Crocodiles, spiders and leeches

11 04 2011

I just wrote a fun little piece for a new section in the journal Frontiers in Ecology and the Environment that they’re calling Trails and Tribulations. The basic idea is that the author recounts a particularly interesting field-related experience through which an ecological concept is woven.

Editor-in-Chief Sue Silver said that I could reproduce my article here as long as I acknowledged Frontiers and the Ecological Society of America. It was fun to write, and I hope you enjoy it too [the PDF of the article is available free of charge here].

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“So does each team get a hand gun?”

“No, you get an oar”

“What good is an oar?”

“Listen, mate. When a 3-metre croc jumps out of the swamp at you, there is nothing more natural in the world than to thump him with a big stick. It’s an autonomous response. With a gun, IF you manage to keep it dry, and IF you manage to get it out in time before the croc bites off your head, chances are you’ll just shoot the bloke in front of you anyway. So you get an oar.”

“Fair enough”.

That is an approximate, paraphrased reproduction of the initial conversation I had with renowned Australian crocodile biologist, Grahame Webb, just prior to my first (and as it turns out, only) trip to collect crocodile eggs for his Darwin wildlife park and crocodile farm. I volunteered to take part in the collection because I had recently begun working with Grahame and his team tracking the world’s largest crocodile species – the saltwater or estuarine crocodile Crocodylus porosus – and modelling aspects of its populations (Bradshaw et al. 2006). Having already been out on several occasions to harpoon and satellite-tag animals (some measuring > 4 m) on the Mary River, and cage-trap others in Kakadu National Park, I thought a little egg collection would be a proverbial walk in the park. Little did I know that it would end up being one of my more memorable experiences.

Let me walk you through the process. First, you wait until the height of the wet season and drive out as far as you can toward the breeding swamp of interest (in this case, Melacca Swamp in the Adelaide River flood plain, about one hour’s drive from Darwin). Then you and two other loonies pile into a small helicopter equipped with landing pontoons which ferries you to one of many previously identified crocodile nests. Because there is usually too much vegetation around the nest itself, the helicopter must land about 100-300 m away. Clothed only in long pants, a long-sleeved shirt and cotton gloves to protect your skin from the slicing blade grass, you jump off the helicopter’s pontoons into impenetrably murky, chest-deep water. One of the team drags an esky (chiller box into which eggs will be placed) and another carries an oar. As the noise of the departing helicopter becomes a faint buzz, you suddenly realise via the rapid expansion of your terminal sphincter that you are in the middle of a crocodile-filled swamp – and you are holding an oar. Read the rest of this entry »


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Categories : Australia, celebrity, conservation, conservation biology, environmental policy, exploitation, extinction, harvest, management, predator, research

Species’ Ability to Forestall Extinction – AudioBoo

8 04 2011

Here’s a little interview I just did on the SAFE index with ABC AM:

Not a bad job, really.

And here’s another one from Radio New Zealand:

CJA Bradshaw


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Categories : connectivity, conservation, demography, extinction, extinction debt, extinction vortex, IUCN, mammal, metapopulation, minimum viable population, modelling, mvp, population dynamics, population viability analysis, PVA, Red List, threatened species

How fast are we losing species anyway?

28 03 2011

© W. Laurance

I’ve indicated over the last few weeks on Twitter that a group of us were recently awarded funding from the Australian Centre for Ecological Synthesis and Analysis – ACEAS – (much like the US version of the same thing – NCEAS) to run a series of analytical workshops to estimate, with a little more precision and less bias than has been done previously, the extinction rates of today’s biota relative to deep-time extinctions.

So what’s the issue? The Earth’s impressive diversity of life has experienced at least five mass extinction events over geological time. Species’ extinctions have kept pace with evolution, with more than 99 % of all species that have ever existed now gone (Bradshaw & Brook 2009). Despite general consensus that biodiversity has entered the sixth mass extinction event because of human-driven degradation of the planet, estimated extinction rates remain highly imprecise (from 100s to 10000s times background rates). This arises partly because the total number of species is unknown for many groups, and most extinctions go unnoticed.

