Every minute, the equivalent of a truckload of plastic enters the sea. Since 2004, humans have produced more plastic than we did in the previous 50 years combined. As the global population rises, our need for cheap and sturdy materials rises with it. The problem with plastics is that they are too sturdy. Every piece of plastic ever produced still exists somewhere in the world. Once the plastic has finally disintegrated, that is by no means the end of the problem. Plastics in the ocean break down into tiny particles known as microplastics. Such particles are found throughout marine ecosystems; from the stomachs of fish, to the stomachs of the seabirds who eat them.
Microplastics are not only dangerous, but also extremely difficult to clean up since they are spread out by currents all across the sea. In order to be classified as a microplastic, a piece of plastic debris must be roughly the size of your little fingernail or smaller. There are over 320 million cubic miles of water in the world’s oceans. For a sense of scale, you could fit roughly 320 million cars into a single cubic mile. Scientists have estimated that there are up to 50 trillion pieces of microplastics in the oceans. Given these figures, to say that removing microplastics from the ocean is no easy task would be the understatement of the century.
The reason that high levels of plastic in the ocean are problematic is that plastics have serious detrimental effects on the health of almost all ocean life. Over 800 species of animals have so far been shown to be negatively affected by plastic pollution. Considering that number was closer to 600 in 2012, it is safe to assume that the figure will continue to rise dramatically in the coming years. What’s more, almost 20% of the animals shown to be affected by plastic pollution are already classified as endangered due to human activity. There are two major ways in which plastics can harm or kill marine life. First, they can be ingested. When marine animals ingest plastic, the pieces can remain in their stomachs for the rest of their lives. As the amount of plastic increases, the space remaining in the stomach decreases, causing the animal to starve. In addition to this, most plastics are toxic to animal life, causing conditions like cancer and birth defects. Second, marine animals can become entangled in the plastic. If this happens at a young age, the plastic can restrict the growth of the animal, causing them to become severely deformed. This is seen most often in sea turtles. The worst offenders when it comes to entanglement are pieces of discarded fishing gear.
The phenomenon of marine life being caught by gear that has been abandoned by fishermen is known as ‘ghost fishing‘. Nets, hooks, lines, and cages continue to catch and kill fish long after the fishermen have stopped using them. Roughly 30% of all fish that are caught by humans are caught in ghost fishing gear. When you consider the sheer scale of human fishing, this percentage is astonishingly high. Leaving plastic fishing gear in the ocean, plastic or otherwise, is both short-sighted and despicable. Fishing gear is specially designed to kill as much marine life as it can. When it is under the control of a fisherman, protected marine life like whales and sea turtles can be avoided or released. Even so, fishing of any sort is devastating to endangered species. When the gear is abandoned, however, there is no targeting of species, leading to indiscriminate destruction of marine habitats.
There have been a lot of stories in the news recently about how companies like McDonald’s and Starbucks are ditching plastic straws. While this is a step in the right direction, straws only account for roughly 1% of the plastic debris in the ocean. In order to make a real difference, the companies would have to stop using plastic straws, containers, bags, cups, lids and everything else. This is a perfect example of what’s known as corporate ‘greenwashing’. If the public perception of a company is that they are trying their best to reduce the environmental damage they are causing, less people will boycott the company’s products, leading to higher revenue. Because of this, companies make the calculated decision to sacrifice a small portion of their profits in order to further their public personas as stewards of the environment. This is not to say that small steps forward like those taken by McDonald’s and the like are not helpful. Carlsberg have recently announced that they are ditching the plastic rings connecting cans in favour of glue dots. This is a positive development, since these connector rings have been shown to strangle and stunt the development of marine life and seabirds.
Plastic is not distributed evenly throughout the ocean. There are 5 major places, known as gyres, where currents have forced plastics to accumulate into huge expanses of debris. The largest of these gyres is called the great pacific garbage patch (GPGP) and contains about 2 trillion pieces of plastic. That’s 250 pieces of plastic for every human on earth in just one place. The GPGP is around the size of Texas and weighs about the same as 500 jumbo jets. The accumulation of plastic in gyres like the GPGP makes it somewhat easier to clean up oceanic plastic, but it is still a monumental challenge.
