All (fisheries) models are wrong, but some are useful (to indigenous people)

1 08 2015

miracle_cartoonAnother post from Alejandro Frid. (Note: title modified from George Box‘s most excellent quote).

As an ecologist working for indigenous people of coastal British Columbia, western Canada, I live at the interface of two worlds. On the one hand, I know that computer models can be important management tools. On the other hand, my job constantly reminds me that whether a model actually improves fishery management depends, fundamentally, on the worldview that shapes the model’s objectives. To explore why, I will first review some general concepts about what models can and cannot do. After that, I will summarize a recent model of herring populations and then pull it all together in a way that matters to indigenous people who rely on marine resources for cultural integrity and food security.

Models do a great job of distilling the essence of how an ecosystem might respond to external forces—such as fisheries—but only under the specific conditions that the modeller assumes to be true in the ‘world’ of the model. Sometimes these assumptions are well-grounded in reality. Sometimes they are blatant but necessary simplifications. Otherwise, it would be difficult to ask questions about how major forces for which we have no historical precedent—such as the combined effects of industrial fisheries, ocean acidification and climate change—might be altering the ocean. For instance, due to our greenhouse gas emissions, the ocean is warming and contains less dissolved oxygen. These stressful conditions hamper the capacity of fish to grow, and appear to be on their way to shrinking the body sizes of entire fish communities1. If you want even to begin to comprehend what the ocean will look like in the long term due to these effects of climate change, it makes sense to assume, in the ‘world’ of your model, that fishing does not exist, even though you know it does. Of course, you would then acknowledge that climate change probably exacerbates the effects of fisheries, which highlights that you still have to examine the combination of these effects. And that is exactly what an excellent team of modellers did1. Read the rest of this entry »

Écologie en France

27 07 2015

DCOUVRI2This is just a quick post to update followers about a few things I’ll be up to over the next 5 months. While I can guarantee that the posts will be more or less as frequent, some of the subject material might shift slightly given my new geographic focus.

I’m most fortunate to have been invited to spend the rest of 2015 in Franck Courchamp‘s Systematic Ecology & Evolution lab at Université Paris-Sud (also check out Franck’s blog here), and I’ll be leaving for France tomorrow. Franck is a long-time mate and colleague, who has not only previously hosted me briefly in his home in France, he and his family also put me up in Los Angeles earlier this year (where both he and his partner Muriel are on sabbatical themselves at UCLA until the end of August 2015). Franck was also kind enough to visit Adelaide last year where he gave some rather kick-arse seminars.

So what will I be doing during my mini-‘sabbatical’ with Franck? Franck is known for many things, not least of which is his reputation for being ‘King Allee Effect‘, but the main focus of my work there will be on the economic impacts of invasive insects in Europe as the climate continues to warm over the coming century. The project is financed by a large French bank (BNP-Paribas) and is known as InvaCost:

InvaCost will look at the impact on invasive insects, when climate change allows them to invade regions that are now too cold for them, but that will warm up in the coming decades. These include the red imported fire ant, the predatory Asian wasp, the disease-carrying tiger mosquito, and many others that are among the worst invaders worldwide.

Of course, that’s just the main topic. Franck is a little like me in that he’s a jack of many ecological trades, so we also plan to work on a few things like the global impacts of feral cats, some more conservation-based things, and perhaps a review or two. Lots planned for five months! Read the rest of this entry »

Ice Age? No. Abrupt warmings and hunting together polished off Holarctic megafauna

24 07 2015
Oh shit oh shit oh shit ...

Oh shit oh shit oh shit …

Did ice ages cause the Pleistocene megafauna to go extinct? Contrary to popular opinion, no, they didn’t. But climate change did have something to do with them, only it was global warming events instead.

Just out today in Science, our long-time-coming (9 years in total if you count the time from the original idea to today) paper ‘Abrupt warmings drove Late Pleistocene Holarctic megafaunal turnover‘ led by Alan Cooper of the Australian Centre for Ancient DNA and Chris Turney of the UNSW Climate Change Research Centre demonstrates for the first time that abrupt warming periods over the last 60,000 years were at least partially responsible for the collapse of the megafauna in Eurasia and North America.

You might recall that I’ve been a bit sceptical of claims that climate changes had much to do with megafauna extinctions during the Late Pleistocene and early Holocene, mainly because of the overwhelming evidence that humans had a big part to play in their demise (surprise, surprise). What I’ve rejected though isn’t so much that climate had nothing to do with the extinctions; rather, I took issue with claims that climate change was the dominant driver. I’ve also had problems with blanket claims that it was ‘always this’ or ‘always that’, when the complexity of biogeography and community dynamics means that it was most assuredly more complicated than most people think.

