Empty seas coming to a shore near you

12 07 2012

Last week I had the pleasure of entertaining some old friends and colleagues for a writing workshop in Adelaide (don’t worry – they all came from southern Australia locations, so no massive carbon footprints for overseas travel). I’m happy to report it was a productive (and epicurean) week, but that’s not really the point of today’s post.

One of those participants was long-time colleague, Dr. Rik Buckworth. Rik and I first met in Darwin back in the early 2000s when he was lead fisheries scientist for Northern Territory Fisheries; this collaboration and friendship blossomed into an ARC Linkage Project (with Dr. Mark Meekan of AIMS) on shark fisheries (see some of the scientific outputs from that here, here, here and here). Rik has since moved to CSIRO in Brisbane, but keeps a hand in NT fisheries’ affairs. Incidentally, Rik trained under one of the most well-known fisheries modellers in the world – Carl Walters – when he did his PhD at the University of British Columbia back in the early 1990s.

During our workshop, Rik pointed out a paper he had co-authored back in 2009 in Reviews in Fish Biology and Fisheries that had completely escaped my attention – it’s a frightening and apocalyptic view of the Australasian marine tropics that seems to confirm our predictions about northern Australia’s marine future. Just take a look at the following two figures from their paper (Elasmobranchs in southern Indonesian fisheries: the fisheries, the status of the stocks and management options): Read the rest of this entry »





No more ecology

9 05 2012

To all ecology people who read this blog (students, post-docs, academics), this is an intriguing, provocative and slightly worrying title. As ecology has matured into a full-fledged, hard-core, mathematical science on par with physics, chemistry and genetics (and is arguably today one of the most important sciences given how badly we’ve trashed our own home), its sophistication now threatens to render many of the traditional aspects of ecology redundant.

Let me explain.

As a person who cut his teeth in field ecology (with all the associated dirt, dangers, bites, stings, discomfort, thrills, headaches and disasters), I’ve had my fair share of fun and excitement collecting ecological data. There’s something quaintly Victorian (no, I am not referring to the state next door) about the romantic and obsessive naturalist collecting data to the exclusion of nearly all other aspects of civilised life; the intrepid adventurer in some of us takes over (likely influenced by the likes of David Attenborough) and we convince ourselves that our quest for the lonely datum will heal all of the Earth’s ailments.

Bollocks.

As I’ve matured in ecology and embraced its mathematical complexity and beauty, the recurring dilemma is that there are never enough data to answer the really big questions. We have sampled only a fraction of extant species, we know embarrassingly little about how ecosystems respond to disturbance, and we know next to nothing about the complexities of ecosystem services. And let’s not forget our infancy in understanding the synergies of extinctions in the past and projections into the future. Multiply this uncertainty by several orders of magnitude for ocean ecosystems.

Read the rest of this entry »





Sharks: the world’s custodians of fisheries

5 05 2012

Today’s post comes from Salvador Herrando-Pérez (who, incidentally, recently submitted his excellent PhD thesis).

Three species co-occurring in the Gulf of Mexico and involved in the trophic cascade examined by Myers et al. (8). [1] Black-tips (Carcharhinus limbatus) are pelagic sharks in warm and tropical waters worldwide; they reach < 3 m in length, 125 kg in weight, with a maximum longevity in the wild of ~ 12 years; a viviparous species, with females delivering up to 10 offspring per parturition. [2] The cownose ray (Rhinoptera bonasus) is a tropical species from the western Atlantic (USA to Brazil); up to 2 m wide, 50 kg in weight, and 18 years of age; gregarious, migratory and viviparous, with one single offspring per litter. [3] The bay scallop (Agropecten irradians) is a protandric (hermaphrodite) mollusc, with sperm being released a few days before the (> 1 million) eggs; commonly associated with seagrasses in the north-western Atlantic; shells can reach up to 10 cm and individuals live for < 2 years. In the photos, a black-tip angled in a bottom long-line off Alabama (USA), a school of cownose rays swimming along Fort Walton Beach (Florida, USA), and a bay scallop among fronds of turtle grass (Thalassia testudinum) off Hernando County (Florida, USA). Photos by Marcus Drymon, Dorothy Birch and Janessa Cobb, respectively.

