Having your fish and eating it

Fish fish fish fish fish.
Fish fish fish fish.
Eating fish!
[Fish, by Mr Scruff]

It is impossible for anyone who has ever studied marine fisheries ecology not to feel a twinge of guilt about joining in Mr Scruff’s enthusiastic refrain. Fish stocks globally are in such a sorry state, subject to such unsustainable exploitation, that to eat wild fish seems incompatible with any kind of environmental sensibility. At the same time, though, seafood’s just so damn tasty, and healthy to boot – so what to do?

Complete avoidance of fish, crustaceans, molluscs, etc. is one option, but (for reasons of taste, health, described above) not a particularly palatable one. An alternative is to ignore the problem – these things are dead anyway, everyone else is eating them, have you even seen Tokyo fish market?! – and eat away whilst ignoring any pangs of conscience. Certainly, I have dined with eminent professors of marine conservation, and watched them tuck into tuna and cod without batting an eyelid. But for me those pangs refuse simply to disappear.

The Marine Stewardship Council scheme therefore seemed to offer the ideal Third Way: by labelling seafood as ‘sustainably produced’, one could scoff away at will, conscience untroubled. And wasn’t the increasing prevalence of the little blue stickers on supermarket fish counters a beautiful illustration of the power of consumer choice?

And then along comes this article by Jennifer Jacquet, Daniel Pauly, and a crack team of other highly respected marine ecologists to piss on this particular eco-consumer bonfire. According to these authors,

Certain MSC-certified fisheries… do adhere to – or even exceed – the principles that underlie the MSC’s certification scheme [i.e. to ‘promote the best environmental choice in seafood’, allowing fishing to continue indefinitely without overexploiting resources, diminishing the productivity of the ecosystem, or violating any local, national or international laws]. It is our assessment that many others do not.

They cite examples such as the US pollock fishery, which is MSC certified despite a recent 2/3 reduction in biomass of the stock; or the Pacific hake stock which was recently certified, although its biomass is just 10% of what it was in the 1980s. Their conclusion?

We believe that, as the MSC increasingly risks its credibility, the planet risks losing more wild fish and healthy marine ecosystems… We believe that the incentives of the market have led the MSC certification scheme away from its original goal, towards promoting the certification of ever-larger capital-intensive operations.

So what should I do? I suppose I can be slightly smug that Waitrose, where I most often buy seafood, has refused to stock some MSC-certified products where it deems certification too lenient, due to destructive fishing methods (Whole Foods has done the same). But is a labelling scheme the right approach to conserving the marine environment? Jacquet et al. argue that if the MSC is not reformed, its £8M budget could be better spent on lobbying to eliminate fisheries subsidies, or to create marine protected areas. That’s maybe true, but it would reinstate a sense of impotence among consumers (at least, among those of us reluctant completely to forego our seafood). I quite like their suggestion of an alternative certification, more akin to the Fairtrade mark used for coffee (which recognises only small cooperatives, not large plantations), which would shift the focus away from huge fishing enterprises back towards smaller-scale fisheries which do tend to be more sustainable.

But for now, I will have to continue lecturing on marine conservation whilst sneaking – well, perhaps not ‘guilt free’, but at least ‘lo-guilt’, certified fish from time to time.

Who needs mosquitoes?

Back in July Nature ran a news feature on A world without mosquitoes, in which the general desirability and feasibility of mosquito eradication was discussed. Kind of a, ‘what have mosquitoes ever done for us?’ Apart, that is, from acting as a super-efficient vector for a multitude of nasty diseases like malaria, yellow fever, and West Nile virus. Now, I agree that we should not a priori rule out any course of action that can reduce the enormous human suffering caused by these diseases, and that no-one regrets the eradication of smallpox, say. But plans to eradicate insects that can be numerically extraordinarily abundant within an ecosystem, in both the aquatic and terrestrial stages of their lifecycles, set ecological alarm bells ringing loud in my head.

It seems I’m not alone, judging by the lively correspondence appearing in print last week, as well as comments on the online version. Stephen M. Smith (Dept. Biology, Waterloo, Ontario) writes of his astonishment at ‘the hubris of the mosquito experts… who believe the ecological consequences of an extinction would be minor, nil, or quickly compensated’, and I tend to agree, based on quotes like this from the original article:

If we eradicated them tomorrow, the ecosystems where they are active will hiccup and then get on with life. Something better or worse would take over (Entomologist Joe Conlon, American Mosquito Control Association, Jacksonville, Florida; my italics)

If you pop one rivet out of an airplane’s wing, it’s unlikely that the plane will cease to fly (Steven Juliano, Illinois State University, Normal; a monumentally unfortunate choice of words, given the Ehrlichs’ famous rivet popper essay in their book on extinction)

And from the main text:

Most mosquito-eating birds would probably switch to other insects that, post-mosquitoes, might emerge in large numbers to take their place [my italics]

Ultimately, there seem to be few things that mosquitoes do that other organisms can’t do just as well

History is littered with the disastrous consequences of well-meaning ecological meddling (very relevant here is the story of malaria eradication in the US, DDT, and its effects on bird populations, so beautifully described in Silent Spring), and so the fact that ‘there is not enough evidence of ecosystem disruption here to give the eradicators pause for thought’ should certainly worry us (shouldn’t we always, anyway, pause for thought?). But there is another angle to this debate, which raises some intriguing questions.

