Tristan da Cunha and SA Agulhas ll

The word Agulhas means different things to different people.  To a geographer, Cape Agulhas is the most southern tip of the continent of Africa.  Many people would think that Cape Horn is furthest south, particularly with its fame among the trading sailors of the 19th century who “Rounded the Horn” on their way to India and the Far East.  Presumably, as these vessels navigated around the southern point of Africa the biggest change of direction was when they changed course around Cape Horn, whereas the change of course just 80 miles later, around Cape Agulhas, was a relatively modest change of angle, prior to the ships running almost due east along what is now the Garden Coast of South Africa.

Bee and Alasdair at Cape Agulhas – to the left is the Indian Ocean, and to the right is the Atlantic

Oceanographers will also know the name Agulhas after the Agulhas Current.  This is a major south-flowing current which runs down the east coast of Africa, roughly from 27o to 40o south.  It is a narrow strip of current close to the shore, varying between 30 and 100 km wide, and travelling at speeds averaging around 2 km/hr but at its maximum reaching speeds of 9.3 km/hr.

The Agulhas that is connected to Tristan da Cunha is SA Agulhas ll, which is a ship that is well known on a global basis.  The Agulhas is a South African icebreaking polar supply and research ship that is used as a platform for a wide range of tasks in the southern polar regions.  The Agulhas is owned by the Department for Environmental Affairs, and is operated by SANAP (South African National Antarctic Programme).  The link with Tristan is that every year the Agulhas passes from Cape Town to Tristan da Cunha, then she goes down to Gough Island 220 miles south of Tristan, where she carries out the change of the staff that are based on Gough for a year, dropping off one annual team and picking up the retiring team after their handover.  The Agulhas then returns to Tristan, and onwards to Cape Town.

Agulhas in her home port of Cape Town

On her way from Cape Town to Tristan the Agulhas takes a large quantity of cargo, and many passengers.  Last September the passengers included the RSPB team travelling out to Gough to do work on the mouse eradication project, two new teachers coming to Tristan, a number of islanders returning to the island from medical visits in Cape Town, a number of scientists coming to work on fisheries, birds and seals, a retail specialist coming to help the Tristan supermarket for six months, a large number of visitors coming to celebrate the 100th birthday of their relative on the island  –  and Bee and myself returning from leave!

The Agulhas has some big advantages for travelling out here compared with the deep sea fishing boats that are the other form of transport.  Firstly, she carries two helicopters.  One of the helicopters is used to take passengers ashore, which can be done even if sea conditions are stormy; thus there is virtually no risk of having to wait days on end while sea conditions allow the harbour on Tristan to be used.  The next advantage is that the Agulhas is a large and powerful ship, and is able to stick to a schedule under almost any conditions.  Visitors to the island are able to come ashore, and to have great confidence that they will be picked up 18 days later when the ship is on her return voyage.  The third advantage over the fishing ships is to do with passenger comforts – the Agulhas has stabilisers, comfortable en-suite cabins, good food, and good facilities including a gym and a couple of bars!

The Agulhas was built in Finland, and was commissioned in 2012.  She is built to “Polar Class 5” and is powered by four 3,000kw Waitsila engines.  Her ice-breaking capability is impressive, with a capacity to drive through 1 metre of ice at 5 knots.  An interesting feature is that her decks are heated, in order to prevent any build-up of ice in polar conditions.  The ship’s stabilisers are interesting – being an ice-breaker she cannot have stabiliser vanes sticking out of the side of the vessel, instead she has water balancing tanks which are joined by massive pumps, capable of pumping water from one side to the other in order to achieve a balanced trim.

One of the main engines in the immaculate engine room
The on-board machinery workshop – capable of any task

The ship has a crew of 45, and accommodation for a further 100 passengers.  With regard to her function as a scientific platform, the ship has 8 fitted laboratories and 6 further container laboratories, a library, as well as an auditorium for 100 people.

Our crossing from Cape Town to Tristan was trouble-free, and we made it interesting since I managed to organise visits to the engine room and to the bridge.  On the bridge we found the famous xylophone that is used as a dinner gong – it is a tradition on board that a crew member on the bridge announces meal times by playing a tune over the public address system!

The improvised dinner gong in the bridge

The Agulhas regularly carries out expeditions in the southern polar regions.  One quite recent expedition, in February this year, was to go down into the Weddell Sea and carry out scientific studies, particularly on the giant iceberg known as A68, leading to greatly increased knowledge of the climatic influences from that area.  One last mission, before the Agulhas left the Weddell Sea,  was to launch an AUV (Autonomous Underwater Vehicle) in order to search for the Endurance, Sir Earnest Shackleton’s famous ship which sank in November 1915.  The mission was not a success – they were on station and began their search on 11 February, but on 14 February, with deteriorating weather and sea ice conditions, the AUV lost contact with her mother ship and the mission had to be called off and the AUV abandoned.

The Agulhas off Tristan da Cunha (viewed from our garden)
The settlement of Edinburgh of the Seven Seas, viewed from the Agulhas helicopter



Ships + Fruit

One of the deep-sea fishing vessels that comes to Tristan is the MFV Edinburgh.  This trusty boat was built in 1970, and was named Hekla.  People who are familiar with the island of Iceland will know that Hekla is also the name of one of the most significant live volcanoes on that island.

