maandag 30 september 2013

What is this researcher afraid of?

A thoughtful article in the Dutch newspaper De Volkskrant of 25 September 2013 deals with publishing in Science and Nature and cites a researcher who wishes to remain anonymous:
We try every now and again to get in the top journals, because Science or Nature look good on your cv (...) But it's nonsense. My two most important articles (...) were not even considered by Science or Nature. On the other hand: I once had a Nature publication on what was absolutely the worst experiment I ever did. But that was on a hot and photogenic topic. (...) What matters to the editing boards of those journals is to keep up the status of the journal, by keeping up their impact factor. This automatically leads to a preference for fields and articles that will be cited a lot. (...) The result is also that editors have less expertise in less popular disciplines, and they have failed recently in that respect.
This is very similar to Ray Hilborn's complaints about the quality of these two journals. But then, why does this researcher want to remain anonymous? What is he or she afraid of? Being sued or ostracized by Nature and Science editors? (If he or she has reason to be afraid, why am I putting this on my blog? Oh wait...)

vrijdag 27 september 2013

My impressions of the 2013 ICES Annual Science Conference

My impressions after a week of presentations, discussions, and lots of delicious food:
  • Of all the interdisciplinary conferences I've been to so far, the ICES meeting was the most scientific (read: least political, notwithstanding ICES's role as advisory body for fisheries policy), and the most constructive in its interaction with social scientists (read: economists). Besides EAERE (which I consider a disciplinary meeting) I was once at an ESEE meeting, and once at the European Congress for Conservation Biology. I had mixed feelings about those for their tendency to bash "mainstream economics" (whatever that may be) and to blur the line between science and activism. Perhaps it's because those communities have the hidden assumption that nature is best left alone by man, whereas fisheries scientists investigate, by definition, a form of interference in nature.
  • Is it just me, or is there a major disconnect between textbook fisheries economics and the practice of fisheries management? Concepts we teach (notably maximum economic yield and the role of the discount rate) are nowhere to be seen - in fact, I once heard a fisheries industry representative refer to maximum economic yield as "a plaything for economists". In our teaching we hardly pay attention to the stochastic nature of fish stocks, but these days fisheries science is all about reference points and harvest control rules - which only make sense in a stochastic context.
  • Economists can make big contributions to fisheries management by further strengthening how fisheries models describe human behaviour. So far those contributions were largely confined to modelling where fishers fish, but what about investments in gear, or boats? Let alone market structures, global developments (tilapia!), value chains, and policy-makers.
  • Iceland is like an extreme version of Norway. Thought the Norwegian landscape was rugged? Iceland has volcanoes, and geysers! And where I thought Norwegians don't give a hoot what the rest of the world thinks of hunting and whaling, only Icelanders can serve raw whale meat and rotten shark to a crowd of foreign scientists. (And it was delicious! The whale, that is.) Neither do Icelandic pubs have qualms with playing the entire Velvet Underground & Nico, including John Cale's ear-piercing viola solo in Heroin.

woensdag 25 september 2013

Are humans like fish?

This spaceship currently hosts about 700 fisheries scientists attending the Annual Science Conference of ICES. ICES is an international body that assembles stock assessments and other results from fisheries research in Northern Europe, Canada, and the United States. Fisheries scientists use a lot of detailed models of the marine ecosystem, which allows them (up to a point) to project how different policies affect such things as fish stocks, catches, and so on. I also entered the vessel (more accurately the Harpa conference center and concert hall in Reykjavik, Iceland) to discuss how such models can take the human factor into account. After all, humans take part in the marine ecosystem (in many cases we are the top predator), but we also develop policies with the interests of humans in mind. So if we can model fish, why not also model humans?

"It can't be done"
A common objection against this is that human behaviour cannot be modelled. Of course, as a model-building economist I don't agree with that. Economists have a large set of quantitative models at their disposal that describe human behaviour at several different spatial scales, from consumer choices to entire economies or even international trade. Some biologists at the meeting explained that similar objections were made when biologists started developing their own ecosystem models, but that has never stopped such models from proliferating. Why would humans be any different? The discussion set me thinking about the similarities and differences between humans and fish, and how they could make modelling human behaviour easier or more difficult than modelling animal behaviour or ecosystems.