When he was just 17, Dutch aerospace engineering student Boyan Slat devised a huge U-shaped machine to clean up the GPGP that he believes could clear 50% of the plastic in just 5 years. The device uses ocean currents to move with the plastic, but since it is largely above the surface, it moves faster than the plastic, gathering it as it goes. It was deployed in the gyre in September of last year but was immediately faced with a slew of setbacks. The device was not travelling fast enough, allowing some of the plastic to escape, then a 60-foot section of the machine broke off, meaning that it had to be brought back to shore for repairs. Another issue with the device is that it cannot collect microplastics. However, it is important to gather up as many of the large pieces of plastic as we can now, since they will become microplastics in the future which will be much more difficult to clean up. We are in full damage control mode.
Despite valiant attempts to reduce our plastic consumption and remove the plastic we have already dumped in the ocean, it is highly unlikely that this problem will be solved any time soon. If anything, it will get much much worse. Humans have a history of showing up at a new location and decimating the native wildlife populations. When we first arrived in Australia, huge animals roamed the land. These included a 2-and-a-half-ton wombat, a flightless bird twice the size of an ostrich, and a predatory marsupial the size of a tiger. Within a few thousand years of humans showing up, 23 of the 24 animals that weighed over 50 kilograms had become extinct. We have spread all over the planet now, leaving only a few havens in which animals may thrive. The new frontier of animal extinction is marine life. Plastic pollution, overfishing and ghost fishing have devastated marine life and seabirds already, and the rate of destruction is only going to increase. All we can hope for is that people wake up to the genocide we are committing under the waves in time to save at least some of the majestic creatures who call the sea their home.
First Published in UCD College Tribune
Pando is the largest living thing on earth. Weighing 6,000,000 kilograms, it is about as heavy as a thousand African elephants or forty blue whales. When you enter Pando, you may hear a soothing sound like the beating of tiny wings. Pando is a grove of 47,000 quaking aspen trees, named for the distinct sound their leaves make in the wind. Every tree in the forest is genetically identical. This is because they are all parts of a single being, connected underground by a huge root system. We cannot be sure of Pando’s age, but based on its rate of expansion, coupled with a knowledge of historic climatic conditions, it could be up to 80,000 years old. If Pando is this old, it is not only the largest known organism on earth but also the oldest. In a painfully familiar twist, humans pose a serious threat to this gentle giant.
Pando’s name derives from the Latin for ‘I spread’ as Pando started life as one seed, then gradually spread itself out over an incredible 106 acres of Utah, an area equivalent to 1,700 tennis courts. Aspen spread through a process called vegetative reproduction. They send out roots underground which travel horizontally for as much as a hundred feet before sprouting into new trees. The roots then carry water and nutrients to the new sprout as needed. One reason why aspen clones like Pando can get so big is that aspen are remarkably quick to repopulate an area following a major destructive event like a forest fire. Aspen compete with conifers for light and nutrients, a competition they may well lose without the help of forest fires. Unfortunately for aspen, humans tend to put out fires wherever we can, leaving conifers to creep into the aspen’s territory. This is just one of the ways in which we are harming Pando.
For the last hundred years or so, humans have been hunting predators like wolves, bears and mountain lions in Utah and the surrounding area, leading to an increase in ungulate (hoofed mammal) populations. The main culprits are a species known as mule-deer, who eat young aspen trees before they have time to grow a thick bark with which to protect themselves. Not only does a decline in predator populations mean that fewer mule deer are being eaten, but it also means that they have become more likely to stick around and enjoy the good eating. With no predators to chase them away, the deer see no reason to move on and find a new feeding spot.
It does not help that the US forest service allows ranchers to graze their cattle on Pando for two weeks every year. Aerial photographs taken over the last fifty years show that Pando is in serious trouble. Given such data, it is extremely irresponsible for the forest service to allow any grazing at all. You may well be wondering at this point why I’m telling you all this. Pando is not like other organisms. While it is a single being, Pando is also a vast ecosystem which is home to a huge variety of animals from black bears to wild turkeys. By saving Pando, we are saving not only a biological marvel but also a forest and everything that lives within it.
A healthy aspen grove should have trees of all ages growing within it. As in a human community, it is far from ideal for the individual trees to all be the same age. If everyone in a town is over 80, there will be no youngsters to replace them when they’re gone, and the town will die with them. This is exactly what is happening to Pando’s trees. The director of the Western Aspen Alliance and Pando expert Paul Rogers has said that in many areas there are “no young or middle-aged trees at all” and that the trees that remain are “very elderly senior citizens”. Aspen trees can live anywhere from around 75-150 years old. Worryingly, the average age of trees in Pando is 130 years; if we are to save it, we are going to have to move very fast indeed.