MFV Edinburgh at anchor off Tristan, February 2019

Hekla was bought by Ovenstones, sometime in the 1980’s.  Ovenstone Agencies is the South African company that currently has the fishing concession on Tristan da Cunha.  At that time the ship had a name-change, and she became MFV Edinburgh.  Presumably this was in recognition of the formal name of the settlement on Tristan, which is Edinburgh of the Seven Seas.  Edinburgh is one of two ships operated by Ovenstones, the other one being the MFV Geo Searcher.  In any one year, the Edinburgh is scheduled to make six visits to Tristan, and the Geo Searcher to make three visits.  Each visit from Cape Town may have a number of different objectives, which can include fishing for lobsters among the off-lying islands, delivering cargo to the island, delivering fuel to the island, long-line fishing for pelagic fish on the Tristan sea-mounts, taking lobster back from the Tristan factory to Cape Town, and of course taking passengers of all sorts from Cape Town to Tristan and back again.  Apart from the once-a-year visit of the ship called SA Agulhas 2, virtually all passengers arriving at Tristan or leaving the island will be carried on these deep-sea fishing ships, each carrying up to 12 passengers.

The visits of these ships are not scheduled to take place regularly throughout the year – there can be long periods with no ship, then two arrive virtually together.  This does not affect the fishing operations, but it does have an effect on all the departments on the island who are dependent on these ships for their supplies, not least of which is the ‘Supermarket’.

MFV Edinburgh lying in Cape Town harbour, viewed from the deck of SA Agulhas 2

The Edinburgh departed from Cape Town for her most recent visit on the 16th of January, with an expected arrival date of the 23rd of January.  This ship was eagerly awaited, particularly for her delivery of fresh fruit and vegetables because the previous shipment was on the 19th of November last year.   However, on Tristan not everything works to plan.  The ship was more than half way across when she encountered engine problems, and had to turn back to Cape Town for repairs.  She departed Cape Town for the second time on January 25th, and finally arrived on the 31st of January, eight days later than expected.  Weather conditions were good enough to get the passengers off that evening, but it was not until the following Monday, the 4th February, before it was possible to start unloading some of the fresh cargo.  Hence, it was some 10 weeks from the last delivery in November to the present one.

The fresh produce was eagerly awaited.  The fruit and vegetable shelves were empty, and islanders were looking forward to stocking up with some healthy food.

Unfortunately, the story does not stop there.  When the first pallet of fresh goods arrived outside the shop, it was found that there was some mouse damage.  In particular, a mouse had eaten its way through some of the sweetcorn, and evidently the cold conditions of the chiller on the boat eventually became too much for the stowaway, because the carcase of the offending rodent was there to be found.

This caused the entire fresh consignment to be condemned.  Five trailer-loads of fresh fruit and vegetables were taken up to the dump at Pig Bite, where they were buried.

A sorry sight – inside the Tristan shop with an empty Fruit and Vegetable counter

There was a similar event with a shipment just before Christmas in 2016.  On that occasion some frozen pig products had been loaded in Cape Town on top of a pallet of fresh fruit, which had then been placed in the chiller unit on board the ship.  The unloading of the ship was delayed by bad weather, the pork thawed and seeped all over the fruit, and the consignment was condemned.

Wearing my hat as agriculturalist, it does seem to me that these two incidents send a very clear message.  This simple message is that it is so important for the island to take seriously the concept of becoming self-sufficient in all possible crops, in order to reduce to the minimum the reliance on imported fresh products.  It is a shame that the islanders have to go without fresh fruit and vegetables while the slow evolution of change takes place.






Visiting boats


We travelled back to Tristan da Cunha early last September, after a long and busy period of leave.  It all worked in very well (at least it has done so far!).  My two year contract was extended for a couple of months, which in turn meant that we had a generous amount of time back in Scotland (and France, and England).  It also meant that I could run ‘hands-off’ on our farming operations on the island, as a sort of trial run, – as well as lining ourselves up for no fewer than four summers in a row!

Through the next four months, we gradually came out of winter in the southern hemisphere, and life continued pretty much as normal.  Farming events continued to take place, expat staff continued to arrive and to leave, and whenever the weather was suitable there were fishing days, harvesting the Tristan Lobster.  However, there was one action that did not take place for that whole time.  There were no visiting ships.

To clarify.  The two fishing factory ships that are operated by the South African company that holds the fishing concession visited as normal.  Each in turn, they arrived off the island, unloaded their cargo onto powered rafts, went fishing, backloaded the packed + frozen lobster from the island, and returned to Cape Town.  These are regular ships, not really visitors.  And in this whole time, there were no visiting ships – no cruise ships, no visiting fishing boats, not even a lonely yacht!

On Friday 4th January, that all changed.  We have three South African engineers working on the island for some months, and for almost four weeks they are pretty much working on their own because the whole island is on holiday.  When they went down to the harbour at 6.30 in the morning to start the day’s work – for the first time ever there was a yacht tied up in the harbour!

Faustin’s Dream in Tristan Harbour

Why would it have been the first time that a yacht tied up in the harbour?  The island authorities always instruct visiting vessels to anchor off; they are never allowed to come into the harbour.  The harbour is extremely shallow, and although it may for a short time have sufficient depth for a shallow-draft boat, when the sea is calm, as soon as any swell enters the harbour it becomes untenable because of the highs and lows that the swell brings.   Some three years ago, contractors carried out a project to deepen the harbour, before which it would certainly have been impossible for a yacht to tie up inside, no matter what the sea conditions.

In the case of the yacht last Friday, it appears that they tried to radio a couple of times shortly before dawn, to check mooring instructions, but since they did not receive a reply they came all the way into the harbour and tied up.  There were some special circumstances, in that they were very short of water and they were running out of food and fuel.  They were on a passage from Brazil to Cape Town, and they had decided to put in a detour to lay in some stocks.  The shop was opened up for them, someone helped them to some cans of diesel fuel, and with typical kindness islanders gave them bread, potatoes and eggs.

Faustin’s Dream heads off to continue her passage to Cape Town

The yacht, called Faustin’s Dream, was a Bavaria 44, with two crew on board – a Frenchman from Lyon and another from La Réunion.  The voyage had started in the Mediterranean, and after passing through Cape Town they were heading eventually for Réunion.  They left Tristan on Friday afternoon, and we wish them a safe passage.

