Boulders pictured here at Annagh Head Co Mayo, some weighing more than 50 tonnes were lifted by Atlantic storm waves, not tsunamis [Pictured: NUI Galway]
The massive boulders deposited at Annagh Head in Mayo, and possibly some other locations along the northwest coastline of Ireland were not caused by a tsunami, but by storm waves breaking on the foreshore for hundreds of years.
That’s according to research by Professor Paul Ryan from Earth and Ocean Sciences in the School of Natural Sciences at NUI Galway and the University of Oxford published in the Proceedings of the National Academy of Sciences.
“This study shows the enormous power of storm waves battering the foreshore over centuries, ripping boulders of over 50 tonnes from the cliff face, piling them 100 metres or more inland,” said Professor Ryan.
The researchers found that the huge boulders, some over 50 tonnes, which are piled at the top of a small cliff, got there due to battering from storm waves.
It had been speculated that many of the larger boulders along the west coast of Ireland had been uplifted by tsunamis, but in 2004, the late Professor Michael Williams argued that the boulders on the Atlantic cliffs of the Aran Islands were due to storm waves, not tsunamis. This thesis caused caused considerable international debate at the time.
The researchers here set out to resolve the debate as to whether the large boulders had been moved by tsunamis or storm waves. They used computer simulations, hydrodynamic equations, as well as oceanographic, historical, and field data. These found that the boulders are a cliff-top storm deposit.
Northeast Atlantic storms can produce waves of over 60 metres, which are capable of lifting massive boulders. This knowledge is important in the context of climate change, the researchers said.
Shorelines are becoming more vulnerable and the ability to understand these piles of boulders along the west coasts will help us understand how much more vulnerable we actually are to storms, the researchers said.
Irleand’s native Atlantic salmon returns from its feeding grounds off the Faroe Islands or western Greenland to spawn in the river of its birth. Photo [RTE]
The Atlantic Salmon is one of Ireland’s iconic species, celebrated on our stamps, coins and in the stories that we read to our children.
Yet the numbers of this powerful, tenacious migratory fish have declined by 60 per cent over the last 40 years and there are real fears that the conservation measures underway may not save the salmon from extinction in the long term.
Dr Niall O’ Maoleidigh, fisheries scientist with the Marine Institute, and was my host for recent visit to the Marine Institute Salmon Research Centre just outside of Newport Co Mayo. Niall told me that records are available that show how bad things have become for the native Atlantic salmon.
The Research Centre at Newport has been a base for research on the salmon since 1955. It lies lies just north of Clew Bay, and at the base of the Nephin Beg Mountain Range in an area of stunning natural beauty.
The site is located at the juncture of two connected lakes, a saltwater lake called Lough Furnace that connects to Clew Bay and the Atlantic Ocean and a freshwater lake, Lough Feeagh that provides access to the upriver salmon spawning grounds in the Nephin Beg Range.
This means that all fish movements upstream and downstream from sea to river, and river to sea can be precisely counted using salmon traps.
The adult salmon start to arrive back from their feeding grounds in the Faroe Islands or of western Greenland in the month of June. Some adult salmon may have migrated more than 4,000 miles across open ocean to get home to arrive back at the Burrishoole river.
I went for a walk with Ger Rogan, a researcher at the Marine Institute, who is in charge of the fish census, or counting, programme. Ger showed me the salmon trapping facility and explained how it works.
On the edge
The scientists at Newport know that there are some 600 adult fish associated with the Burrishoole river. That indicates a population living on the edge, as 600 is also the so-called conservation number for this river, meaning the number of adult fish needed to replenish the population.
The Burrishoole river is an index river for the other 144 Irish salmon rivers. This means that the trends affecting this river are seen as indicative for native salmon generally. This suggests salmon across Ireland are living on the edge too.
Pat Hughes, is the rod fishery manager of the Burrishoole fishery and a local man, and he is concerned about the fall in salmon numbers since he began as the fishery manager in Newport in the late 1980s.
I spoke to angler Brian Lovering from Bristol who has been coming for 20 years, despite the steady fall off in salmon numbers. He said he was attracted to the west of Ireland’s unique charm and the friendliness of its people.
Saving the salmon, will require adherence to the strict conservation plans for each of our salmon rivers, added to strong international cooperation to identify and deal with the problems this magnificent fish faces while feeding out at sea.
