Tristan da Cunha in the South Atlantic, one of the world’s smallest communities, forms part of a United Kingdom Overseas Territory.  The major source of the island group’s income is from fishing, primarily inshore for Tristan Crayfish or Rock Lobster Jasus paulensis within its 12-nautical mile territorial waters.  In addition a single vessel, the MFV Edinburgh, currently undertakes demersal longlining, including over seamounts, within Tristan’s 200-nautical mile Exclusive Economic Zone (EEZ) which covers 750 000 square kilometres.  The resource targeted is deep-water Antarctic or Southern Butterfish Hyperoglyphe antarctica  (known in Tristan waters as “Bluefish”), a species – under several other common names - that is caught by similar fisheries in Australian and New Zealand waters.

Tristan da Cunha (made up of the main island of Tristan and the outlying islands of Gough, Inaccessible and Nightingale) supports large numbers of breeding seabirds, including six ACAP-listed species, which forage within the EEZ, as well as farther afield.  Of these six ACAP species, three albatrosses are considered to be globally threatened: Tristan Diomedea dabbenena (Critically Endangered), Atlantic Yellow-nosed Thalassarche chlororhynchos (Endangered) and Sooty Phoebetria fusca (Endangered).  The Spectacled Petrel Procellaria conspicillata, endemic to Inaccessible Island, is Vulnerable, The Grey Petrel P. cinerea is Near Threatened and the Southern Giant Petrel Macronectes giganteus is categorized as Least Concern.  All these species are at a greater or lesser risk of being caught on longlines and may be seen around the Tristan fishing vessel during line hauling and waste discarding.

In order to prevent bycatch of these ACAP species, as well as of other seabirds, the Tristan Fisheries Department (TFD) in its demersal longline fishery has followed ACAP’s best-practice guidelines, employing the mitigation measures of paired bird-scaring lines, line weighting and night setting.  In addition, defrosted bait is used to help hooks sink more quickly, deck lighting is minimised with downward-directed lights during setting, and discarding takes place in batches on the opposite side of the vessel to the hauling bay; all listed as responsible practices by ACAP.  Tristan Fishery Officers acting as observers aboard ensure these measures are carried out and also collect information on seabird interactions with the fishing operation.

Downward-directed lights at night on the FMV Edinburgh, photograph by Oli Yates

Shortly before the end of their summer breeding season, Great Shearwaters Ardenna gravis (which breed in huge numbers on the outlying Tristan Islands) have been observed to forage aggressively in ‘frenzies” in order to build up reserves for their trans-equatorial migration.  Even with the suite of mitigation measures listed above, the deep-diving ability of the shearwaters means they can still access baited hooks, leading to incidental mortality.  Following advice received from the UK’s Centre for the Environment, Fisheries and Aquaculture Science (CEFAS) a seasonal closure of longline fishing in Tristan waters from February to June has now been established to reduce mortality of Great Shearwaters.  This seasonal closure should also benefit ACAP-listed albatrosses and petrels occurring in Tristan waters.

Great Shearwater

Read more here and here.

With thanks to Laura Beasley, Royal Society for the Protection of Birds, Anton Wolfaardt, Co-convenor, ACAP Seabird Bycatch Working Group and Oli Yates, CEFAS.

John Cooper, ACAP Information Officer, 14 December 2018

Wisdom, the famous Laysan Albatross Phoebastria immutabilis who is the world’s oldest known wild bird, has returned once more to Midway Atoll National Wildlife Refuge in the USA’s North Western Hawaiian Islands to commence the 2018/19 breeding season.

This season she was first seen at her usual nest site on the atoll’s Sand Island on 29 November, and it has been confirmed that she has laid an egg.  Wisdom was first banded as an adult on Midway in 1956, and is considered to be at least 68 years old, factoring in the age of maturity for the species.  Wisdom and her colour-banded mate Akeakamai ("Love of Wisdom") have been returning to the same nest site on Midway Atoll each year since at least 2016 – although it is likely she has had a number of mates over her long life.