So what can be done to save Pando? Paul Rogers recently conducted an experiment in which parts of Pando were fenced off to stop ungulates from getting in. The experiment showed very promising results, although, despite the fences being 8 feet tall, the deer were somehow able to jump over them in some places and damage the new shoots. Some have suggested that to save Pando, wolves need to be reintroduced into the ecosystem to kill the deer. The proximity of Pando to campsites and cottages makes this idea hard to sell. The evidence suggests that taller fences around larger sections of the grove and a ban on all grazing should allow new trees to flourish. Once a new generation of trees come up and live to maturity, Pando will be in a strong position to live on for years to come. However, it will also face the very real threat of global warming if we do not significantly reduce our emissions soon.
Pando’s downfall is emblematic of the large scale ecological and climatic devastation that humans have wrought on this planet. By altering certain variables, we may have sealed Pando’s fate without even knowing it was there. It is important that knock-on effects like these are understood so that we may avoid repeating the same mistakes. Pando is also a symbol of how, with a bit of elbow grease and a bit less greed, we can at least partially right many of the wrongs that we have done to the natural world. When you are responsible for a problem, it is your responsibility to fix it. We can save Pando. Maybe by joining together to preserve this one beautiful colossus, we can create a success story that can serve as a poster-child for conservation efforts around the globe.
First published in the UCD College Tribune
In November of 2018, Chinese scientist He Jiankui made an announcement that astonished the scientific community. He claims to have helped to make the first ever gene-edited babies with the use of a revolutionary technology called CRISPR. The babies, twins by the names of Lulu and Nana, were born to a father infected with HIV, the virus which causes AIDS. If Dr He’s experiment is successful, the twins will have an immunity to the virus. While this may seem at face value to be a noble goal, many believe that the risks involved outweigh the benefits.
Dr He’s experiments used a type of editing called ‘germline’ editing, meaning that any children that Lulu and Nana may have in the future will also carry this immunity. Germline editing involves making changes to reproductive cells. This means that any changes made to the individual’s genome will be passed on from generation to generation. This can be distinguished from somatic editing, in which the only person affected by the edit is the person who undergoes the procedure.
One reason why somatic editing is seen as more acceptable than germline is that people who undergo somatic editing have given informed consent prior to the procedure. While the parents of Lulu and Nana have given consent, the children themselves and any future children the twins may conceive have not consented to the potentially high risks. While HIV immunity could potentially be inherited by the descendants of these CRISPR babies, so could a myriad of unwanted and possibly even deadly side-effects.
Another concern that has been raised is that it is not clear whether Dr He’s treatment fulfilled an ‘unmet medical need’. With modern HIV treatments, someone who is carrying the virus can have the same expected lifespan as someone who is not and their chance of transmitting the virus to their children can be brought down to just 5%. Hence, geneticists worldwide have called for a moratorium on human germline trials. Critics say that gene editing technology has not yet been developed or tested sufficiently for use on human embryos. We simply do not yet know the long-term effects of genetic modification using CRISPR.
Despite a myriad of imaginable ethical hazards, CRISPR has the potential to revolutionize the biomedical sciences. CRISPR allows biologists to edit genetic information by using an enzyme called Cas9, which has the ability to cut strands of DNA. The process was pioneered in bacteria as a defence mechanism against viruses. Geneticists use CRISPR to target specific areas of genetic code and cut it in a specified region. Cutting a strand of DNA in the right place can cause a certain gene to be disabled, activated or replaced by one introduced by scientists. The possible applications of CRISPR range from curing cancer to eliminating malaria from mosquitos. One team at Harvard led by Prof. George Church even famously claimed that they will be able to ostensibly resurrect the woolly mammoth in the next year or two using the technology.
Some scientists, including mammoth-man George Church, have come out in defence of He. While Church had reservations regarding He’s level of transparency, he suggested that enough studies had been carried out that maybe it was the right time to end the moratorium anyway. While he accepted the risk of off-target mutations, he said that the risk ‘may never be zero’ and that Dr He had done enough to minimise it. This contradicts the views of most scientists and institutions, including a statement released by Francis Collins, the director of the National Institutes of Health. Collins denounced He’s work, saying, among other things, that ‘the possibility of damaging off-target effects has not been satisfactorily explored’.
