A Guide To Residential Wind Turbines

26 11 2009

Here’s my latest offering for Our Green Earth. I really enjoyed researching and writing this one and learnt a lot about the viability of wind-generated electricity in the UK. I hope you do too!

A Guide to Residential Wind Turbines

[Edit 3rd December 2010: Sadly, Our Green Earth no longer exists but the owner has very kindly handed back copyright of my articles to me. Here, for your reading pleasure, is A Guide to Residential Wind Turbines…]

A Guide to Residential Wind Turbines

Love them or hate them, wind turbines are here to stay. The Environment Agency aims to help the UK generate 15% of its electricity by using renewable, sustainable and clean sources of energy by the year 2020 (1) and one of the ways that it intends to meet this target is through the use of wind.

Wind Farms in the UK

Wind farms are a relatively common sight in the UK nowadays, with 260 operational wind farms around the country, comprising 2718 individual turbines generating enough energy for over 2 million homes (2). This handy map shows the locations of these wind farms, plus those under construction and those given the go-ahead for construction. Although many people complain about the “blot on the landscape” that wind turbines create and the noise that they make, to me it seems logical that we should be utilising this free, non-polluting energy resource to reduce our fossil fuel consumption and lower our carbon footprint. Technology improves all the time and today’s wind turbines are quieter and more efficient than ever before.

Residential Wind Turbines

Commercial wind farms generate electricity that is then fed into the national power network, the National Grid. The Energy Saving Trust however estimates that approximately 800,000 homes in the UK are well placed to benefit from the generation of their own “off the grid” wind-powered electricity by installing smaller scale residential wind turbines. In addition, many more homes could reduce their reliance on grid energy (and their electricity bills!) by around 25% by supplementing their homes with a domestic turbine (3).

How Does A Residential Turbine Work?

Residential turbines work in much the same way as a large commercial-scale turbine, but on a much smaller scale. The plastic or fibreglass rotor blades are designed in a very similar way to aircraft wings in order to provide “lift”. Because of the angling of the blades, they spin rather than rise upwards and do so at potentially very high speeds. Contrary to what some might think, adding more or wider blades will in fact not increase spin speed since airflow over the blades needs to be kept smooth; too many blades, or blades that are too big would create turbulence that would actually reduce the rotational speed (4).

Electrifiying

The rotation of the turbine’s blades drives a permanent magnet alternator, or generator, which in turn spins a coil of wire inside a magnet to generate electricity. This electricity can be fed into the grid system or, since wind speed is rarely consistent, the electricity can be stored in batteries for later use (4).

Location Location Location

In July 2009, the Energy Saving Trust published a report on the findings of a survey in which 712 homes around the UK who were already using either a free-standing or building-mounted residential turbine, were monitored for 1 year. Parameters including wind speed, turbine efficiency and electrical power were measured in order to determine whether or not small-scale wind-generated electricity is a viable alternative to fuel-generated power. The results of the study showed that wind-drive electricity generation is a worthwhile investment for some, but not all people (5).

Rural Locations

Unsurprisingly, wind turbines were found to be most beneficial to homes in rural, open locations with few topographical features such as hills, mountains or trees to get in the way of air flow. The free-standing turbines of many homes in high wind-speed areas of rural Scotland were found to operate at more than 30%, which is in fact consistent with the efficiency of some large-scale commercial turbines and generates some 18,000 kWh of electricity. Building-mounted turbines in urban or suburban areas were significantly less effective (5).

Installing your own wind turbine

Domestic wind turbines cost somewhere in the region of £1500 to buy and install so before considering to buy one, it is wise to thoroughly research whether or not a wind turbine would be a wise investment for you. To generate enough electricity to be financially viable, wind speeds in your area need to average at 5 m/s, but ideally much more. The Energy Saving Trust has a clever little wind-speed predicting tool here, but also recommends that if you are serious about investing in wind power, you should use an anemometer to measure your wind speed for at least 3 months. If your area has a low average wind speed, alternative solutions may be better for you so investigate maximising the energy efficiency of your home instead (5).

Industry standards

If your home would be suitable to host a turbine, there are several things that need to be taken into consideration. Firstly, at present, there is no industry standard for manufacturers of home turbines, so makes and models may vary considerably in their efficiency as well as cost. The Energy Efficiency Trust recommends that customers only purchase turbines from suppliers accredited under the Microgeneration Certification Scheme, but acknowledges that guidelines for turbine specifications need to be established (5).

Buy Back Schemes

Home turbines need to be properly erected and sited in an unobstructed location to work most efficiently. If you are lucky enough to live in an area where your turbine may generate more electricity than you actually need, many energy companies offer a “buy back” scheme where you can sell your excess energy back to the National Grid. In the Energy Saving Trust survey, those people who were most satisfied with their turbines were unsurprisingly those who had seen the greatest savings in their energy bills, although some concern was expressed as to the real benefit of these schemes in their present state. Finally, you should always remember that wind is highly variable and cannot always be relied upon (5). A plan B is highly recommended!

References

  1. http://www.environment-agency.gov.uk/research/library/position/41201.aspx
  2. http://www.bwea.com/ukwed/index.asp
  3. http://www.gaia-wind.co.uk/small-scale-wind-projects/
  4. http://www.energybible.com/wind_energy/wind_turbines.html
  5. Location, Location, Location: Domestic small-scale wind field trial report, Energy Saving Trust, July 2009
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5 Great Environmentally-Friendly Products

25 11 2009

Think it’s not easy being green? I didn’t think so either, but then, while I was researching this article for Our Green Earth, I discovered that actually, there are lots of really cool gadgets out there to help you save the planet and do your bit for the environment too!