The following day, we had another visitor!  This time it was the Falklands Islands registered fishing boat the Argos Vigo, that had come to Tristan waters to go south and fish on some of the sea mounts south east from here.  They came here to pick up two island observers, which always accompany fishing ships when they are working in Tristan waters.  So, after 4 months of no visiting vessels, we have two in two days!

Argos Vigo, just before picking up her fisheries observers





Mice on Gough Island

Tristan da Cunha is remote, by any standards.  But within the archipelago that Tristan encompasses, there is an island that is considered remote even by the people of Tristan. Around 220 miles further south from Tristan is Gough Island, named after Capt. Charles Gough of the ship called the Richmond, who discovered it in 1732.

Gough Island is around 13 km long and 5 km wide.  It is home to around 10 million seabirds as well as two species of land birds – the Gough Bunting and the Gough Moorhen.  In recognition of Gough being a hugely important place for bird life, with a unique largely unspoiled habitat, the island became a UNESCO World Heritage Site in 1995.  It’s classification was added to by being joined by Inaccessible Island (another small island in the Tristan archipelago) in 2004.

Gough Island is uninhabited.  However, for the last 62 years the South African Weather Service has had a lease arrangement with the Tristan Government, and during this time it has maintained a scientific base on the island.  Teams of staff spend an uninterrupted 12 months on the island, the main purpose of which is to monitor weather conditions in order to help with the forecasting of weather in southern Africa.  In addition to the meterologists, the team includes engineers and a medic. There are also normally three staff from the RSPB (Royal Society of the Protection of Birds) who are bird scientists, and whose job it is to monitor the bird population on Gough.

The South African met station on Gough Island             Photo – Richard Hall

The importance of Gough can be seen, for example, in the fact that 99% of the world population of Tristan Albatross nest on the island, and 100% of Gough Buntings nest there.  Both species are critically endangered.  There are also populations of a large range of other Albatross, Shearwater, Petrel and Prion species, some of which are also classified as being endangered.

Tristan Albatross and chick                                                                      Photo – Steffen Oppel

Around 2006, the use of camera traps was able to prove conclusively what a few observers had already suspected.  This is that mice were predating on the wild bird chicks.  Mice had been on the island for many years, probably brought there originally by sealers in the 19th century.  The mice lived in harmony with the bird population, their diet consisting of plant seeds and insects.  Then – they evolved into chick-eaters.  This evolution, the change in eating habits of mice, has been seen in a parallel situation on Marion Island, where by means of careful monitoring during the space of just four seasons, ‘normal’ mice had evolved into predators of bird chicks. The scale of this predation on Gough is enormous – in 2016 it was estimated that mice were responsible for the killing of 600,000 chicks.  Following a scientific study on Gough some weeks ago, this has now been revised and updated to 2 million chicks and eggs a year. There have been some quite gruesome pictures of groups of mice eating albatross chicks alive.  The interesting thing is that the parent albatross just looks on unconcerned.  One stab of the adult albatross beak could easily kill a mouse, and bear in mind that an adult albatross might weigh 2 kg as compared to a mouse of about 25 grams.  The problem is that the Albatross (and other species) have nothing in their genetic makeup to tell them that mice are dangerous.

Mice on an albatross chick – while the adult looks on                            Photo – Ben Dilley

The RSPB team stationed on the island, together with visiting specialists in September / October this year, came up with some alarming figures.  For example, they found that this year the population of the critically endangered Tristan Albatross reared just 309 chicks from of 1,435 nests – only 21% instead of the 80 – 100% that would be the target for the species to have a long-term future.

In recent years, just as there have been huge technical advances in camera traps and other monitoring devices, so also there have been major advances in rat and mouse eradication from islands.  Islands lend themselves to eradication programmes since, provided that strict bio-security measures are introduced and enforced, re-infestation can be prevented, whereas in any mainland situation re-infestation is inevitable.  There have been some highly successful island eradication programmes, including from South Georgia, Macquaire Island off Australia and Campbell Island off New Zealand.   All of these programmes have used helicopters with underslung spreaders that distribute pellets made of a cereal-based toxic bait.  The spreaders are standard agricultural fertiliser spreaders fitted with a small Honda engine, and the bait generally used is one of the second-generation anticoagulants called Brodificoum.

The world centre for this eradication work is New Zealand, and it was that country that the RSPB turned to when it set about the planning stages of an eradication programme on Gough Island.  Initially, the plan was to carry out the eradication programme in the winter of 2019, but this has now been postponed to 2020.  The winter months are chosen because it is at that time that there are no birds nesting, and the mice are keen to find all food alternatives – making them eager for the toxic bait that is used in the eradication programme.

In August + September this year, a small specialised team travelled out on the SA Agulhas 2, the ship used by the South African Government to conduct their annual maintenance and team-change visit on Gough Island.  This team was organised by the RSPB, and consisted of an eradication specialist and a specialist helicopter pilot (both from New Zealand), an aerial systems engineer, and a bird captivity and release specialist.  The purpose of the visit was to have a detailed look at the site so that they could modify and confirm a master-plan for the operation, in order to give this expensive operation the highest possible chance of success.

The interior of Gough Island showing ‘Hag’s Tooth’                               Photo – Richard Hall

The overall plan is that in the early winter of 2020, a logistical team will travel out to Gough Island, to take out stores and set up accommodation on the island – a team of around 30 people will be needed.  The bird captivity and release specialist will be in this advance party.  His role will be to set up a large aviary-type structure, and to capture a good number of buntings and moorhens to act as a security population.  If these species suffer from poisoning of the toxic bait, at least there will be a protected reserve of such birds in captivity, available to be released when the active bait is no longer present on the island.  The albatrosses and the rest of the sea birds do not pose a problem in this respect – the do not come to the island during this time of year, and in any case they do not eat while they are onshore.