The hips of John Travolta, the sword of Luke Skywalker, and the teeth of Jaws marked an era. I still get goose pimples with the movie soundtrack (bass, tuba, orchestra… silence) solemnizing each of the big shark’s attacks. The media and cinema have created the myth of man’s worst friend. This partly explains why shark fishing does not trigger the same societal rejection as the hunting of other colossuses such as whales or elephants. Some authors contend that we currently live in the sixth massive extinction event of planet Earth (1) 75 % of which is strongly driven by one species, humans, and characterized by the systematic disappearance of mega-animals in general (e.g., mammoths, Steller’s seacow), and predators in particular, e.g., sharks (2, 3).

The selective extirpation of apex predators, recently coined as ‘trophic downgrading’, is transforming habitat structure and species composition of many ecosystems worldwide (4). In the marine realm, over the last half a century, the main target of the world’s fisheries has turned from (oft-large body-sized) piscivorous to planctivorous fish and invertebrates, indicating that fishery fleets are exploiting a trophic level down to collapse, then harvesting the next lower trophic level (5-7).

Myers et al. (8) illustrate the problem with the fisheries of apex-predator sharks in the northeastern coast of the USA. Those Atlantic waters are rife with many species of shark (> 2 m), whose main prey are smaller chondrichthyans (skates, rays, catsharks, sharks), which in turn prey on bottom fishes and bivalves. Myers et al. (8) found that, over the last three decades, the abundance of seven species of large sharks declined by ~ 90 %, coinciding with the crash of a centenary fishery of bay scallops (Agropecten irradians). Conversely, the abundance of 12 smaller chondrichthyes increased dramatically over the same period of time. In particular, the cownose ray (Rhinoptera bonasus), the principal predator of bay scallops, might today exceed > 40 million individuals in some bays, and consume up to ~ 840,000 tonnes of scallops annually. The obvious hypothesis is that the reduction of apex sharks triggers the boom of small chondrichthyans, hence leading to the break-down of scallop stocks. Read the rest of this entry »





Where are they? Finding (and conserving) the biggest fish in the sea

16 11 2011

A post from my PhD student, Ana Sequeira, on her latest paper just out in Diversity and DistributionsOcean-scale prediction of whale shark distribution.

© W Osborn (AIMS)

The ocean is our major source of water, it stabilises our breathable atmosphere and provides many supplies such as medicines (e.g., anti-cancer therapy drugs1) and food. Despite its the importance for human life, many marine species are now at a high risk of extinction owing to human changes to the oceans.

The whale shark (Rhincodon typus, Smith 1828) – an icon of the oceans of a spectacularly huge size and docile character – is just one of those species.

Despite being a fish that many people (mainly in Southeast Asia) are happy to have on their plate, whale sharks are worth millions of dollars every year in the ecotourism industry worldwide. One would then expect that being such a profitable species, their ecology would be well known and thoroughly studied.

The reality is quite different.

Basic information on whale sharks such as the whereabouts of their breeding areas, the average number of offspring per female, or even how many individuals still exist, is not currently known. Moreover, despite the genetic evidence that whale sharks worldwide are connected among different oceans, it is unclear if they move from places where they are protected to places where they are still illegally fished.

Information on distribution and patterns of occurrence in space and time is essential for conservation, and can help to save entire ecosystems if used correctly, for example: to isolate important mating and breeding areas.

To identify the whale shark’s seasonal distribution patterns in the Indian Ocean, to test if records follow a decreasing trend over time, and if occurrence is related to variation in climatic signals, we used multivariate distribution models of seasonal and inter-annual whale shark sightings opportunistically collected over 17 years by the tuna purse-seine fishery. Read the rest of this entry »





Oceans need their giants

2 11 2011

Another great post from Salvador Herrando Pérez.

from adsown.blogspot.com

Commercial and sport fishing establish minimum body sizes for catches of many species to preserve fish stocks. Recent work reveals that sustainable fisheries also depend on the regulation of the harvest of the biggest fish, at least in long-lived species.