5 Great Environmentally-Friendly Products

[Edit 3rd December 2010: Sadly, Our Green Earth no longer exists but the owner has very kindly handed back copyright of my articles to me. Here, for your reading pleasure, are 5 Great Environmentally-Friendly Products…]

 

5 Great Environmentally-Friendly Products

A couple of weeks ago my flatmates and I were somewhat irked when we inexplicably lost our cable Internet connection for a day or two. The reason? The local council had been putting up Christmas lights in the street and had accidentally knocked our cable box and disconnected us. Bah-humbug. It’s that time of year again! Christmas shopping seems to start earlier and earlier each year, but what to buy for your environmentally conscious friend or relative? I’ve been investigating the latest eco-friendly gifts for all the family.

Save Water, Save Money, Save The Planet

We take for granted the fact that we can turn on any tap for a fresh flow of drinkable, safe water every day. As I write, it’s pouring with rain, which makes it harder to believe that water in the UK is not so plentiful as you might think. According to the UK Environment Agency, the average availability of potable water in Britain is 1334 m3 per annum, with densely habited and lower rainfall areas like the southeast having significantly less (1). The rise of products like washing machines, dishwashers and power showers mean that the average UK household uses 50% more water than 25 years ago, yet if every person in the country reduced their shower time by just one minute, it would save the equivalent of all the water used in one day in London, Leeds and Birmingham combined.

The Efergy Showertime Monitor

The Efergy Showertime Monitor is a clever little device that not only times how long you’ve been in the shower, but actually measures how much water you use thanks to an inbuilt flow rate monitor. It only costs £8.99 from e-store Green Stamp, run from the home of earth-loving Cornish couple Anthony and Sarah, who only use recycled and reused packaging in the delivery of their products (2).

A responsible solution for eliminating pet waste

Clearing your pet’s excrement from your garden, or poopascooping on a walk is not the nicest of chores, but this invention at least helps to get rid of it in an environmentally friendly way! Instead of deposit your dog’s droppings into a pet waste bin (the contents of which will often be incinerated) or flinging it over the neighbour’s fence, the Pet Poo Loo contains detritivorous worms that safely decompose the waste into a nutrient rich compost that can be used to fertilise your garden.

The Pet Poo Loo

The hardy plastic container is buried in the ground and contains a population of tiger worms that naturally and organically mulch Fido’s faeces into a harmless and beneficial product. Because tiger worms are so effective at this, the waste is reduced down in a matter of days, so the Pet Poo Loo only has to be emptied approximately once a year. It comes complete with worms and a bran-based accelerator medium and biodegradable corn starch bags are also available for “on the go” pet hygiene. Price: £73.40 from The Recycle Works (3).

Nigel’s EcoStore

There are so many exciting and innovative products at www.NigelsEcoStore.com that I could write enthusiastically about any of them, but one that particularly caught my attention is Nigel’s bestseller – the Radiator Booster. The fact that this product once appeared on Dragon’s Den has no doubt boosted its popularity, nevertheless with more than 80 positive reviews it certainly seems as though it’s a successful product in its own right (4).

Radiator Booster

The Radiator Booster is a simple plug-in fan device that sits on the top of your radiator and circulates the warm air that would otherwise be lost through the back and out of the wall. It claims to cost a mere 30p in electricity costs per year and can help to reduce your overall heating expenditure by up to 50% since it boosts the efficiency of your radiator by so much that you won’t need to leave your boiler on for as long, or the temperature turned up the maximum. Despite reports that the whirring of the fan is a little annoying, others say that it’s no louder than a computer in the background and, in any case, the Radiator Booster Mark II has an extra-quiet fan as standard. For just £19.99 plus postage and packing, I’m definitely putting this on my Christmas list! (4)

A load of balls

No, I’m not being rude, this product is exactly that – Ecoballs® are reusable plastic balls that you place in your washing machine instead of powder, tablets or washing liquid. The balls are filled with mineral pellets that release ionised oxygen into the wash, which combined with the pounding action of the balls as they spin with your laundry, lift dirt and stains out of your clothes (5).

Chemical-free laundry

Because they don’t contain enzymes or detergents like many washing powders, you can forgo the rinse cycle and set your washing machine to a very low temperature or even a cold wash, thus saving time, money and water. You won’t need to buy washing powder again in a hurry as the balls last up to 1000 washes – plus you’ll be helping to reduce chemical effluent outflow into the nation’s waterways. For hard water areas, you can add a supplement called Magnoball® which will improve the efficiency of the Ecoballs®, but for most washes the Ecoballs®, plus a little stain remover on stubborn stains, are all you will ever need. They are available for £29.99 + P&P from www.NigelsEcoStore.com (5).

Economical Driving

If you must drive, drive green. There have been a few adverts around lately advising us that if we don’t accelerate quite so hard, or if we change gear more smoothly, then we could save pounds on our fuel costs and reduce vehicle carbon emissions by up to 20% (6).

The Vexia Econav

Vexia, a Swedish manufacturer of satellite navigation devices, has recently launched the “Econav” – an in-car satnav device that warns you if you’re driving too fast or if you’re braking to hard, knows exactly when you ought to change gear to maximise fuel efficiency and plots the greenest route from A to B. It is cleverly programmed to the make and model of your car so advice is tailored to the particular specifications of your vehicle. For an extra fee, you can add the function to show the speed cameras along your route, but then if you’re following the Econav’s advice anyway, you shouldn’t need this! The Vexia Econav has won several awards for environmental innovation and four different models go on sale in March 2010 (ok, so maybe an Easter present…) for £160-230 (6).