Genes are extremely complex things. Locating a single gene and modifying it requires an extraordinary level of precision and even when it is successfully targeted it is impossible to fully predict the consequences. Though we have been studying certain genes for a very long time, we still do not know what the indirect effects of certain edits may be as no long-term studies of how edits affect the human body have been carried out as of yet. Such unintended effects are known as ‘off-target mutations’.
The final concern is perhaps the most serious. While CRISPR may in the future be used to treat some forms of cancer, it is possible that premature germline editing like the kind He carried out may actually increase the risk of cancer in people like Lulu, Nana and their descendants. Two recent studies have raised concerns about an off-target effect that CRISPR may have on a gene for a protein known as the ‘guardian of the genome’: p53. This protein is responsible for repairing or destroying damaged DNA. A mutated or ineffective p53 gene has been shown to be responsible for nearly half of all ovarian cancers and a significant portion of many other types of cancer too. CRISPR interventions activate p53, since DNA has been cut and must be either repaired or destroyed and p53 undoes the work CRISPR has done. The worry is that this could result in a kind of artificial selection on the cellular level, as CRISPR is more successful in cells with ineffective copies of the p53 gene, which are more at risk of becoming cancer cells. So far, only certain forms of cells have shown evidence of raising the risk of cancer when modified using CRISPR and no company is attempting clinical trials using CRISPR on these cells. Some scientists have called the recent studies concerning p53 a ‘cautionary tale’ since they may affect future CRISPR trials that are yet to begin.
CRISPR is an incredible technology that will surely be responsible for many breakthroughs in biological and medical science. It may someday give us powers that we cannot even conceive of today. However, that time has not yet come. It is imperative that we do not jump the gun. Dangerous, premature experiments like Dr He’s harm the public perception of gene editing and, in turn, harm the funding available for important research. While we should not give up on gene editing, we should also not use it to play with human lives until we know more about the benefits and the risks.
In the wake of recent studies showing how dangerously close to the brink we are when it comes to climate change, it is more important now than ever to seriously consider every possible alternative to environmentally damaging fossil fuels. One such alternative comes in the form of biofuels. Humans have been using biofuels for as long as we’ve been using wood to fuel our fires. In the last hundred or so years, however, we’ve begun to understand how plant matter can be converted into liquid fuels that could soon power a plane. In this piece, I’ll be looking at where biofuels are now and where they need to be if they are to significantly reduce CO2 emissions. I’ll be concentrating my efforts on recent attempts by the scientific community to make grass a viable fuel for transportation.
Grass is the most abundant plant on the planet. In my home country of Ireland, more than two thirds of all land is covered in naturally growing grass. If we could refine and perfect the process of turning grasses into fuel (grassoline), this could be a real contribution towards slowing the march of climate change. The problem right now is that it is expensive and inefficient. Many scientists in the field, however, think that given time and money, we could tap into this huge source of unharnessed power and perhaps help to save the planet in the process.
The reason grass in particular is being considered as a biofuel is not because it is necessarily the most efficient plant to use, but rather because of its abundance and willingness to grow in fields that are inhospitable to food crops, known as marginal lands. Another reason that grass is attractive as a biofuel is that it is not really needed for anything else. Other candidates for biofuels (like wood, sugarcane and soybeans) have the disadvantage of being useful for things like furniture, rum and tofu.
But why aviation fuel? One reason is that while cars are slowly turning electric, it is unlikely that planes will follow suit any time soon. This means that in the near future, cars could be powered by renewable sources whereas planes will continue to require liquid fuel. The other more pressing reason is that travelling by plane is far worse for the environment than any other mode of transport. This is down to two factors; first, planes are less efficient than other modes of transport in terms of emissions per passenger mile. Second, planes allow us to travel a far greater number of miles than we would otherwise be able to travel. The carbon footprint of flying from London to Hong Kong and back again is about a quarter of the average UK person’s annual carbon footprint.
