Graham Robertson (Kingston, Tasmania, Australia) and colleagues have published in the journal Biological Conservation on how underwater setting can improve the conservation status of fisheries-affected seabirds.

The paper’s abstract follows:

For many decades pelagic longline fisheries have been responsible for the deaths of large numbers of seabirds worldwide. Baited hooks deployed onto the sea surface attract seabirds to fishing vessels leading to attacks on baits, capture and death by drowning. An alternative is to deploy baits underwater where they are less detectable, more difficult to reach and less likely to be taken by seabirds. In 2010 and 2012 proof-of-concept experiments were conducted in the Uruguayan pelagic longline fishery with a newly developed device designed to set baits underwater. The experiments examined the differences between setting baits at the sea surface and setting baits underwater with regard to the abundances of seabirds following the vessel, incidences of attacks on baits and mortality. Underwater setting led to marked reductions in the numbers of seabirds following the fishing vessel and attacks on baits, the behavioural precursors to mortality. Mortality rates of seabirds on baits set to the relatively shallow depth of 4 m were 87% lower than on baits set at the surface. No seabirds were caught on baits released 10 m underwater, a reduction of 100% compared to the surface setting mortality of 11.6 birds/1000 hooks. No differences were detected between the two setting methods in the catch rates of target and non-target fish species. The evidence from the experiments, combined with the known dive depths of the white-chinned petrel (Procellaria aequinoctialis), a deep diving, difficult-to-deter species, suggests that baits released 10 m underwater could reduce the incidental mortality of albatrosses and petrels to negligible levels”.

Solving the problem underwater?  A hooked White-chinned Petrel, photograph by Nicolas Gasco

Robertson, G., Ashworth, Phillip, Ashworth, Peter, Carlyle, I., Jiménez, S., Forselledo, R., Domingo, A. & Candy, S.G. 2018.  Setting baited hooks by stealth (underwater) can prevent the incidental mortality of albatrosses and petrels in pelagic longline fisheries.  Biological Conservation 225: 134-143.

John Cooper, ACAP Information Officer, 02 August 2018

The Albatross and Petrel Agreement develops advice and guidance to mitigate threats to albatrosses and petrels on land and at sea, including best-practice advice for reducing the impact of pelagic longline fisheries on seabirds.  Branch-line weighting is an effective strategy for reducing seabird bycatch, and is one of the mitigation measures recommended by the Agreement.

When a bite off or tear out occurs during the recovery of the line, some flyback events may have the potential to cause injury to crew involved in hauling the catch.  ACAP recognises the importance of improving safety in pelagic longline fisheries, and in response to safety concerns about flyback events, the Agreement commissioned the Australian Maritime College to undertake independent research examining the potential hazard posed by flyback events to crew members.  The analysis conducted identifies technologies and techniques that may be implemented to avoid or mitigate this workplace hazard.

After three years of investigations and two comprehensive technical reports, ACAP is in the process of producing its advice on improving safety when hauling branch lines during pelagic longline fishing operations.  To that end, a winter internship at the Australian Antarctic Division (AAD) was undertaken by James Johnston, as part of his Bachelor of Environmental Policy and Management studies at the University of Adelaide, South Australia. In helping to prepare the proposed advice for ACAP, James spent most of his time working at the AAD under the supervision of Australia’s ACAP National Contact Point, Mr. Jonathon Barrington. He also spent some time working with the ACAP Secretariat. His valuable contribution will be submitted as a working paper to the next meeting of the ACAP Seabird Bycatch Working Group (SBWG9) in May 2019 in Florianópolis, Brazil.

Jonathon Barrington (left) and James Johnston (right) working at the ACAP Secretariat on 26 July

Marco Favero, ACAP Executive Secretary, 01 August 2018

The 2018 intersessional meeting of the International Commission for the Conservation of Atlantic Tunas (ICCAT) Sub-committee on Ecosystems (SC-ECO) was held in Madrid, Spain, over 04-08 June 2018. The Albatross and Petrel Agreement was represented by Anton Wolfaardt, Co-convenor of its Seabird Bycatch Working Group.

The meeting considered a number of seabird-related papers, one of which was submitted and presented by ACAP, outlining its latest best-practice advice for mitigating seabird bycatch in pelagic longline fisheries.  Representatives from Brazil and the NGO Projeto Albatroz presented two papers, both of which reported the results of research investigating the efficacy of hook pods at reducing seabird bycatch. The SC-ECO acknowledged the scientific evidence in support of hook pods as an effective seabird bycatch mitigation measure, and recognised that the re-usability of the pods is a positive attribute. The SC-ECO encouraged further research be undertaken on hook pods. It was noted that information on practical aspects of usage among different fleets would be helpful, and that it would be important to collect information on the longer term use and durability of the hook pods in commercial fleets.

Representatives from Uruguay presented results from experimental work they have undertaken to investigate the effects of seabird bycatch mitigation measures on bycatch rates of other non-target taxa. The focus of the study was on bird-scaring lines and branchline weighting. In both cases, they were unable to detect any impacts on other non-target species, highlighting that these mitigation measures recommended to reduce seabird bycatch do not inadvertently increase bycatch rates of other non-target species.

Another issue discussed and progressed at the meeting was the development of an ICCAT Ecosystem Report Card. A key objective of the report card is to serve a mechanism to help facilitate communication between scientists and managers on a range of ecosystem and fisheries-related matters of relevance to ICCAT (including seabirds).

Yellow-fin Tuna

Click here to access the meeting’s report.

Anton Wolfaardt, Co-convenor, ACAP Seabird Bycatch Working Group, 31 July 2018

Jennifer Provencher (Department of Biology, Acadia University, Wolfville, Nova Scotia, Canada) and colleagues have published in the journal Science of the Total Environment on levels of microplastics excreted by Northern or Arctic Fulmars Fulmarus glacialis.

The paper’s abstract follows:

Plastic pollution is [a] global environmental contaminant. Plastic particulates break down into smaller fragments in the environment, and these small pieces are now commonly found to be ingested by animals. To date, most plastic ingestion studies have focused on assessing retained plastics or regurgitated plastics, but it is likely that animals also excrete plastic and other debris items. We examined the terminal portion of the gastrointestinal tract of a seabird known to commonly ingest plastics, the Northern Fulmar (Fulmarus glacialis), to determine if seabirds excrete microplastics and other debris via their guano. We also examine how guano collections may be used as an indicator of retained plastics. The frequency of occurrence of microplastics did not correlate between the gut and faecal precursor samples, but there was a positive relationship between the number of pieces of plastics in the gut and the number of microplastics in the guano. Our findings suggest that seabirds are acting as vectors of microplastics and debris in the marine environment where their guano accumulates around their colonies. This transport of microplastics and debris by colonial seabirds needs to be further examined, and considered when designing environmental monitoring for microplastics in regions where seabird colonies are found.”

Northern Fulmar in flight

Provencher, J.F., Vermaire, J.C., Avery-Gomm, S., Braune, B.M. & Mallory, M.L.2018.  Garbage in guano?  Microplastic debris found in faecal precursors of seabirds known to ingest plastics.  Science of the Total Environment 644: 1477-1484.

John Cooper, ACAP Information Officer, 30 July 2018