The Bushmeat Trade

Bushmeat hunting is the most widespread resource extraction in tropical rainforests, above  even deforestation. The definition of bushmeat is simply meat that is caught in the forest, and used to be reserved for local families and tribes. The prevalence of hunting and eating of bushmeat has risen greatly in the past decades though, due to a number of factors:

• ·      Risen human populations result in scarcity of other protein sources
• ·      Bushmeat is a status food and is often chosen over other meats
• ·      Growing urban populations in previous largely rural countries want for a large supply of bushmeat
• ·      Deforestation brings in roads and therefore easier and quicker access to the animals and greater transport potential.
• ·      Advances in hunting technology, such as traps, night vision technology and guns.

In a report by John et al, from the Durrell Wildlife Conservation Trust in Jersey, biodiversity of bushmeat species were analysed in the Congo and Amazon basins. They found that bushmeat is eaten by 0.15 million people in South America, compared to a staggering 4.9 million people in tropical Africa. This is, not surprisingly, reflected in the species exploitation rates with the extraction to production ratio being 30x greater in the Congo than in the Amazon. This equates to 60% of the mammal taxa that are hunted for bushmeat in the Congo being unsustainable, whereas in South America all taxa were at sustainable levels in 2000 when the paper was written.

Primate bushmeat

It is hard to accurately estimate such things, and John et al highlight this, stating that their estimates are higher than previous papers written by their peers. However, it is clear that in Africa, the bushmeat trade is a huge problem for biodiversity.

One such animal family that is highly affected by the trade is primates. Jane Goodall rates it as the greatest threat to primates, and has worked extensively in Africa, particularly with chimpanzees and bonobos. She, rather shockingly, says that within the next 50 years all African apes (chimpanzees, bonobos and gorillas) could be extinct purely from the bushmeat trade alone.

Chimpanzee and bonobo populations. As you can see their distribution has already been depleted into a number of fairly small pockets. This puts the populations at greater risk of dying out from hunting, disease or habitat loss.

This "delicacy" is not just served in Africa and South America, it can be found in parts of Europe and Canada but I implore you to please never try it and encourage the bushmeat trade. I have no problem with local, rural families sustainably eating bushmeat, but a worldwide market it for it will be appalling for the fauna of our tropical forests.

NB: John et al may need a institutional log-in for access

Leaked IPCC report

Yesterday the scientific online community was buzzing with news of the next IPCC report having been leaked online. I read about it on the New Scientist home page, and was shocked to see that upon its release many climate bloggers have been claiming that natural solar forcing is behind the warming we have experienced in the past 100 years, and not humans.

I wanted to highlight this to you all to remind you to take it with a very large pinch of salt. Although a paragraph in the report says that solar forcing may have taken a larger part in global warming than was once thought, that chapter goes on to say that there is too little evidence to meaningfully support this. The summary of the report too states that anthropogenic warming is far greater than solar.

No doubt more research shall be done into this hypothesis, yet I hope that governments and other bodies will not listen too much to these claims and use any excuse to avoid the mounting problems our world faces.

NB: One of the "expert reviewers" of the IPCC report leaked it onto this site, should you wish to look at it yourself. Obviously there is no backing behind the contents by the IPCC, the final report is set to start being released in September 2013.

BGS Risk List (4)

It is that time of the week already: the continuation of the countdown! Last week we examined the slightly-hard-to-spell molybdenum, and now we are onto number four on the countdown: the very pretty bismuth!

RANKING:

4

ELEMENT NAME AND SYMBOL:

Bismuth (Bi)

RELATIVE SUPPLY RISK INDEX:

9.0

WHY?:

Recently the production of bismuth has risen due to its use as lead replacement, because it has similar chemical properties but is very much less toxic. China holds 75% of the deposits and therefore is nearly at a state of monopolising them. Bismuth is also very difficult to recycle because of the nature of its use. It is scattered in products and so tricky extraction methods have to be used to isolate it from other elements.