The idea that we could use grass, algae and other plants to produce aviation fuel is not nearly as crazy as it sounds. The fossil fuels which we currently use are themselves made of organic matter that has, over a very long time, undergone a natural process called pyrolysis. Human beings have been using the process of pyrolysis for our own gain for thousands of years in the form of charcoal burning. Pyrolysis involves separating materials into their constituent molecules in the absence of oxygen. This means, very roughly, heating up the material to a specified temperature, covering it, and allowing it to separate into liquid, solid and gas. These products can then be refined into fuels. Recently, it has been found that microwave heating produces a higher pyrolysis yield than traditional methods since it can be done entirely in the absence of oxygen and at a very precise temperature. Another benefit is that the characteristic ‘hot spots’ of microwave heating aid in pyrolysis.
You might be thinking that grass is an important source of food for livestock. The beauty of using grass as a biofuel is that this resource would not be lost. The solid by-product of grass pyrolysis can still be fed to livestock. What’s more, by removing the liquid constituents, the feed can be preserved much longer than fresh grass cuttings. In the UK, biofuels already account for nearly 3% of all road and non-road mobile machinery fuel, but with the predicted change in efficiency given a few years, they could eventually account for a lot more than that.
Right now, scientists can only produce a few drops of biofuel from grass in the laboratory. Tests carried out at Ghent University in Belgium show, however, that there is a potentially very efficient energy source in grass if we can learn to harness it correctly. In April 2017, the researchers at Ghent found that a certain type of bacteria (clostridium) can be used to metabolize certain grasses into decane, a key ingredient in both petrol and aviation fuel. While this breakthrough cannot yet be used effectively, it is key knowledge that will inform future research into better biofuel technologies.
Hang on, you might say, if refining plant matter gives us the same fuel as we are already using, then why is it better for the environment? Surely biofuels release the same amount of CO2 as fossil fuels? This is indeed true. The difference is that the CO2 in living plants has only recently been absorbed from the air by the plant and is simply being released again. As the grass grows, it sequesters CO2 from the air. When it burns, that recently absorbed CO2 returns to the atmosphere to be trapped by the next batch of grassoline. Because of this, biofuels are said to be ‘carbon neutral’. With fossil fuels, the CO2 has been absent from the environment for a very long time, trapped underground. By burning it, we are releasing extra CO2 rather than what was already there.
A major obstacle to biofuel efficiency growth is that governments and companies are not willing to invest heavily in something that may not yield solid results for years to come. This is simply short-sightedness. The science will continue to improve. Lack of investment only slows down the process. The people who invest heavily now will surely see a huge return in a matter of years. Another well-known obstacle in the way of all renewable energies is the huge sums of money tied up in the fossil fuel industry. The industry is worth about 7 trillion USD globally. No wonder, then, that lobby groups are able so easily to sway policy-makers.
Biofuels are controversial among environmentalists, since they come with a number of downsides. Perhaps the most worrying is that every square foot of land which is used to produce the fuel is land that could instead be used to nurture biodiversity. Species are currently being lost so quickly as to constitute the sixth mass extinction in earth’s history. For me, using food crops like corn as feedstock is entirely off the table, since it opens the door to a future in which rich elites use corn-fed biofuel to fly away on their holidays while depriving poor people of food which is vital to their survival.
Another drawback is that biofuels are not very efficient when it comes to land use. According to Mike Berners-Lee, using solar panels instead to generate the power for flying would require 270 times less land than growing wheat for biofuel. The problem, however, is building a good enough battery. Right now, 1 kilo of jet fuel carries about the same energy as 20 kilos of premium lithion-ion batteries. One ray of hope came in March of 2015; ‘Solar Impulse 2’ began its attempt to become the first entirely solar powered plane to fly around the world. The journey was arduous and long for the two pilots. One of the pilots was named Bertrand Picard, a Swiss medical doctor who who was already the first person to fly around the world non-stop in a hot air balloon. Captain Picard of the USS Solar Impulse finally landed the plane in Abu Dhabi on July 26th 2016, from the spot where it had departed 505 days earlier.
Regardless of what figures like the US president may say, climate change is a very real and very serious danger. Biofuels are just one example of the many ways in which we can combat this danger, but they are one which will continue to grow in importance for years to come. The question is whether our money would be better spent developing renewable energies like solar and wind which require far less land and are thus better for wildlife conservation. When it comes to planes, however, grassoline may help to ease the transition to a low-carbon world. Every little helps in the fight against the huge and menacing entity that is climate change.