Why humans are like fish
Basically we discussed three objections that were made against biological models, and are now made against modelling humans. First, people object that the object of the model is too complex. That's true, but so are the global climate, the cascade of nuclear fission and fusion in a hydrogen bomb, and a horde of blood-thirsty zombies climbing over a 50 meter high wall. But that never stopped people from modelling these processes in a plausible manner (admittedly, one of these examples is fictional and no, it's not the first one). If we don't model these processes we will never understand them or how they interact with other processes.

In the fish tank
A second objection is that the processes are uncertain. But although uncertainty complicates matters, it can be dealt with. You can do a sensitivity analysis to assess the robustness of your results. There are methods to optimize uncertain systems, such as stochastic dynamic programming models or uncertainty analysis. Such steps are necessary, they can be difficult, but that is no reason not to try.

A third objection is that models tend to induce tunnel view, where effects that are not "in the model" are ignored. This is a fair point, and as an economist I must admit that my profession has not been immune to this effect. So we need a diverse ecosystem of theories, approaches, and models, in order to stay open-minded for arguments or effects we hadn't thought of. Again, this objection has also been made with respect to biological models, and it has never stopped biologists from modelling.

Why humans are not like fish
This is where it gets interesting. First of all, fish don't read. People, however, may read your report and respond. There is evidence that negative news coverage on consumer confidence further reduces that same consumer confidence. This is a typical feature of social science research: as a researcher you have an impact on your object of research (i.e. people) that goes much deeper than any quantum physicist could get. Your results could be self-fulfilling, as in the consumer confidence case. They could also be self-defeating, as some people argued was the case with Limits To Growth: the stir caused by this report inspired efforts to reduce pollution and resource use to such an extent that we evaded the environmental catastrophe predicted by the report. (I'm not sure I'm buying the argument about this particular example but you get the idea.)

Second, I would argue that humans are much better at anticipating what other humans, including governments, do. For example, a common objection against vessel buybacks is that they create an expectation among fishers that the government will buy access capital (at tax-payers' expense) when the going gets tough for fishers - an open invitation for creating excess capacity because fishers face only part of the financial risks. Likewise, fishers may anticipate what other fishers do in their decision whether to fish, and how much to fish.

Who needs a window if you can have a view on virtual nature?
Third, many properties of humans, such as customs, habits, and technologies, are much more subject to change than those of animals. Over the 200,000 years of its existence, homo sapiens has developed sticks, houses, wheels, fish nets, purse seines, and pulse trawls. We're the only animal with such a massive change in capability and impact. And although economists commonly assume that preferences don't change over time, I'm not so sure. Suppose we estimate the recreational value of a natural park to be, say, €5 million, will it remain like that forever? There was a time when forests were for cutting down - they were seen as collecting grounds of villains and predators. Now we want to protect them out of love of exercise, hunting, and nature. What if our descendants develop a taste for hikes in virtual reality (or simply get glued to their iPads), and hikes in real forests fall out of fashion?

Fourth, on the bright side, we cannot communicate with fish but in social research we can do surveys and interviews to gain insight into their considerations, their lines of reasoning, and so on. These methods are not perfect (people can lie, or withhold information), but neither are biological measurement tools such as the ones used in stock assessments.

Should we? Can we? How?
The bottom line is that we can to some extent model human behaviour, and by doing so we can address a lot of pressing problems. But it will be tricky. I can't judge whether it will be trickier than modelling fish, but it will surely be tricky in different ways. Again, that should not be an impairment to doing it.

maandag 16 september 2013

Confusing Nemo (3): Enjoy your fish in 2049

Next in my little fact-checking exercise of The Black Fish's movie Losing Nemo:

If the fishing industry keeps fishing at its current rate, science predicts that all fish will be gone by 2048

This statement is based on a paper in Science (see a copy of the article here) by marine scientist Boris Worm, published in November 2006. Intriguingly, the objective of the article is not to predict anything like stock collapse: rather, it investigates the importance of biodiversity for the provision of a host of marine ecosystem services, such as fisheries, nursing juveniles of marine species, and filtering of waste from human sources. The article finds a crude but nevertheless convincing positive correlation between species richness and such traits as productivity and speed of recovery from overfishing: in other words, species-rich ecosystems produce more biomass than species-poor ecosystems, and also recover more easily from overexploitation. So is that where the 2048 prediction comes from, a projection of biodiversity decline that should lead to worldwide stock collapse around 2048?

