Should We Be Focusing on Lonesome George's Legacy?

     Now you've heard his story, we should look at the specifics of the conservation work going into 'resurrecting' Lonesome George's subspecies, and whether we should actually expend resources into this.

   As discussed previously, Yale researchers analysed more than 1,600 DNA samples taken in 2008 from tortoises living near Wolf Volcano, on Isabella Island, identifying 17 individuals that share some of Lonesome George's genes - 3 males, 9 females and 5 juveniles. The researchers believe there could be additional hybrids in the area, and possibly some pure specimens of the subspecies, based on the presence of juvenile first-generation hybrids. The paper detailing their findings and speculations is due to be published in Biological Conservation, however it is as yet unavailable.

Lonesome George - not the last Pinta Island giant tortoise?

    It is speculated that the Pinta Island tortoises likely reached the neighbouring Isabella Island by 19th Century whaling and naval vessels throwing individuals overboard when they were not needed for food. This has lead to similar findings with another Galapagos Giant Tortoise thought to be extinct; Chelonoidis elephantopus (Floreana Island) genes have been rediscovered in hybrids analysed in Garrick et al., 2012, in Current Biology.

   Now that surviving Pinta Island tortoise genes have been discovered, geneticists can begin to attempt to reconstruct the species. In theory (and what is hoped will result from this) the hybrids can be selectively bred, hopefully producing individuals that are almost entirely pure, effectively bringing back the subspecies 'from the dead'. Who knows, with luck the further expedition planned for next year may even be able to find a wild pure Pinta Island tortoise.

   But should we even bother to spend the incredible amount of time and money that this subspecies regeneration will take? And all the work for a group not even distinct enough to be classified a species; as a subspecies, Pinta Island tortoise genomes are very similar (virtually identical) to other taxa of the same species (particularly those of Espanola Island). Would these not fill any ecosystem gaps? Also, work will likely never come up with an individual fully of the subspecies, but only continue a line of hybrids, and as they breed very slowly, this will take a very long time and many generations to be achieved. It is still very unsure whether there will be any pure-breeds of the species, or whether there will even been enough hybrids left to breed out a pure line and regenerate the Pinta Island subspecies.
 
    Despite all this, the action of these researchers is possibly worthwhile as an example of what conservation work can achieve, and for inspiring work with other species. This tale of Lonesome George, and the possible resurrection of his subspecies symbolises the current rapid loss of biodiversity on Earth, and inspires the beginning of conservation efforts in other places: "Because of George's fame, Galápagos tortoises which were down to just a few animals on some islands have recovered their populations. He opened the door to finding new genetic techniques to help them breed and showed the way to restore habitats," said Richard Knab of the Galápagos Conservancy, which is running giant tortoise breeding programmes with the Ecuadorean government."
Furthermore, work into his subspecies can already be seen as having great positive effects on the conservation of other species; Lonesome George has inspired major conservation programmes in the Galapagos, causing many other species of highly endangered giant tortoise to recover, for example the Hood Island subspecies has recovered from 15 individuals to around 1200.


    So, despite his death in June, and the resulting reports of the loss of another publicised (sub)species, clearly Lonesome George's legacy is still going strong, inspiring many researchers and conservationists. I believe it is not the focus on his subspecies that is important, but the fact that conservation actions receiving more support will be able to reach more endangered species, helping prevent some extinctions.

Critically Endangered Species of the Week: the White Ferula Mushroom!

About:
    This week I thought I would highlight a species of critically endangered fungus (which the majority of people would obviously overlook), rather than the typical furry or enigmatic animals usually focused on.

    The White Ferula Mushroom (or Bailin Oyster Mushroom; Funcia di basilicu), Pleurotus nebrodensis, grows in Sicily on Limestone [1], and is a creamy white to yellow colour. At maturity, the fungus can reach a diameter of 5-20cm, and develops extremely angled gills [2].


The White Ferula Mushroom, Pleurotus nebrodensis. Picture from [2].



    On its discovery in 1866, Italian botanist Giuseppe Inzenga described it as "the most delicious mushroom of the Sicilian mycological flora" (which might give you some idea as to why the species is critically endangered) [1, 2].


Number left in existence:

    It is estimated that less than 250 individuals reach maturity in the wild each year [1, 2, 3].



The geographical location of the White
Ferula Mushroom; Sicily. Map from [3].



Geographical Range in the wild:



    The species only occurs in Northern Sicily, growing in scattered localities in the Madonie Mountains at an altitude of 1,200-2,000m [1, 2, 3]. The area where the White Ferula Mushroom can be found covers less than 100 square kilometers, and populations are extremely fragmented [1, 2, 3].

Why they are endangered:
    The mushroom is so edible it is considered as prized for consumption. This has led to collection both by amateurs and professionals, causing severe damage to population numbers. To make matters worse their rareness has dramatically increased their price to around 70 Euros per kilo, meaning sellers and collectors are now picking unripe specimens (stopping them reproducing) [1, 2, 3].   
    The species is also under threat by anthropogenic habitat degradation and trampling by live stock.