So how are we going to improve on our highly imprecise estimates? One way is to look at the species-area relationship (SAR), which to estimate extinction requires one to extrapolate back to the origin in taxon- and region-specific SARs (e.g., with a time series of deforestation, one can estimate how many species would have been lost if we know how species diversity changes in relation to habitat area). Read the rest of this entry »


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Categories : anthropocene, biogeography, conservation, deforestation, ecology, extinction, extinction debt, fragmentation, habitat loss, island biogeography, logging, modelling, research, species-area curve

Classics: demography versus genetics

16 03 2011

Here’s another short, but sweet Conservation Classic highlighted in our upcoming book chapter (see previous entries on this book). Today’s entry comes from long-time quantitative ecology guru, Russ Lande, who is now based at the Silwood Park Campus (Imperial College London).

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© IBL

In an influential review, Lande (1988) argued that

“…demography may usually be of more immediate importance than population genetics in determining the minimum viable size of wild populations”.

It was a well-reasoned case, and was widely interpreted to mean that demographic and ecological threats would provide the ‘killer blow’ to threatened species before genetic factors such as inbreeding and fitness effects of loss of genetic diversity had time to exert a major influence on small population dynamics.

Read the rest of this entry »


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Categories : conservation, conservation scholars, demography, extinction, extinction debt, genetics, minimum viable population, mvp, threatened species

What the hell is a banteng?

21 02 2011

A few years ago (ok, 6 years), ABC‘s Catalyst did a piece on our banteng research programme in Garig Gunak Barlu National Park in the Northern Territory. The show basically talks about the conservation and management conundrum of having a successful feral species in Australia that is also highly endangered in its native range (South East Asia). Do we shoot them all, or legislate them as an endangered species? It’s for Australians to decide.

I finally got around to uploading it on Youtube. I hope I haven’t contravened some copyright law, but I figure after such a lag, no one will care. I await the imminent contradiction from the ABC’s lawyers…

I hope you enjoy.

For the scientific papers arising from the work, see: Read the rest of this entry »


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Categories : Australia, bushmeat, conservation, extinction, harvest, invasive species, management, population dynamics, research, science, tropical

Evolution here and now

17 02 2011

Here’s a guest post from one of my PhD students, Salvador Herrando-Peréz. Salva is working on theoretical aspects of density feedback mechanisms among different species, and is especially eclectic with his interests in biology. Salva regularly contributes to lay natural history magazines, especially in his native tongue Castellano (Spanish), and he is an active member of the Spanish organisation Bioestudios Saganta, a non-profit national organisation fully devoted to scientific research and its popularisation with a focus on biodiversity conservation.

I’ve asked my students to start contributing to ConservationBytes.com, and Salva is leading the charge.

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Evolution evokes ideas such as fossils, geological eras and time scales of hundreds of thousands to millions of years. Only recently have we started to appreciate that such ‘macro-evolution’ is the result of accumulated changes in the morphology and genes of species from one generation to the next: days for HIV strands, months for a planktonic rotifer, or years for a poplar.

The Britons Peter and Rose Mary Grant published in 2002 a 30-year study on Darwin’s finches from Daphne Major (Galapagos, Ecuador) – a popular study organism since Charles Darwin’s Origin of species (Grant & Grant 2002). In such a short period of time, covering only six generations of these granivorous birds, several extreme droughts altered the type and abundance of seeds, and potentially triggered the evolution of body size, and beak shape and size, up to three times (Figure 1). The two biologists from Princeton reveal that:

  1. evolution is reversible – generations of finches experiencing overall increase in body and beak sizes can lead to future generations with smaller sizes (of course within limits; a finch will never develop the beak of a stork or a hummingbird), and
  2. phenological shifts across generations are unpredictable in so far as they respond to random climatic fluctuations – should droughts of contrasting intensity have occurred in different years over the study period, beaks and bodies might have evolved in other particular fashions. Read the rest of this entry »

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Categories : climate shift, conservation, extinction

Biodiversity begins at home

20 01 2011

A few months ago I was involved in a panel discussion entitled ‘Biodiversity begins at home’ held at the Royal Institution of Australia in Adelaide and sponsored by the Don Dunstan Foundation.