A large, widening crack has appeared in the Larsen B Ice Shelf [Credit: British Antarctic Survey]
If a 180 km crack was appearing across continental Europe there may be a sense of public panic. Well, that’s just what is happening across another continent, in Antarctica, where scientists early this year spotted a crack in a lump of floating ice called the Larsen C ice shelf, which is about twice the size of Wales.
A secondary crack, or fork, has now appeared in Larsen C, leaving just 20km of solid ice left preventing it from total collapse. Scientists believe that nothing can now stop the collapse of Larsen C, and when it does break up it will be even more dramatic than the break up of the nearby Larsen B ice shelf in 2002.
In February, scientists at the British Antarctic Survey reported that they had found a large crack, about 180 km – about the distance between Dublin and Galway – in an ice shelf called the Larsen C Ice Shelf.
This crack has been monitored by scientists over the past few months and they have found that it is widening. More recently, a fork has split away from the main crack, and this secondary crack is heading straight for the open ocean.
The continent of Antarctica is famous, among scientists at least, for having several large shelves of ice around its coastline. These ice shelves are huge, floating platforms of ice, which form i the ocean and are fed ice from the continental landmass.
The Larsen C ice shelf is part of the larger Larsen ice shelf, which is one of the largest in Antarctica and has been breaking up now for a number of decades. The Larsen B, ice shelf, which was about the size of Rhode Island, some people may recall, broke away in 2002.
The area is closely watched by scientists interested in climate change because the western side of Antarctica is the fastest warming area of the world, and an indicate of how fast climate change is happening.
The ice shelves of western Antarctica were stable for 10,000 years, and it is only in the last 30 years that they have started to break up.
Scientists are very concerned, as with just 20km of ice for the breakaway fork to travel to get to the sea, the breakup of Larsen C appears to be close. When Larsen C breaks away, it will produce the largest iceberg in history, which will be cleaved off the Larsen ice shelf to float off into the southern ocean around Antarctica.
The fact that ice shelves float in the ocean means they are susceptible to changes in ocean temperature. Scientists know that the temperature of the oceans is heating up, and this heat is being transferred, they believe, to the bottom of ice shelves, which can make the ice unstable, fracture and break.
There have been cycles of ice shelves forming, and breaking away throughout Earth’s history, with repeated cycles of warming and cooling. At one point, for example, during the last ice age a large ice sheet existed off the west coast of Ireland.
What is worrying scientists is that the current fracture of Larsen C is mimicking the processes that led to the breakup of Larsen A and B. In those cases there was destabilisation of the front of the ice shelf, where the ice cliffs – as big as the cliffs of moher – meet the open water.
Scientists, like Dr Paul Dunlop, who has studied glaciers, and is based at the School of Geography and Environmental Sciences, Ulster University, Coleraine, is worried that what’s happening could be a sign of something bigger, and far more serious.
Another worry is that if the Larsen ice shelf breaks away that this will expose land based glaciers to the open ocean, meaning they will melt faster.
At the moment, the ice shelves in the western Antarctica are acting like a buffer between the glaciers and the sea, but if that goes, it may be something akin to pulling the plug out of a bath.
It tells us that the waters underneath the ice shelves in the western Antarctica are warming. That is worrying because the deep waters around Antarctica were considered to be the last ocean locations to experience global warming, but that now appears to be happening, as deep cold water, cycles up and is warmed.
There will still be climate deniers that will say that the breakup of Larsen C is simply part of a cycle of the formation and breakup of ice shelves that has gone on for millions of years, and that it is not linked to climate change. However, this view is simply that and it is not remotely credible to climate scientists.
Climate scientists believe that the deep ocean waters around Antarctica are starting to warm and that is the source of the problem. This is part of a pattern going in recent decades not just in Antarctic, but around the world, with Alpine and Himalayan glaciers retreating and the Greenland ice sheet thinning for example.
Earlier this year, a British scientific team had been on the Larsen C ice shelf, surveying the seafloor beneath. The information they gathered, and other data, suggested that a break up was likely, so they decided not to set up camp on the ice as would be normal practice. Instead, they made one-off airplane trips from the UK’s Rothera Research Station, as it was considered too dangerous to stay.
It’s getting pretty dangerous for scientists on Antarctica, especially those working on the ice shelves around the continent. In January, the Halley VI British Antarctic Station was shifted – on skis – to a safe remove on health and safety grounds as a result of a crack in the Brunt Ice Shelf that was growing in size just to the north of their futuristic modular facility. The designers deliberately designed the base so that it would sit on stilts with skis and could be moved if required.