Once all the on-island preparations have been completed, the dosing team will travel to the island on a second ship.  This team will include four helicopters (one as a reserve) and a whole team of specialist pilots.  The systems engineer sets out an electronic GPS-based grid pattern of the routes to fly to ensure 100% coverage – indeed each swath is arranged to give 50% coverage of the previous swath, thus arriving at a double dose of the toxic pellets for any given area.  Two applications of bait would be spread, ideally 3 weeks apart for maximum effectiveness.  The winter in these latitudes can be very severe, and it is anticipated that with any lull in the weather the team will have to work from dawn to dusk, to seize the opportunity before the weather closes in again.

No-one is pretending that the task will be simple.  Mice are more difficult to eradicate than are rats, partly because they can find protection from the weather (and the toxic bait) in all sorts of caves and holes.  The whole project is expected to cost in the region of £9 million.  The success of the project will be measured by two elements.  Firstly, 100% kill of the mouse population is needed.  If a single breeding pair remain, then the breeding birds will just have a short respite until the mouse population once again builds up to the present levels.  Secondly, it is vital that the bio-security arrangements in Cape Town and on the island must be so thorough and so effective that there is no possibility of the re-introduction of mice in the future.  I am sure that everyone involved in the project knows full well that they have just one chance to succeed.

A group of Yellow Nosed Albatross, nesting on Nightingale Island

Extraordinary people on TDC

With the development of the society in such a very remote place as Tristan da Cunha, going back over 200 years, it is not surprising that there are some extraordinary aspects to the people on the island, both as far as individual people are concerned, and also relating to how some noteworthy social customs have developed.  That is not, however, the limit to the incidence of extraordinary people on the island.  Some of the expat staff stationed here certainly fit into this category, and some of the visitors also deserve a mention.  All in all, it seems that through its extreme remoteness the island does nurture and attract people who are extraordinary!

Through the eyes of a visitor to the island, some of the working practices are remarkable.  In particular it is astonishing how all members of the community come together for specific work tasks.  For example, when a ship has to be unloaded everyone leaves their normal places of work and becomes part of the unloading team – working as a stevedore on the ship, manning the barges bringing cargo into the harbour, driving a relay of tractors and trailers from the harbour to the warehouse, unpacking crates, and being part of a human chain to stack boxes in the warehouse. There are other events when an ‘all hands day’ can be declared – for example when everyone is needed to replace a roof on a house.

Islanders teamed up to re-roof the church

There are also the examples of remarkable people in connection with the island fishing industry.  For the most part, fishing on Tristan means crayfish fishing.  Each boat is crewed by two men, and eleven small open boats go out on the days that have been declared as ‘fishing days’.  The boats make a very early start, the little boats wallow horribly in the water particularly when they are not making way when the pots are being hauled.  The boys leave the harbour at first light, and in the shoulder months the low temperatures and the chill factor can be really testing. Every man a hero!

Fishing boats coming back into harbour at the end of a long day

Once the crayfish are landed, they are transported to the factory.  The people who work at the factory are also remarkable.  During the week it is largely pensioners who do this work, some of them approaching the age of 80.  They may work for 8 hours or more during the day, or in the evening the factory siren may call them out for an evening shift of anti-social hours.  The Tristan fishing industry is dependent on this reliable and loyal work-force.  It is another example of the extraordinary people of Tristan.

It should not be thought that all Tristanians are alike – they may come together for specific tasks, but they are generally highly individual.  The population today is just 250 people, and I could probably detail them one by one to show how a high proportion of them are individually extraordinary – but that would not go down well on the island.  I must not be seen to have any sort of bias or favouritism!

At any one time, there are around 12 – 15 expatriates stationed on Tristan.   For example, at present these include three teachers, a doctor and a nurse, the Administrator, a finance man, a factory manager and engineer, a retail specialist, and an agriculturalist (me!), as well as a short-term postdoctoral researcher from the Natural History Museum.  Most of these expats are on 2-year contracts, except for the Administrator who is generally here for three years and the doctor who may be here for five months.  In a general sense, the expats can be described as being extraordinary.  They have committed themselves to spending a couple of years on a tiny island where the facilities are extremely limited (shops, restaurants, healthcare facilities, etc), where they leave behind family and friends, and for the most part where the opportunities for professional contact and CPD (Continuous Professional Development) are quite limited.  These privations are not for everyone!

As a result of Tristan’s location, deep in the South Atlantic, there are many scientists and specialists who come to the island.  In the course of the two years that we have been here somewhere over 140 people have passed through.  These may be fisheries experts, conservation specialists, seal experts or bird professionals.  They may be South African personnel going to Gough Island for a 12-month tour of duty, or the team coming off Gough after their 12-month stint.  They may be the construction staff who built the new health centre, many of whom had experience in Antarctica.  Or they may be specialists in seismology, volcanology, global magnetism or nuclear detection.  It is a real experience for the people on Tristan, both Tristanians and expats, to be able to have contact with all of these visitors, many of whom can be described as extraordinary.

Of special mention is the dentist from Edinburgh, who comes to the island every year for three week’s work, bringing her daughter with her.  Her much-travelled daughter slots back into the little school on Tristan, where she catches up with all her island friends.  This must be the most extreme example of taking your child to work with you!

A cruise ship at anchor off Tristan
Our dutch friends at the harbour, with their yacht at anchor behind them

We also have a small number of tourist-related people coming to the island.  A few small cruise ships make a visit, weather permitting, as do a small number of sailing yachts.  That gives us a further  chance to meet some more extraordinary people.  I am thinking here of the two Dutch men in a yacht, who stopped off to buy some groceries and then continued on to Melbourne and finally Adelaide, stopping off on the way at Les Isles de la Desolation.  I am also thinking of the young girl who sailed single-handed from Sweden to Tristan – real adventurers come to Tristan!  And how about the cruise-ship tour guide who came earlier this year – it materialised that before that job, she had joined her partner on a small wooden yacht deep in Brazil.  They sailed the ‘wrong way’ round Cape Horn, and in two years they sailed back to Norway – in fact she made history by becoming the first Norwegian female ever to sail through the North West Passage.  After passing eastwards through the North West Passage, they of course passed Baffin Island – this is the home of another extraordinary visitor we had here for a few weeks this year!

