Verónica Cortés (Departament de Biologia Evolutiva, Universitat de Barcelona, Spain) and colleagues have published in the journal Marine Ecology Progress Series on bycatch mortality of Scopoli’s Calonectris diomedea, Balearic Puffinus mauretanicus and Yelkouan P. yelkouan Shearwaters in the north-western Mediterranean Sea.

“Bycatch mortality in longline fisheries is considered the main threat at sea for numerous seabird species. These incidental catches occur worldwide, but mortality levels are mainly determined by the specific traits of the fishery operating in each area and the feeding behaviour and local abundance of seabirds. In the Mediterranean, demersal artisanal longliners are known to catch several seabirds, but bycatch rates and the main factors influencing both the probability and the level of seabird bycatch are poorly known. From 2011 to 2015 we conducted 220 trips onboard demersal longline vessels of the Balearic Sea, aiming to study their interaction with seabirds, as well as to understand the detailed procedures of the fishery and the factors that might influence seabird bycatch. Additionally, we recorded bird catches reported by fishermen. We found an average overall bycatch rate of 0.58 birds per 1000 hooks (0.13−1.37, 95% CI), which would imply a conservative estimate ranging from 274 to 2198 seabirds caught annually on demersal longliners in the study area. The most affected species were the 3 endemic and threatened Scopoli’s, Balearic and Mediterranean shearwaters of the Mediterranean (Calonectris diomedea, Puffinus mauretanicus and P. yelkouan, respectively), likely due to their highly aggregative behaviour and diving capabilities. Overall, the main factors influencing bycatch risk were season and time of day. Other influential factors were bait type, wind conditions, gear configuration (specifically, distance between weights), proximity to the breeding colony and the number of hooks. This study shows that mortality caused by demersal longliners is high and may be jeopardizing the viability of the shear water populations. Therefore, the identification and implementation of mitigation measures is urgently required.”

Balearic Shearwaters killed by a longliner, photograph by Verónica Cortés  

Reference:

Cortés, V., Arcos, J.M., & González-Solís, J. 2017.  Seabirds and demersal longliners in the northwestern Mediterranean: factors driving their interactions and bycatch rates.  Marine Ecology Progress Series 565: 1-16.

John Cooper, ACAP Information Officer, 23 February 2017

Stefan Schoombie (FitzPatrick Institute, University of Cape Town, Rondebosch, South Africa) and colleagues have published in the journal Emu - Austral Ornithology on tracking Endangered Sooty Albatrosses Phoebetria fusca at sea.

The paper’s abstract follows:

“Sooty Albatrosses (Phoebetria fusca; Endangered) breed only on sub-Antarctic islands in the South Atlantic and south-west Indian Oceans, with most of the population at Gough Island (≈37%), the Prince Edward Islands (≈24%) and the Tristan da Cunha archipelago (≈20%). Breeding Sooty Albatrosses from all three of these populations were tracked during the incubation and brood-guard periods. Birds from Marion Island (Prince Edwards) ranged farther north, despite being the most southerly of the three study sites. Tristan-Gough Sooty Albatrosses concentrated mostly around the Sub-Antarctic Front (SAF) in the southern Atlantic Ocean, whereas Marion birds were associated with both the SAF and the Sub-Tropical Front (STF) in the southern Indian Ocean. Our tracking data describe where 80% of breeding Sooty Albatrosses forage during the incubation and brood-guard period, including the first records of birds from Marion and Tristan. Such data are important to identify key areas where these threatened birds need protection from mortality on long-line fishing gear. Overlap with the distribution of tuna long-line effort was greater for Sooty Albatrosses from Tristan da Cunha and Gough Island than for Marion birds, suggesting that birds breeding at Atlantic colonies might be at greater risk of bycatch mortality in this fishery.”

Sooty Albatross by Andrea Angel and Ross Wanless

Reference:

Schoombie, S., Dilley, B.J., Davies, D., Glass, T. & Ryan, P.G. 2017.  The distribution of breeding Sooty Albatrosses from the three most important breeding sites: Gough, Tristan and the Prince Edward Islands.  Emu - Austral Ornithology doi/full/10.1080/01584197.2017.1289804.

John Cooper, ACAP Information Officer, 22 February 2017

Kathrin Munro and Theresa Burg (Department of Biology, University of Lethbridge, Lethbridge, Canada) have published in the Australian journal Emu - Austral Ornithology on the genetic structure of Southern Ocean seabirds, including ACAP-listed albatrosses and petrels.

The paper’s abstract follows:

“Genetic signatures of historical, behavioural and environmental processes are evident in contemporary seabird populations. Molecular markers have allowed us to determine historical patterns of gene flow, relationships among taxa, and contemporary dispersal barriers. The Southern Ocean contains a number of small, isolated islands that are home to four families of seabirds: albatrosses, petrels, penguins and skuas, which have been the focus of a number of population genetic studies. While capable of travelling large distances, many seabirds have restricted dispersal and exhibit high levels of population structure; typically in northern areas and areas with high endemism (e.g. New Zealand). We reviewed 29 studies of 25 Southern Ocean seabird species comparing biogeographic patterns, glacial history and barriers to gene flow, especially at-sea distribution and ocean currents. Despite diversity in behaviour and life history, our review demonstrates that population genetic structure of the seabirds corresponds to the same barriers. For penguins, currents are the major impediment to dispersal whereas at-sea distribution and island location influence population structure for many seabirds with genetically distinct populations on islands at the periphery of their range. As environmental conditions change, it will become more important to assess how seabirds respond and how these changes influence both dispersal and population structure. It is particularly important as a disproportionately high number of Southern Ocean seabirds are threatened or near threatened. Future studies need to focus on adaptive genetic markers, range-wide comprehensive sampling, influence of behaviour on genetic structure and lesser studied seabirds such as terns and cormorants.”