Dr Louise Allock, senior lecturer in Zoology at NUI Galway has visited Antarctica for her research into octopuses, corals and sea pens many times over the last 15 to 20 years, and was on a research vessel in the southern ocean off Antarctica when the Larsen B shelf dramatically collapsed in 2002.
She told me what scientists will be watching closely – as the Larsen C collapses – so see whether this has the potential to cause large scale ice shelf collapse.
Listen to discussion on the plastic problem in our seas on Today with Sean O’Rourke RTE Radio 1 (broadcast, 8th March ’16)
Plastics rubbish in our oceans is becoming a huge environment and health issue (Credit: The Daily Telegraph)
Plastic is all around us, in our clothes, glasses, computers, phones, toys and the packaging for food and drink products. Behind most election posters we looked at recently, there were strong plastic cables, holding those posters in place.
Plastic is lightweight, flexible, clear, opaque, almost unbreakable, and cheap to manufacture. It is a wondrous modern product, but it also has a dark side.
In Ireland we are producing in the region of 210,000 tonnes of plastic per year. Yet, we only recycle 36 per cent this plastic waste. That means that more than 100,000 tonnes of plastic here each year ends up buried in landfill sites, where experts say it could take 1,000 years to breakdown, or it finds it way to the sea.
Scientists in Ireland, and elsewhere, have grown concerned about a ‘steady stream’ of plastics entering our oceans and how that is affecting marine life. The evidence now emerging suggests that plastics are disrupting the balance of marine life to such an extent that it presents a real threat to all life on Earth.
About 45% of plastic waste is sent for burning, or waste-to-energy, as some would call it, while 15% or 30,000 tons is sent to landfill each year. The new Dublin ‘Waste-to-Energy’ plant due to open at Poolbeg in 2017, operated by Covanta, may help if it takes plastic waste that currently ends up put into domestic black bins – about 20% of all plastic waste.
Currently municipal solid waste, including plastic waste is sent for burning to European incinerators. Dealing with the plastic here, is in line with the proximity principle – that waste be dealt with as close to source as possible. It will also create jobs.
However, Repak are keen to say to people that they want more plastics put in the recycling, green bin, and not in the black bin, as some still do.
The amount of plastic waste is growing year on year by about 4% so this is not a problem that will be going away. The dumping of plastic waste is a big problem, according to a spokesperson for Repak (Ireland’s only industry-funded packaging recycling firm) with 80% of marine litter being plastic.
Repak that they are seeing less newspapers these days, and more cardboard (as a result of Internet shopping) and more plastic.
It is relatively easy to sort plastic bottles, he said, as they use optical sorters, which spot a bottle on a conveyor line and an air nozzle shoots the bottle off.
Interestingly, he said that some of the worst plastic packaging they have to deal with are rasher packs as they are made from a number of different plastic laminates and are very hard to break down.
This difficult mixed plastic is, however, useful as a ‘solid recovered fuel’ which is used as a replacement for coal in cement kilns.
All of the cement kilns in Ireland use this SRF and this is helping to reduce the amount of coal which we have to import – so plastic is not all bad,
Plastic products are everywhere in our modern societies, as manufacturers are attracted to its durable, inexpensive properties (Credit: http://www.aboutuganda.com)
Plastics products have been ubiquitous since around 1939, as during WW11 plastics production increased to replace scarce natural materials such as rubber.
But, it wasn’t until 1972, when scientists, by accident, that plastic waste was becoming a huge problem in our oceans.
A group of marine researchers were on a vessel in the Sargasso Sea, in the North Atlantic Ocean, trawling the surface of the ocean to collect a brown algae seaweed called Sargussum why they were interested in studying.
When they hauled in their first catch, they fund lots of tiny plastic particles. Further tows brought in further ‘catches’ of plastic. The finding of plastics in such numbers in the centre of the Ocean was a surprise and a concern.
Now, scientists estimate that there is more than 268,000 tons of plastic in the world’s oceans, some collecting, due to currents, in huge agglomerations of rubbish, and plastic with nicknames like the Great Pacific Garbage Patch (GPGP).
In parts of the GPGP there are 2 million pieces of plastic per square mile of ocean. But, as well as what are called macro-plastics, which can end up inside fish and marine creatures, blocking intestines, there are micro-plastics, which are much smaller, sometimes tiny piece of plastic, which are problematic too.
There are other garbage patches too, one off California, one close to Japan.
Plastic waste can enter the sea from cities and towns on the coastline, but it can also travel along inland waterways from places far from the coastline.