References

  1. http://www.environment-agency.gov.uk/homeandleisure/drought/38519.aspx
  2. www.greenstamp.co.uk
  3. http://www.recycleworks.co.uk/the-pet-poo-loo-c-289-p-1-pr-16416.html
  4. http://www.nigelsecostore.com/acatalog/Radiator_Booster.html#aRB_2d01
  5. http://www.nigelsecostore.com/acatalog/eco-balls-wash-kit.html#aECOBALLS01
  6. www.vexia.com




The World’s Rarest and Most Threatened Species

24 11 2009

The International Union for Conservation of Nature (IUCN) recently updated their “Red List” – the results of an ongoing survey to assess the threat to the world’s plant and animal species. In my newest article for Our Green Earth, I describe some of the most threatened species in the world and discuss the reasons for their plight. There are some pretty pictures too.

The World’s Rarest and Most Threatened Species.

[Edit 3rd December 2010: Sadly, Our Green Earth no longer exists but the owner has very kindly handed back copyright of my articles to me. Here, for your reading pleasure, is The World’s Rarest and Most Threatened Species…]

The World’s Rarest and Most Threatened Species

The International Union for Conservation of Nature (IUCN) is the world’s largest global environmental organisation and seeks to “provide pragmatic solutions to our most pressing environment and development challenges” (1). It supports and actively carries out work on climate change, energy, human livelihoods and greening of the world’s economy. Another of its major research efforts is the monitoring of the world’s animal and plant species in order to gain a deeper understanding of the biodiversity of our planet and the issues affecting them.

IUCN Red Lists

Every year, following extensive field surveys and data collection exercises, building on knowledge gleaned in previous years, the IUCN produces a “Red List” from its vast database of species from all over the world. The Red List – in reality much more than a simple list – provides a wealth of information about the animals and plants that are considered to be the most at risk. The latest update of the Red List, published in November 2009, describes a staggering 17,291 species (out of almost 50,000 species surveyed) that are threatened with extinction (1).

Red List classification

There are 6 classifications used by the IUCN to group the species that they study according to their level of threat.

  1. Extinct (EX) – when there is no reasonable doubt that the last individual of a species has died
  2. Extinct in the wild (EW) – when the species is known only to survive in captivity
  3. Critically endangered (CR) – when the species has dramatically reduced in population size and distribution according to IUCN criteria
  4. Endangered (EN) – when the species has significantly reduced in population size according to IUCN criteria
  5. Vulnerable (VU) – when the species has reduced somewhat in population size and distribution according to IUCN criteria
  6. Near threatened (NT) – where the species does not meet the threshold levels to be classified as CR, EN or VU, but shows signs that they will meet these criteria in the future (2)

According to the most recent Red List, there are 809 new EX species since the last List was produced, 66 EW, 3325 CR, 4891 EN, 9075 VU and 3650 NT species. Of these species, 72 are on our own British shores (3). Without a doubt, climate change, the destruction of habitats, excessive hunting and other human activities are largely to blame. For example, considering the presence of the highly biodiverse Amazon Rainforest across Brazil, a total of 6% of the species on the Red List are native to this country, hinting towards the negative impact of deforestation on species survival (4).

The most threatened species

There are too many animals and plants that have been classified as critically endangered in this year’s Red List, but presented here is a brief biography of 5 of the most threatened species in the world.

Gorgeted Puffleg (Eriocnemis isabellae) (Photo © Alex Cortes)

This critically endangered bird is native to southwestern Colombia where it inhabits a tiny area of “elfin” (dwarf) cloud forest in the Serraníadel Pinche. Although the species probably has a naturally limited spatial range, the Gorgeted Puffleg is only known to inhabit an area of less than 10km2. The world’s taste for cocaine and the riches to be gained from its export means that illegal coca plantations are replacing the bird’s preferred nesting sites and feeding grounds. In addition, a new road being built to connect mountain settlements is further removing elfin forest and has serious implications for the livelihood of many species, including the Puffleg (5).

Rabb’s Fringe-limbed Treefrog (Ecnomiohyla rabborum) (Photo © Brad Wilson)

The nocturnal Rabb’s Fringe-limbed treefrog lives high in the canopy of primary rainforest in Panama. Females lay their eggs in waterlogged holes in trees while the males were once heard croaking away at nighttime to attract mates. In the last 30 years however, this amphibian has declined in population numbers by over 80%. The reason is thought to be largely owing to a fungal infection of Batrachochytrium dendrobatidis, with the additional stress of habitat loss due to forest clearing to make way for luxury holiday homes. Conservationists have earmarked this species for captive breeding programs but so far these have proved somewhat unsuccessful, meaning that this poor frog could end up extinct in just a matter of time (6).

Giant Pangasius (Pangasius sanitwongsei) (Photo © Chavalit Vidthayanon)

Mercilessly pursued for food and the aquarium trade, the Giant Pangasius fish lives on the bottom and midwaters of the freshwater Mekong River that flows through Thailand, Cambodia, Laos and Vietnam, as well as China. Overzealous fishing, as well as the alteration of river flow to make way for irrigation dams and improved river transport has seen a decline in population numbers of this fish of over 99% in the last three decades. The government in the state of Yunnan, China, have classified this fish as a grade II protected species, however illegal poaching still occurs (7).

Smoky-winged Threadtail (Elattoneura leucostigma) (Photo © Matjaz Bedjanic)

Love them or hate them, insects play an important role in the food chain and the ecosystem as a whole. This critically endangered Sri Lankan dragonfly may in fact already be extinct as it has not been seen for approximately 60 years, but further research is needed to confirm this speculation. The threadtail’s freshwater habitat is mainly under pressure from water pollution, but deforestation, the planting of non-native tree species and water redirection have meant that its natural habitat is changing at great speed (8).