Actually not. One of the driving forces considered in the article is fishing pressure, so it describes how more and more fish stocks have collapsed (defined as catches dropping below 10% of the highest catch ever recorded) since 1950, according to data from the Sea Around Us project. Based on these data the authors estimate a mathematical formula to describe this trend:

y = 0.0168*x1.8992

where y denotes the percentage of fish species currently collapsed and x denotes the number of years after 1950. Later in the article the authors make the following remark:
This trend is of serious concern because it projects the global collapse of all taxa currently fished by the mid–21st century (based on the extrapolation of regression in Fig. 3A to 100% in the year 2048).
2048 is 98 years after 1950: indeed, 0.0168*981.8992 is about 101.

The perils of extrapolation
So that's where the 2048 comes from. A trend, based on data over about 50 years, extrapolated another 50 years until we reach 100 percent. This claim, and how the authors arrived at it, has attracted a lot of criticism, which I won't discuss in detail here, but in my view the most fundamental objection is that extrapolating any trend, especially an exponential trend describing a number with a natural maximum (like a percentage), by as far as twice the observed range is bound to give extreme and unrealistic outcomes. In this particular case, as more and more stocks 'collapse', you are bound to have stocks left that are actually quite well-managed. Most Atlantic pelagic stocks, such as herring and mackerel, are healthy and well-managed. Not only are the stocks large enough to ensure plenty of replenishment that compensates fishing mortality, the institutions to manage the fishery, like Exclusive Economic Zones, scientists doing stock assessments, and stringent government policies, are also in place. North Sea herring is MSC certified. Iceland has practically its own national cod stock which it would be crazy to deplete. A lot of overfishing is due to poor exclusivity of stocks and the ensuing Prisoner's Dilemma, but these institutional flaws are largely absent for most North Atlantic stocks. And this is just one example.

How a side remark came to define a paper
If the 2048 estimate is so shaky, why do the authors make this claim? Remember that the objective of the article has never been to predict fisheries collapse: the authors wanted to assess the importance of species richness for marine ecosystem services. The 2048 claim was a side remark that ended up as a red flag in the associated press release. Interestingly, in the same month the 2048 article was published, the American fisheries scientist Ray Hilborn complained in the American magazine Fisheries (see a copy of the article here) that more and more articles in marine science, especially in leading journals such as Nature and Science, were published not for their scientific merit but for the public impact of their press release:
These four examples [not including the 2048 article, RG] illustrate a failure of the peer review system and lack of the basic skepticism needed in science, and are unfortunately but a few of the many papers now appearing with similar sensational but unsubstantiated headlines. [...] Critical peer review has been replaced by faith-based support for ideas and too many scientists have become advocates.
Indeed, Worm's paper was accompanied by a press release running the secondary headline "Current trends project collapse of currently fished seafoods by 2050". Apparently, the headline was meant as a wake-up call:
In a note to colleagues that was mistakenly sent to The Seattle Times, Worm wrote that the projection could act as a "news hook to get people's attention." "One reason why nobody cares about marine biodiversity is that there seemed no clear end in sight," he continued. "... Well, it's time to wake up — IF the current trend continues we will see drastic consequences in our own lifetime." (Excerpt from The Seattle Times)
Trevor Branch recently published a very insightful analysis of how the article was received in the scientific community. He found that among the articles citing the Worm et al. paper, the ones referring to the 2048 claim "had characteristics that suggest unfamiliarity with the controversy surrounding this projection, namely papers with few authors, published in journals with low impact factors, in fields far removed from ecology and fisheries, and sharing no coauthors with the Worm et al. paper." In other words: it's the rebels without a clue who cite the article for its doomsyear 2048.

