Driving Down Pests – The Scientist, August 28 2017

 A computer model estimates that gene-drive technology could wipe out populations of an invasive mammal on islands. 

The government of New Zealand has a goal: to wipe out the most damaging introduced predators in the nation by the year 2050 through the Predator Free 2050 program. At present, rats, possums, and stoats have pushed native species such as the kakapo to near extinction and cost the country NZ$70 million (USD$50.5 million) in pest control measures and NZ$3 million (USD$2.2 million) in agricultural losses annually.
Acknowledging that the existing pest-control methods are not going to be enough for this ambitious project, scientists involved in the program have placed their hopes in engineered gene drives: a technology that involves meddling with the rules of inheritance and increasing the likelihood a deleterious gene will be passed to the next generation of a species. With the advent of the gene-editing tool CRISPR-Cas9, which allows scientists to alter DNA at precise locations using a single guide RNA and a DNA-cutting molecule called Cas9, the idea of using gene-drive technology to turn populations on themselves is now within reach.

In a study published August 9 in the Proceedings of the Royal Society B, researchers at the University of Adelaide have provided modeling evidence that gene drives could indeed be an effective means to wipe out entire populations of invasive vertebrates on islands.

“The most obvious potential advantage to using gene-drive technology for this purpose is species specificity,” says Luke Alphey, a genetic pest management expert at the Pirbright Institute in the U.K. and a cofounder of Oxitec, which is commercializing other genetic-modification methods to control insects. “Genetic approaches are transmitted through mating, so the direct effect is only on the target species.”

“That aspect alone is phenomenally powerful if we are talking about working in an ecologically fragile environment,” notes Alphey, who was not involved in the study. He says the current approach for managing invasive species consists predominantly of “harmful mass poisoning.”

In this recent study, the scientists chose to test gene-drive strategies on a simulated island population of 50,000 mice that they constructed in silico. Invasive rodents are likely responsible for the greatest number of extinctions and ecosystem changes on islands, according to a 2006 study. The house mouse (Mus musculus) in particular has been shown to have a devastating effect on seabird colonies in places such as Gough Island in the South Atlantic and New Zealand’s Antipodes Islands.

“We also focused on islands because in the long term . . . if this technology is deemed a good idea and acceptable by society, islands will be the first place it is carried out as it is easier to control,” explains coauthor Paul Thomas. “There’s a long way to go before we think about using it, but we wanted to conduct this study to see if it could be a possibility.”

Using a mathematical model, the scientists tested four CRISPR-based gene-drive strategies that could be readily developed based on what is within the current literature. The “heterozygotic XX sterility” strategy, also known as the “daughterless strategy,” involves using the gene drive to spread a male sex-determining gene so that all carriers develop as males regardless of their sex chromosomes. As a result, there will be a deficiency of females and the population will eventually crash.

“Heterozygotic XX sex reversal” is a similar technique, but contains additional genetic cargo that enables XX males to transmit the gene drive. “Homozygotic XX sterility” achieves population suppression through the infertility of homozygous females. The final strategy, “homozygotic embryonic non-viability,” causes embryonic fatality through gene mutation. All of these strategies were based on the basic CRISPR-Cas9 system using a single guide RNA.

The heterozygotic XX sterility strategy failed to present itself as a viable method, the researchers found, as carrier XX males are infertile and therefore unable to pass on the gene drive. The paper notes that this method would only prove effective on the basis of a continuous release of gene drives into a population, a process that would be costly and time-consuming.

The remaining three strategies proved capable of causing rapid population decline to the point of elimination. The researchers conclude that a single introduction of just 100 mice carrying one of these gene drives could destroy an island mouse population of 50,000 individuals within four to five years.

The researchers acknowledge that, for all of these strategies, the potential for the formation of resistant genes poses a problem, as has been observed in laboratory studies of mosquito gene drives. However, by conducting further tests that involved targeting several different DNA sequences with more than one guide RNA, they found that the possibility of this resistance is reduced.

