This year a long-awaited attempt to eradicate Black Rats Rattus rattus and House Mice Mus musculus on Australia’s Lord Howe Island took place, as reported in ACAP Latest News (click here)

Following an aerial bait drop coupled with ground baiting volunteers are now required to help mop up the last few rodents on Australia’s World Heritage Island in an effort to give a more secure future for its populations of shearwaters and petrels, including the Flesh-footed Shearwater Ardenna carneipes (globally Near Threatened and a proposed candidate for ACAP listing).

“Volunteers will help recover one of the world’s rarest insects while taking part in a program that will change the lives of critically endangered animals.  The project reached the halfway point for ground-baiting operations in August 2019 and is now entering one of the most critical phases of the project – hunting down the few remaining individual rodents.  The volunteer field officer will undertake pest and weed management and revegetation work.  Volunteer field officers will join the ground-baiting crew servicing 18 900 external bait stations and 2200 monitoring devices over the settlement area of the island, replenishing bait, logging bait take and rodent sign.”

Serried ranks of roofed bait stations on Lord Howe pasture land, photograph by Ian Hutton

The starting date is stated as to be as soon as possible.  For additional information regarding the project visit the Lord Howe Island Rodent Eradication Project.

Read conditions and requirements for the positions and how to apply here.

John Cooper, ACAP Information Officer 06 September 2019

The current season’s crop of globally Endangered and nationally Naturally Uncommon Northern Royal Albatross or Toroa Diomedea sanfordi chicks on New Zealand’s Taiaroa Head will be fledging soon.  Similar to other albatross species chicks close to fledging regurgitate their accumulated stomach contents to "lighten the load” before their first flight.  In a “normal” situation the regurgitated boluses are made up of hard undigested parts emanating from the meals fed to them by their parents, such as squid beaks, fish bones, and sometimes pieces of pumice.

Unfortunately, the situation for albatrosses is no longer normal and chick boluses (most notably of North Pacific species) now often contain fragments and pieces of hard plastic that had been fed to them.  Taiaroa’s Toroa chicks are no exception as Department Of Conservation (DOC) Wildlife Ranger Sharyn Broni has posted to The Royal Albatross Centre Facebook page:

“Items of plastic have been found in regurgitations from three albatross chicks over the weekend.  This piece of a handle from a scoop for infant formula I witnessed being regurgitated by our oldest female chick on Sunday [25 August] amongst 150 g of squid beaks and liquid.  It all looked very uncomfortable and she went and sat down for some time afterwards.  It is better out than in but is a very worrying trend that we are seeing here.”

Enfamil infant formula scoop regurgitated by a Northern Royal Albatross chick, photograph by Sharyn Broni

It will take a massive reduction in single-use plastic on a global scale to address properly this problem (click here for DOC’s suggestions).  Until then, albatross chicks will have to continue to regurgitate their unwanted plastic loads before heading out to sea.

John Cooper, ACAP Information Officer, 05 September 2019

Sebastián Jiménez (Laboratorio de Recursos Pelágicos, Dirección Nacional de Recursos Acuáticos, Montevideo, Uruguay) and colleagues have published in the journal Biodiversity and Conservation on effects of bird-scaring lines and branch line weighting on catch rates of fish, turtles and seals.

The paper’s abstract follows:

“Fisheries bycatch is one of main conservation problems for many threatened seabirds.  Currently, it is unknown whether existing best practices to mitigate seabird bycatch in pelagic longline fisheries influence the capture of other vulnerable taxa.  We assessed the effect of two seabird mitigation measures for pelagic longline fisheries on 13 threatened, protected and/or bycaught species, including elasmobranchs, teleosts, sea turtles and fur seals.  Analyses were from two experimental studies in Uruguay assessing the effect of a bird scaring line (BSL) and branch lines with weights close to the hooks (weighted branch lines) on these taxa.  One hundred longline sets with randomized use of a BSL were deployed.  In turn, 224 paired longline sections, with control branch lines versus weighted branch lines, were deployed. BSL use did not increase the capture of any of the species addressed.  No detectable differences in capture rate were recorded in our branch line weighting study.  However, the effect of branch line weighting in the capture of Porbeagle shark (Lamna nasus) remains unclear and requires further research.  Our study suggests that effective measures to reduce seabird bycatch in pelagic longline have no negative connotations for other vulnerable species.  Caution should be exercised when interpreting our results as analyses were underpowered to detect small and subtle differences in the catch rates.  We strongly encourage researchers to conduct similar studies to elucidate potential regional and across fisheries differences in the effect of seabird mitigation measures in other vulnerable taxa, as well as the effect that mitigation measures for other taxa may have on seabirds.”

Bird-scaring lines deployed behind a fishing vessel, photograph by Ed Melvin

With thanks to Sebastián Jiménez.

Reference:

Jiménez, S., Forselledo, R., Domingo, A 2019.  Effects of best practices to reduce seabird bycatch in pelagic longline fisheries on other threatened, protected and bycaught megafauna species.  Biodiversity and Conservation  doi.org/10.1007/s10531-019-01842-4 -4.

John Cooper, ACAP Information Officer, 04 September 2019

Agustina Quadri Adrogué (Laboratorio de Ecotoxicología y Contaminación Ambiental, Universidad Nacional de Mar del Plata, Argentina) and colleagues have published in the Marine Pollution Bulletin on levels of Persistent Organic Pollutants (POPs) in Black-browed Albatrosses Thalassarche melanophris and Pintado or Cape Petrels Daption capense.

The paper’s abstract follows:

“Persistent Organic Pollutants (POPs) are accumulated through time and can exert different effect on ecosystems.  POPs and Chlorpyrifos, a current use pesticide, were assessed in body feathers of males and females of Blackbrowed albatross (Thalassarche melanophris, BBA) and Cape petrels (Daption capense, CAP) during their nonbreeding seasons at the Patagonian Shelf, Argentina.  Chlorpyrifos showed the highest values among all pollutants in both species (49.56–84.88 ng g−1), resulting from current agricultural practices.  The pattern OCPs>PCBs>PBDEs was observed in both species, and CAP showed higher concentrations than BBA probably as a consequence of higher lipid mobilization and pollutants availability during dispersion.  Non-significant differences between sexes about POPs levels were found; however a slight tendency was observed, females> males in CAP, and males>females in BBA.  More attention and further studies are needed to understand seabirds' physiology and its relationship with the pollutants distribution in their tissues and considering breeding season.”

Black-browed Albatrosses, photograph by Graham Robertson

Reference:

Quadri Adrogué, A., Miglioranza, K.S.B., Copello, S., Favero, M. & Seco Pon, J.P. 2019.  Pelagic seabirds as biomonitors of persistent organic pollutants in the Southwestern Atlantic.  Marine Pollution Bulletin doi.org/10.1016/j.marpolbul.2019.110516.

John Cooper, ACAP Information Officer, 03 September 2019