The species is just too tasty!

What can we do to help?
     Stop picking, buying and eating them! (although this is obviously restricted to a minority of people that do trade in the species). Unfortunately there are currently no laws protecting this species, and even in protected areas there is no ban on collection. However draft rules have been prepared, and if these are approved collection in certain areas of protected parks will be illegal [1].

    Thankfully populations of the species are now getting some respite as the species is being cultivated ex situ (outside of its natural habitat) to reduce collection pressure on wild populations [1, 2, 3]. But much greater legal attention is still required to prevent harmful collection practices, and extinction of the species.

References:
1. http://www.iucnredlist.org/details/61597/0
2. http://en.wikipedia.org/wiki/Pleurotus_nebrodensis
3. http://i.iucnredlist.org/documents/amazingspecies/pleurotus-nebrodensis.pdf

Lonesome George's Legacy Lives on

     Last night I introduced (or possibly reminded) you of the Chelonoidis nigra abingdonii bachelor Lonesome George, recently deceased. His story extends back to 1971, when Hungarian József Vágvölgyi discovered him on the island of Pinta; the single survivor of the indigenous population. 

Pinta, Galapagos Islands, Ecuador; picture source.

    As mentioned, the destruction of his species is very likely an anthropogenic effect caused by the introduction of invasive species and hunting. However humans have also kept him safe in captivity since his discovery at the Charles Darwin Research Station, Santa Cruz Island. His keeper, Fausto Llerena, and other conservationists have tried hard to rejuvenate his species in the past; bringing in two female tortoises of a different subspecies (Chelonoidis nigra becki), believed to be genetically closest to George. George produced two clutches of eggs over two years with one of the females; however all eggs failed to hatch and were deemed inviable. In 2011, two different females from the subspecies C. n. hoodensis were brought to the Research Station, and the Ecuadorean government even offered a $10,000 reward for a suitable female. 

Giant tortoise on-going conservation attempts at Pinta Island.

    Unfortunately it was announced on the 24th of June, 2012, that Lonesome George had been found dead by his keeper, likely as a result of heart failure as part of a natural life cycle. A necropsy confirmed he died of 'old age', and was to be embalmed and put on display, in what is presumably meant to be an inspiration for conservation work. Thus Lonesome George's subspecies was pronounced officially extinct (also here, reported on in many publications).

    However in the last few days a breakthrough has been announced: despite the death of Lonesome George, we may still be able to preserve the subspecies! This follows the news that George may not have been the last of his kind (although this is slightly ironic and depressing to know, following his death). It appears the genes of the subspecies have survived in several hybrids located on Isabella Island (nearby) - 17 tortoises have been identified as first or second generation Pinta hybrids (the former meaning one of the parents was entirely of the Pinta subspecies as George). Significantly, some of these hybrids are juveniles; this suggests some purebred individuals may still survive on Isabella at the site Volcano Wolf. The paper detailing the genetic tests and methods used to determine this is due to be published in the journal Biological Conservation.

    A follow-up expedition is planned for the Spring to search for one (or more) of these C. n. abingdonii purebreds, and to collect the first generation hybrids in the hope of propagating some of the remaining Pinta genes. 
My next post will take a more in-depth look at this new advance in the tale of Lonesome George, and will debate whether there really is any legitimate point to this research-saga, other than nostalgia from acquaintance with George.

The Sad Tale of Lonesome George

     On June the 24th this year a Galapagos giant tortoise by the name of Lonesome George died. The 100 year old male Pinta Island tortoise was believed to be the last known individual of the subspecies Chelonoidis nigra abingdonii, and served as the symbol for conservation efforts in the Galapagos.

Lonesome George, in life. Photograph: Rodrigo Buenia/AFP/Getty Images.

      George's death had many in mourning, particularly those promoting conservation of the area, as it was believed that this was the extinction of one of the Island's unique lineages of giant tortoise. George was likely made the so-called 'rarest creature in the world' by the actions of humans - giant tortoises on Pinta Island and others were historically hunted almost to extinction, and the island's vegetation, serving as habitat and food, had been devastated by introduced feral goats.

    We will follow Lonesome George's story, including the past attempts at conserving his subspecies, and certain recent scientific breakthroughs, to investigate not just the negative effect humans can have on other species, but also the lengths they can go to trying to reverse these mistakes.

A BBC video introducing Lonesome George.

Parasites and Zombies!

   Today I just thought I would freak everyone out a little with some horrible stories about, unfortunately real, parasites! How's this for highlighting the amazing-ness of Earth's biodiversity? Here's some of the creepiest parasites in nature:


 Cordyceps unilateralis = Ant Zombies:
      This fungus has spores which enter the body of an ant, where they begin to consume non-vital soft tissues of the ant. They spread through the ant, where they perform some strange mind-control technique by unknown compounds or mechanisms; causing the ant to become a 'zombie', climbing up the stem of a plant and using its mandibles to secure itself.