Michael Wade, who studies population genetics and mating at Indiana University, is not convinced that this solution to resistance comes without consequence. He says that by using multiple guide RNAs as the authors suggest, one could increase the risk of targeting the genome at unintended sites, which may lead to other problems.

“Release of this type of construct raises the risk of reducing the target specificity of CRISPR-Cas9 and increasing the possibility of it jumping to a different species, possibly an endemic relative of the invader species targeted for eradication,” he writes in an email to The Scientist.

Concerns have been raised by members of National Academies of Sciences, Engineering, and Medicine in a consensus study report about the potential consequences of using gene drives for species eradication, including the unintentional spread to other populations, unpredictable negative effects on the ecosystem, and ethical implications. Thomas and his colleagues are “very conscious” of these worries, he says.

“I think this method definitely has potential but we do need to do more studies, have the conversation around whether it is safe to use, and see if the benefits outweigh the risks. We are keen to engage with all members of the community,” he says. His team has now begun conducting a mouse-based gene-drive experiment in the laboratory.

 

T.A.A. Prowse et al., “Dodging silver bullets: good CRISPR gene-drive design is critical for eradicating exotic vertebrates,” Proc Royal Soc B, doi:10.1098/rspb.2017.0799, 2017.

 

(First published on The Scientist online on August 28 2017. Available online at: http://www.the-scientist.com/?articles.view/articleNo/50180/title/Driving-Down-Pests/)

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What is the best antidote for a jellyfish sting? (Clue: it’s not urine) – The Guardian UK, May 9 2017

What should you do if a jellyfish stings you? Scientists have found that applying vinegar is the best solution, and that popular remedies including urine, lemon juice, and shaving foam could make the situation worse.

A recent study in Toxins, which investigated the efficacy of various remedies for stings from the Portuguese man o’ war (Physalia physalis) concludes that rinsing with vinegar before applying heat is the most effective treatment. The commonly recommended treatment of seawater and ice was found to cause more harm than good.

Dr Tom Doyle, a biologist at NUI Galway and co-author of the paper, conducted research on both the Atlantic and Pacific man o’ war. He said the findings represented a complete U-turn.

“For me it was certainly surprising as we have been recommending seawater and ice for the last 10 years,” he said. “But that’s the nature of science; we have to hold up our hands and say we were wrong. We went back to basics and tested different methods. There’s no doubt about our findings. We are absolutely 100% certain that vinegar does the trick.”

The scientists tested various solutions on sheep and human blood cells suspended in agar. The method of scraping away tentacles was found to increase pressure on the affected area, causing the stinging capsules to fire more venom into the victim. However, applying vinegar was shown to prevent further venom release, allowing the tentacles to be safely removed. Immersing the area in 45C water or applying a heatpack resulted in fewer red blood cells being killed.

In contrast, rinsing with seawater was found to worsen stings by spreading venom capsules further, while cold packs caused them to fire more venom. The infamous urine theory – popularised by an episode of Friends – was also found to aggravate stings. Baking soda, shaving cream, soap, lemon juice, alcohol and cola yielded similar results.

Although vinegar is used for many other jellyfish stings, the man o’ war has long been considered an exception, with many guidelines warning against its use. While it’s true that the man o’ war is different – they are technically a siphonophore and not a jellyfish – the scientists behind this research are now arguing that all stings be treated equally.

Biologist and jellyfish expert Dr Lisa Gershwin agrees that treatment with vinegar works, but expressed concern about the hot water recommendation.

“Hot water does take away the pain but this is a neurological process; it has nothing to do with denaturing the venom,” she said. “Fresh water activates discharge and by applying heat, you are dilating the capillaries and allowing venom to go further into the body.”

The study was prompted by an influx of man o’ war on European coasts last summer and built upon the findings of a study on box jellyfish conducted by the University of Hawaii at Mānoa. The researchers will now turn their attention to the lion’s mane jellyfish to determine if the same conclusions apply.