Polynesian Tree Snail (Samoana attenuata) (Photo © Trevor Coote)

Happily, this tiny tree-dwelling snail has come back from the dead. It was thought to be extinct until very small populations were found on the islands of Moorea and Tahiti. The species is still classified as critically endangered since its population size and distribution is extremely limited and threats that caused it to become extinct on the island of Bora Bora still remain. Of these, the most significant threat is that of the carnivorous snail Euglandina rosea. E. rosea was introduced by humans to several French Polynesian islands as a biological control agent to rid the islands of a pestilent species of crop-eating snail. Unexpectedly, E. rosea turned out to be equally as problematic as the species it was intended to keep in check since it has a voracious appetite for other, native, non-pestilent snails and slugs such as Samoana attenuata (9).

The future for threatened species

The alarming rate of the loss of biodiversity and the continued pressure on vulnerable species from human activity is a real cause for concern. Much-needed conservation work supported by the IUCN and other charitable organisations is ongoing but lacking in resources and funding. Breeding programs in zoos and safari parks and genetic research at scientific institutions around the world may help to alleviate part of the problem, but the real dilemma lies in the way we as humans treat our planet. With a few exceptions, species extinction today is largely the fault of our own activities and if we are to halt or reverse these downward trends then education and information is crucial.

References

  1. Press release, IUCN, November 2009: http://www.iucn.org/?4143/Extinction-crisis-continues-apace
  2. IUCN. (2001). IUCN Red List Categories and Criteria: Version 3.1. IUCN Species Survival Commission. IUCN, Gland, Switzerland and Cambridge, UK. ii + 30 pp.
  3. Platt, J, IUCN Red List update: 17,291 species are threatened with extinction, Scientific American, November 2009,
  4. Choppin, S., Red List 2009: Endangered species for every country in the world, The Guardian Data Blog, November 2009
  5. BirdLife International 2009. Eriocnemis isabellae. In: IUCN 2009. IUCN Red List of Threatened Species. Version 2, www.iucnredlist.org
  6. Livingstone, S., Mendelson, J. & Angulo, A. 2009. Ecnomiohyla rabborum. In: IUCN 2009. IUCN Red List of Threatened Species. Version 2, www.iucnredlist.org
  7. Jenkins, A., Kullander, F.F. & Tan, H.H. 2007. Pangasius sanitwongsei. In: IUCN 2009. IUCN Red List of Threatened Species. Version 2, www.iucnredlist.org
  8. Bedjanič, M. 2007. Elattoneura leucostigma. In: IUCN 2009. IUCN Red List of Threatened Species. Version 2, www.iucnredlist.org
  9. Coote, T. 2007. Samoana attenuata. In: IUCN 2009. IUCN Red List of Threatened Species. Version 2, www.iucnredlist.org




The Importance of Coral Reefs

23 11 2009

I was inspired to write this article after reading about a recent deep sea expedition off the coast of Australia in New Scientist. The expedition revealed new species of weird and wonderful marine life never seen before. It’s true that we know more about the moon than we do the oceans, and as a Scuba-fanatic, I think that’s incredible.

The Importance of Coral Reefs

[Edit 3rd December 2010: Sadly, Our Green Earth no longer exists but the owner has very kindly handed back copyright of my articles to me. Here, for your reading pleasure, is The Importance of Coral Reefs…]

The Importance of Coral Reefs

In May 2008, I was lucky enough to be staying on the Indonesian island of Gili Trewangan. This tiny island, just 4 miles in circumference, lies off the coast of Lombok and is a veritable Scuba diver’s paradise. As a self-confessed Scuba addict, I spent most of my four-day stay 30 metres under the water marvelling at the beautiful array of corals, fish and turtles. When I spotted a poster advertising that the local dive schools were organising a free “Earth Day” dive, I simply couldn’t resist and signed right up. Myself and around 30 other divers, plus snorkellers and landlubbers, took part in a clean-up operation to rid the reef and surrounding shoreline of litter. I’m pleased to say that my net was half empty when I surfaced as this particular reef was rather unpolluted but I dare say that this is not the case in reef systems elsewhere on the planet, and litter is certainly not the only problem that faces the world’s corals.

What is coral?

The structure we know as coral is in fact made up of thousands of tiny animal organisms called polyps. Polyps are closely related to jellyfish and have soft bodies complete with miniature tentacles. They have been in existence for over 200 million years (1) and have evolved to adapt to relatively nutrient-poor waters by forming a symbiotic relationship with another species of organism called zooanthellae.

A mutually beneficial relationship

Zooanthellae are single-celled algae that live inside the body of the polyps. By living in this way, polyps protect the zooanthellae from being eaten by fish and other grazers, and in return, the zooanthellae provide the polyps with some of its food, created by the process of photosynthesis, which stores carbon compounds by utilising the energy from the sun. As the polyps grow and reproduce they secrete a hard skeleton of calcium carbonate that helps the coral to maintain their position within the top 100m or so of sea level so as to afford the zooanthellae the best position for photosynthesis (1). Over many years, this skeleton builds up to form a coral reef ecosystem.

The importance of coral reefs

Of course, coral is not the only thing that makes up a coral reef ecosystem. Many other organisms depend on the coral reef for shelter, food and breeding sites and complex webs of biotic and abiotic interactions help to maintain the reef’s health. Humans too, use the reef as an important resource for generating income from tourism and fishing, amongst other things. It is estimated that approximately 15% of the world’s population rely wholly or in part on coral reefs for their livelihood. In Australia, for example, tourism of the Great Barrier Reef generates $1 billion USD per annum in revenue, and in developing countries, 25% of the fish caught annually comes from fisheries associated with coral reefs, thus providing a significant proportion of the protein required for a healthy diet (1).