    The fungus slowly grows through the ant, consuming its tissues and eventually killing it. When it is ready to reproduce, the fruiting bodies sprout out of the head of the ant, releasing their spores to begin the process all over again!

If you want to freak yourself out, here is a video from

the BBC's Planet Earth on the fungus!

Cymothoa exigua or tongue?
    Otherwise known as the tongue-eating louse, this crustacean enters through the gills of a fish and attaches itself to the base of the fish's tongue. It then extracts blood through its front claws for nutrition, eventually causing the tongue to atrophy (die and float off) from lack of blood.

   Horribly, the parasite then replaces the fish's tongue by attaching itself to the fish's tongue muscles. Strangely it then functions as the fish's new tongue, in a form of symbiotic relationship. This is the only known case where a parasite functionally replaces a host organ. Much of this parasite's life cycle and occurence in Red Snappers are detailed in this study by Ruiz and Madrid, from 1992.

 It looks even scarier in real life!

Gordian Worm, aka Horsehair Worm:
    Actually an entire phylum (Nematomorpha) of worms, but the species Spinochordodes tellinii is one of the scariest. The larvae develop inside grasshoppers and crickets, again influencing its host's behaviour. When the worm is reproductively developed it causes the host to seek out and jump into a pool of water.

    The parasite then exits the host (through the anus...) into the water, where it lives and reproduces as an adult, while the unfortunate host inevitably drowns. The species' behaviour and host preferences have been discussed in a paper from 2005 by Schmidt-Rhaesa, Biron, Joly and Thomas.


A Horsehair Worm, exiting its grasshopper host.

    There you have it, 3 pretty scary parasitic species which I think serve to show the interesting diversity our planet can support!

Critically Endangered Species of the Week: The Gharial!

    Our critically endangered species this week is the Gharial (Indian Gharial; True Gharial; Gavial) - I have specifically chosen this species because it is one of the lesser known species of an otherwise well-known group, and its evolutionary relationships are the subject of my dissertation! If this species were to go extinct no further research could be undertaken, likely limiting this extremely contentious area of research.

About:
     The Gharial, Gavialis gangeticus, is a crocodilian with a characteristic elongate, narrow snout adapted for its fish-based diet [1,4]. Males of the species can also be classified by their bulbous growth on the tip of the snout called a Ghara (after the Indian word for 'pot') [2,]. Gharials are also much more agile in the water (related to their piscivorous diet) than on land, and cannot move in a 'high-walk' gait, like many other crocodilian species [2].
     The species is one of the largest crocodile species alive, behind the salt-water crocodile; males can grow to be around 6m long [3; 2].


The Gharial, Gavialis gangeticus, displaying the extremely slender
snout and bulb at the snout-end. Photo from [4].

The extremely elongated, thin snout of the Gharial. Photo from Saravana Kumar at [3].

Number left in existence:
     Recent surveys indicate there may be less than 200 surviving individuals in the wild [3;1], with the highest total number across all populations found to be around 436 in the peak year of 1997 [1]. 182 made up the estimated number of individuals from 2006; indicating a currently declining population [1].

Geographical Range in the wild:

Geographical range of the Gharial; along 3 rivers in
India, and one in Nepal - these are clearly widely separated.
From [1].

     The Gharial can be found in both India and Nepal. However it is likely that only three actually breeding subpopulations survive in India (Chambal River, Girwa River and Son River), and one in Nepal (Rapti/Narayani River) [1; 2; 3]. Furthermore, these are all widely separated, giving no chance of recovery without human intervention if one subpopulation fails.

    The remaining populations of the Gharial are remnants of mostly unsuccessful reintroductory programmes [1]. The species historically lived in Pakistan, other parts of India, Bangladesh, Myanmar and Butan, but are now extinct in these areas [1; 3].



Why they are endangered:

• Mainly anthropogenic alteration of habitat, through: damming, (throughout all the present range of the Gharial), divertion for irrigation (Gharials cannot move between dried rivers) and sand-mining [1; 2; 3].
• Increased intensity of fishing; decreasing food stocks, as well as causing the death of many adults through gill-netting [1; 2; 3].
• Crop planting and animal farming during the dry months interrupts the breeding season and uses the sandbanks where this takes place [1].
• Hunting and use of the Gharial and traditional medicines, mainly in Nepal [1; 2; 3].
• Gharial eggs are sought out as food; leading to almost all of the nests being raided between 2001 and 2005! [1; 2].

What can we do to help?
     Conservation programmes have already been undertaken in India and Nepal, establishing the present frail populations by captive breeding and restocking [1;]. Around 5,000 young adults were released to these river systems, however recruitment or retention of these reintroduced individuals (survival rate and breeding) has been very low, at 3-10% [1; 2; 3].
     If the species is to survive, more effective methods need to be put in place for their protection, as the reintroduction attempts have been less than effective so far (and mostly a waste of resources!). Conservation now needs to turn to habitat assessment and protection, fisheries enhancement and local education if the species is going to have any hope [1; 2; 3]. Perhaps after education of residents and increased knowledge on why previous reintroduction attempts have failed, individuals could be released into their historical ranges.


