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I meant to throw these stockfish photos up during Science Online as compensation, but there wasn't exactly any downtime at that conference. At all. Shocking and entirely unexpected, I know.
Evidently, I don't post enough creepy things around here, so here's an attempt to make up for it. Stockfish are outdoor dried cod, and was traditionally the main export of rural maritime villages in northern Norway. The seaside villages are covered in cod drying racks and dessicated cod, accompanied by a wonderful smell. Or an awful smell if fish rotting in the sun isn't a part of your culture (in Russia we salt and dry our river fish -- delicious! Good with beer too). The heads are chopped off in the process, and used to scare tourists. I find them adorable.
Notice how "rotting" was mentioned above. The inner microbiologist in you might immediately jump up at the sight of that wonderful word, and with good reason. These stockfish photos might not be so frivolous after all -- the drying process involves microbial action! Some of us who love fermented foods also have an unhealthy obsession with plugging random delicious things into Google Scholar and seeing if there's anything on their microbiology and biochemistry. Stockfish aren't as widespread as some other fermented things (like beer, perhaps), but -- as you might expect -- studies have been done on the microbiology of [properly] decaying cod. Not many though.
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According to Valdimarsson & Guðbjörnsdóttir (2008 J App Microbiol), the fermentation process begins with Moraxella and Acinetobacter bacteria. The fish are then further ripened with a Lactobacillus plantarum-type bacterium. As suggested by the name, Lactobacillus are lactic acid bacteria (Kleerebezem et al. 2003 PNAS), often found in things like fermented dairy and pickles, giving them that deliciously sour flavour. Lactic acid producers are generally desired in food fermentation, due to improving taste and also taking up resources before undesirable bacteria get to them. Fermentation is essentially an ecosystem management process -- you who thrives and who is kept out by altering environmental conditions, as well as the stuff present in the food itself. Being of Eastern European origin, I find that practically everything tastes better after having passed through the metaphorical 'digestive tracts' of a vibrant microbial ecosystem!
This works in coastal Nordic areas because the temperature and humidity there is amenable to this particular cocktail of bacteria; even so, in unusually wet drying conditions (Valdimarsson & Guðbjörnsdóttir 2008 J App Microbiol), an "off" taste appears and the stockfish becomes of low quality -- most likely as a result of a different microbial collective thriving there. As climate conditions vary from region to region, so does the bacterial diversity, and the types of fermented products that can or cannot come from that area -- leading to a rather fascinating case of an interplay of microbiology and geography dramatically influencing what we eat around the world. Curiously, a big chunk of the stockfish end up in Portugal and rehydrated as bacalhau(bacalao in Spain). While cod can be caught off the Iberian coast, it does not appear that it can be dried there in a stockfish kind of way. A case of trade established not only due to differing flora and fauna found in respective countries, but their microbial ecosystems as well. The microbial biome on the chilly Norwegian coast plays an active role in their economy, regardless of whether people are aware of its existence.
Microbioanthropology(?) is kind of fascinating -- and, again, delicious!
The fish pictured above ain't cod but is among the first things that greets you in the tourist info centre in Moskenes. I'm not sure what fish it is, but it sure wants to be frightening!