Whales are notoriously vocal animals. Indeed, the catalyst for the ‘Save the Whales’ campaign of the 1970s can be said to be the release of the album ‘Songs of the Humpback Whale’ recorded by bio-acoustician Roger Payne. This was the first time that the public was able to hear and appreciate the astonishing variety and beauty of the Humpback’s songs. This love affair with the whales came in the nick of time, since the humpback population had at that time fallen to a historic low. It is estimated that by the late 1960s, over 90% of humpbacks had been wiped out by human activity.
Since the early 1920s, a technique known as ‘reflection seismology’ has been used to locate reserves of natural resources such as oil, gas and salt. Reflection seismology operates on much the same principle as sonar. Sound waves are emitted which reflect off the sea floor and are then measured by an array of sensors. Using this technique, areas of the sea floor can be accurately mapped, and it is possible to determine whether natural resources lie beneath the rock.
Modern reflection seismology is carried out using huge arrays of seismic ‘airguns’. These airguns can produce sounds of up to 240 decibels, over twice the volume of a standard rock gig. What’s worse, this noise level is produced every 10 seconds, 24 hours a day. According to Oceana, a single survey ship may carry up to 96 airguns at a time.
Whales and dolphins use sound to communicate with each other and, in some cases, for the echolocation of prey. Although insufficient research has been conducted to ascertain the detrimental effects of seismic testing on whales, preliminary data shows that almost all cetaceans give seismic airguns a wide berth. Further, sightings of cetaceans fall significantly when seismic testing is being conducted in a given area. Even in the absence of solid data, mere common sense dictates that the levels of noise produced by seismic testing may well prove to seriously harm the hearing of cetaceans, as well as disrupting their feeding, mating and migratory habits. In any case, if reflection seismology is at all likely to damage already strained marine environments, it is imperative that we halt that practice before the damage is irreversible.
It is not just whales that are at risk. During periods of seismic testing, local fishermen have reported an increase in dead fish floating in the sea. Squid, crabs and fish eggs have also been shown to be harmed by seismic airguns. It seems, then, that as well as deafening and disorienting endangered whales, seismic testing is also harming their ecosystem and thus limiting the availability of their prey. One study found that the number of zooplankton – tiny creatures that are the backbone of marine ecosystems – fell by 64% within 1,219 meters of airgun activity. That is guaranteed to have huge knock-on effects not just for whales and dolphins, but for all ocean life.
On the 1st of February 2018, seismic airgun testing off the coast of Newcastle, Australia was approved by NOPSEMA. The tests, which will be carried out by Asset energy, are approved right up until the 31st of May, with the whale migration set to begin around the 1st of June. This has been met with serious resistance. Greenpeace Australia campaigner Nathaniel Pelle noted that “Whales and other endangered species do not adhere to the Gregorian calendar and do not know the difference between May 31 and June 1”. The fact that this must be noted at all speaks to the greed and short-sightedness of regulators and fossil fuel companies.
In December of 2018, the U.S. (under the command of Donald Trump) began extensive seismic surveys of the entire east coast. This happened despite vehement opposition from almost all U.S. environmental agencies and state governments. The area which the U.S. has begun to survey is the home and breeding grounds of the North Atlantic Right Whale, a species so endangered that there are less than 500 of them alive today.
A final and crucial point to consider is that even if seismic tests did not damage marine populations directly (which they certainly do), they are a gateway to offshore drilling, a practice which damages marine populations in a number of ways. First, there is a possibility of oil spills which, as we all know, can be cataclysmic events for marine ecosystems. Further, when the oil is successfully extracted, it will be burned as fuel, releasing carbon dioxide into the atmosphere and accelerating the already severe effects of climate change. Renewable energy sources such as wind, solar and wave energy are the planet’s last hope for any sort of meaningful recovery. One may consider it an added bonus, then, that these energy sources do not require that we seriously harm marine species while they attempt to recover from the immeasurable damage that humans have already inflicted upon them.
Beachapedia – Seismic Surveys
Gordon, Jonathan C.D et al. – A Review of the Effects of Seismic Survey on Marine Mammals
Greenpeace Australia – Humpback whale migration threatened by seismic blasts
Stone, Carolyn J. and Tasker, Mark L. – The effects of seismic airguns on cetaceans in UK waters