References:
1. http://www.iucnredlist.org/details/8966/0
2. http://nationalzoo.si.edu/animals/reptilesamphibians/facts/factsheets/gharial.cfm
3. http://www.gharialconservation.org/
4. http://www.bbc.co.uk/nature/life/Gharial

A Strange Impact of Global Warming: Biodiversity Increases

     In their paper published this September, Mayhew et al. concluded as their title illustrates that 'Biodiversity tracks temperature over time'. Their finding that Earth's biodiversity has a general pattern of increase with increasing temperature seems completely at odds to the type of mass extinction generally associated with global warming. This follows the known understanding that biodiversity constantly decreases with latitiude; reaching its peak species richness in warmer biomes, although the finding contrasts strongly with extinction models of global warming; making the paper of great interest.

    These findings may cause some to debate any models which predict increasing extinctions with future anthropogenic global warming. However, Mayhew openly debates the use of his paper in this way, stating that emergence of new species due to genetic adaptation still leads to extinctions (a few million years later), and that current species do not flourish, but new species take their place. The graph below from Mayhew et al., 2012, demonstrates that extinction rates also increased, and it is only that the emerge of new species was slightly greater than this. Additionally, it is likely that models for present global warming still hold - this is because temperature increases are happening on such a faster scale that speciation cannot keep up with the increased amounts of extinction:
       
"I'm afraid it's not good news in terms of what we might experience from global warming in the next few decades. Because obviously extinction can happen rapidly, but speciation [the generation of new species] can't happen rapidly. So unfortunately we're quite likely, simply because of the rate of climate change today, to see extinctions occurring. And we're unlikely to see the benefits that might go along with that, which is the generation of new species."  Mayhew speaking on his study.

Graph from Mayhew et al., 2012, B and D displaying the positive
correlation of speciation and extinction with temperature.

    Contrastingly to this paper, however, is the fact that their previous similar study (albeit with inferior techniques, as they note) from 2008 contradicts this finding, where biodiversity was found to decrease with increasing temperature - although this does seem unlikely, given the current spacial increase in species richness with temperature (i.e. towards the equator). Additionally, focusing purely on temperature correlations (by proxy measures and carbon dioxide concentrations) seems much less reliable than a cohesive study with several possible impactors of biodiversity; this may have been the reason why not all studied periods in Mayhew et al., 2012, showed an increase in biodiversity with temperature (or this was due to palaeontological sampling bias; a very real issue, as they note).

Sustainable Fishing

      Sourcing fish from sustainable companies has recently become a big concern to many consumers given the recent attention paid to decreasing numbers of wild fish. Overfishing is becoming such a huge issue to conservationists and the food industry that numerous organisations have been set up offering guidelines to sustainability and papers published attempting to establish a solution.

     The Marine Stewardship Council is one of the most well-known organisations promoting sustainable fishing of our oceans. The group assesses the practices of different fisheries, and awards the seafood ecolabel, which can feature on the packaging of the fish, if the methods are found to reach sustainable standards. They also attempt to raise awareness in consumers by providing information about suitable suppliers, restaurants and stores, and giving a list of certified 'fish to eat' as well as recipes. Similarly, the Monterey Bay Aquarium in the USA has a Seafood Watch Programme. This is one of many organisations directly attempting to educate and influence consumers about overfishing, giving information about what consumers and businesses can do to help. The website provides a 2012 Culinary Chart of Alternatives for various fish and seafood, for example that below for Cod.

       Papers such as Cummins, 2004, entitled The Marine Stewardship Council: A Multi-Stakeholder Approach to Sustainable Fishing elaborate on the guidelines fisheries should follow to gain the label of sustainability as above. A paper by Potts, O'Higgins and Hastings this year also believes a policy reform is needed on managing marine resources - they state that there is a call for integrated and ecosystem-based approaches towards marine management in government, and that we need to "build a sense of oceans citizenship".

     Many companies and organisations striving for sustainable fishing believe fish farming can be used in part to reduce the need for wild overfishing. This often features as a key solution in establishing sustainable practices; but while farming may be promoted as good for marine conservation in the face of fishing, numerous scientific papers have been published demonstrating this can have severe loading effects on ecosystems if not managed properly. Wu as far back as 1995 published this paper on the environmental impact of fish cultures, and their management for sustainability in the industry. Additionally Lee, Choi and Arega, 2003, also wrote on this topic. Both papers note serious problems with this other side of the drive to marine sustainability:

• Fish farming causes high nutrient loading, which may alter ecosystems: around 85% of phosphorus, 80-88% of carbon and 52-95% of nitrogen inputs into fish culture systems as feed may be lost through feed wastage, excretion and respiration.
• The use of chemicals can negatively affect the surrounding environment (vitamins, antifoulants etc.). 
• Introduction and spread of pathogens and new genetic strains can damage the wild fish populations may farms are attempting to protect.
• The development of antibiotic-resistant bacteria has been reported near fish farms; this could severely damage wild populations.