LEADING PRODUCER:

China

TOP RESERVE HOLDER:

China

WHY THE DEMAND?:

Bismuth is commonly used is cosmetics; particularly in pigments to colour eye shadows and nail polishes. It also has pharmaceutical applications; in indigestion tablets, treatment of eye infections and peptic ulcers. Examples of where it has replaced lead in alloys include fishing sinkers, bullets and solders.

Dangers of wind turbines

A few weeks ago I wrote an introduction to a few of the renewable energy options our planet had, and concluded that wind power seems to be the most popular and widely implemented of them. As wind farms continue to grow and spread, however, bird and bat fatalities are rising with them. 

This trend is particularly prevalent with migratory species, which have their set routes that they have used year or year, and continue to do so even with rotor blades in their way. Cryan and Brown, 2007, looked into the causes of the fatalities in bat species, and concluded that the most deaths occur during the autumn migration. The bats choose to travel when there is low moon illumination and wind speeds but high cloud coverage and so when these conditions arise the death toll rises.

Graph from Cyran and Brown, 2007, showing the peak in fatalities during the autumn months.

However, as always in life, there are exceptions to the rule. A study by Arnett et al in 2008, in which they amassed data from 21 reports from the USA, also found a peak in bat deaths in autumn. Yet they also found a pattern of female deaths in May and June. Interestingly although the US Federal Aviation Administration had floodlit some wind farms in a bid to reduce bat and bird deaths there was no disparity found in fatality numbers between these lit sites and unlit ones.

Kuvlesky et al, 2007, examined wildlife impacts as a whole from wind farms, not just in flying species. They found that even worse than the turbines themselves were transmission lines and roads associated with the infrastructure, because they lead to habitat fragmentation which can harm species populations, and also allow invasive species easy access to habitats not their own. This can bring in disease and competition for resources which the native wildlife may not be able to cope with. Exotic plants spread particularly well alongside roads, unlike small mammals and reptiles which find it hard to cross them safely. The power lines also obviously pose a risk of electrocution for flying organisms.

In summary, we know where the problems arise: generally in migratory paths during autumn for birds and bats. Could wind turbines could be turned off when the optimum conditions of bat flight coincide with these known migration times? It is of course possible, although economically that may not be the standpoint we humans decide to take. A future precaution that could be implemented would be to study and record migratory paths more thoroughly, and purposefully not place wind farms in them.

For wildlife as a whole it is the ground habitat disruption which is causing the most problems. Some measures can be taken to alleviate this, highlighted by Kuvlesky et al. Simple changes such as putting wind farms on agricultural land as opposed to native lands can help reduce the biodiversity loss. More research needs to be done onto the impacts of biodiversity as so far the focus has been on birds and bats.

Note: links to papers may require an institutional log-in.

BGS Risk List (5)

Last week saw us looking at our element in position number 6; strontium. This week we can safely say we’re halfway through our countdown, and the lucky element that gets to share that landmark with us is…molybdenum!

RANKING:

5

ELEMENT NAME AND SYMBOL:

Molybdenum (Mo)

RELATIVE SUPPLY RISK INDEX:

8.6

WHY?:

The main reason for Mo’s risk is an economical one. As will be apparent below, it is mostly used in alloys for stainless steel pans amongst other items. Many countries are facing recessions and as people stop spending money on kitchenware the value of molybdenum is decreasing. Subsequently producers are focusing their efforts on our more valuable metals often found alongside molybdenum, for example copper, and so the supplies of Mo are decreasing.

LEADING PRODUCER:

China

TOP RESERVE HOLDER:

China

WHY THE DEMAND?:

Molybdenum has the sixth-highest melting point of any element, is extremely hard and will readily form chemical bonds with other elements. Therefore it is extensively used in various steel alloys, including superalloys; in fact 80% of Mo produced is used in these processes.

The remaining 20% is used in fertilizers (particularly for cauliflowers!) and in the mechanism for mammograms, amongst other applications.

A cure for mouldy bread?

As a student mould is unfortunately something I come across quite often. Cooking for one can lead to opening the fridge and finding that your last few cherry tomatoes are starting to look a bit fluffy, or you go to make a piece of toast but realise your bread has an odd green hue.