Coral bleaching

Coral reefs are an incredibly delicate ecosystem in balance (1). The average species of coral polyp has adapted to survive within very narrow limits of temperature such that changes of just 1ºC can cause the polyps to respond to this stress by releasing their zooanthellae in a process known as “bleaching” (1). The polyp itself is often a translucent, colourless organism; the bright colours of coral so often seen in spectacular underwater photography come from the photosynthetic pigments found in the zooanthellae. When the polyp releases its complement of zooanthellae, the coral turns white; hence the name “bleaching”. Once bleached, the coral often dies.

Too much salt is bad for you (and coral)

Salinity is another parameter to which corals have become very finely tuned; mass bleaching can and does occur after heavy rains that dilute the saltiness of the ocean only very slightly (1).

The impact of humans on coral reefs

Coral bleaching is a reaction of the coral to stress. This stress can occur as a result of natural cycles, an example of which is the El Niño phenomenon, which when it strikes, can cause mass bleaching. However, research increasingly shows that this is a problem with anthropogenic roots that will only increase in severity as human activities continue to increase (2). Climate change as a result of increased atmospheric carbon dioxide (CO­2) and the depletion of the ozone layer has already seen sea levels and sea temperatures rise, leading to bleaching of some of the world’s most beautiful reefs. Not only bleaching, but mining of corals, over fishing and irresponsible tourism means that today, not a single coral reef on the planet remains unaffected by human activity (3), and 50-70% of them are deemed as at risk (1).

Coral reefs as a biodiverse ecosystem

The depletion of coral reefs has many serious implications for both humans and the ecosystem at large. Coral reefs are characteristically renowned for their vast biodiversity of millions of different species of fish, mammal, plant and algae. Loss of coral would result in the subsequent loss of not only those organisms such as coral-grazing fish that rely directly on the biomass of the coral, but also those of complex webs of myriad organisms. Biodiversity is important in itself from a genetic point of view as it increases the gene pool from which natural selection can continue to occur. It is also important for the survival of individual species that have carved a specialised niche for themselves that cannot be replaced by any other.

Coral as a primary producer

The sheer size of coral reefs means that they are an extremely important primary producer. Primary productivity is the storage of inorganic carbon into organic compounds, most often done via the process of photosynthesis. We are now familiar with the concept of carbon offsetting by planting a tree to neutralise the CO2 released by our activities, but corals as well as plants also play a part in reducing our carbon footprint, fixing as much as 40g of carbon per square metre of reef per day (1). Although attempts are underway in various parts of the world to create new coral reefs, mass bleaching and the death of corals is a rapid end for a very slow-growing organism so the practice of reef planting is always in debt.

Coral as a food source

Carbon fixing by coral is not only important for reducing the effects of our carbon footprint but is also an invaluable source of food. Polyps and zooanthellae form part of the food chain for a whole host of organisms, and these in turn are the food source for higher animals, ending ultimately in humans ourselves.

Intensive fishing

As the human population continues to increase, intensity of fishing also increases at the same rate, and for coral reefs, this is becoming unsustainable. Removal of the top fish predators from the food chain means that fishermen will need to hunt further down the chain, eventually fishing for juvenile species that do not have a chance to breed and replenish their numbers. Removal of the larger grazing and predatory fish has also been shown to result in an increase of coral-grazing invertebrates such as the Crown of Thorns sea star, which voraciously feeds on coral at a destructive rate if left unchecked, and fleshy brown algae that competes for light (4).

A vicious cycle

Not only this, but the death of coral itself removes the safe haven of the breeding and nursery ground altogether such that even those eggs that are laid will not survive to adulthood because they are exposed to predators. This vicious cycle impacts on other organisms that feed on young or larval seafood and leads to an overall reduction in biodiversity.

No-take areas

The establishment of “no take areas” (NTAs) will go some way towards maintaining sustainable fish stocks, but these must be effectively policed and become more numerous if we are to cope with the problem at large (3).

Coral as a source of tourism income

As previously mentioned, tourism of coral reefs provides a major source of income for many countries associated with the reefs. I for one am hopelessly in love with the colour and richness of life beneath the waves and there is no shortage of dive operators willing to exploit this fascination that we have with the sea.

Irresponsible diving

Unfortunately, as with many other forms of tourism, not all companies or their clients are as scrupulous or as concerned with the welfare of the reef as others. Irresponsible diving practices including hunting, coral mining or even simply a fin kicked in the wrong direction can damage the infrastructure of the reef. This in itself can stress the coral enough for it to bleach, but also encourages visiting species of fish and mammal to find new feeding and breeding grounds and disrupts the balance of the ecosystem.

Who wants to dive in a dead reef?

Coral bleaching by any of the other means previously mentioned also reduces the appeal of the reef to tourists. People Scuba dive because they want to see the glorious array of colours and animals that they’ve seen on TV; not uninteresting, crumbling skeletons of dead coral. Without the income from reef tourism, many countries would suffer and without the interest from the public that reef tourism creates, much needed scientific research programs would find a lack of funding. Clearly, tourism is both help and hindrance to the reef and needs to be kept in balance, like the reef itself.