Yacht Lady Free ice bound going through the North West Passage (Photo Cecilie Evjen)
Yacht Lady Free approaching a Beluga whale (Photo  Jan Martin Nordbotten)





High-tech Tristan

Tristan da Cunha can not in any way claim to be particularly high tech.  In a practical sense, levels of both mechanisation and automation are well behind most other countries.  There is no system for the use of credit cards, and there is no mobile phone system.  Government and Departmental accounts have only just been digitalised, and the internet is not at all reliable, to say the least.

Yet, the island is home to some of the most high-tech installations imaginable.

The UN organisation CTBTO has a monitoring station on Tristan.  The Comprehensive (Nuclear) Test Ban Treaty Organisation was formed in 1996.  Over 180 countries have signed up to the Treaty.  In the original documentation there were 44 countries listed as being countries with nuclear capability, and signatures from all of these were needed before the Treaty could become Law.  It is noteworthy that 8 of these countries have yet to sign (China, Egypt, India, Iran, Pakistan, Israel, N. Korea and the U.S.A.)

World map of CTBTO installations

The history of nuclear testing goes back to 1945, when the U.S.A. tested a device in New Mexico.  Between then and 1996, over 2,000 tests were carried out worldwide.  Of these, 1,032 were carried out by the U.S.A., 715 by the Soviet Union, and 210 by France.  Between 1945 and 1980, nuclear tests have totalled 510 Mt (mega-tons), of which the atmospheric tests totalled 428 Mt – equivalent to 29,000 Hiroshimas.

Since 1996, there have been just 10 nuclear tests.  India and Pakistan each carried out 2 tests during a period of sabre-rattling in 1998, and North Korea has been responsible for 6 tests.  All of these tests were detected by the CTBTO.

This is the background to the CTBTO.  The monitoring station on Tristan is one of about 250 around the world, with around 320 eventually planned.  Clearly, the island is wonderfully well placed to host a monitoring station, in that any signals that are detected can be accurately triangulated with other monitoring stations in countries on either side of the Atlantic Ocean – and there are no land areas anywhere near that could provide the same service!

Each CTBTO monitoring station measures, with extreme accuracy, a number of parameters that are able to detect and record that a nuclear explosion has taken place.  The wealth of information that is generated is transmitted in real-time to the IDC – International Data Centre – in Vienna, where the central computer system can immediately identify that a nuclear explosion has taken place, and exactly the location of the explosion.

On Tristan, as is the case with all the other CTBTO monitoring stations, three distinct physical parameters are monitored.

  1. A network of sensors monitors infrasound waves, using micro barometers which are able to detect minute infrasound pressure waves.
  2. Air quality is monitored, the sampling being aimed at detecting evidence of nuclear activity as well as being able to determine the type of nuclear device.
  3. Seismic movement is detected by a group of 3-axis seismometers –  information from these instruments could also be useful in giving advance warning of active volcanic activity on the island.

The first category of sensors takes place on the Western Plain, beyond the Potato Patches.  There are five separate sensing units, each having four sensing hub.  Each hub has around 24 tubes radiating from it, like spokes of a wheel.   The purpose of this arrangement is to average out all variations in infrasound waves, to arrive at a true reading. Computer triangulation of the signals received by the five sensing units determines also the direction of the nuclear explosion.  Readings are sent by a microwave system to the station’s central computer, where they are computed and sent continuously via satellite link to Vienna.  One of the five sensing units also has a chamber in which, as well as the electronic package that looks after the infrasound information, there is a seismometer, ready to sense and calculate any tremor in the earth’s surface at that point.  As part of the fail-safe technology that is part of the station, whenever the cover is opened on the chamber notification is instantly sent to Vienna.

The western plain looking west, with a CTBTO sensing station in the mid-foreground   (Pic – Bernard Pronost)
Overhead shot of one of the sensing stations   (Pic – Bernard Pronost)

The remaining elements of the CTBTO station are all to be found in a cluster in the field immediately to the west of the Settlement.  For determining air quality, there are two distinct systems used.  The first machine is called Snow White, which is manufactured in Finland.  This unit samples 20,000 cubic metres of air each day, collecting all particles in the air onto a filter pad, which is then removed and compressed into a wafer by processing it in a hydraulic press at 400 bar pressure.  After 24 hours, the wafers are placed in a spectrometer, which is able to identify around 12 substances that are known to be produced by nuclear explosions.  The technology that is required in this process is impressive, and it requires temperatures below -220 Centigrade, and electrical voltages of over 2,000V. The second system is made in Sweden and is called Sauna.  This unit samples the noble gas xenon, and identifies the isotopes of that gas.  In the event of a nuclear explosion, the ratio between the four isotopes will determine what sort of bomb is being detected.

Snow White

Seismometers are also located in chambers nearby.

The CTBTO station is managed by a French company, with a French station manager on the island.  For the last two years, Leo Duval was on Tristan.  We have just had a handover to the new station manager Maxim Sanders, with Maxim Le Maillot actually doing the handover.  Maxim Le Maillot was Leo’s predecessor, so he knew well the island and the installation.  Each of these station managers are known on the island as “Frenchie”, which is a simple system for most of the year but which can cause a little confusion when there are two of them here!