(First published in The Guardian UK. Available online at: https://www.theguardian.com/environment/2017/may/09/vinegar-best-antidote-jellyfish-stings-urine-lemon-juice-make-worse-study)

Parachuting birds into long-lost territory may save them from extinction – Science magazine, May 5 2017

Saving the Spanish imperial eagle was never going to be easy. This enormous bird, which once dominated the skies above Spain, Portugal, and northern Morocco, saw its numbers drop to just 380 breeding pairs in 2014, thanks to habitat loss, poaching, poisoning from farmers and hunters, and electrocution from power lines. Now, a new study highlights a potential way of restoring eagle populations to their former glory: dropping them into long-abandoned habitat.

One common approach for bringing threatened species back from the brink is to reintroduce them to the places they were last known to live. For example, the sea eagle in Scotland—which was hunted to extinction on the Isle of Skye in 1916—was successfully reintroduced in 1975 to Rùm Island near its last known breeding ground. But not all such efforts bear fruit: When scientists tried to release the same bird to its former range in western Ireland in 2007, the newcomers fell victim to the same poisoning that had done them in 107 years earlier.

“The tendency is to think that the last place that an animal was present is the best place for the species, but this isn’t always the case,” says Virginia Morandini, a biologist with the Spanish National Research Council’s Doñana Biological Station near Seville.

So Morandini and her colleagues teamed up with conservation biologist Miguel Ferrer of the Migres Foundation at Doñana to try a different approach. Along with the Andalusian government’s Spanish Imperial Eagle Action Plan, they introduced imperial eagles into a territory they last inhabited some 50 years ago, far from established populations. Their method had some strong theoretical underpinnings because relict populations that have been pushed into small, low-quality habitats—often the “last known address” of threatened species—are thought to have relatively low breeding rates.

From 2002 to 2015, the Doñana team monitored 87 eagles that had been released in the south of Cádiz province of Spain, some 85 kilometers from the nearest established eagles. Meanwhile, the researchers monitored a naturally occurring population of eagles in south-central Spain. When scientists analyzed the breeding success of the two groups—a proxy for how well the eagles might survive over the long run—they found that the relocated population produced nearly twice as many chicks, they reported last month in Ecology and Evolution. Morandini attributes their success to the ready availability of prey and breeding partners, as well as efforts to reduce threats from hunters and exposed power lines.

The results suggest such reintroductions can be helpful in recovering endangered populations, especially when natural range expansion isn’t a possibility, says Doug Armstrong, a conservation biologist at Massey University in Palmerston North, New Zealand. But Armstrong, who was instrumental in rehabilitation efforts in New Zealand of a honeyeater-like bird called the hihi, also warns that this method won’t work for every threatened species. Lots of factors can lead to failure: selecting an inappropriate site, unpredictable environmental factors, and stress after reintroduction.

Cornell University ecologist Amanda Rodewald says that—even with its upsides—the approach should be seen as a last resort. “With ongoing climate change and habitat destruction, we are likely to be turning to [reintroduction] methods more and more,” she says. “However, taking proactive conservation steps such as habitat protection before a species becomes critically endangered is always going to be the most cost-effective and successful approach.”

(First published by Science magazine on May 5 2017. Available online at: http://www.sciencemag.org/news/2017/05/parachuting-birds-long-lost-territory-may-save-them-extinction)

Enniscorthy’s new social housing will be the first passive house scheme in country – Enniscorthy Guardian, December 10 2016

Enniscorthy will receive €1.5m in government funding to purchase eight new passive homes in what is the first scheme of its kind in the country.

Based in Madeira Oaks in Enniscorthy, the homes have been awarded an A minus BER rating which means that they produce more energy than they require. They were constructed by Michael Bennett of Enniscorthy Passive Developments and will cost €190,000 each.