They demonstrate that while we clearly need methods to increase our marine sustainability, and to prevent extinction of wild species, fish farming requires strict controls to have a positive impact. Fish farming can greatly aid fishing sustainability, however this requires careful site selection, control of stock density, improved feed methods and prevention of pollution reaching ecosystem carrying capacities.

EDGE of Existence

       Before my next long post I just wanted to draw attention to an organisation I have previously linked to (and to their blog that I follow); EDGE of Existence. They work towards highlighting and conserving some of the world's rarest species, according to how 'Evolutionary Distinct and Globally Endangered (EDGE)' they are. The presence of large, motivated groups such as this demostrates what a positive impact we can have on biodiversity, if we work hard to maintain species richness.

     To this end, they also run and fund conservation work for graduates to undertake for a 2 year period, researching and working with particular rare species. For anyone interested in biodiversity this would be an amazing opportunity! EDGE additionally utilises modern technology to bring species observation and identification to the internet-masses; their Instant Wild cameras post photos of wild animals in different locations over the globe for visitors to their site to help identify.

Critically Endangered Species of the Week: The Black-Faced Lion Tamarin!

About:
    The Black-Faced Lion Tamarin, Leontopithecus caissara, is a small monkey of the New World group. The species was recently featured on the BBC documentary 'Attenborough's Ark' (as mentioned in a previous post). The monkeys have golden-orange hair down the back, and black haired head, limbs and tail [1;4]. It is often considered the rarest of the South American primates [5], and one of the world's 25 most endangered primates [2].

    Tamarins (and Marmosets) are distinguished from other New World monkeys by their very small size (adults usually around 30cm long; 3), having claws rather than nails aside from on the big toe and the occurrence of twin births [1]. Individuals live in family groups in forests, feeding on small fruit, insects, small vertebrates and flowers [1; 5]. At night, the entire family group retires to a tree hole to sleep [2; 5].



A Black-Faced Lion Tamarin, Leontopithecus caissara, in the rain!

Photo from [2].

A close up of a Black-Faced Lion Tamarin.
Photo from [2].

Number left in existence:



     The most recent studies believe around 260 individuals of 3 subpopulations remain; Therefore giving an estimated figure of no more than 400 animals existing at this time [1; 2; 3], with a decreasing population trend.



The small geographical range of the Black-Faced
Lion Tamarin (in orange). Map from [1].



Geographical Range in the wild:



     The Black-Faced Lion Tamarin is endemic (only found in) Brazil. Small populations exist on the island of Superagüi, on the coast of the state of Paraná. The species has also been found in certain areas of the mainland nearby this island, in the states of Paraná and Sao Paolo [1; 2; 3; 5]. The species' available habitat may may total approximately 68 square miles [3], but may be larger or smaller.

Why they are endangered:

•  Main threats are forest destruction and degradation due to the increase of agriculture, human development and tourism [1; 2; 3; 4].
• Utilisation of forest resources destroying their habitat, notably the harvesting of heart of palm [1; 2; 4].
• Capture of live individuals for the illegal pet trade, and during hunting is threatening populations [2; 4]. 

 What can we do to help?

      Thankfully there have been some measures put in place for conservation of the species; it is listed on the Brazilian Offical List of Species Threatened with Extinction, and regional lists in the two states it is native to [1; 4]. Additionally the Superagui National Park and Jacupiranga State Park cover most of the Black-Faced Lion Tamarin home ranges [1; 4]. The IPE (Instituto de Pesquisas Ecologicas) has a conservation programme for the species, which gathers research, information about threats and aims to educate people about these [2; 4].

    However, the protected habitats of the species have so far not been safe from destruction, and have found to offer little protection against hunting and collection for pets [1]; greater education is needed in this area to protect the species. Furthermore, there are currently no captive breeding programmes for this extremely rare, declining species [1; 2] - these are necessary as a safeguard against extinction, and should be a priority for future conservation.

References:

1. http://www.iucnredlist.org/details/11503/0

2. http://www.arkive.org/black-faced-lion-tamarin/leontopithecus-caissara/#ref6 

3. http://www.animalinfo.org/species/primate/leoncais.htm

4. http://en.wikipedia.org/wiki/Superagui_lion_tamarin

5. http://www.wildinvest.com/projects_tamarin.html

Planetary Boundaries: Re-visited

      A couple of weeks ago I posted on the Planetary Boundaries concept, devised by Röckstrom et al., 2009, which attempted to define limits of nine environmental categories of such importance that crossing them risks such catastrophic, irreversible change to the planet so that Humans can no longer survive. The reason for focusing on this study was that we have already dramatically crossed the biodiversity (extinction rate) threshold, however there has been a great deal of recent debate over the concept.
  