The main thrust of the evening was to have both academic (me & Andy Lowe) and on-the-ground, local conservationists (Sarah Lance, Craig Gillespie and Matt Turner) talk about what people can do to stem the tide of biodiversity loss. The video is now available, so I thought I’d reproduce it here. We talked about a lot of issues (from global to local scale), so if you have a spare hour, you might get something out of this. I did, but it certainly wasn’t long enough to discuss such big issues.

Warning – this was supposed to be more of a discussion and less of a talkfest; unfortunately, many of the panel members seemed to forget this and instead dominated the session. We really needed 4 hours to do this properly (but then, who would have watched the video?).

Read the rest of this entry »


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Categories : biodiversity, climate change, conservation, conservation biology, ecological literacy, ecosystem services, education, environmental economics, environmental policy, environmental science, extinction, habitat loss, human overpopulation, management, planning, prioritisation, protected area, restoration, science communication, South Australia, The University of Adelaide

History and future (of Australian ecology and society)

11 12 2010

I’ve just returned from a week-long conference in Canberra where the Ecological Society of Australia (of which I am a relatively new member) has just completed its impressive 50th anniversary conference. It was a long, but good week.

It’s almost a bit embarrassing that I’ve never attended an ESA1 conference before, but I think I waited for the right one. However, the main reason I attended was that I was fortunate to have received the ESA’s 3rd Australian Ecology Research Award (AERA), and the kick-back was a fully funded trip. My only reciprocation was to give a 40-minute plenary lecture – a small price to pay.

I entitled my talk ‘Heads in the desert sand: why Australians should wake up to the biodiversity crisis’, and I received a lot of good feedback. I talked about the global and Australian trends of biodiversity loss and associated ecosystem services, focussing the middle section on some of our work on feral animal ecology (see example). I then gave my views on the seriousness of our current situation and why some of the fastest losses of sensitive ecosystem services are happening right here, right now. I finished off with a section on how I think Australian ecologists could get more relevant and active in terms of research uptake by policy makers. I hope that the talk will be podcastable soon, so stay tuned.

But that was just ‘my’ bit. This post is more about a quick summary of the highlights and my overall impressions.

Read the rest of this entry »


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Categories : Australia, biodiversity, climate change, conference, conservation, conservation biology, conservation scholars, ecology, ecosystem, ecosystem function, ecosystem services, environmental policy, extinction, famine, food, human overpopulation

One billion people still hungry

12 11 2010

 

overpopulationA few days ago, that printed mouthpiece of Murdoch’s News Corporation in Australia – The Australiani, attacked Paul Ehrlich with a spectacular piece of uninformed gibberish (‘Population bomb still a fizzer 40 years on‘) that we both feel compelled to contest.

The Australian, well-known for its ‘War on Science’, refused to give us the opportunity to respond officially in an Opinion Editorial, so we are compelled to fight back using the blogosphere and our collective networks (which, we might add, probably exceed the distribution of said newspaper). Frankly, it was no surprise that The Australian chose to ignore us.

The article in question was written by Oliver Marc Hartwich of the so-called ‘Centre for Independent Studies’, the hyper-conservative Australian propaganda machine reminiscent of the ultra-right wing American Enterprise Institute, made up of some of Australia’s most powerful business magnates and with no academic affiliation whatsoever. Anything vaguely left-of-centre and even remotely promoting environmental responsibility is considered a viable target.

Recently, we blew the whistle on an equally dangerous man and the institutes he represents – climate-denier Alan Oxley; he and the business interests he represents are responsible for more deforestation, biodiversity loss and financial inequity in South East Asia over the last few decades than almost any single group.