The future of coral reefs

Coral reefs are beautiful ecosystems that we can enjoy for our own pleasure as well as being a source of food, money, building materials and even a source of new drugs and biochemicals. They create storm barriers for our coastlines and help to set up the environmental conditions needed for the health of other crucial ecosystems such as mangroves and sea grass beds (1). It is imperative that we use coral reefs responsibly and sustainably, and protect them carefully if they are to survive in the future.

  1. Hoegh-Guldberg, O, Climate change, coral bleaching and the future of the world’s coral reefs, Marine Freshwater Research 50:839-866, 1999
  2. Vidal-Dupiol, J., et al, Coral bleaching under thermal stress: putative involvement of host/symbiont recognition mechanisms, BMC Physiology 9: 14, 2009
  3. Hughes, T.D., et al, Climate change, human impacts and the resilience of coral reefs, Science 301: 929, 2003
  4. Scheffer, M., et al, Catastrophic shifts in ecosystems, Nature 413: 591-596, 2001




The Most Important Discovery of 2009

21 11 2009

My second article on Our Green Earth discusses Nobel Prize-winning research into telomeres. You can read it here: The Most Important Scientific Discovery of 2009.

One of the Nobel Prize winners, Professor Elizabeth Blackburn, happens to be on the editorial board of the Biology Image Library, the website I work on for my full-time job. Well done Elizabeth!

[Edit 3rd December 2010: Sadly, Our Green Earth no longer exists but the owner has very kindly handed back copyright of my articles to me. Here, for your reading pleasure, is The Most Important Scientific Discovery of 2009…]

The Most Important Scientific Discovery of 2009

Deoxyribose nucleic acid, or DNA, is a molecule that provides the code for life. This long polymer of four nitrogenous bases; adenine (A), cytosine (C), guanine (G) and thymine (T), along with its “backbone” of sugar and phosphate molecules, is found in almost every cell in the body in the form of 46 pairs of chromosomes. It gives the instructions for our cells to create the thousands of proteins that carry out specific functions in our bodies. Proteins control everything from the colour of our hair to the digestion of our food, and even tiny mistakes in the code can cause mayhem in the form of genetic diseases, cancers and mutations.

The Integrity of Life

Every cell in our body is ultimately generated from the division of one cell, the zygote; an egg cell fertilised by a sperm cell. As this cell grows and divides, the DNA that it contains; 23 chromosomes from our father and 23 from our mother, is copied exactly so that almost every cell in our body contains the same genetic information. Different cell types look different, perform different functions and produce different proteins due to a complex system of switching on the genes for proteins that are needed for that cell type, and switching off those that are not needed. Given that there are approximately 10 trillion cells in the average human body, and each cell is on average just 10 µm in diameter, it is remarkable to think that every single one of these tiny units contains up to 3 metres of the same DNA for the duration of our lifetime.

The Nobel Prize for Medicine or Physiology, 2009

The integrity and longevity of DNA has been attributed to regions on the ends of chromosomes called telomeres. Telomeres are long sequences of DNA that repeat a particular pattern of the four bases: CCCCAA. Repeats of this sequence, found on the ends of chromosomes, act as a “cap” and have been known for some time to stabilise the DNA molecules (1). However, three researchers – an Australian, Elizabeth Blackburn, American Carol Greider and British Jack Szostak – have recently been awarded the Nobel Prize for Medicine or Physiology for their collaborative research and discovery of a gene lying within the telomeres. This gene codes for a protein called telomerase.

Telomeres and Telomerase

Telomerase is a protein with a very special function. A minimum number of CCCCAA repetitions are needed to protect the coding regions of DNA within the chromosomes from degradation by enzymes (specialised proteins that catalyse chemical reactions). If the telomeres are broken down, this puts the main body of DNA – the part that codes for all the proteins that carry out our life functions – at risk of being degraded itself. Telomerase contains a short sequence of RNA, a similar molecule to DNA, which has the same sequence – CCCCAA (2). This acts as a template to repair and replenish the DNA repeats when they are broken down, and so this is how the stability of the molecule is maintained during cell growth and division (3). Without telomerase, our cells would lose repeats at a steady rate with each cell division until the coding DNA was eventually damaged (4). Animal cells have only a limited supply of this protein however, and so with the passing years, the ability of telomerase to protect our telomeres gradually decreases until the telomeres are completely degraded and the more important DNA begins to be eroded. This partially explains why we age and our cells eventually senesce, or die.

Implications for health and disease

This important discovery has many implications for further research. If we can understand how and why we age, this may lead us towards discovering more about diseases of ageing such as dementia and Parkinson’s, or cures for rare premature ageing diseases such as progeria. It may also help us to understand more about cancer, since a feature of many cancer types is that the production of telomerase is up regulated such that there is never a shortage of the protein. HeLa cells for example, a malignant cell line used commonly in cancer research, are considered to be “immortal” since propagation of these cells can occur indefinitely. The cells used in research today are exactly the same as those originally taken from the tumour of a woman called Henrietta Lacks who died from cancer in 1951. These and some other cancer cells produce enough telomerase that the telomeres do not shorten and the mutated DNA is preserved. By finding a way to down-regulate the telomerase gene in this case, it may be possible to develop treatments to halt or even reverse the proliferation of cancerous cells. Indeed, clinical trials are already underway to test a vaccine that targets cancer cells with high telomerase activity. A cure for cancer is a long way off yet, but thanks to these three researchers highly deserving of their Nobel Prize, we may just be one step closer.

