Eat frozen food and avoid line-caught fish, says eco study
Enviro-profs clash with Greenpeace advice
Enviro-profs studying the ecological impact of food production have come out with some counter-intuitive results. According to a new study, it is greener to eat frozen salmon than fresh, and catching fish en masse in nets does less damage to the planet than taking just a few using hooks and lines.
The new research was carried out by enviro-scientists from Nova Scotia, Sweden, Oregon and Chile. The study focused on salmon, as it is a food produced both from wild and farmed sources by many different methods and consumed all year around the world.
One interesting conclusion of the research is that "food miles" are a largely pointless measure. Far more important than the distance food has travelled before being eaten is the means of travel used.
This is why it is actually more eco-friendly to eat frozen salmon than fresh. Frozen fish can and will be sent by a ship, a very energy-efficient way of moving stuff, even accounting for the power used by freezer containers. Fresh fish, on the other hand, is likely to move mostly by air and road.
It's generally better for the planet to eat frozen grub that's come a lot of food miles than fresh which has travelled fewer miles by air, in fact. According to the enviro-scientists:
The choice to buy frozen matters more than organic vs conventional or wild vs farmed.
There were other conclusions from the study which could be seen as flying in the face of conventional eco-wisdom. According to the assembled boffins:
Catching salmon in large nets as they school together has one tenth the impact of catching them in small numbers using baited hooks and lures.
This directly contradicts the advice offered by Greenpeace, for instance, which says "choose line-caught fish wherever possible".
Deep waters, these.
The study, Not All Salmon Are Created Equal: Life Cycle Assessment (LCA) of Global Salmon Farming Systems, is published here (free) in the journal Environmental Science and Technology. ®
Economics and counter-inutitive conclusions
Now I'm not exactly always in agreement with Lews when he goes off on one of his ScFi, flying car or selective misuse of statistics trips. However, in this general area, there is, indeed a lot of counter-intuitive stuff. I'd agree whole heartedly that the whole "food miles" thing is wildly misused and misleading. For instance, the Supermarkets get hammered for their use of centralised depots and bulk distribution. However, if you start looking at the actual fuel used compared to local distribution and the fact that local distribution requires very large numbers of short journeys with vehicles less than optimally loaded, the supermarket distribution model is often far more fuel efficient. After all, fuel costs money - it is in the supermarkets interests to optimise transport costs, of which fuel is a very large part (of course there is a fuel cost issue with people travelling by car to centralised supermarkets, but that's a ratgher different matter).
Then there is the kicking the supermarkets get for generating excessive waste. However, again, it's not in the supermarkets interests to generate waste. They have very sophisticated ways of managing stocks and demands and modern food preservation systems (including freezing) are far less wasteful than the techniques of the past (which truly did have much loss of food due to spoiling, pests and so on). it's funadamentally impossible to avoid some food wastage, and the wider and better the choice to consumers, then the higher that will be. But there are still ways of dealing with it - unused food can be used in other parts of the food chain (such as animial feed), or even in anaerobic digesters.
As for food miles - adding up the total mileage travelled by the food on your plate makes absolutely no sense at all. Does that sprinkle of pepper from Asia suddenly add 6,000 miles? Of course not - it's the total energy input that matters, which is a far more relevant measure. It's also a measure that can very neatly get wrapped up in the costs of transportation. Fill a refrigerated ship with frozen good, and the energy input per Kg-mile involved in transportation is tiny. Drive to your local supermarket for a packet of asparagaus and that same number is huge.
The lesson on all this is to use economics to change behaviour. It is, for instance, completely ridiculous to tax 4WD vehice owners just for posession. What you want to do is tax the usage of fuel, something which fuel duty does very well.
Of course many of the fantics in this area want to micro-manage people's lives with often, counter-productive advice (or maybe orders might be a better way). For instance, those boxes of organic vegetables delivered to your doorstep via a local farmer are very likely to have used more energy, and involved more wastage, than the same goods delivered by a supermarket.
The study you cite concerns salmon farming. I'm pretty sure salmon farmers would never catch fish with a hook and line.
The Greenpeace advice is to do with the sustainability of fish stocks and avoiding bycatch, not the efficiency of the method.
Have just issued a Red Herring.