a photograph below).

The only vascular plant recorded on Bishop Islet is the cushion plant Colobanthus muscoides “covering much of the central plateau”, along with two species of lichens.  Fifteen invertebrate species were collected during the 1993 visit.

Two views of the Black-browed Albatross colony on Bishop Islet in 1993

On all three visits, ACAP-listed and Near Threatened Black-browed Albatrosses Thalassarche melanophris have been recorded ashore on Bishop Islet.  At least 14 large chicks were identified on aerial photographs taken in 1967 along with at least 107 adults; 44 half-grown chicks and “many adults" were reported in 1976.

During the most recent visit in 1993 “[a] total of 141 nests [of Black-browed Albatrosses] was recorded.  Of these, 78 contained a chick, 13 an egg, ten had egg-shell fragments and 40 were empty.”  An eleven-year-old bird banded as a fledgling on Macquarie Island was present, showing interchange between the two localities.

A Black-browed Albatross on its nest on Bishop Islet in December 1993

A single Salvin’s Albatross T. cauta “of adult appearance” was present among the breeding Black-browed Albatrosses in 1993.  It did not appear to be breeding.

Other procellariiform seabirds confirmed breeding on Bishop Islet during the 1993 visit were Fairy Prion Pachyptila turtur, Wilson’s Storm Petrel Oceanites oceanicus and Common Pelecanoides urinatrix and South Georgian P. georgicus Diving Petrels.

The Bishop and Clerk Islets fall within the Macquarie Island Nature Reserve managed by the Tasmanian Parks and Wildlife Service. The island and its islets were declared a World Heritage Site in 1997.  Bishop & Clerk Islets have been assigned the status of a Special Management Area (SMA) restricting future landings.  The islets are surrounded by the Australian Commonwealth’s Macquarie Island Marine Park declared in 1999.

With thanks to Rachael Alderman, Noel Carmichael and Margaret Koopman for information and photographs.

Selected Literature:

Brothers, N. & Ledingham, R. 2008.  The avifauna of Bishop and Clerk Islets and its relationship to nearby Macquarie Island.  Papers and Proceedings of the Royal Society of Tasmania 142: 117-121.

Davies, K.F., Greenslade, P. & Melbourne, B.A. 1997.  The invertebrates of sub-Antarctic Bishop Island.  Polar Biology.

Environment Australia 2001.  Macquarie Island Marine Park Management Plan 2001-2008.  Canberra: Department of Environment and Heritage.

Frost, Leslie 2006.  Macquarie Island Nature Reserve and World Heritage Area Management Plan 2006.  Hobart: Parks and Wildlife Service, Department of Tourism, Arts and the Environment.  176 pp. + 15 maps.

Lugg, D.J., Johnstone, G.W. & Griffin, B.J. 1978.  The outlying islands of Macquarie Island. The Geographical Journal 144: 277-287.

MacKenzie, D. 1967.  The birds and seals of the Bishop and Clerk Islets, Macquarie Island.  Emu 67: 241-245.

John Cooper, ACAP Information Officer, 14 March 2014

BirdLife International’s Global Species Programme collates information on globally threatened birds from the published literature and from a worldwide network of experts.  This is used to evaluate the status of each species using the IUCN Red List categories and criteria.

“New information on the population or range size and trends of a species, or the threats impacting it, may indicate that a species warrants uplisting or downlisting to higher or lower categories of threat.  In such cases, BirdLife’s web-based Globally Threatened Bird Forums are used to advertise the proposed change and to solicit relevant information or comment from a wide network of experts and organisations."

The Globally Threatened Seabird Forum is currently considering implications arising from recent taxonomic splits of shearwaters as summarized below.

BirdLife’s taxonomic treatment of the Little Shearwater Puffinus assimilis/Audubon’s Shearwater P. lherminieri complex is being revised to reflect improved understanding of their taxonomy, and the recently described Bryan’s Shearwater P. bryani is to be recognised as a species.  Audubon’s and Little Shearwaters will be provisionally listed as of Least Concern in the 2014 Red List update, whereas Bryan’s Shearwater will likely be listed as Data Deficient.

Click here for the full arrangement proposed to be adopted by BirdLife for taxa in this complex of 11 species of small shearwaters.

BirdLife is also proposing to split Cory’s Shearwater Calonectris diomedea sensu lato (a proposed candidate for ACAP listing) into Scopoli’s Shearwater C. diomedea of the Mediterranean and Cory’s Shearwater C. borealis of the Macaronesian Islands.  Both species will likely be listed as of Least Concern in the 2014 Red List update (click here).

The initial deadline for comments on these changes is 7 April 2014.  However, discussions on Audubon’s Shearwater and the Calonectris split will remain open until at least February 2015.

Click here for earlier ACAP Latest News accounts for the recently described Bryan’s Shearwater.

Cory's Shearwater, photograph by Paulo Catry

John Cooper, ACAP Information Officer, 13 March 2014