Now we turn our attention to expose the true colours of the Centre for Independent Studies and Mr. Hartwich. Read the rest of this entry »


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Categories : Australia, climate change, conservation, corruption, ecosystem services, environmental policy, extinction, planning, poverty

The bomb is still ticking…

11 11 2010

Apologies for the silence over the last week – it’s been a whirlwind here with Paul Ehrlich visiting The University of Adelaide (amazing for a 78-year old man). In the meantime, Sharon Ede over at Post Growth wrote a great response to the LOLstralian‘s high-school effort to attack Paul a few days ago. Our response is coming shortly, but Sharon’s article is a great precursor.

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More than forty years after its publication, the predictions made in Paul Ehrlich’s landmark book ‘The Population Bomb’ are still the subject of debate. Australian think-tank the Centre for Independent Studies (‘Population bomb still a fizzer 40 years on’, The Australian, 8 November, 2010), says Ehrlich’s warnings of dire consequences, including of mass starvation as a result of overpopulation, have not materialised:

“More than 40 years ago, American biologist Paul Ehrlich sketched a doomsday scenario for planet Earth in his book The Population Bomb…Since the publication of the book, the global population has nearly doubled but most of its gloomy predictions have not come true…”

By all means, let’s have a robust debate on population, both at the national and global level. Both are long overdue.

But let’s make it a sophisticated debate, grounded in the science we have available and a thorough understanding of all the issues in play.

According to the United Nations’ Population Division, the global population has increased from one billion in 1804 to over six billion in 2010.

It has taken most of human history to reach one billion people. It took just over a century to add the second billion.

The rate of population growth since then is such that it has taken only twelve years to add the most recent billion people.

The moderate UN scenario is for a population of 9 billion by 2050 – that’s within the lifetime of many of us. Read the rest of this entry »


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Categories : Australia, climate change, conservation, conservation scholars, ecosystem, ecosystem services, environmental policy, extinction, propaganda, The University of Adelaide

Global erosion of ecosystem services

14 09 2010

A few months ago I was asked to give a lecture about erosion of ecosystem services to students in the University of Adelaide‘s Issues in Sustainable Environments unit. I gave that lecture last week and just uploaded a slidecast of the presentation (with audio) today.

I’ve reproduced the lecture here for your viewing pleasure. I hope you find the 45-minute presentation useful. Note that the first few minutes cover me referring to the Biodiversity film short that I posted not too long ago.

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CJA Bradshaw


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Categories : anthropocene, Australia, biodiversity, carbon, climate change, coasts, coral reefs, deforestation, disease, ecosystem services, environmental policy, extinction, fire, fisheries, flood, fragmentation, governance, habitat loss, harvest, health, human overpopulation, illegal fishing, kelp, logging, marine protected area, MPA, pollination, predator, protected area, Red List, seagrass, shark, The University of Adelaide, threatened species, water

Biodiversity: from conservation science to action

11 09 2010

© tidechaser.blogspot.com

About 3 weeks ago I blogged about Guillaume Chapron‘s vision to notch up conservation implementation around the globe. After that little piece Guillaume invited me and a few others (including one of Australia’s own conservation gurus, Hugh Possingham) to co-author a piece on the new Nature Network‘s ‘Soapbox Science‘ blog. The Soapbox Science blog is:

“… a new group blog, covering the whole of science. Over the coming months, we’ll be inviting researchers from all over the world to write one-off posts. The subjects may be controversial, opinionated, speculative, or just plain interesting, and may be written by any scientist with something to say.”

We managed to grab the first post in this endeavour, so I reproduce it here for ConservationBytes.com readers. Enjoy!