     Numerous other papers have been published this year exploring or supporting Röckstrom et al., 2009; for example Barnosky et al.,2012; 'Approaching a state shift in Earth's biosphere', in Nature. This reiterates the points made by Röckstrom et al., 2009; that critical transitions caused by threshold crossings are likely, it is human forcing mechanisms that cause this (human population growth, resource consumption, habitat degradation, climate change etc.), and that past events (particularly slow recovery after extinction events) show how serious this can be. The paper also concentrates on the way these thresholds are tracked, and the evidence for climate trends along with this concept.

Potential drivers of critical transitions across planetary boundaries: a=fragmenting landscapes, b=indirect changes, c=accumulation of change to the Earth's surface, showing 40% are now agricultural areas, d=accumulation from pollutants, e=release of greenhouse gases changing ocean/atmospheric chemistry, f=changing seasonal temperatures, g=changes to reservoirs of biodiversity by species introduction and climate change, h=global trend to warming and ice melting. From Barnosky et al., 2012 (fig.1).

'Earth May Reach Tipping Point'; Barnosky, A.D., 2012. UC Berkley.

   
       However, several other recent papers hotly dispute the concept - such as a report by Shellenberger et al. (Breakthrough Institute), 2012, which states the idea "has serious scientific flaws and is a misleading guide to global environmental management", and is "a poor basis for policy and for understanding local and global environmental challenges." Key findings in their assessment of the planetary boundaries hypothesis are:

• That six of the nine planetary boundaries do not have specific global thresholds in themselves - i.e. land-use change, biodiversity loss, nitrogen levels, freshwater use, aerosol loading and chemical pollution have no actual global tipping points beyond which these processes function in entirely different ways than they do now or have historically. This makes the setting of these boundaries particularly arbitrary - crossing the thresholds may have no affect; they don't help us understand possible results.
• Aside from the effects on global climate, the above six boundaries operate on local and regional scales, not globally - changes to these and what they can cause in some areas are independent of their processes in other regions (e.g. land-use change).
• There is little evidence to support the idea that transgressing these six boundaries would have a net negative effect on human welfare - net benefits and costs vary with locality, economic position etc.
• Lewis' column in Nature commenting on planetary boundaries (2012) also believes the idea isn't defined enough to be of use - he states that there should be a distinction between thresholds, as some are true lines that we can cross, whereas other categories have fixed limits (like Phosphorous-use) that we cannot cross. This might change the way we act on the process; preventing its impact on the environment, but harming our own systems like food production by not noticing all the angles. However, Galaz, 2012 does dispute Lewis' contentions.
• There have been several papers and letters exploring problems with specific planetary boundaries, which are too detailed to go into here. The individual thresholds can be researched to read more on the justifications, or lack of evidence, for them; for example Allen's commentary from 2009 in Nature Reports on the Carbon Dioxide limits.

      It could be said that regardless of this the concept is important in directing thinking and action in sustainability; I do believe this to be true, as it does provide a useful framework for further research. However, as the Shellenberger et al., 2012, report notes, using an idea fraught with issues as a basis for policy can lead to more miss-led action and confusion, such as:

• Specifying regional processes as global may negatively affect local-level policies, due to the trade-off between positive and negative impacts on welfare.
• Most of the six non-threshold boundaries integrate with climate change; assigning them all as different boundaries is likely necessary, but confuses the causes and effects of one of the largest global processes.
• Ecological degradation so far has shown little correlation with specifically human material welfare.
• The limits and crossing of them do not necessarily need 'fixing' as the concept implies, but more balancing with human welfare needs - there will be various courses of action and trade-offs that cannot here be explored.
• Lewis, 2012, believes all government bodies focusing on all the nine planetary boundaries could spread political will too thinly. He states that those affected by regional problems should instead work to solve these, and global combined efforts should focus on those clear global changes of climate change, biodiversity loss and ocean acidification.

     An article from July 2012 in The Economist provides a useful summary of the current aspects of this debate, and whether the concept of planetary boundaries is still useful. It uses a strange but apt metaphor to explain the thoughts of those supporting its application:
        "PULL a spring, let it go, and it will snap back into shape. Pull it further and yet further and it will go on springing back until, quite suddenly, it won't. What was once a spring has become a useless piece of curly wire. And that, in a nutshell, is what many scientists worry may happen to the Earth if its systems are overstretched like those of an abused spring."

The idea has clearly taken root, despite some objections, as it has even been used in many political conferences on sustainability. I do see the merit in the criticisms above; clearly if a system such as this is to be used for policy-making and action on such an idea as possible catastrophic environmental change there should be more defined, less abitrary, limits put in place. As human action tends to be a balancing act, great care should also be taken when using this to advise. However I do see this basis could be of importance once developed, and is worth the further debate.

The Latest in the Ash Dieback 'Saga'

      Anyone that regularly watches or reads news stories cannot possibly have missed the number of articles in a flurry about the arrival of Chalara ash dieback in the UK. There has been truly extensive media coverage on the effects of the Chalara fraxinea fungus; damaging, killing or necessitating removal of Ash trees that act as habitats to many organisms; and the its spread around the UK. To read about why this could be a disaster-in-process, visit one of many BBC articles on it here.