  • Greider, C.W. and Blackburn, E.H., Identification of a specific telomere terminal transferase activity in tetrahymena extracts, Cell 43: 405-413, 1985
  • Press release of the Nobel Assembly at Karolinska Instituet, 10th October 2009, http://nobelprize.org/nobel_prizes/medicine/laureates/2009/press.pdf
  • Wang, X., Kam, Z., Carlton, P.M., Xu, L., Sedat, J.W., Blackburn, E.H., Rapid telomere motions in live human cells analyzed by highly time-resolved microscopy, Epigenetics and Chromatin 1: 4, 2008
  • Yu, G.-L., Bradley, J.D., Attardi, L.D., Blackburn, E.H., In vivo alteration of telomere sequences and senescence caused by mutated Tetrahymena telomerase RNAs, Nature 344 (6262) pp. 126-132




New Biofuel Research – Watermelon Bioethanol Production

18 11 2009

I have just started contributing science articles to this charming little website called Our Green Earth, run by a nice chap called Tom who also has a sideline in African percussion instruments. Here’s my first post. I’m rather chuffed with the amount of comments it’s been getting, especially on BioMed Central’s Facebook page (thanks to Charlie Webber for posting the link!).

New Biofuel Research – Watermelon Bioethanol Production

[Edit 3rd December 2010: Sadly, Our Green Earth no longer exists but the owner has very kindly handed back copyright of my articles to me. Here, for your reading pleasure, is New Biofuel Research – Watermelon Bioethanol Production…]

New Biofuel Research – Watermelon Bioethanol Production

We’re all aware that the world faces an energy crisis. Our reserves of fossil fuels (coal, oil and natural gas) are running low because we’re using them much faster than the Earth can replenish them – and burning them contributes to atmospheric pollution and global warming to boot. Finding ways of making renewable and more environmentally friendly energy sources usable, sustainable and economically viable is a challenge faced by governments worldwide. While solar power and wind generated electricity are usually the first things that people think of when asked to name a renewable energy source, it is biofuel that is currently the subject of much research and development since their use requires less modification to our current infrastructure than other sources.

Our current fuels of choice are all derived from oil, coal and natural gas. These materials contain a large amount of stored energy in the form of carbon bonds from multimillion-year old skeletons of animals and plants, decayed and compressed under pressure. Since fossil fuels took millions of years to form, they are not quickly regenerated and this is where our problem lies. Aside from the fact that we’re running out of them, we’re also releasing millions of years-worth of stored carbon in the form of carbon dioxide (CO2) that our photosynthetic organisms cannot recycle quickly enough to maintain stasis.

Biofuels however, are fuels which are produced from sustainable materials, such as crop plants and organic waste. Although biofuels still need to be burnt to release their energy to drive our cars and work our power stations, the exhausts that they emit contain less harmful impurities and the CO2 that they release is only as old as the plants themselves. Therefore, by increasing biofuel use, we can significantly reduce our overall carbon footprint. By maintaining sustainable biofuel production, or even better, by using waste that would otherwise be land filled or burnt in an unhelpful way, we can help to keep CO2 levels in balance.

Buses running on 85% bioethanol made from fermented wheat by-products or “veggie vans” that use biodiesel as their fuel of choice are gradually becoming more common on the UK’s streets. In the UK, most bioethanol is manufactured by fermenting surplus wheat that farmers are unable to sell to flour producers or breweries, and biodiesel often comes from excess rapeseed oil stocks. Clearly, not every country or region around the world has the same staple crops and so current research into the viability of other crops or waste products is being carried out so that feedstock type or availability or does not limit the progress of biofuel use. In Brazil, the world’s largest user of bioethanol, the main ingredient for the national cocktail caipirinha, also doubles as the source of biomass for their bioethanol production needs. In other parts of South America, maize has been successfully used to produce fuel. Other countries however, have started to think outside the box…

Researchers at the South Central Agricultural Research Laboratory in the USA published an article in August 2009 claiming that watermelons may be an important and previously untapped source of feedstock for bioethanol production (Fish, Bruton and Russo, Watermelon juice: a promising feedstock supplement, diluent and nitrogen supplement for ethanol biofuel production, Biotechnology for Biofuels 2: 18, 2009). 44 of the 52 states in the USA grow watermelons commercially and yet because of our penchant for perfectly shaped melons, 20% of this crop is left to decompose in the fields and is wasted each year. In addition, a significant proportion of the watermelons that are sold commercially – somewhat surprisingly – go to pharmaceutical companies who extract the compounds lycopene and L-citrulline that are then incorporated into drugs for treating prostate disorders and high blood pressure. This generates even more organic waste that researchers now propose could be put to use towards more environmentally-friendly fuels. By combining concentrated watermelon juice with yeast and fermenting under controlled conditions, Wayne Fish and colleagues estimate that the 8.4 tons per hectare of surplus melons could produce as much as 200 litres per hectare of bioethanol.

Also utilising an unusual source for the production of biofuel is South Korea who, rather than excess or waste crops, are turning to waste furniture for their biomass needs (Heo et al., Bio-oil production from fast pyrolysis of waste furniture sawdust in a fluidized bed, Bioresource Technology 101: 1, supplement 1, 2010). An estimated 2.4 million tons of tables, wardrobes and other wooden furniture items were land filled in Korea between 2005 and 2008 and, so say researchers collaborating between several Korean universities, this waste wood could be better put to use in the process to produce bio-oil. By heating wood chippings to temperatures of 450ºC in the absence of oxygen (during a process known as pyrolysis), biomass material can be condensed into a high-energy content oil that can be burnt in order to generate electricity. What’s more, gases produced as a by-product of this process can be recycled and combusted to generate the high temperatures needed for the reactions to occur, thus the production of bio-oil (not to be confused with the ointment used to fade scars and pregnancy stretch marks!) can be completely self-sustaining.