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Ecosystem degradation and species extinction rates are steadily accelerating, mainly as a result of unbounded human population growth, extravagant consumption patterns and associated land and sea degradation. Researchers are pushing science forward in an attempt to reverse the biodiversity ‘crisis’. In their papers they systematically stress how their results can serve to enhance conservation management or implement new corrective actions to reduce biodiversity loss. Still, they are becoming increasingly frustrated that their published research is having little, if any impact in halting the ongoing sixth mass extinction. Everything remains purely theoretical and is not leading to direct action. Read the rest of this entry »


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Categories : biodiversity, blog, conservation, conservation biology, ecosystem, ecosystem services, environmental policy, extinction, minimum viable population, planning

Webinar: Modelling water and life

27 08 2010

Another quick one today just to show the webinar of my recent 10-minute ‘Four in 40’ talk sponsored by The Environment Institute and the Department for Water. This seminar series was entitled ‘Modelling as a Tool for Decision Support’ held at the Auditorium, Royal Institution Australia (RiAus).

“Four in 40″ is a collaboration between The University of Adelaide and the Department for Water, where 4 speakers each speak for 10 minutes on their research and its implications for policy. The purpose is to build understanding of how best to work with each other, build new business for both organisations and raise awareness of activity being undertaken in water/natural resource management policy and research.

CJA Bradshaw


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Categories : anthropocene, biodiversity, biogeography, connectivity, conservation, conservation biology, deforestation, ecosystem services, environmental policy, extinction, habitat loss, health, island biogeography, management, marine protected area, mathematics, minimum viable population, modelling, protected area, research, The University of Adelaide, threatened species

Linking disease, demography and climate

1 08 2010

Last week I mentioned that a group of us from Australia were travelling to Chicago to work with Bob Lacy, Phil Miller, JP Pollak and Resit Akcakaya to make some pretty exciting developments in next-generation conservation ecology and management software. Also attending were Barry Brook, our postdocs: Damien Fordham, Thomas Prowse and Mike Watts, our colleague (and former postdoc) Clive McMahon, and a student of Phil’s, Michelle Verant. At the closing of the week-long workshop, I thought I’d share my thoughts on how it all went.

In a word, it was ‘productive’. It’s not often that you can spend 1 week locked in a tiny room with 10 other geeks and produce so many good and state-of-the-art models, but we certainly achieved more than we had anticipated.

Let me explain in brief why it’s so exciting. First, I must say that even the semi-quantitative among you should be ready for the appearance of ‘Meta-Model Manager (MMM)’ in the coming months. This clever piece of software was devised by JP, Bob and Phil to make disparate models ‘talk’ to each other during a population projection run. We had dabbled with MMM a little last year, but its value really came to light this week.

We used MMM to combine several different models that individually fail to capture the full behaviour of a population. Most of you will be familiar with the individual-based population viability (PVA) software Vortex that allows relatively easy PVA model building and is particular useful for predicting extinction risk of small populations. What you most likely don’t know exists is what Phil, Bob and JP call Outbreak – an epidemiological modelling software based on the classic susceptible-exposed-infectious-recovered framework. Outbreak is also an individual-based model that can talk directly to Vortex, but only through MMM. Read the rest of this entry »


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Categories : Allee effect, buffalo, cattle, connectivity, conservation, demography, extinction, harvest, management, metapopulation, modelling, population viability analysis, PVA, software

Faraway fettered fish fluctuate frequently

27 06 2010

Hello! I am Little Fish

Swimming in the Sea.

I have lots of fishy friends.

Come along with me.

(apologies to Lucy Cousins and Walker Books)

I have to thank my 3-year old daughter and one of her favourite books for that intro. Now to the serious stuff.

I am very proud to announce a new Report in Ecology we’ve just had published online early about a new way of looking at the stability of coral reef fish populations. Driven by one of the hottest young up-and-coming researchers in coral reef ecology, Dr. Camille Mellin (employed through the CERF Marine Biodiversity Hub and co-supervised by me at the University of Adelaide and Julian Caley and Mark Meekan of the Australian Institute of Marine Science), this paper adds a new tool in the design of marine protected areas.

Entitled Reef size and isolation determine the temporal stability of coral reef fish populations, the paper applies a well-known, but little-used mathematical relationship between the logarithms of population abundance and its variance (spatial or temporal) – Taylor’s power law.