Thankfully these problems could soon be a thing of the past! In a BBC news article it is claimed that an American company has created a process of zapping bread with microwaves in a particular way which may increase it's freshness to sixty days, thanks right, not 6 but 6-0!

The giant microwave, which unlike home ones does not heat the bread, but does destroy fungi in it which could cause mould.

This process could avoid manufacturers having to add lots of additives that consumers do not want in their food, and may cut bread waste by a third in the UK alone. Food waste is a massive problem in the Western World, and with agricultural land and other resources becoming very tight, cutting down the amount we throw away will help us both economically and environmentally.

And the best news is, the technology will very likely be able to be used on other foods, such as meat and vegetables, too.

The Methane Hydrate Risk

Methane hydrates are a ice-like solid, with a structure composed of methane molecules trapped in a water lattice. These hydrates are found on continental slopes of seabed sediments and are stable at 400-1000m depth; at low temperatures (less than 10^oc) and high pressures (greater than 3.5Mpa). 

These criteria make their distribution fairly regular and therefore easy to find. This could be of huge importance due to the potential of methane clathrates as a huge energy source. The USGS conservatively estimates worldwide carbon bound in these formations as double the total carbon known from all fossil fuels on earth! 

BGS diagram showing the distribution of organic carbon in Earth Reservoirs (note gas hydrates eqaute to over 50%)

Zhang et al have this year looked in great depth at this source of hydrocarbon. 1m³ of hydrate contains the equivalent of 164m³ of methane under normal conditions! Therefore it could be a very efficient source of energy if harnessed. Due to the precise environment needed for the hydrates to form it is relatively easy and successful to predict where they occur.

Distribution of known methane hydrate deposits, concentrated on the continental slopes.

However there is a great danger in doing so, as the risk of methane leaking to the atmosphere could be detrimental to global climate. Overpeck and Cole, 2006, discussed the risk of methane release, not only from accidental leakage if we were to mine them, but also from less invasive human interaction: climate change. Anthropogenic climate change results in the hydrates becoming unstable very quickly due to a warmer environment. Decomposition leads to decreased stability of the sea bed and therefore landslides, releasing huge quantities of methane into the ocean and (eventually) the atmosphere. It has ben estimated that 2000-4000 gigatonnes of carbon could be released if CO2 reaches 3x Pre-Industrial levels! This would kick-start a horrific climate feedback cycle, whereby the increased methane would keep further warming the planet, leading to further methane clathrate decay. 

The possibility of this happening is all too real. It is thought that abrupt climate and ocean change at the PETM (see my colleague's blog, A Warning From the Past, for more information) was driven by methane clathrate release, and the affects lingered for 100,000 years! This led to decreased ocean pH, dissolution of seafloor carbonates and extreme global warming, resulting in the largest mass extinction Earth has ever faced!

So, by humans potentially causing methane releasing landslides from extraction and anthropogenic climate change, could we be facing a similar demise??

Currently we are not at imminent risk, even though methane is starting to become unstable and dissociate in the very Northerly latitude seas, resulting in traces of methane in the water column. In a "first of it's kind" report last year by Elliot et al, a simulation of how clathrate-derived methane is currently behaving in the oceans was made. The results of this test were surprising; currently although methane build up in the Arctic is enhanced it is not reaching the atmosphere. This is because fresh polar surface waters are working to block the escaped methane and transport it to deeper ocean. Further studies will of course have to be done to be sure of this mechanism, but it is reassuring to know that heightened methane levels are not leaking to the atmosphere yet. 

Methane concentrations are rising fastest in the Arctic (yellow and red areas)

As climate change continues to take a hold of our planet's processes, however, the likelihood is ocean currents shall be affected and may divert their paths or be weakened. What then, if the methane enahanced water is not dragged down to the depths? There are though to be far more methane hydrates on the continental shelves today compared to 55Ma, at the time of the PETM. I therefore worry that Earth's most powerful mass extinction is actually still yet to come. 

Note: Institue log-ins may be required for the scientific papers linked to.