Growing up in Spain in the 1980s, I was taken by a Spanish television spot featuring a shoal of little fish sucking colourful dummies, and at the same time (how they managed, I never questioned) singing the motto Little fish? No, thanks. The then Ministry of Agriculture, Fishery and Food created this media campaign to create awareness among consumers not to buy immature fish at local markets – “…a 60-gram hake will only weigh 2 kg after two years” the add stated.

Indeed, the regulation of fish harvest by age classes is substantial to any fishery. In particular, the protection of younger fish has been a beacon of fishery policy and management that dates back to the 19th century when, among others, the British ichthyologist Ernst Holt concluded that: “…it is desirable that fish should have a chance of reproducing their species at least once before they are destroyed” 1. Very much in line with such principles, conventional fish stock management has in practice neglected the mature age classes2, other than for the fact that they are the end point of extraction and what we consumers eat on the table. Read the rest of this entry »





Twenty landmark papers in biodiversity conservation

13 10 2011

While I can’t claim that this is the first time one of my peer-reviewed papers has been inspired by ConservationBytes.com, I can claim that this is the first time a peer-reviewed paper is derived from the blog.

After a bit of a sordid history of review (isn’t it more and more like that these days?), I have the pleasure of announcing that our paper ‘Twenty landmark papers in biodiversity conservation‘ has now been published as an open-access chapter in the new book ‘Research in Biodiversity – Models and Applications‘ (InTech).

Perhaps not the most conventional of venues (at least, not for me), but it is at the very least ‘out there’ now and freely available.

The paper itself was taken, modified, elaborated and over-hauled from text written in this very blog – the ‘Classics‘ section of ConservationBytes.com. Now, if you’re an avid follower of CB, then the chapter won’t probably represent anything terribly new; however, I encourage you to read it anyway given that it is a vetted overview of possibly some of the most important papers written in conservation biology.

If you are new to the field, an active student or merely need a ‘refresher’ regarding the big leaps forward in this discipline, then this chapter is for you.

The paper’s outline is as follows: Read the rest of this entry »





Rise of the phycologists

22 09 2011

Dead man's fingers (Codium fragile) - © CJA Bradshaw

I’ve had an interesting week. First, it’s been about 6 years since I was last in Japan, and I love coming here; the food is exquisite, the people are fantastic (polite, happy, accommodating), everything works (trains, buses, etc.) and most importantly, it has an almost incredible proportion of its native forests intact.

But it wasn’t for forests that I travelled to Japan (nor the sumo currently showing on the guest-room telly where I’m staying – love the sumo): I was here for a calcareous macroalgae workshop.

What?

First, what are ‘macroalgae’, and why are some ‘calcareous’? And why should anyone in their right mind care?

Good questions. Answers: 1. Seaweeds; 2. Many incorporate calcium carbonate into their structures as added structural support; 3. Read on.

Now, I’m no phycologist (seaweed scientist), but I’m fascinated by this particular taxon. I’ve written a few posts about their vital ecological roles (see here and here), but let me regale you with some other important facts about these amazing species.

Some Japanese macroalgae - © CJA Bradshaw

There are about 12,000 known species of macroalgae described by phycologists, but as I’ve learnt this week, this is obviously a vast underestimate. For most taxa that people are investigating now using molecular techniques, the genetic diversity is so high and so geographically structured that there are obviously a huge number of ‘cryptic’ species within our current taxonomic divisions. This could mean that we’re out by up to a factor of 2 in the number of species in the world.

Another amazing fact – about 50 % of all known seaweed species are found in just two countries – Japan and Australia (hence the workshop between Japanese and Australian phycologists). Southern Australia in particular is an endemism hotspot.

Ok. Cool. So far so good. But so what? Read the rest of this entry »





The few, the loud and the factually challenged

18 06 2011

© The Guardian

Here’s a little paraphrased response I received from a colleague who works for a particular agency concerned about the ridiculous politicking and misinformation associated with marine parks proposed for South Australia.