‘In the past while, we have been looking at ways of addressing the housing supply issue and asked people with ideas to get in touch. Michael Bennett contacted us and we liked his scheme in terms of the way it uses sustainable energy, reduces the need for heating and also addresses the issue of fuel poverty,’ said Senior Executive Housing Officer Liz Hore. ‘We were delighted to get word that we will receive €1.5 m to work with him.’

These homes typically have energy costs of about €200 per year in comparison with the average household bill of €2,500. According to Ms Hore, the first two will be ready to move into in the new year.

She added that the scheme has allowed them to deliver fast-track social housing in Enniscorthy.

‘We have been discussing about the need to accelerate the delivery of social housing. These passive houses are being turned around within eight months.’

This is first time that passive homes have been acquired for social housing in Ireland. According to Ms Hore, they are hoping that their scheme will serve as a demo model for others around the country. She said that passive homes are the way forward, due to their affordability and lower fuel requirements.

‘They are ticking all of the boxes,’ she said.

(First published in the Enniscorthy Guardian newspaper: print edition. Also available online at: www.independent.ie/regionals/enniscorthyguardian/news/enniscorthys-new-social-housing-will-be-the-first-passive-house-scheme-in-country-35270416.html)

Geese flock into Wexford for the winter – Wexford People, November 5 2016

Five hundred Greenland white-fronted geese touched down in Wexford last week following a treacherous 15 hour flight.

The visitors are some of the first of this year’s migrants to flock to Wexford Wildfowl Reserve, with an estimated 7,500 more of the species expected to fly in over the next few weeks.

‘It was a great sight to see them coming in,’ said Education Officer at Wexford Wildfowl Reserve John Kinsella. ‘At about half seven or eight in the morning, we could see them in the air flying over the Raven Woods before they landed next to the pond here.’

It was no easy feat for the birds to get here. According to John, the birds were subjected to strong winds, a non-stop flight and significant weight loss to reach their winter home.

‘They burn off half a kilo on the flight. That’s like us losing two stone,’ he said.

Over the next eight weeks, the remaining white-fronted geese will arrive in Wexford, where they will settle down until March. However, they cannot begin their journey until the wind direction changes to blow from the north.

‘The flight takes from 15 to 18 hours so they need the wind behind them to be able to do it,’ said John.

The Greenland white-fronted goose breeds in west Greenland and migrates via Iceland to winter in Ireland and Britain. They winter at less than ten sites in Ireland and the Wexford Slobs record the highest numbers.

Several thousand brent geese are also expected to arrive in the coming weeks and at peak time, John expects there to be a total of ’25 tons of geese’ on the lake at the Wildfowl Reserve.

In honour of the arrival of the birds, several events as part of Goose Week were organised by the Wexford Wildfowl reserve. These included dawn and evening watches and a walk at the Raven to see geese rise from their roost.

Hen harriers, godwits and plovers are some of the other birds observed.

(First published in the Wexford People newspaper: print edition. Also available online at: http://www.wexfordpeople.ie/news/geese-flock-into-wexford-for-the-winter-35176442.html)

Wexford Forest School initiative aims to bring learning to the great outdoors – New Ross Standard, October 15 2016

Bringing learning to the great outdoors is the aim of the new Wexford Forest School initiative which planted its roots in the Irish National Heritage Park recently.

The first forest school in the county to be funded by a local authority, it will welcome children from schools across Wexford to learn about protecting the environment, bushcraft, building shelter and identifying nature. It came together through the collaboration between Outdoor Park Manager Chris Hayes, Ciara Hinksman of Earth Force Education and local Forest Rangers Orla Gallagher and Shane Furlong.

‘There is a phrase that has been coined by Richard Louv called “nature deficit disorder” that is used to describe the negative consequences that occur when children don’t spend enough time outdoors. Parents and families are so busy with school, homework and dinners to be made so it can be challenging for them to get the kids out in the evening,’ explained Orla. ‘We are looking at this as a way of getting children to come and engage with nature and develop a passion for the outdoors. Kids are the future stewards of the environment. If they don’t learn how to care for it and appreciate it, who will?’