I’m happy to say that our latest paper indeed demonstrates the complexity of megafauna extinctions, and that it took a heap of fairly complex datasets and analyses to demonstrate. Not only were the data varied – the combination of scientists involved was just as eclectic, with ancient DNA specialists, palaeo-climatologists and ecological modellers (including yours truly) assembled to make sense of the complicated story that the data ultimately revealed. Read the rest of this entry »

Can we save biodiversity? Not as long as ‘democracy’ is for sale

16 07 2015
© Bill Day

© Bill Day

Like you, I’m tired of the constant battle with ill-informed politicians who claim all sorts of nonsense reasons for the bad environmental decisions they make in the name of so-called ‘democracy’. The flesh of my right hand is sore from the constant fist-bashing of tables as I let loose yet another diatribe concerning why our politicians are corrupt whores for sale to the highest bidder. My teeth are becoming worn from the nights of grinding as I lay awake contemplating why we as a society are taking more steps backward than forward.

Yes, we have politicians today claiming that “coal is good for humanity” and that climate change is a “hoax” designed by communists to disrupt society. They spew all sorts of nonsense in public about how they are making their decisions to approve yet another coal mine, limit renewable energy investments or allow continued deforestation because “it’s good for the economy”. All these despite the overwhelming evidence to the contrary.

I used to invoke the comforting feeling of intellectual superiority that these (mostly male) politicians were merely stupid, and that as a democracy, we cater to the lowest intelligence denominator of civil society (i.e., we get the politicians we deserve). However, that excuse is about as stupid as the label we give politicians who make decisions that fly in the face of all evidence. Yes, there are stupid people that have been elected to represent us, but I submit that truly stupid politicians are probably quite rare.

No. Ironically, stupidity cannot explain these moronic and generationally bankrupt decisions. Only money can. Read the rest of this entry »

Cartoon guide to biodiversity loss XXXI

9 07 2015

Fourth batch of six biodiversity cartoons for 2015, because I’m travelling and haven’t had a lot of time for a more detailed post (see full stock of previous ‘Cartoon guide to biodiversity loss’ compendia here).

Read the rest of this entry »

Grim tale of global shark declines

25 06 2015
Please don't eat me

Please don’t eat me

How do you prevent declines of species you cannot even see? This is (and has always been) the dilemma for fisheries because, well, humans don’t live underwater. Even when we strap on a metal tank full of air and a pair of fins, we’re still more or less like wounded astronauts peering through a narrow window of glass at the huge, largely empty, ocean space. It’s little wonder then that we have a fairly crap system of estimating fish abundance, and an even worse track record of managing them sustainably.

But humans love to eat fish – the total world estimate of legal fisheries landings is something in the vicinity of 190 million tonnes in 2013, up from 18 million tonnes in 1950 (according to FAO). We’re probably familiar with some of the losers of that massive harvest, with species like tunas, bill fishes and orange roughy making the news for catastrophic declines in abundance over the last 30-40 years. And we’re not even talking about the estimated tragedy that is illegal, unreported and unregulated (IUU) fishing.

Back in 1999, the FAO started to report that sharks – the new-ish target of many world fisheries resulting from the commercial extinction of many other fin fish fisheries – we’re starting to take the hit. Once generally ignored by fishing industries, sharks soon became popular target species. Then in 2003, Julia Baum and colleagues famously (and somewhat controversially) sounded the alarm for sharks in the Gulf of Mexico by some claims of major and catastrophic declines of large, predatory sharks. While some of the subsequent to-ing and fro-ing in the literature challenged these claims, Baum’s excellent work was ultimately vindicated.

Since then, more and more evidence that sharks are in trouble has surfaced, including the assessment of the reported (again, only legal) catch indicated heavy depletion of coastal sharks even by 1975, and the estimate that 25% of all shark and ray species have an elevated extinction risk, mainly resulting from overfishing. Now even the direct fisheries landings statistics are confirming this grim tale. Read the rest of this entry »

National commitment to conservation brings biodiversity benefits

16 06 2015

united-nations-dayWhat makes some conservation endeavours successful where so many fail to protect biodiversity? Or, how long is a piece of string?

Yes, it’s a difficult question because it’s not just about the biology – such as resilience and area relationships – in fact, it’s probably more about the socio-economic setting that will ultimately dictate how the biodiversity in any particular area fares in response to disturbance.

In the case of protected areas (that I’ll just refer to as ‘reserves’ for the remainder of this post), there’s been a lot of work done about the things that make them ‘work’ (or not) in terms of biodiversity preservation. Yes, we can measure investment, how much the community supports and is involved with the reserve, how much emphasis is put on enforcement, the types of management done within (and outside) of the reserves, et ceteraet cetera. All of these things can (and have to some extent) been correlated with indices of the fate of the biodiversity within reserves, such as rates and patterns of deforestation, the amount of illegal hunting, and the survival probability of particular taxa.

But the problem with these indices is that there are just indices – they probably do not encapsulate the overall ‘health’ of the biodiversity within a reserve (be that trends in the overall abundance of organisms, the resilience of the community as a whole to future disturbances, or the combined phylogenetic diversity of the ecosystem). This is because there are few long-term monitoring programmes of sufficient taxonomic and temporal breadth to summarise these components of complex ecosystems (i.e., ecology is complex). It’s no real surprise, and even though we should put a lot more emphasis on targeted, efficient, long-term biodiversity monitoring inside and outside of all major biodiversity reserves, the cold, hard truth of it is that we’ll never manage to get the required systems in place. Humanity just doesn’t value it enough. Read the rest of this entry »


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