     The breaking news in this story is that the government has announced (based on scientific advice) that it will not be possible to eradicate the disease - mature trees are too important in English ecosystems, supporting too many species, to be felled; meaning progress of the fungus can only be slowed. The hope is that some British Ash individuals will show genetic resistance to the disease, and that these can be found and cultivated to prevent colossal tree dieback. BBC's latest update on this (from today) can be viewed here. In this case it appears absolutely necessary for the survival of the species and maintenance of biodiversity that humans intervene, and remove young infected trees.

Above is an image of a mature Ash, and below an up-to-date map of known cases of Ash 

dieback across Britain, both obtained from the BBC (sources above; map

produced by the Forestry Commission).

   

      In (possibly) less depressing news, Sir David Attenborough's new documentary 'Attenborough's Ark' aired today, where the man himself chose ten species he would most like to save from extinction. Yesterday's EDGE Blog introduces the species, and more information on the show can be seen here on the BBC's page. I'm looking forward to watching this documentary special!

Guardian Series: 'The Sixth Extinction'

     While researching my previous post, I came across the series 'The Sixth Extinction' on The Guardian online (referring of course to the huge impact humans have had on increasing extinction rates). I just wanted to highlight its location, for any that might be interested - it appears to aggregate current news articles in biodiversity and conservation, and has some interesting links.

    For the last Critically Endangered Species of the Week I actually used the article titled 'The 100 most endangered species on the planet - the list in full', which was compiled by the IUCN and Zoological Society of London. While one should bear in mind that these are not necessarily the top 100, as research into population numbers is often difficult and speculative, this is a useful list that includes primary threats and required conservation action for each species. 

   The series also has an interactive map that really is worth playing with - it shows locations and numbers of recently extinct and critically endangered species globally by the IUCN. I unfortunately can't link an interactive map, but go have a look at the series if you're interested!

Critically Endangered Species of the Week: Attenborough's Pitcher Plant!

About:
      Attenborough's Pitcher Plant, Nepenthes attenboroughii, is a species of insectivorous terrestrial shrub characterised by its large bell-shaped pitcher and narrow upright lid. It was discovered in 2007, and named in 2009 after Sir David Attenborough, because he is "a  keen enthusiast of the genus" [2; 6]. The stem can reach a height of 1.5m, and the pitcher may grow as large as 2 litres in volume [2].
     The pitcher of the plant holds water as two layers that do not mix: the lower region is viscous, and the upper is watery. The pitcher and liquid act as a trap; the plants often have slippery edges, meaning insects lured by colours and scents that land on the rim fall into the pitcher consequently drown and are digested by the enzyme-containing fluids.

Attenborough's Pitcher Plant, Nepenthes attenboroughii. The middle image displays the
huge amounts of liquid the pitchers hold. Images by A.S. Robinson, from [3].

Number left in existence:
     The plants grow singly, or in sparsely scattered groups, with few individuals in an area. This gives a population density of only one individual per ~20m², meaning the two-three known colonies only consist of a few hundred plants [1]. Actual population numbers are very low, but specifics are unknown.

Geographical Range in the wild:
     The species is known only from Mount Victoria, in central Palawan, Philippines. The plants grow on ultramafic slopes from 1,600m up to the summit [3; 6]. The actual area the species occupies comprises a few hundred square meters on each of the summit region, meaning the range is significantly below 10km2 [1].

Why they are endangered:

• The biggest threat to Attenborough's Pitcher Plant is poaching. Thankfully the mountain is mostly inaccessible, which means hiking and human development has little affect on populations. However the monetary value of this rare plants is high, notably on the Taiwanese and Japanese markets [1; 4].
• The species occurs only on ultramafic soils (nickel and magnesium-rich), and has separate male and female plants (dioecious). This means no single plant can reproduce just by itself, and so even light collection pressure and human influence can have a great impact on the reproduction of the species.
• The habitat of these endemic plants is under future threat from mining - a nickel mine operates at the base of the mountain, and the summit has been prospected for future potential [1].

What can we do to help?
     There are no current conservation measures in place for this species - Mount Victoria is mined, and the summit has no protected status (i.e. for National Parks) [1]. Control measures are in place for the trade of the endangered species of the genus Nepenthes, but these need to be better enforced, and the area made a designated protected zone [4].


BBC Wildlife and David Attenborough's documentary 'The Private Life of Plants' contains a clip full of excellent footage of the genus of Pitcher Plants, which is included below for interest's sake [5]!

References:
1. Robinson, A.S. & Madulid, D.A. 2012. Nepenthes attenboroughii. In: IUCN 2012. IUCN Red List of Threatened Species. Version 2012.2. <www.iucnredlist.org>
2. Nepenthes attenboroughii. 2012. At Wikipedia. <http://en.wikipedia.org/wiki/Nepenthes_attenboroughii>
3. International Institute for Species Exploration. 2010. Attenborough's Pitcher. <http://species.asu.edu/2010_species01>
4. Malein, F. 2012. The 100 most endangered species on the planet - list in full. From: IUCN and Zoological Society of London. <http://www.guardian.co.uk/environment/2012/sep/11/100-most-endangered-species-planet>
5. Attenborough, D. 1995. The Private Life of Plants. BBC. <http://www.youtube.com/watch?v=trWzDlRvv1M>
6. Walker, M. 2009. Giant 'Meat-Eating' Plant Found. BBC. <http://news.bbc.co.uk/earth/hi/earth_news/newsid_8195000/8195029.stm>

Is the 'Jaws' Legacy Still Felt Today?

