Lose biodiversity and you’ll get sick

14 03 2014

dengueHere’s a (paraphrased) recommendation I did recently for F1000 about a cool avenue of research I’ve been following for a few years now. Very interesting, but much, much more to do.

The core concepts of conservation ecology are well-established: we know that habitat lossfragmentation, invasive species, over-exploitation and of course, climate change, are bad for biodiversity. This well-quantified scientific baseline has led the discipline recently to embark on questions pertaining more to the (a) implications of biodiversity loss for humanity and (b) what we can do to offset these. A recent paper by Morand and colleagues addresses perhaps one of the most compelling reasons that human society should appreciate biodiversity beyond its intrinsic value; as biodiversity degrades, so too does human health.

Some argue that the only way to convince society in general that biodiversity is worth protecting is that we link its loss directly to degrading human health, wealth and well-being. Confirmation of such relationships at a variety of spatial and temporal scales is therefore essential. Morand and colleagues used data from a variety of sources to test two predictions: (1) that the number of infectious disease should increase as overall biodiversity increases and (2) that biodiversity loss, inferred from species threat and deforestation data, should increase the number of infectious disease outbreaks in humans. Using data from 28 countries in the Asia-Pacific region, they confirmed both predictions. Read the rest of this entry »





Sick environment, sick people

30 10 2009

sickplanetA quick post to talk about a subject I’m more and more interested in – the direct link between environmental degradation (including biodiversity loss) and human health.

To many conservationists, people are the problem, and so they focus naturally on trying to maintain biodiversity in spite of human development and spread. Well, it’s 60+ years since we’ve been doing ‘conservation biology’ and biodiversity hasn’t been this badly off since the Cretaceous mass extinction event 146-64 million years ago. We now sit squarely within the geological era more and more commonly known as the ‘Anthropocene’, so if we don’t consider people as an integral part of any ecosystem, then we are guaranteed to fail biodiversity.

I haven’t posted in a week because I was in Shanghai attending the rather clumsily entitled “Thematic Reference Group (TRG) on Environment, Agriculture and Infectious Disease’, which is a part of the UNICEF/UNDP/World Bank/World Health Organization Special Programme for Research and Training in Tropical Diseases (TDR) (what a mouthful that is). What’s this all about and why is a conservation ecologist (i.e., me) taking part in the group?

It’s taken humanity a while to realise that what we do to the planet, we eventually end up doing to ourselves. The concept of ecosystem services1 demonstrates this rather well – our food, weather, wealth and well-being are all derived from healthy, functioning ecosystems. When we start to bugger up the inter-species relationships that define one element of an ecosystem, then we hurt ourselves. I’ve blogged about this topic a few times before with respect to flooding, pollination, disease emergence and carbon sequestration.

Our specific task though on the TRG is to define the links between environmental degradation, agriculture, poverty and infectious disease in humans. Turns out, there are quite a few examples of how we’re rapidly making ourselves more susceptible to killer infectious diseases simply by our modification of the landscape and seascape.

Some examples are required to illustrate the point. Schistosomiasis is a snail-borne fluke that infects millions worldwide, and it is on the rise again from expanding habitat of its host due to poor agricultural practices, bad hygiene, damming of large river systems and climate warming. Malaria too is on the rise, with greater and greater risk in the endemic areas of its mosquito hosts. Chagas (a triatomine bug-borne trypanosome) is also increasing in extent and risk. Some work I’m currently doing under the auspices of the TRG is also showing some rather frightening correlations between the degree of environmental degradation within a country and the incidence of infectious disease (e.g., HIV, malaria, TB), non-infectious disease (e.g., cancer, cardiovascular disease) and indices of life expectancy and child mortality.

I won’t bore you with more details of the group because we are still drafting a major World Health Organization report on the issues and research priorities. Suffice it to say that if we want to convince policy makers that resilient functioning ecosystems with healthy biodiversity are worth saving, we have to show them the link to infectious disease in humans, and how this perpetuates poverty, rights injustices, gender imbalances and ultimately, major conflicts. An absolute pragmatist would say that the value of keeping ecosystems intact for this reason alone makes good economic sense (treating disease is expensive, to say the least). A humanitarian would argue that saving human lives by keeping our ecosystems intact is a moral obligation. As a conservation biologist, I argue that biodiversity, human well-being and economies will all benefit if we get this right. But of course, we have a lot of work to do.

CJA Bradshaw

Add to FacebookAdd to NewsvineAdd to DiggAdd to Del.icio.usAdd to StumbleuponAdd to RedditAdd to BlinklistAdd to Ma.gnoliaAdd to TechnoratiAdd to Furl

1Although Bruce Wilcox (another of the TRG expert members), who I will be highlighting soon as a Conservation Scholar, challenges the notion of ecosystem services as a tradeable commodity and ‘service’ as defined. More on that topic soon.





Deforestation and disease

10 09 2008

Humans have such a short memory…

A recent theme in many of my posts is the concept of ecosystem services provided to us essentially free of charge, and their continued degradation due to the burgeoning human population, bad land management and excessive resource consumption. We are indeed degrading the very life-support system species assemblages provide us. I’ve previously posted a long list of ecosystem services that you can consult here, but this recent paper in BioScience highlights one that is probably largely overlooked – the role of forests in reducing the incidence of human disease.

In their article entitled Deforestation, mosquitoes, and Ancient Rome: lessons for today, Lara O’Sullivan and colleagues discuss the evidence from Ancient Rome that deforestation rapidly increased the prevalence of malarial diseases. They also go on to cite several examples from the modern world where deforestation appears to be linked to greater manifestation of diseases like malaria.

The evidence isn’t just linked to Africa and the Amazon, but the authors suggest that the incidence of mosquito-borne diseases in Australia such as Ross River fever may also be on the rise as forests are quickly degraded and destroyed.

In two previous posts (see here and here), I commented on the escalating biodiversity crisis in the tropics driven largely by habitat loss (i.e., deforestation) – add increasing human disease to the long list of negatives associated with degrading or disappearing ecosystem services such as increased frequency and severity of floods, reduced food provision, reduced availability of clean water, reduced pollination, etc. We MUST educate the masses with the increasing body of scientific evidence that our behaviour is self-defeating (see previous post on this issue).

Indeed, it’s no longer the days of the capitalists versus the ‘greenies’ – the rapid decline in the quality of human life and and our own survival is affecting all of us, including the wealthy. In fact, I would argue that environmentalism has fully developed as the principal rationale in conservation ecology, such that it has become much less of an esoteric struggle for maintaining all things beautiful (the capitalist viewpoint of the traditional ‘greeny’), to a science-driven means to maintain human life and prosperity. Can we afford to continue along this path? Definitely not. Only an idiot with the foresight of a slug could ignore our current trajectory – and that includes the millionaire sport heroes, actors, and entrepreneurs who have benefited directly from our collective resource exploits. If you give a shit about the quality of life you and your descendants will have in the very near future, do not ignore habitat loss any longer.

CJA Bradshaw

Add to FacebookAdd to NewsvineAdd to DiggAdd to Del.icio.usAdd to StumbleuponAdd to RedditAdd to BlinklistAdd to Ma.gnoliaAdd to TechnoratiAdd to Furl