Former Station Manager Leo Duval
A pair of “Frenchies” – new Station Manager Maxime Sanders (left) and former Station Manager Maxime Le Maillot (right)

There are two other monitoring stations on the island.    The first is a station that was set up in 2004 by Austrian Jurgen Matzka for the Danish Magnetic Institute.  Jurgen is now with the German Research Centre for Geosciences (GFZ) who now have taken over the station.  This station measures changes in the Earth’s magnetism.  Generally, these changes reflect changes in the Earth’s core, but they can also react to local influences such as the construction of the new hospital, or even someone with metal buttons on his jacket walking too close to the sensing unit.  The station is accurate enough to measure changes in magnetism of one thousandth of a degree, which Jurgen likens to kicking a football through a goal which is 500km distant!

Finally, in the same field there is a third monitoring station.  This one is operated by the USGS (US Geological Survey) and consists of seismometers that are specifically set up to monitor volcanic activity, earthquakes and landslides.  The information from these seismometers is continuously being monitored in the United States. The USGS was set up in 1879, and is set up to monitor a wide range of natural sciences around the world.

General view of the “high-tech” field








In the last few weeks a few people have asked me where the “Comments” section has gone.

I am not sure exactly where it has gone – but I am pleased to report that it has indeed gone.  With that out of the way, I will be able to continue writing and publishing relevent posts, without having to spend all my time deleting spam!

I have received a number of very interesting comments in the last two years, particularly from people who themselves were on the island years ago, and from people whom Bee and I know from other stages of our lives.  We will always be interested to hear from our friends from the past, on our usual email addresses.  If, however, you are ‘coming in from the outside’, I should now be able to receive comments on a new email address that I have opened for the purpose – penguins.potatoes AT   I may perhaps publish an occasional post that is simply an abstract of comments received.

Let’s hope that these steps have enabled me to shake off the scourge of the spammer!

Farming News

Part of my work on Tristan da Cunha involves keeping the islanders informed as to what we are doing, and why. It is important that I try to develop a general understanding of the steps that we are taking, the advances that we are making, and our overall objectives.

I have just sent out the following notes, which may be of interest off-island as well.

TDC Farming News                       Issue 3                          April 2018

Cattle Ear Tags

 I am sure that everyone has seen the new ear tags in the cattle, which were applied last week. There is a high-visibility tag in one ear, and a little button tag in the other ear, each with the same number. These tags will serve as an individual ID for each animal, and they will enable the Department to maintain full records of each animal from birth to death, including breeding details, treatments, and ownership details. All cattle on the Settlement Plain have been tagged. From now on, soon after calves are born they will be tagged.

Cattle owners may choose, if they wish, not to cut-mark their calves in the future since the ear tags will provide a clear identification of each animal.

Vannessa has a list of owners and numbers, which is available if anyone wishes to check what numbers their own cattle carry.

Cattle owners are asked to please notify the Department if they give or sell an animal to another person, so that the records can be updated. Also the Department needs to be informed in the event of the death of an animal, whether through slaughter or any other cause. Also, cattle owners are asked to please notify the Department in the event of the loss of an ear tag, so that a replacement tag can be fitted.

Cattle on the Western Plain with their new ear tags


As part of the Department’s programme of pasture improvement, a 4-acre plot just to the west side of Jenny’s Watron has been fenced off and reseeded.

The area inside the fence was sprayed off some three weeks ago, and in the last week the ground has been limed, fertilised, a seed-bed prepared, a grass seed mixture sown, and finally the area was rolled.

The seed mixture has been especially prepared for us by a specialist seeds company in Scotland, based on their experience of broadly similar conditions in the western Highlands. The mixture includes specific varieties of Italian ryegrass, perennial ryegrass and cocksfoot, with some white clover. These grasses are high-yielding and high-digestibility varieties. If we are able to obtain good establishment of these productive grasses they should go some way towards addressing the acute overgrazing that we see on the island (together of course with all the other actions that are needed, including the ongoing application of lime and fertiliser and the reduction in herd size)

If weather conditions permit, we hope to reseed a large area at Pigbite, where the alluvial deposits brought down by the floods a year ago currently represent a net loss of grazing land. It would be very good if we can in this way recover some of the land lost to the floods.

It is also intended to reseed the Hospital Field, once all the débris left by Gulliford Try has finally been cleared.

It was mentioned above that the reseeded area at Jenny’s Watron was rolled after sowing the grass seed. The reason for this is that rolling helps boost germination, and it helps grass establishment by conserving soil moisture. The rolling was carried out by an island-made machine comprising two recycled gas bottles welded together and filled with concrete – it is a perfect size and weight, and cost virtually nothing!

Our new pneumatic seeder being used for the first time to reseed a block of grazing land
Two empty gas bottles and ¾ tonne of concrete produces a perfect roller for the newly seeded area

Sheep Breeding

Our new burdizzos (bloodless castrators) arrived some weeks ago, and the Department spent a day selecting ten of the best ram lambs to be kept, and castrating all the rest. This operation should be carried out every year from now on. In the meantime we are hopeful that we can bring some fresh blood into the island sheep by using AI. This is a much more complicated procedure than cattle AI, and we are in touch with a specialist who may be able to help us with this breeding programme.

Gypsum for Potatoes

We had a very positive reaction to our notice about applying gypsum to the ground before planting potatoes, in order to improve cell structure and keeping qualities of the potatoes, with a likely reduction in the incidence of soft rot. An order is now being processed for two tons of gypsum, which will be sold through the Agrishop.

Winter Feed for Cattle

 A number of people have taken us up on the offer of seed and lime for the winter production of fodder crops in the Patches, these crops include swede, turnip and kale. The Department has also planted some of these crops in the Mission Gardens, to give us first-hand experience of the problems and potential for this sort of winter fodder production.

Fruit Trees

 We hope to repeat the programme we carried out last year for the import of young fruit trees – apples, pears and plums. However, our supplier from last year has just told us that he is only prepared to supply minimum quantities of one hectare (2.4 acres) per variety! We are looking now for a nursery that can be more accommodating.

a small plot of Dwarf Crinkly Kale in the Mission Gardens, – winter greens about to be available in the shop!]