I’ve posted several times before why marine parks are a win for all involved, from the biodiversity it is meant to protect, to the fishers who benefit from the free, public-good resource that they assist in maintaining (see here, here and here). The evidence is clear world-wide: marine parks benefit pretty much everything and everyone.

However, just like the climate change denalists who use every psychological tactic in the book to try to convince people that climate change is a belief when in fact, it is a soundly evidenced phenomenon, there are those Luddites who think that any change in the marine setting fundamentally threatens their way of life.

Here’s what my colleague had to say about some recent ill-informed comments on this blog:

I wondered when they would find your blog. In my experience, do not engage. A game of intimidation has started. Read the rest of this entry »





Does the pope wear a funny hat?

5 04 2011

Does a one-legged duck swim in circles? Does an ursid defecate in a collection of rather tall vascular plants? Does fishing kill fish?

Silly questions, I know, but it’s the kind of question posed every time someone doubts the benefits (i.e., for biodiversity, fishing, local economies, etc.) of marine reserves.

I’ve blogged several times on the subject (see Marine protected areas: do they work?The spillover effectInterview with a social (conservation) scientist, and Failing on ocean protection), but considering Hugh Possingham is town today and presenting the case to the South Australian Parliament on why this state NEEDS marine parks, I thought I’d rehash an old post of his published earlier this year in Australasian Science:

Science has long demonstrated that marine reserves protect marine biodiversity. Rather than answer the same question again, isn’t it about time we started funding research that answers some useful scientific questions?

As marine reserves spread inexorably across the planet, the cry from skeptics and some fishermen is: “Do marine reserves work?” The science is pretty clear but acknowledgement of this by the public is another story. Let me begin with a story of my experience answering this question while communicating to stakeholders the subtleties of marine conservation planning during the rezoning of Moreton Bay.

I was asked by the then-Queensland Environmental Protection Agency to explain to stakeholders the process of marine reserve system design as it applied to the Moreton Bay rezoning. I told the gathering that the rezoning was about conserving a fraction of each mappable biodiversity attribute (species and habitats) for the minimum impact on the livelihood of others. Read the rest of this entry »





Big sharks. Big mystery.

9 03 2011

My PhD student, Ana Sequeira, has just written a great little guest blog post for the Environment Institute‘s blog. Given I’m en route to Tasmania for a quick consultancy meeting, I thought I’d let myself off the hook and reproduce the post here. Well done, Ana (and hint to my other students – your time on ConservationBytes.com is coming…).

This week is Seaweek and guest blogger Ana Sequeira describes how whale shark distribution might be shifting according to seasonal environmental predictors.

Ana Sequeira is a PhD student at the University of Adelaide (Global Ecology Group). Her main research interests are to develop models applied to the marine environment to describe key environmental processes, species distribution patterns and ecological interactions.

The main objective of her PhD thesis is to investigate behavioural ecology of whale sharks. She is now trying to understand which environmental variables may affect whale shark distribution.

The whale shark (Rhincodon typus, Smith 1828) is the largest fish in the ocean and can reach more than 12 m in total length. Although little is known about their habitat selection or migration patterns, the whale shark appears to be a highly mobile species. They predictably form near shore aggregations in some coastal locations (e.g. off Ningaloo reef in Western Australia) what makes them the subject of highly lucrative marine ecotourism industries. Also, artisanal and small-scale fisheries for the species still exist in many parts of the tropics.

Since the whale sharks is classified a Vulnerable species (IUCN Red List), understanding their migratory behaviour became of chief importance as they can be travelling from regions where they are protected to regions where they are still harvested. Read the rest of this entry »





Classics: Shifting baselines

14 02 2011

The Conservation Classics series will soon be collated and published in a special chapter for the book ‘Biodiversity’ to be published later this year by InTech. The chapter is co-authored by Barry Brook, Navjot Sodhi, Bill Laurance and me. This is a snippet of one ‘classic’ I haven’t yet really covered extensively on ConservationBytes.com.