Taylor’s power law is pretty straightforward itself – as you raise the abundance of a population by 1 unit on the logarithmic scale, you can expect its associated variance (think variance over time in a fluctuating population to make it easier) to rise by 2 logarithmic units (thus, the slope = 2). Why does this happen? Because a log-log (power) relationship between a vector and its square (remember: variance = standard deviation2) will give a multiplier of 2 (i.e., if x ~ y2, then log10x ~ 2log10y).

Well, thanks for the maths lesson, but what’s the application? It turns out that deviations from the mathematical expectation of a power-law slope = 2 reveal some very interesting ecological dynamics. Famously, Kilpatrick & Ives published a Letter in Nature in 2003 (Species interactions can explain Taylor’s power law for ecological time series) trying to explain why so many real populations have Taylor’s power law slopes < 2. As it turns out, the amount of competition occurring between species reduces the expected fluctuations for a given population size because of a kind of suppression by predators and competitors. Cool.

But that application was more a community-based examination and still largely theoretical. We decided to turn the power law a little on its ear and apply it to a different question – conservation biogeography. Read the rest of this entry »


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Categories : Australia, biogeography, connectivity, conservation, coral reefs, extinction, fish, island biogeography, marine, marine protected area, minimum viable population, modelling, MPA, mvp, protected area, stochasticity, The University of Adelaide, tropical

Australian Ecology Research Award

7 06 2010

I had the immense pleasure of receiving a telephone call a few weeks back from the Ecological Society of Australia telling me that I had been awarded the 2010 Australian Ecology Research Award (AERA). They’ve just announced it, so I’m now allowed to boast a bit on Conservation Bytes.

If you’re going to the 50th Anniversary ESA annual conference in Canberra this year ‘Sustaining Biodiversity – the next 50 years‘ (6-10 December), I’ll be giving the AERA Plenary Lecture then. Thanks to the ESA for my selection, the University of Adelaide (The Environment Institute & School of Earth and Environmental Sciences), the South Australian Research and Development Institute, and all my students, post-docs and collaborators for your support. Many thanks also to Prof. Bill Laurance for the nomination!

The AERA blurb from the ESA site follows: Read the rest of this entry »


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Categories : conservation, extinction, harvest, invasive species, mathematics, modelling

Where in the world to invest in plant conservation

31 05 2010

© CBD

It’s been a good few weeks with many of our papers coming out online early – for example, I highlighted one last week on ecosystem function breakdown from global warming.

Although this has been out for a few weeks, our new paper lead by PhD candidate Xingli Giam (formerly of National University of Singapore, recently completed Australian Endeavour Scholar, now at Princeton University and all-round up-and-coming research star), and with contributions from Hugh “Vascular” Tan and Navjot Sodhi of National University of Singapore and me, is entitled Future habitat loss and the conservation of plant biodiversity (just published online in Biological Conservation).

This one is a bit of a complicated one, so let me walk you through it.

Plants not only represent a huge component of global biodiversity (~320 000 species), they represent the ‘habitats’ in which animals live and provide the major source of nutrients to food webs. They also provide most of our food and other materials essential for human existence. Basically we’d be screwed without them.

Because so many of the world’s biomes are severely threatened now because of massive habitat loss, degradation, over-exploitation, invasive species, extinction synergies and climate change, we need to maximise our efficiency in protecting what’s left. While global prioritisation schemes have a fruitful scientific history since Myers & colleagues’ classic paper (see Biodiversity Hotspots), there are a number of problems that plague the concept and its implementation. Read the rest of this entry »


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Categories : conservation, deforestation, extinction, habitat loss, modelling, planning, prioritisation, research, reserve, species-area curve

Why and how did Pleistocene megafauna go extinct?

27 05 2010

Just a quick post to say that I’m currently at Duke University in the USA attending a special National Evolutionary Synthesis Centre ‘Catalysis Meeting’ entitled: Integrating datasets to investigate megafaunal extinction in the Late Quaternary.