      A couple of days ago I caught a recent documentary over on Channel 4 called 'Jaws: The Great White Myth' (being a film and shark fan; linked for your viewing pleasure). The programme discussed and interviewed on the impacts on sharks this incredibly popular film had; some positive (such as greater interest in marine biology) and many negative. It really is a good watch, although often depressing, and I found it telling to view the huge extent of the backlash on sharks after the film - many sharks were simply brutally killed all through the heightened fear and ignorance this caused.

     As is clear in the documentary, this was a disastrous and unintended side effect - interviews with the wife of late Jaws author Peter Benchley show how saddened the pair were that a story meant to purely explore what could happen if a predator developed 'a taste for humans' caused so much unnecessary slaughter. The two were so against this unfounded cultivated fear that they spent the remainder of their lives working in shark conservation and discouraging shark killing.

The poster image of the excellent, and unfortunately highly convincing,
Jaws, by Spielberg. Image from this blog post [1] on whether other
shark films live up to Jaws.

     The release of this documentary reminded me of a series of news stories I read over the past summer which I had been meaning to post about (and is also appropriate after our last critically endangered species). This was the debate on whether Great Whites in Australia should be taken off the protected list.

     Towards the end of August, news came in about how 5 fatal attacks in the past year in Western Australia was leading officials and many beach-goers alike to call for action against the species apparently responsible for this higher-than-average figure (see The Guardian's article on the subject; 3). This is despite Great Whites being listed in the area as "rare or likely to become extinct" since 1999. As the article and many since have noted, these sharks are apex predators and hugely important to the maintenance of the marine ecosystem.

     Unfortunately, around a month later The Guardian published a further article here [4] on how the aforementioned Western Australian officials have approved a plan that allows tracking and killing of sharks that venture too near the coast, regardless of any previous sightings or implications in attacks. This is a drastic reversal on the previous policy of species protection, largely due to public fear and pressure (most of which I do believe is down to utter ignorance of shark behaviour). A package of £4.41m has also been made available to aim to reduce the risk of sharks on humans by positive aspects such as further research on patterns of aggression, and negative including the catching and killing of sharks close to shore. The statement from the local government allowing these measures can be found here [6]. 

In Australia, these rare and important sharks can now be
preemptively hunted if they stray too close to beaches.
Image from Science Faction/Cor at [4].

     Many, including myself, believe this to be applying a 'guilty until proven innocent' approach - The Conservation Council of Western Australia issued a statement rejecting this ruling [5]. They state that this drastic measure will not protect swimmers, and additionally will induce further fear in the public by misrepresenting all large sharks as possible killers. They instead, and I agree, urge further research and education into why mistakes like shark attacks happen, that they are not purposeful, and that sharks are not repeatedly implicated.


      I do understand the fear in the public mindset of such a powerful animal and the damage they can inadvertently cause, but when it comes down to it swimmers are knowingly entering the domain of an apex predator. I just don't understand why anyone would have the desire to kill such significant, rare individuals, and even have photos taken in front of a butchered shark as the documentary depicts! How arrogant and ignorant must much of our species be to believe we have the right to kill a species in their adaptive environment that we invade for recreation? (Sorry for this being much like a rant). I can only conclude, based on the imminent killing of the individuals of a vulnerable species, that clearly the fear that Jaws inspired in many is still having a hugely detrimental effect on our biodiversity and ecosystems.



References:
1. Offutt, M. 2012. Is Jaws the only good shark story? [Blog]. <http://slckismet.blogspot.co.uk/2012/09/is-jaws-only-good-shark-story.html>
2. Channel 4. 2012. Jaws: The Great White Myth. <http://www.channel4.com/programmes/jaws-the-great-white-myth/4od>
3. Rourke, A. at The Guardian. 2012. Fatal attacks prompt call to lift ban on killing great white sharks. <http://www.guardian.co.uk/environment/2012/aug/25/great-white-shark-attacks-australia>
4. Associated Press at The Guardian. 2012. Plan to kill great white sharks that swim too close to Australian beaches. <http://www.guardian.co.uk/environment/2012/sep/28/great-white-sharks-killed-australia>
5. CCWA. 2012. 'Guilty until proven innocent' not the right approach for large sharks. <http://ccwa.org.au/media/%E2%80%98guilty-until-proven-innocent%E2%80%99-not-right-approach-large-sharks>
6. Government of Western Australia. 2012. Shark mitigation to protect beachgoers. <http://www.mediastatements.wa.gov.au/Pages/Results.aspx?ItemId=151064>