A recent study in the United States, published in the top journal Science, showed how far plastic can travel to end up in the ocean The ocean is always downstream of illegal dumping sites, where rubbish, including plastics, first ends up in rivers, streams and lakes. That’s true in the US, and in Ireland too.
There is clearly a plastic problem in Irish rivers. For example, the River Liffey at the Strawberry Beds outside Dublin. When the river Liffey is low, plastic bags can be seen hanging like vegetation out of trees normally submerged in the water. This plastic will end up, like the Liffey’s waters, entering the Irish Sea.
The extent of the problem of plastic in rivers in developed countries can be judged from the few cities, like Los Angeles and Baltimore, where there are engineering measures in place to prevent waste, including plastic waste, from entering the sea.
In 2015, Baltimore caught 118,670 plastic bottles alone which were prevented from entering the sea, as they would otherwise have done. Baltimore, by the way, has about twice the population of Dublin. If we assume that Baltimore and Dublin are pretty similar economically, then there are more than 50,000 plastic bottles – conservative estimate – entering the sea at Dublin each year.
Microplastics smaller than 5 mm are entering the marine food chain (Credit: Archipelagos Institute)
Particularly damaging are micro-plastics; tiny pieces of plastic, which form when plastics are exposed to sunlight. micro-plastics are consumed by marine river life and then, when they make their way to the sea, by ocean creatures too.
Other research has shown that rivers and lakes in the US are full of tiny fibres of polyester and nylon, which are shed from clothes when they are laundered. The fibres are so small, they wash down drains into sewers and pass through the filtration system of wastewater plants, and end up out in the oceans too.
The fibres are swallowed by fish, and become lodged in their bodies, along with any bacteria or chemicals which may have been attached to the fibres in transit.
Ocean currents can transport plastic huge distances and computer models have shown that some plastics can travel more than 1,000 km in 60 days. So a piece of plastic could enter the sea in Dublin at the start of April, and end up floating off the coast of Lisbon by the end of May. It’s an international problem.
Marine life can mistake the larger plastic pieces for food, and plastics can thus get caught in their intestines. The fish or birds can’t get the plastic out of their bodies, and this hampers their ability to consume nutritional foods they need. They can ultimately end up starving to death. This has been reported in seabirds, turtles, fish and marine mammals.
When plastic pieces are smaller than 5 mm they are called micro-plastics. Micro-plastics act as an attractive solid surface for marine microbes, because nutrients, which the microbes need tend to accumulate on flat surfaces.
Marine creatures consume the micro-plastics, and the level of plastics then enters the marine food chain from the bottom up. There is on definite view on where this might end up, but certainly there are some very bad scenarios.
In May 2013, the two researchers were alerted when three beaked whales were found stranded on the north and west coast of Ireland. These creatures feed on squid in deep waters and little is known about them. They are rare, and it is highly unusual for three to be stranded within a few days and weeks of each other as happened here
An adult female was stranded at Five Fingers Strand in Donegal and two days later a whale calf was found washed ashore about 2km away. Then two weeks later, a second adult female beaked whale was found stranded at Ballyconneely in Co Galway. The immediate questions were why?
Post mortem results found that the two adult females had macro-plastics in their stomachs, while micro-plastics were identified throughout the digestive tract of the single whale that was examined for micro-plastics.
Simon Berrow told me in an email that it was “very disturbing” that micro-plastics were found throughout the digestive tract of the one beaked whale which was examined for micro-plastics, as these whales are offshore, deep-diving species which are very rarely even sighted by humans.
This was the first study, he said, that had directly identified micro-plastics, using a new technology, in the body of a cetacean species. Cetaceans are a group of 88 different species of whale, dolphin and porpoise. It suggests that even marine animals at the top of the food chain, feeding in deep waters, are ingesting significant amounts of micro-plastics into their bodies.
Simon is preparing a new research paper on the levels of micro and macro plastics in a range of dolphin species sampled in Irish waters over the last few years, and it will be interested to see if a similar result is confirmed again.
There can be many reasons why a marine creature gets stranded, or washed up on a beach. For example, there has been an increase in the number of dead dolphins washing up on the west coast of Ireland since the start of 2016, with 28 animals stranded, the second highest number every recorded for the first two months of the year.
Most of the strandings, scientists say, were in Mayo, Sligo and Donegal and the evidence showed that the dolphins died when they were caught up in the large fishing nets of foreign registered super-trawlers fishing in Irish waters.