The meeting is basically about nailing down some of the remaining mysteries and controversies surrounding the extinction of many species during periods of rapid climate change 11-60 thousand years ago.

It’s been fun so far, and a lot of exciting analysis will ensue, but for the meantime I’ll just summarise what we’re trying to do. Read the rest of this entry »


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Categories : climate change, conservation, extinction, extinction debt

Fanciful mathematics and ecological fantasy

3 05 2010

© flickr/themadlolscientist

Bear with me here, dear reader – this one’s a bit of a stretch for conservation relevance at first glance, but it is important. Also, it’s one of my own papers so I have the prerogative :-)

As some of you probably know, I dabble quite a bit in population dynamics theory, which basically means examining the mathematics people use to decipher ecological patterns. Why is this important? Well, most models predicting extinction risk, estimating optimal harvest rates, determining minimum viable population size and metapopulation dynamics for species’ persistence rely on good mathematical abstraction to be realistic. Get the maths wrong, and you could end up overharvesting a species (e.g., 99.99 % of fisheries management), underestimating extinction risk from habitat degradation, and getting your predictions wrong about the effects of invasive species. Expressed as an equation itself, (conservation) ecology = mathematics.

A long-standing family of models known as ‘phenomenological’ models (i.e., because they deal with the phenomenon of population size which is an emergent property of the mechanisms of birth, death and immigration) has been used to estimate everything from maximum sustainable yield targets, temporal abundance patterns, wildlife management interventions, extinction risk to epidemiological patterns. The basic form of the model describes the growth response, or the relationship between the population’s rate of change (growth) and its size. The simplest form (known as the Ricker), assumes a linear decline in population growth rate (r) as the number of individuals increases, which basically means that populations can’t grow indefinitely (i.e., they fluctuate around some carrying capacity if unperturbed). Read the rest of this entry »


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Categories : alien species, conservation, demography, exploitation, extinction, fisheries, harvest, invasive species, management, metapopulation, minimum viable population, modelling, mvp, population dynamics, population viability analysis, PVA

The maggot of the plant world – mangroves

12 04 2010

I don’t know how many of my readers have waded through a mangrove swamp before – if you have, you’ll know it’s no ‘walk in the park’. They are generally mosquito-infested with waist-deep mud, have more creepy-crawlies than you can poke a stick at, and in some places (such as my former stomping ground, the Northern Territory of Australia) are down-right dangerous due to lovelies such as saltwater crocodiles.

But, most people probably don’t know just how important mangroves are. Just like the maggot who can sicken the hardiest of individual, under-appreciated mangroves provide major ecosystem services.

For example, did you know that mangroves:

  1. Protect inland human communities from damage caused by coastal erosion and storms?
  2. Provide critical habitat for a variety of terrestrial, estuarine and marine species? Indeed, it has been estimated that ~80 % of fish catches globally depend directly or indirectly  on mangroves.
  3. Are a source and sink for nutrients and sediments for other inshore marine habitats including seagrass beds and coral reefs?
  4. Protect coasts from floods?
  5. Process nutrient and organic matter?
  6. Control sediment?
  7. Provide at least US$1.6 billion per year in ecosystem services worldwide?
  8. Sequester up to 25.5 million tonnes of carbon per year?
  9. Provide more than 10% of essential organic carbon to the global oceans?
  10. Occupy only 0.12% of the world’s total land area?

Pretty staggering, no?

So, even if you don’t like them, it’s difficult to deny that they’re important.

But, like almost every other habitats worldwide, mangroves are on the big downward slide. In a new paper in PLoS One by Polidoro & colleagues entitled The loss of species: mangrove extinction risk and geographic areas of global concern, the authors not only highlight the above benefits, they quantify just how badly the 70 mangrove species around the world are faring. Read the rest of this entry »


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Categories : conservation, ecosystem services, environmental policy, extinction, fisheries, flood, habitat loss

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