The usual disclaimer
I'm no environmental Pangloss. There is plenty to be worried about, like the criminally exploited bluefin tuna stocks, or the continuous decline of European eel. Institutional problems abound in many regions of the world, making it exceedingly difficult to implement a sustainable system of stock management. And then there are pressures like ocean acidification, proliferation of invasive species, accumulation of plastics, and so on.

But I also believe that activist science will eventually eat itself. If a scientist bases his claims on wild extrapolations such as these, he or she is making it the pseudo-skeptics just too easy.

zondag 8 september 2013

Lava, limpets, and lotsa fresh fish

What I did last Summer: spent two weeks on the Azores.

Why The Azores? Because they have the perfect climate for a summer holiday (a steady 25 degrees), lots of hiking trails, plenty of fresh seafood, many small natural swimming pools, and great opportunities for spotting whales and dolphins. And I was fascinated by this Portuguese outpost almost in the middle of the Atlantic Ocean, where locals still caught sperm whales in the 1980s with small rowing boats, and where the ocean is a natural part of the landscape.

It's magnificent. All nine islands originated from volcanic activity, the remnants of which are visible in the form of dead volcanoes in the landscape. Settlements are crammed between the steep slopes of the volcanoes on one side and the ocean on the other side, often on what the Azoreans call fajas: small areas of flat land, often consisting of rubble from collapsed rocks. On one side the volcanoes, which used to spew fire and sulfur but are now covered in sinister dark boulders of basalt; on the other side the ocean, thriving with life but also unpredictable and dangerous. You can truly say the Azoreans live between the devil and the deep blue sea.

A taste of local marine biodiversity:
grilled limpets on the island of Sao Jorge
Before you go, read Moby Dick. The American sperm whale fishery of the nineteenth century, so vividly described by Herman Melville, brought whaling to The Azores. Until the Azoreans abandoned whaling in 1983, their method of whaling was very similar to the method described in the book. The Azorean whalers approached the whale in small rowing boats, from which they drove a harpoon into the sperm whale's body. In panic the whale would quickly dive to escape his attackers, who, by means of the rope attached to the harpoon, would be able to track the whale's location. When the whale resurfaced, the whalers would further wound the whale until it succumbed. Catching one whale could take a dangerous and blood-drenched struggle of several hours.

I admit it must have been the most gruesome way of killing an animal, and I'm sure few visitors mourn its demise. But for the Azoreans, especially the people from whaling towns like Lajes do Pico, it was a valuable tradition and a source of pride. We were so lucky to arrive on Pico in the middle of its Whalers Week. Lajes do Pico features two whaling museums, a few whale watching companies, and a small fleet of traditional whaling boats. During the Semana Dos Baleeiros, as the week is called in Portuguese, the people of Pico honor Our Lady of Lourdes, the whalers' patroness saint. The week is a mix of live music (lots of brass bands), folkloric and religious processions, and lots of food (fish, fish, and some meat) and drink (we stuck to the caipirinhas).

The whaling industry has disappeared, not because of animal welfare concerns or because they ran out of sperm whales, but because the products from whaling (oils, fats, proteins, with many applications in cosmetics, agriculture and industry) got more and more competition from cheaper synthetic alternatives. But no more than three years after the local whale oil factory closed down, the first whale watching company emerged. Nowadays a complete industry has evolved in whale watching, swimming with dolphins, diving with sharks, and so on. I'm not sure I agree with all of it, but in any case we enjoyed seeing real-life sperm whales (their flukes, at least). As regards the dolphins, if you're lucky you only have to take the ferry to spot them:

video

The Azores have a small-scale tuna fishery that catches mainly skipjack tuna by pole-and-line. The islands have their own brands, certified with the Friend of the Sea label, and they export most of it to Italy where their particular brand is much preferred. We didn't get to see much of the fishery but we could see the vessels in many of the harbors we passed.

And that, I must say, was perhaps the main treat of the place: fresh fish, fresh seafood, everywhere you go. Species you never heard of but that taste deliciously. A waiter warning you that the fish is not fresh but frozen (the only Dutch restaurants not serving fish from the deep-freeze are vegetarian restaurants). And all that washed down with some delicious Pico wine or mainland vinho verde.

Back to work.