Daniel Pauly’s (1995) concept describes the way that changes to a system are measured against baselines which themselves are often degraded versions of the original state of the system. Pauly (1995) originally meant it in a fisheries context, where “… fisheries scientists sometimes fail to identify the correct ‘baseline’ population size (e.g., how abundant a fish species population was before human exploitation) and thus work with a shifted baseline”. It is now considered a mantra in fisheries and marine science (Jackson et al., 2001), but it has been extended to many other conservation issues. Yet, quantifying shifting baselines in conservation is difficult, with little empirical evidence (but see Jackson et al., 2001), despite the logic and general acceptance of its ubiquity by conservation scientists. Read the rest of this entry »





Colour-blind sharks

3 02 2011

A few weeks ago I was interviewed on Channel 10 (Adelaide) about some new research coming out of the University of Western Australia regarding shark colour vision.

I’ve received permission from Channel 1o to reproduce the news snippet here. The first bloke interviewed is Associate Professor Nathan Hart, the study‘s lead author. I’m the bald one appearing in the middle at at the end.

It certainly was an interesting story, although two claims were made that probably needed better contextualisation.

First, the authors claim that because of this taxon’s colour blindness, they probably notice pigment transitions more when using visual cues to identify potential prey. What this means is that bright colours set against duller backgrounds might provide that contrast enough to attract sharks. The upshot from the interview is that brightly coloured and patterned togs (bathers) might make sharks think you are potentially a tasty treat. Read the rest of this entry »





Blog Action Day 2010 – Water neutrality and its biodiversity benefits

16 10 2010

In my little bid to participate in Change.org’s Blog Action Day 2010 – Water, I’ve re-hashed a post from 2008 on ‘water neutrality’. This will also benefit my recently joined readers, and re-invigorate a concept I don’t think has received nearly enough attention globally (or even in parched Australia where I live). So here we go:

The world’s freshwater ecosystems are in trouble. We’ve extracted, poisoned, polluted, damned and diverted a large proportion of the finite (and rather small!) amount of freshwater on the planet. Now, most people might immediately see the problem here from a selfish perspective – no clean, abundant water source = human disease, suffering and death. Definitely something to avoid, and a problem that all Australians are facing (i.e., it’s not just restricted to developing nations). Just look at the Murray-Darling problem.

In addition to affecting our own personal well-being, freshwater ecosystems are thought to support over 10000 fish species worldwide (see also a recent post on Africa’s freshwater biodiversity’s susceptibility to climate change), and the majority of amphibians and aquatic reptiles. Current estimates suggest that about 1/3 of all vertebrate biodiversity (in this case, number of species) is confined to freshwater. As an example, the Mekong River system alone is thought to support up to 1700 different species of fish.

So, what are some of the ways forward? The concept of ‘water neutrality’ is essentially the wet version of carbon neutrality. It basically means that water usage can be offset by interventions to improve freshwater habitats and supply. Read the rest of this entry »





September 2010 Issue of Conservation Letters out

13 10 2010

Conservation Lettersfifth issue (September) of Volume 3 is now out. Some good ones here.

CJA Bradshaw





Humans 1, Environment 0

27 09 2010

© flickr.com/photos/singapore2010

While travelling to our Supercharge Your Science workshop in Cairns and Townsville last week (which, by the way, went off really well and the punters gave us the thumbs up – stay tuned for more Supercharge activities at a university near you…), I stumbled across an article in the Sydney Morning Herald about the state of Australia.

That Commonwealth purveyor of numbers, the Australian Bureau of Statistics (ABS), put together a nice little summary of various measures of wealth, health, politics and environment and their trends over the last decade. The resulting Measures of Australia’s Progress is an interesting read indeed. I felt the simple newspaper article didn’t do the environmental components justice, so I summarise the salient points below and give you my tuppence as well. Read the rest of this entry »





The lost world – freshwater biodiversity conservation

6 09 2010

Even the most obtuse, right-wing, head-in-the-sand, consumption-driven, anti-environment yob would at least admit that they’ve heard of forest conservation, the plight of whales (more on that little waste of conservation resources later) and climate change. Whether or not they believe these issues are important (or even occurring) is beside the point – the fact that this particular auto-sodomist I’ve described is aware of the issues is at least testament to growing concern among the general populace.