A third and more controversial area of research, recently reviewed by collaborators at several Californian institutions, has suggested that genetically modified plants may one day be important for the production of biofuels (Simmons, Loque and Blanch, Next-generation biomass feedstocks for biofuel production, Genome Biology 9: 242, 2008). Since the genomes of several important and common bioethanol feedstock crops are now known, genetic modification of other crops to incorporate required characteristics for ethanol production may be possible. Lignin, for example, is a compound found in plant cell walls that contains a high concentration of starch. Starch, in turn, is made up of units of sugar, which drives the fermentation process. If high lignin content could be genetically transferred to crop plants which do not normally have such a high potential for bioethanol production, then even more otherwise wasted crop resources could be utilised for our energy needs. As always, genetic modification remains a touchy subject and is certainly one that needs further research and testing if it is to be viable.

While 100% of petrol stations in Brazil now sell biofuels, progress in the UK is relatively slow. To be able to use bioethanol, vehicles must be specially modified so as to prevent engine damage and that, of course, costs money that in this dreaded time of “economic downturn” sees any investment of this kind, both by companies and individuals alike, way down the list of priorities. A growing number of companies do now use bioethanol for their fleet vehicles, and a small but growing number of hybrid cars for personal use do now exist, but our infrastructure must change radically if we are to see the use of biofuels really take off.

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What Would Martin Lewis Do?

9 11 2009

I’ve been a big fan of Martin Lewis, the Money Saving Expert for quite some time. If you don’t already receive his weekly email, I strongly recommend it. Sign up here. He’s made it easy for the general public to understand finance – something that many people are in the dark about – and is educating us in the ways of consumer activism. Retailers don’t always play fair, and consumers don’t always know their rights. With this in mind, I did a little bit of complaining today, for the good of the people.

Whilst checking my personal emails at lunchtime today, I came across a marketing email from a Volkwagen dealership, asking me to test drive a new VW Polo. There’s nothing unusual about that. I get quite a lot of these emails since I had a spate of “comping” a while back so my email address is no doubt on quite a few mailing lists. What was intriguing about this email was that, for such a large corporation as Wolkswagen, the email was incredibly poor and broke several fundamental rules of e-marketing. The sender had not included an “unsubscribe” option and worse, the recipients of the email had not been blind-copied, meaning that everyone who received the email could see the email address of everyone else it was sent to. Finally, and in my humble opinion, the worst thing of all, was that the spelling was atrocious.

So, I did what Martin Lewis would do and complained, not only to Volkswagen directly, but also to the sender – and copied in everyone else on the list. Here’s the letter.

“Dear Mr Uxxxxx,

Firstly, please be advised that I have written to your office to raise a formal complaint about the email, below, which I received from you today. There is strict legislation regarding what can and can’t be done in mass mailing of this type and it seems that you are entirely unaware of these rules. I appreciate that there are certain companies that sell people’s contact information for marketing purposes, and I realise that at some point in the past I may have left myself open to being included on one of these lists by erroneously not ticking the “Please do not contact me” box when filling in an online form, etc. That said, I have no idea who you are, have no interest in Alan Day VW and did not ask to be kept informed of your news. This email is completely unsolicited, and further breaks the law by not having an “unsubscribe” option.

Secondly, your mail contained attachments. While these may well have been harmless pictures of Volkswagen cars, forgive me for exercising caution in opening these attachments – owing to the nature of the spam you have sent me. If this was indeed a virus, you could have just infected the entire network of some 500 or more machines at my workplace seeing as I used a company computer to read the mail.

Finally, and in my eyes the most importantly, you have not blind copied the recipients of this email, i.e. the email addresses of every recipient are visible to every other recipient. Again, this breaks legislation. At the very least you have now opened us all up to even more unsolicited spam, as well as being in breach of the Data Protection Act and putting our online security at risk. You will notice that I have “replied to all” so that the other people who received your mail might also take action. (To those people, please ignore/delete as you see fit – I won’t be spamming you or using your email addresses again, but this is something that I feel very strongly about and I hope you will also report this matter!)

I look forward to an explanation and apology (you may just reply to me this time instead of bothering everyone else again!)

Regards, although not kind ones,

Lisa Martin”

I regret slightly the “unkind regards”, but hey I was in the flow.

Over the course of the day, I received several emails from people on the mailing list congratulating me on my efforts, which was nice. Later in the day I received a telephone call from Mr. U who personally apologised (I think he must have got into a lot of trouble!). Later still, I received an email from the managing director of the dealership, and this is what he said.

“Dear Customer,

I am writing to sincerely apologise for the unapproved actions of one of my Sales Executives earlier today which may have offended you or caused you to call into question the very strict Data Protection policies that the AXXX DXX VW Group has in place.

I would like to confirm and reassure you that this incident was isolated and the Sales Executive concerned will be dealt with internally upon the results of a full investigation due to be held this week. I would also like to assure you that all data held by the AXXX DXX Group is dealt with in the strictest of confidence and that new measures have been put in place today to prevent any such incident occurring in the future.

As a gesture of goodwill and by way of apology for any distress or inconvenience caused, I would like to offer you two complimentary cinema tickets for a film of your choice. If you would like to accept this offer, I would be grateful if you could email or telephone my PA, DXXXX HXXXXXXXX.

[Telephone no. and email supplied]

I would like to thank you on behalf of myself and my team for the interest that you have shown in the new VW Polo and sincerely hope that this incident will not prevent you from considering this excellent vehicle as your first choice in the future.

Apologies once again,

Yours faithfully

PXXX TXXXXX
Managing Director, AXXX DXX VW Group”

Well! Free cinema vouchers just for a little complaint letter! Yeah!








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