Greenhouses and Gardens

 On a small scale, we are now in production of our winter crops including broccoli, cauliflower and cabbages, and for the first time crinkly kale should be in the shop this week. In the greenhouses, cucumbers and green peppers are in production, and we should be shopping tomatoes again very soon. We have some lettuces that are now ready, although we have had a bit of a set-back in that some lettuce varieties that we planted are not the varieties that it said on the packet. The intention is to grow salad crops, including lettuces and radishes, throughout the winter months.

A large consignment of produce was sold to the cruise ship Le Lyriol, and we hope to keep in touch with the cruise ships in order to produce to their requirements in future years.

We have quite a number of indoor and outdoor ornamental plants in the greenhouses, and it is intended to set up a day for these to be sold outside the Agrishop very soon.

Bee and I hope to be off on our annual leave on the Edinburgh – we wish everyone a pleasant winter with enough rain to obtain good grass germination without it being too much for personal comfort!

Alasdair Wyllie – Agriculture Adviser and editor of TDC Farming News

The Governor Visits Tristan

In the early days of January this year, we had a visit from the RMS St. Helena. This vessel also visited Tristan in April 2016. In both cases the itinerary was Cape Town to Tristan da Cunha to St. Helena, and the Royal Mail Ship has made the journey many times in the past. The 2016 visit was supposed to be the last such journey, on account of the new airport on St. Helena making the vessel redundant. However, the well recorded problems with the airport resulted in the ship making another last voyage this year.

RMS Saint Helena at anchor off Tristan

On both the 2016 voyage and the 2018 voyage, there was one particular passenger. In 2016, Lisa Phillips was able to set foot on Tristan for only a couple of hours, her time being limited because of weather conditions. At that time she was Governor Designate, on her way to be sworn in as Governor of the British Overseas Territory known as ‘St. Helena, Ascension and Tristan da Cunha’. This year she arrived on Tristan as Governor.

The Governor arrives at Tristan harbour, with a fishing boat behind

Ever since 1659, there has been a British Governor on St. Helena. To start with, and until 1834, the Governor was appointed by the East India Company, but since then the appointment has been made by the British Crown. Today, the Governor is appointed by the British monarch on the advice of Her Majesty’s Government. Meanwhile, on Tristan da Cunha, from the time of the settlement of the island in 1812 governance was carried out by the people of Tristan themselves, with the unofficial role of governor being taken by visiting clergy men who often stayed on Tristan for a number of years. This prevailed on Tristan until 1950, when for the first time an Administrator was appointed who worked under the direction of the Governor on St. Helena. This level of delegation is essential when you consider that 1350 miles of ocean separates St. Helena from Tristan, and in another direction Ascension Island is 1295 miles away from St. Helena.

The British Overseas Territories consist of 14 separate colonies, including Gibraltar, the Pitcairn Islands, The British Pacific Islands, and the Falkland Islands. Each of them has a Governor, who is the de facto Head of State.

Lisa Phillips is the 68th Governor of St. Helena, and the first female in that position.

It is with that background that the people of Tristan were looking forward to the forthcoming visit of their Governor. Preparations were made for a full 3-day 2-night visit, with a business and social programme that included a meeting with the Island Council and visits to all the places of importance, including the school, the new hospital, the old thatched house and the 1961 volcano, and with a number of receptions, lunches, a community dance, and so on.

On the island of Tristan da Cunha, no planning can be set in stone thanks to the uncertainties of the weather and the precariousness of the harbour, and as the planned arrival day approached and the weather forecast looked poor, some contingency programmes were arranged. The ship arrived on the 3rd, as planned, but it was not possible to get passengers off. The following day, the weather and sea state had improved but it was still marginal to be able to get passengers off the ship. The decision was made that the only people who would be allowed to come ashore would be the people stopping on the island, and the Governor. Around 150 passengers had to stay on the ship, in case worsening sea conditions prevented them getting back on board. So, in effect the Governor’s visit started around 10.00 in the morning, and her programme on that first day had to be severely modified and flexible – sea conditions were constantly monitored to make sure that she could get back on the ship and not be abandoned on Tristan!

The Governor prepares to leave Tristan, a RIB taking her out to the St. Helena

The Governor presided over a meeting with the Island Council, and she visited the school and Aunt Ellen, at 99 the oldest islander. In the afternoon, we were able to take her out west, to view all the damage from the land slips and particularly to view the damage to all the Patches at Red Body Hill. We also discussed many of the issues to do with the cattle and the overgrazing. During this part of the visit we had a radio message – the Governor had to be at the harbour by 4.00 pm, so we cut short her visit to the farming areas and delivered her quickly to the new hospital for her final visit of the day.

Her Excellency Lisa Phillips, CBE, Governor of Saint Helena, Ascension and Tristan da Cunha, presides over the meeting of the Island Council

The following day there was no possibility of anyone landing at the harbour, and the ship stayed in the lee of nearby Nightingale Island to see if conditions would improve. Meanwhile, the captain of the RMS was in contact with the operators of the vessel to see if the ship’s schedule could be modified the following day, to allow for a much later departure than had originally been planned.

The weather and sea conditions did improve, and the following day the Governor made it ashore again, as did the majority of passengers that were on the ship. This was a chance for the Governor to catch up on some of the duties that had been cut from her programme two days earlier. It was also a chance for many of the people from St. Helena (“Saints” as they are called) to renew old friendships on Tristan – the social links between the two islands are well established, and go well beyond matters of governance.