Conservation organisations are rapidly adopting an ecosystem services approach, whereby we conserve nature because of the bounty with which it provides us (fish to eat, clean water, climate regulation, psychological wellbeing, and so on and on). Mosquito eradication can thus be framed in a more utilitarian way: do they provide us with any benefits? Sure, adult mosquitoes are major pollinators (but not of major crops), but other than that? As medical entomologist Janet McAllister (Centers for Disease Control & Prevention, Fort Collins Colorado) puts it in the original article, ‘If there was a benefit to having them around, we would have found a way to exploit them’. This point is picked up in the correspondence by Fern Wickson (Genøk Centre for Biosafety, Tromsø, Norway) who asks,

…what else might we reasonably eliminate from the face of the planet – deadly snakes, plague locusts? …ecologists have to ask what minimum level of biodiversity is required for functional provision of ecosystem services to sustain humanity.

It is not clear to me whether Wickson is advocating this kind of audit, or simply raising it as the logical endpoint of the eradication stance, but it is a really important question: how far should we go in deciding which species ‘deserve’ to share the planet with us?

Even within the mosquitoes this is complex. There are, after all, around 3500 species, only a few of which are a health hazard. So should we eradicate the malaria-carrying Anopheles species? What about Aedes aegypti, which carries yellow fever? And if those, why not the bloody midges that can ruin Scottish holidays? Or the wasps which seem to exist only to cause havoc at picnics (although of course they are much more important – see buglife’s new Stop Swatting Wasps campaign).

It’s a question conservation biologists are not very good at addressing, because there is no objective, scientific answer: where do we start managing nature? And where do we stop?

On hard luck and hard work

A couple of recent posts have stimulated discussions into the relative roles of luck and hard work in a successful scientific career, and have led me to revisit one of my favourite popular science books of recent years, The Drunkard’s Walk by Leonard Mlodinow. This is an excellent and – trust me – entertaining primer on the basics of probability and statistics that every science graduate ought to know (indeed, given the importance of understanding risk in medicine, the judicial process, etc. – and Mlodinow provides the clearest description of the prosecutor’s fallacy that I’ve read – any well-informed citizen should see it as their duty to be familiar with these principles). But the book’s subtitle, How Randomness Rules our Lives, gives a clue as to Mlodinow’s wider thesis, re. the pre-eminent role that chance plays in picking out the specific path our personal and professional lives wend through the chaos of the possible. And this is chaos in a formal sense, in that outcomes are enormously sensitive to small changes in initial conditions:

When we look back in detail on the major events of our lives, it is not uncommon to be able to identify… seemingly inconsequential random events that led to big changes

Certainly, when I think, for example, of all the jobs I’ve nearly been offered, I can see a panoply of alternative mes living rather different lives. But while I’m sure we can all appreciate that luck (good or bad) has been important in our own life histories, where Mlodinow is very good is in turning this same insight to examine, post hoc, success and failure in others.

For instance, he tracks the company performance of 500 imaginary CEOs, each with exactly the same probability of ‘success’ (however defined) each year; and then uses simple probability to illustrate the wildly differing fortunes of these CEOs after 5 years – differences entirely due to chance. Of course, what happens is that

Executives’ winning years are attributed to their brilliance, explained retroactively through incisive hindsight.

And likewise, the losers are judged to have lost because of their relative lack of talent and ability. And what applies to CEOs applies equally in other walks of life, including sports coaches and, of course, scientists. As Mlodinow puts it:

We miss the effects of randomness in life because when we assess the world, we tend to see what we expect to see. We in effect define degree of talent by degree of success and then reinforce our feelings of causality by noting the correlation.

There’s a good psychological reason why we make this leap from correlation to causation. Mlodinow quotes renowned social psychologist Melvin J. Lerner:

Realising that ‘few people would engage in extended activity if they believed that there were a random connection between what they did an the rewards they achieved,’ Lerner concluded that ‘for the sake of their own sanity,’ people overestimate the degree to which ability can be inferred from success.

Elsewhere, he quotes Bernoulli: “One should not appraise human action on the basis of its results”, but whilst it is easy to agree with Mlodinow’s assertion that “…all who strive to achieve… should be judged more by their abilities than by their success”, it does beg the question, how do we judge ability, if success is not allowed to be a criterion? A further complication (certainly in science), is that I suspect that ability may very well develop as a result of success. For instance, if you succeed (against a field of similarly able candidates) in securing a long-term research fellowship, complete with significant financial, administrative and – well – moral support, chances are you will develop over that time into a much more able scientist that when you started.

The one place where I find myself disagreeing with Mlodinow, however, comes right at the end, where the ‘life lessons’ are expounded, and Mlodinow makes the following claim, regarding the positive effects of realising that chance is important in life:

What I’ve learned, above all, is to keep marching forward because the best news is that since chance does play a role, one important factor in success is under our control: the number of at bats, the number of chances taken, the number of opportunities seized.

The basic thesis: that life’s unfair, that some people have all the talent or get the breaks; but through hard work and persistence you can overcome these obstacles to become successful. It’s hard to argue with the basic premise of what is, in effect, the American Dream. But, what’s implicit here is that an ability to work hard is somehow different from any other ability. When this assumption is made about other abilities, it sounds silly (brilliant cricketer Viv Richards was a notoriously poor coach, because he couldn’t understand why his charges weren’t simply able to be brilliant at cricket); but people who thrive on 5 or 6 hours sleep, who are completely driven to succeed, and who dedicate their every waking moment to that end, see this as a state that anyone could achieve if they put their mind to it. My contention is that having that drive is as innate as King Viv’s majestic flick over midwicket.