Dolphins and other cetaceans (whales and porpoises) are under pressure in Irish waters from the nest of super-trawlers, as well as depletion of their natural prey – fish – due to over-fishing by the same trawlers. Add to that, the issue of micro-plastics and it’s no surprise to note that dolphin numbers are declining.
It will require a systematic, international response, from governments around the world, but, getting that, is always difficult.
It has been left to individuals to try and do something. For example, Boyan Slat, a Dutch guy in his early twenties, got a lot of publicity in 2013 for coming up with a plan to clean up the ocean using a V-shaped array of floating barriers.
The array was designed in such a way that the plastic pieces concentrated in the centre of the V, where they were then scooped up by a conveyor belt driven by solar panels and dropped in a collecting station for recycling. A modification of this approach will be used off the coast of Japan later this year.
Individuals can also help by signing up to an app called Marine Debris Tracker. This involves people on the beach logging litter finds, which is fed into a database which can better help scientists study ocean rubbish patterns.
Barrack Obama signed legislation in December last to ban the use of plastic micro-beads in cosmetics. Micro-beads are used as exfoliating agents, and in toothpaste. They are made from petrochemical plastics like polyethylene, and they are so small that they pass through waste water treatment plants.
The micro-beads remain in the environment for 50 years, and are causing a build up of micro-plastic pollution in places such as Lake Erie in the USA.
The Plastisphere is the term that scientists use to describe how organisms have adapted in the oceans and elsewhere to live in harmony with human-made plastics.
Microbes are naturally attracted to plastics, which provide a solid surface to cling to in open ocean, and an all day buffet, as nutrients collect there too.
Some of the microbes ingest plastic too, and these plastic-loaded microbes are in turn eaten by plankton, which are tiny floating living organisms, which are in turn eaten by larger creatures such as fish and whales.
The reasons that scientists are concerned is that they have no idea how the presence of plastics in the marine food chain will play out into the future.
There is a concern, for example, that this could make global warming worse. Normally, in pre-plastisphere days, the oceans were a ‘carbon sink’ which absorbed excess carbon which could otherwise causing global warming.
This happened because tiny marine plants absorbed carbon dioxide, they were eaten by fish and other creatures, who pooped, and this poop, with carbon in it, fell safely to the bottom of the ocean.
The evidence now shows that plastic in poop causes it to break up easier, and this liberates carbon before it falls to the bottom of the ocean. So there is more carbon available to contribute to global warming.
There is also concern that plastics may be carrying harmful organisms, such as the carol pathogen reported in Hawaii and the Caribbean in 2014.
The worry is that plastics could transport some kind of microbe superbug across the world by travelling via ocean currents. The plastisphere offers microbes the chance to eat well and travel the world, even if they are dangerous pathogens.
The suspicion has to be that while micro-plastics have not been proven by scientists to have detrimental effects on marine life, that is what’s happening.
By the time the definitive proof is available, we may have already done irreparable damage to our oceans, as once something enters the food chain, as micro-plastics have done, it is going to be very difficult to remove it.
Scientists are loath to say seafood is not safe, and it is an important source of protein, as well as Omega 3. It’s know that plastics also attract chemicals, some very nasty ones like mercury, which can end up in the food chain.
The consensus is that the risk from plastics, and the chemicals they attract is still low in fish generally and not enough to outweigh the benefits from eating fish But, if we continue the way we are going, that consensus could change.
Black smoke emerging from a hydro-thermal vent located on the mid-Atlantic ridge at the bottom of the Atlantic ocean (Source: Wikipedia)
Hydro-thermal vents, or ‘black smokers’ such as the one pictured here on the right are akin to small volcanoes, located at the bottom of our deep oceans.
These vents are home to undiscovered new animal species that survive without light and under great pressure.
The vents are also home to valuable metals, including gold, silver, copper and zinc.
Mining companies long knew of a ‘pot of gold’ at the bottom of the ocean at these vents, but they didn’t have the technology that would allow them to retrieve them.
That’s changing and new technology has allowed for the first mining operation at a deep-sea hydro-thermal vent to begin off the coast of Papua New Guinea.
In the next decade, it is likely that mining companies will have the technological capability to mine for metals at all hydro-thermal vents, even those that might be located at the bottom of a 3,000 metre column of water.
In these circumstances, it is crucial that a code of practice be put in place to guide companies that will seek to mine for metals at the bottom of the ocean, according to Dr Patrick Collins, marine scientist based at NUI Galway.
A workshop at NUIG will be held next week to try and put some international guidelines in place, and there will be contributions from scientists in many countries, as well as the mining company working at the Papua New Guinea vent.