Wisdom on her egg this breeding season, showing her identifying colour band Red Z333; photograph by B. Peyton, USFWS

“Wisdom was first banded during a bird survey in 1956 by a biologist named Chandler Robbins.  At the time, Wisdom wasn’t particularly special, she wasn’t even Wisdom.  She was just one of the hundreds of thousands of returning to Midway and one of 8,400 albatross that were banded that year.  In a strange twist of fate, it was Robbins himself who “rediscovered” Wisdom 46 years later during a survey near the same nesting location.  As he recorded her band number, he noticed that he had been the original recorder all those years ago during his first season on Midway”.  Chandler Robbins passed away in 2017 at the age of 98.

The banded chick that Wisdom fledged in 2001 was observed close to her usual nest site nest in 2017; the first time a returning chick of hers has been documented.

Read more here and view many photos and videos of Wisdom here.

You can read more about Wisdom in the many postings to ACAP Latest News over the last eight years or so (click here).

John Cooper, ACAP Information Officer,13 December 2018

While nearly 100 km out to sea on a voyage aboard the Australian Commonwealth Scientific and Industrial Research Organisation (CSIRO) RV Investigator on a trip to explore underwater mountains off Tasmania's coast, scientists observed an albatross that had apparently swallowed a balloon.

Marine biologist Alice Forrest aboard said "we thought it had a squid in its mouth and upon closer observation we realised that what we thought was a squid with tentacles was a rubber balloon with a string trailing from its mouth”.  On the same day the scientists aboard saw a group of albatrosses investigating a floating plastic drinks bottle: “one of the birds was picking the plastic bottle up and throwing it around".

A Shy-type Albatross T. cauta trails a balloon string

Two Shy-type Albatrosses approach a plastic drinks bottle at sea

Photographs from the Commonwealth Scientific and Industrial Research Organisation

Read more here.

ACAP Latest News has previously posted on ACAP-listed albatrosses and petrels swallowing or becoming entangled by balloons, including Black-footed Albatross Phoebastria nigripes, Black-browed Albatross Thalassarche melanophris, Grey-headed Albatross T. chrysostoma, Light-mantled Albatross Phoebetria fusca, Southern Giant Petrel Macronectes giganteus and Northern Giant Petrel M. halli (click here).

Further, 17 of the 31 ACAP-listed species have been reported in a scientific study as becoming entangled in plastic litter, including 12 albatross species, both giant petrels Macronectes and two Procellaria petrels (click here).

Click here for an account of balloons being seen previously from the RV Investigator 250 km out to sea.

John Cooper, ACAP Information Officer, 12 December 2018

New Zealand’s  Department of Conservation (DOC)  is undertaking field work at the Auckland Islands this austral summer to inform the planned pest eradication project that aims to rid the main island in the group of its feral pigs and cats and House Mice – and thus free the whole island group of introduced mammals.

Carnely Harbour in the south of Auckland Island

This year teams will be going to the island to look at where infrastructure sites can be set up for the eradication exercise, and to catch and tag cats so as to monitor and track their behaviour so as to “inform how we might go about removing them in the future."  Further, in early January next year a team will use a helicopter equipped with thermal imaging technology to see how they could track the pigs.  Pig hunters will then try to eradicate pigs in a 56-ha area on Falla Peninsula that will later be used to monitor mice.  In the same month a team will then carry out mice monitoring using non-toxic bait with a fluorescent marker and yet another team will check the cat monitoring.  It is hoped the monitoring data will be collected by March so a business case can be completed by mid-2019.

A feral pig on Auckland Island

DOC also reports that the New Zealand Government has contributed NZ$ two million for the initial scoping work, and that the total eradication cost could rise to NZ$ 40-50 million over a 10-year period.

The main Auckland Island was rid of its feral goats in 1992 and Enderby Island, in the group no longer has feral cattle, European Rabbits or House Mice following eradication exercises.

Read more here.

John Cooper, ACAP Information Officer, 11 December 2018