Children from Crossabeg National School are the first to dive into the project and will visit the park each Thursday over the next seven weeks. Their first visit to the site was met with great enthusiasm from not only the children, but the teachers themselves.

‘The kids had really positive feedback about the day and did everything with great enthusiasm. Even the third class teacher and principal Eamonn Codd were getting involved,’ said Orla.

The forest school leaders try to encourage children to engage with nature in a fun way through the medium of stories and songs. They also teach them about wildlife tracking, pointing out various species of plants and animals as they explore the site.

‘We teach in a way that is really accessible to kids,’ said Orla. ‘A lot of the time, they don’t even realise the amount that they are taking in.’

The children will also be given the chance to channel their inner Bear Grylls as bushcraft and survival skills form a big part of Forest School. Making and using tools and building fires are some of the areas that they delve in to and although participants are young, the rangers ensure that safety is the top priority.

‘We have about 22 students at the moment and there are at least three adults there at any one time,’ explained Orla. ‘A big part of what we do in the fire skill section is help them to develop their own risk assessment abilities. We teach them that fire is really beneficial as it keeps us warm and we can cook with it but also instil the risks in them such as the possibility of getting burned. These lessons will stand to children as they get older.’

Forest School programmes can run throughout the year, in all weathers, except for high winds.

The founders of Wexford Forest School all have one shared aim: to establish a regional hub for forest schools over time. However, they understand that it will take time for the initiative to grow and flourish. The current phase of Wexford Forest School is a pilot scheme with Crossabeg National School. Wexford County Council have provided funding of approximately €2,700 under Local Agenda 21 Environmental Partnership Fund for this first seven weeks. Following this, Orla said that they hope to spread interest to schools across the county.

‘The first bit of funding is for seven weeks but hopefully we might get some more next year all going well,’ said Orla. ‘Schools that are also interested in getting involved can also provide some funding themselves.’

(First published in the New Ross Standard newspaper: print edition. Also available online at http://www.independent.ie/regionals/newrossstandard/news/wexford-forest-school-initiative-aims-to-bring-learning-to-the-great-outdoors-35119379.html)

Rosslare jellyfish influx leads to red flag during sunny spell – Gorey Guardian, September 3 2016

Sunbathers in need of some cool relief during this warm spell are unable to take a dip at Rosslare Strand as reports of Lion’s Mane Jellyfish forced lifeguards to raise the red flag.

The red flag has been flying at Rosslare Strand since Thursday August 25 due to a large increase in jellyfish numbers. Water Safety Development Officer with Wexford County Council Tom Doyle said that Rosslare Strand is receiving a much larger amount of the creatures compared to beaches elsewhere in Wexford.

‘This is new for us. We have never experienced this quantity of jellyfish in Rosslare before,’ he explained. ‘They are quite unusual on Wexford beaches. It is more common to find a type that just gives a mild sting.’

According to Mr Doyle, bathers are being warned to stay out of the water in Rosslare for the foreseeable future. He also said that the lifeguards have received basic first aid to treat anybody who has been stung.

This summer, only several incidents of stings in Rosslare Strand have been reported.

Earlier this summer, warnings about the jellyfish were issued by Irish Water Safety following reports that they had been spotted in waters around the country. The creature delivers a painful sting which has been known to cause anaphylactic shock in certain people.

Irish Water Safety advise those who have been stung to go to their lifeguard when possible. To treat the sting, it is advisable to rub the affected area with sea water and seek medical attention if the pain persists.

(First published in the Gorey Guardian newspaper: print edition. Also available online at: http://www.independent.ie/regionals/goreyguardian/news/rosslare-jellyfish-influx-leads-to-red-flag-during-sunny-spell-35004778.html)