Wandering Albatross and chick, Marion Island, photograph by John Cooper

With thanks to Barry Baker.

Reference:

Munro, K.J. & Burg, T.M. 2017.  A review of historical and contemporary processes affecting population genetic structure of Southern Ocean seabirds.  Emu - Austral Ornithology  doi.org/10.1080/01584197.2016.1271988.

John Cooper, ACAP Information Officer, 21 February 2017

Based on the available evidence a rough estimate would suggest that up to 25 000 seabirds, mainly albatrosses, are killed in fisheries in the southern cone of South America each year. The species affected are predominantly from the Falkland Islands (Islas Malvinas)* and South Georgia (Islas Georgias del Sur)* and Chilean islands off the southern tip of South America.

The fisheries concerned are trawl fisheries that target different species of hake along the Patagonian Shelf, around Cape Horn and up into the Humboldt Current.  These Large Marine Ecosystems are some of the most productive ecosystems in the world and represent critically important foraging grounds for many species of seabird.  The resulting overlap in fishery effort and seabird abundance is what leads to the unfortunate interactions, where seabirds are struck by trawl cables or drowned in fishing nets.

In both Argentina and Chile, national fishery research institutes (Instituto Nacional de Investigación y Desarrollo Pesquero (INIDEP) in Argentina and Instituto de Fomento Pesquero (IFOP) in Chile) employ fishery observers to monitor fish catch and operations. As part of their daily duties, fishery observers are now recording seabird mortality and using that information to report to the Agreement on the Conservation of Albatrosses and Petrels (ACAP). Through this work we are able to gain a better understanding of the levels of seabird bycatch in the region, and the cumulative impact of multiple fisheries on endangered seabird populations.

The BirdLife Albatross Task Force (ATF) in Argentina and Chile, has been working in parallel to identify the characteristics of seabird bycatch in these fisheries and to develop and trial solutions - seabird bycatch mitigation measures - that can reduce the interactions to negligible levels. Incredibly, the trials have shown that seabird bycatch can be reduced by >85% in these fisheries when mitigation measures are used.

The next steps toward reducing the unsustainable levels of bycatch across the southern cone will need a process of the governments passing fishery regulations that require all vessels to implement mitigation measures, and for the national fishery observers to record and report on compliance levels. To encourage swift progress and provide support, BirdLife International hosted a workshop in Valdivia, Chile in January this year entitled “Incidental Capture of Seabirds: Solutions in the Southern Cone”.

In the workshop staff from the ATF and BirdLife International, representatives from the two national fishery research institutes and government worked with the ACAP Executive Secretary, Marco Favero to collaborate on planning a path toward more sustainable fisheries, through the introduction of seabird bycatch mitigation measures in the fisheries and seabird monitoring programmes to record compliance with these measures.

The participants of the workshop: “Incidental Capture of Seabirds: Solutions in the Southern Cone"

One message from the workshop stood out: individual efforts often make a crucial difference in the fight to save endangered species, and the workshop attendees signed a declaration of intentions – The Valdivia Declaration – to indicate their joint dedication toward driving seabird conservation efforts over the next two years. The balance between threatened seabird populations recovering or declining further will rest with many of the people attending the workshop, marking a hugely important occasion and providing great hope for albatrosses.

Oli Yates, Head, Albatross Task Force, BirdLife International, 20 February 2017

*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.

Declaration of Valdivia

Working towards the reduction of seabird bycatch in Southern Cone fisheries

Workshop "Incidental Capture of Seabirds: Solutions in the Southern Cone"

Valdivia, Chile - 11 to 13 January 2017

Recognising that:

Seabirds, and albatrosses in particular, are threatened with extinction, in large part due to interactions with fisheries;

There are simple, economical and effective solutions that, when properly implemented, can mitigate the negative effects of these interactions;

Understanding that:

States are responsible for the administration, sustainable use of natural resources and conservation of ecosystems;

Fisheries research institutes have a fundamental and mandatory role in data collection and generation of information on fishing activity including effects on the ecosystem, which contribute to decision making;

The main objective of BirdLife International's Marine Programme is to improve the conservation status of seabirds, through a collaborative approach with national and international organisations;

Highlighting that:

Frequently, efforts by individuals and teams within different government agencies, national research institutes and NGOs are often key drivers of sustainable change;

In light of the reasons stated, the participants of the Workshop "Seabird Bycatch: Solutions in the Southern Cone" declare our willingness to collaborate in conducting actions to improve the conservation status of seabirds, including:

(1) Improve the standardised collection of seabird interactions and mortality data that allow spatially and temporally stratified analyses;
(2) Promote the integration of information between the different organisations at a national and international level;
(3) Develop, propose and implement conservation measures to mitigate the incidental mortality of seabirds in southern cone fisheries;
(4) Promote the revision and implementation of National Plans of Action to reduce the interactions between seabirds and fisheries;

Signed [in Spanish] in Valdivia on 13 January 2017

NOTE:  ACAP’s Executive Secretary, Marco Favero, who attended the workshop, writes to ALN that the ACAP Secretariat welcomes the Valdivia Declaration and offers secretarial assistance in implementing its actions.