But so many issues in conservation science go unnoticed even by the most environmentally aware. Today’s post covers just one topic (I’ve covered others, such as mangroves and kelp forests) – freshwater biodiversity.

The issue is brought to light by a paper recently published online in Conservation Letters by Thieme and colleagues entitled Exposure of Africa’s freshwater biodiversity to a changing climate.

Sure, many people are starting to get very worried about freshwater availability for human consumption (and this couldn’t be more of an issue in Australia at the moment) – and I fully agree that we should be worried. However, let’s not forget that so many species other than humans depend on healthy freshwater ecosystems to persist, which feed back in turn to human benefits through freshwater filtering, fisheries production and arable soil accumulation.

Just like for the provision of human uses (irrigation, direct water consumption, etc.), a freshwater system’s flow regime is paramount for maintaining its biodiversity. If you stuff up the flow regime too much, then regardless of the amount of total water available, biodiversity will suffer accordingly.

Glen Canyon Dam

Image by James Marvin Phelps (mandj98) via Flickr

Thieme and colleagues focus specifically on African freshwater systems, but the same problems are being seen worldwide (e.g., Australia’s Murray-Darling system, North America’s Colorado River system). And this is only going to get worse as climate change robs certain areas of historical rainfall. To address the gap in knowledge, the authors used modelled changes in mean annual runoff and discharge to determine fish species affected by 2050.

The discharge/runoff results were: Read the rest of this entry »





Marine protected areas: do they work?

13 08 2010

One measure that often meets great resistance from fishermen, but is beloved by conservationists, is the establishment of marine protected or ‘no take’ areas.” Stephen J. Hall (1998)

I’m going to qualify this particular post with a few disclaimers; first, I am not involved in the planning of any marine protected areas (henceforth referred to as ‘marine parks’) in Australia or elsewhere; and second, despite blogging on the issue, I have never published in the discipline of protected area design (i.e, ‘conservation planning’ is not my area of expertise).

That said, it seems to becoming more imperative that I enter the fray and assess not only how marine parks should be designed, but how effective they really are (or can be). I’ve been asked by several conservation NGOs to provide some insight into this, so I thought I should ‘think aloud’ and blog a little mini-review about marine park effectiveness.

Clearly there is a trend to establish more marine parks around the world, and this is mainly because marine conservation lags so far behind terrestrial conservation. Indeed, Spalding et al. (2008) showed that only 4.1 % of continental shelf areas are incorporated within marine parks, and ~ 50 % of all marine ecoregions have less than 1 % marine park coverage across the shelf. Furthermore, marine protection is greatest in the tropical realms, while temperate realms are still poorly represented.

The question of whether marine parks ‘work’ is, however, more complicated than it might first appear. When one asks this question, it is essential to define how the criteria for success are to be measured. Whether it’s biodiversity protection, fisheries production, recreational revenue, community acceptance/involvement or some combination of the above, your conclusion is likely to vary from place to place.

Other complications are, of course, that if you cannot ensure a marine park is adequately enforced (i.e., people don’t respect the rules) or if you don’t actually place the park anywhere near things that need protecting, there will be no real net benefit (for any of the above-mentioned interest groups). Furthermore, most marine parks these days have many different types of uses allowed in different zones (e.g., no fishing, some fishing, recreational diving only, no boat transport, some shipping, etc., etc., etc.), so it gets difficult to test for specific effects (it’s a bit like a cap-and-trade legislation for carbon – too many rules and often no real net reduction in carbon emissions – but that’s another story).