There is no doubt that the visit from the Governor was of great importance, partly because of the way in which this facilitated and enhanced numerous areas of understanding. This is reflected in the following statement that Lisa Phillips sent me for this article:-

“I was concerned to see some of the damage done following recent landslips and floods.  I deeply appreciate the way the community dealt with this demonstrating their usual pragmatism and dedication.  It is greatly to their credit that the road was made passable and that the potato patches were salvaged as much as they could be.  I was also interested to hear about the plans to improve pasture and reduce cattle going forward.  These are difficult but necessary decisions but I was glad to hear that there was commitment to protect resources for future generations.  I was struck by the way the Tristan da Cunha community comes together to consider what is best going into the future in the areas of agriculture, livestock, livelihoods etc.  As Governor of Tristan da Cunha I am committed to supporting decision making on island”

The massive landslip, as seen by Lisa on her visit

Cattle and Overgrazing on Tristan Da Cunha

It is not known exactly when the first cattle arrived on Tristan, but it was certainly in the very early days of the community in the early 1800’s. The Leader of the island then was Corporal William Glass, who had somewhat utopian plans for the structure of the social community which included shared ownership of all the island’s assets, including the cattle. However, this cooperative ownership idea was changed before long, and individual ownership was established. Some individuals built up quite large herds, and they profited by bartering the meat with visiting ships, in exchange for tea, flour, sugar, and hardware items. Overstocking rapidly became a problem, and cattle numbers were controlled by hard winters resulting in starvation and death. The worst year was in 1906, when numbers had built up to about 700 head of cattle, and the bad winter resulted in the death of around 360 individuals.

Individual ownership of cattle remains to this day. Every household has a quota of cattle, and these cattle are largely run as a herd, with the Agriculture Department carrying out some of the services for the cattle, including health treatments, fertiliser and fencing of the pastures, and the provision of bulls and AI. However, because the cattle are all individually owned it is not possible for the Agriculture Department to make any of the all-important management decisions, such as the selection and culling of animals for genetic improvement, and such as limiting overgrazing by means of herd reduction.

One of our new young Aberdeen Angus bulls

Efforts have been made in the past to improve the bad situation that had resulted from overgrazing. Back in 1975, a quota system was introduced, with each household being limited to 4 breeding cows. This was later reduced to 3 per household, and in 1983 it was reduced further to 2 per household.

Overgrazing, on the scale found on Tristan da Cunha, has resulted in a circle of negatives. Cattle have been undernourished, and the poor growth rates have meant that steers go to slaughter at well below optimum weights, and are kept far too long in the herd before slaughter resulting in animals being on the pastures for too long, thus there are too many mouths to feed on a continuous basis. The cattle themselves have to spend far more time grazing than they should, and thus they spend too much energy in the grazing process. On Tristan, another dimension is that the fact that the cattle are having to graze grass that is too short means that they are grazing grass that is loaded with volcanic grit which is very abrasive, and which wears their teeth down at an unacceptable rate, this itself resulting in early death. Meanwhile, the forces of grassland ecology have progressively resulted in the surviving grasses being those that are adapted to growing very close to the ground – the grasses that try to grow upwards merely get chewed down as soon as they rise from the ground. Also, with so little leaf area, the overgrazed grass takes far too long to recover and to start growing again when the stock are moved to another pasture. To this whole process can be added the shortage of nitrogen fertiliser being applied, and a very low pH because of no lime being applied to the grasslands (resulting in very poor grass growth rates). Lifetime stunted growth in the cattle, and fertility problems, are two other consequences of poor nutrition.  Altogether, the overgrazing has made the situation with both cattle and grass progressively worse, year after year. To this unhappy cycle you can add the effects of mineral deficiencies that are known to exist here, and a further dimension is the loss of roughly 10% of the grazing area as a result of the silt and rock slides that took place in the floods of April 2017.

Our new tractor spreading fertiliser on stunted grass

Nearly a year ago, I presented a report which went into great detail on the cattle crisis, and which listed some options that could be selected. This included the possibility of reducing the quota from two cows per household to one. The Department was obliged to carry out a referendum on the subject, which showed no public appetite for change. However, although the reduction in herd size was not at the time selected, the issue was widely discussed throughout the year, particularly when the condition of the cattle was visibly deteriorating. The matter came up to the Island Council once again just a few weeks ago, and the decision was made to reduce the quota from two cows to one. A brave and historic decision!

Lots of cattle – and very little grass

The benefits of this decision will not be immediate. The action to halve the adult cow quota will not be effective until the end of March 2019, to give people time to select and cull the surplus animals. Bearing in mind that the adult cows make up only about one third of the total herd, it will then take three years before the reduction in cow numbers passes through to all the young stock. Thus we are looking at a four-year programme of cattle number reduction.

Although there are very obvious economic and management benefits of greatly reducing cattle numbers and overgrazing, it is not possible to predict with any accuracy how the actual numbers will evolve. This is because it is a dynamic situation with many different factors involved. For example, the islanders may follow trends elsewhere in the world and reduce red meat consumption in favour of fish (which of course is plentiful here) resulting in a reduced interest in maximising individual ownership of cattle. Also, there is a declining human population on the island, hence there will be a decline in the number of households having a cattle quota. In addition, it can be expected that better grazing will result in faster growth rates, resulting in beef cattle reaching slaughter weight far quicker, so that at any given time there will be proportionally fewer young stock than is the case at present. This latter point is key – if the cattle reach slaughter weight quicker, they will be less time on the hoof taking all the costly inputs of medication, fertiliser, fencing, and so on. It is noteworthy that the two young bulls that arrived recently from South Africa, at 16 ½ months of age, were massively heavier than any of the island steers which are generally slaughtered at an average age of more than three years. This point was certainly not lost on the islanders, and the timing of the arrival of the new bulls, just a few weeks before the Island Council decision, was fortuitous in providing visual evidence!

Around the community, the feedback I am being given since the Island Council decision is that “something had to be done”.   It is interesting to reflect on the processes of debate and decision-making on the island. In brief, it seems that the ‘voice of the people’ is an essential element in the debate on important local issues, but that there is respect for the hard but sensible decisions that sometimes have to be made by the elected representatives on the Island Council.

Cattle on the overgrazed Western Plain