All these conditions aside, I think it’s a good idea to present what the real experts have been telling us about marine park effectiveness from a biodiversity and fishing perspective over the last decade or so. I’ll summarise some of the major papers here and give an overall assessment at the end. I do not contend that this list is even remotely comprehensive, but it does give a good cross-section of the available evidence. Read the rest of this entry »





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 xy2, 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 »





Interview with a social (conservation) scientist

22 06 2010

I was contacted recently by Josh Cinner, a self-titled ‘social’ scientist (now working at the Centre of Excellence for Coral Reef Studies) who has published rather a lot in the conservation literature. He was recently highlighted in the journal Science for his work, and he thought CB readers would enjoy the coverage. He stated to me:

“…as a social scientist, I have spent the past decade or so working with ecologists and managers trying to integrate social science better in conservation. There are often calls for the importance of integrating social science in conservation and I thought your blog readers might appreciate some high-level recognition of the importance of this. Additionally, as far as I can tell, this is the first of these profiles that has focused on someone working in conservation.”

So, while fully crediting the source of this article and its author, Helen Fields, here is the entire text reproduced for your reading pleasure.

In the late 1980s, things were not going well for the coral reefs at Jamaica’s Montego Bay Marine Park. Overfishing had taken out a lot of the fish that eat algae, and algae were taking over the reef. “It was a classic case of ecosystem decline,” human geographer Joshua Cinner says. He arrived in Jamaica in 1996 as a Peace Corps volunteer after graduating from the University of Colorado, Boulder, with a double major in environmental conservation and geography. He was particularly interested in parks and preserves.

He’d landed in the middle of a war. Lobbying by tour operators and others got spearfishing, one of the main culprits in overfishing, banned in the park. The ban did not go over well with local people. “All the park equipment got vandalized. We had park rangers get threatened; their families got threatened at spear point,” Cinner says. Spearfishing equipment is cheap and you don’t need a boat; men who do it are generally poor and are fishing as a last resort. “The cultural lens through which the fishermen viewed this issue was of struggle in a post-slavery society, of the rich, predominantly white expatriates making a law that oppressed the poorest of the poor locals to benefit the wealthy.”

The conflict got Cinner thinking about how conservation really works. “It wasn’t really about the ecology,” he says. “Making conservation work in Jamaica had a lot to do with understanding the local culture and people.” It also opened his eyes to the role oceans play. “The ocean is often viewed as an open-access resource. That extra layer of complexity interested me,” he says. “Land can often be private property,” but “the ocean is typically viewed as free for anyone to fish in, for anyone to swim in and use.” Read the rest of this entry »





The spillover effect

18 04 2010

© everlessaday

The so-called ‘spillover effect’ is a long-standing debate in conservation ecology. The idea is relatively simple – put in a marine reserve (or, no-take zone, park, whatever you wish to call it as long as it restricts blanket over-fishing) and the area around the reserve eventually profits from the nearby over-production of fish (and other taxa). The idea is very attractive because even if you’re thick enough not to understand the absolute necessity of marine reserves in our age of mass, global over-exploitation, at least you might have enough grey matter to appreciate the value of more fish ‘spilling over’ into your favourite fishing area. More proposed marine reserves have been sold to the more Luddite ‘stakeholder’ this way than I care to count.

However, as attractive an idea it was, early on in the marine reserve literature (i.e., the early Devonian 1990s), there was limited (Rowley 1994; Willis et al. 2003) or only circumstantial evidence (Russ & Alcala 1996; Roberts et al. 2005) for the effect. Indeed, many have suggested that the spillover benefit, if present, depends entirely on the size of the reserve and whether adjacent areas are managed at all (Allison et al. 1996; McClanahan & Mangi 2000). Others have even suggested that marine reserves can displace fishing effort into smaller areas and change local community structure enough to facilitate invasion by exotic species (Kellner & Hastings 2009).

It is happier time now that we have more than ample evidence that marine reserves do in fact result in species spillover (e.g.,Roberts et al. 2001; Russ et al. 2004; Abesamis & Russ 2005). So it is not with any great claims of novelty that I highlight Garry Russ & Angel Alcala’s latest paper, Enhanced biodiversity beyond marine reserve boundaries: the cup spilleth-over; rather, it’s how they quantify the long-term evidence, the mechanisms for how spillover occurs and how the community changes that they deserve a mention. Read the rest of this entry »








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