Wednesday, September 5, 2007

Nordnatur Day 7: In which I learn that cod can eat tofu and that geology actually is relevant to studying fish

After three days of fishing in Eyjafjörður, we headed across the mountains to Hólar University College by way of Siglufjörður so we could stop at the Herring Era Museum and have our much-anticipated non-fish dinner at the Pizza 67 in town. I had already been through the museum, of course, but I’m never one to complain about spending time in a museum with old wooden boats, and I did get a chance to see a few things I’d missed before. One of these was the Danish film about Iceland made in 1937 for the New York Expo in 1938, which included a lot of footage of the herring industry in Siglufjörður in the midst of a lot of mushy idyllic and industrious countryside sort of commentary. I was particularly fond of the comment that “only a small number of the fish that pass near Iceland are ever caught” followed by echoes of Thomas Henry Huxley’s commentary on the natural fecundity of fishes and inexhaustibility of fisheries – in a film made only thirty years before the stock collapse. I also got a chance to see the museum’s library, which included a pairing of books on the shelf that I couldn’t pass without a picture:

Mark Kurlansky’s Cod, the book that introduced me to cod fisheries (in the Icelandic version of course), right next to one of the early scientific books on Iceland’s fisheries written by Bjarni Saemundsson, the namesake of the ship that introduced me to Iceland’s fisheries research.

We spent the night in Hólar, the former capitol of northern Iceland home of the Hólar University College (well, its predecessors) since 1106, but just stayed for the night before moving on to the College’s fisheries branch nearby in Sauðarkrókur. It’s a very small town, but very pretty and with a lot of history.

This was the view at sunset looking out over the town church towards the mountains:

And before leaving the next morning, I had a chance to walk though the “New farmhouse,” a restoration of a typical 19th century turfhouse in northern Iceland.

In Sauðarkrókur, we heard from a few of the faculty members, first about aquaculture and then about freshwater fisheries in Iceland, and got to see the laboratory facilities where they run both teaching experiments and also larger-scale research on fisheries and aquaculture.

These are large tanks of cod being used for experiments:

And another room contains rows upon rows of buckets set up for small-scale experiments, both for teaching and for student and faculty research.

For a tiny school (only about 150 students) mostly of undergraduates, I was impressed at the rather extensive laboratory facilities – I guess Iceland really is the right place to study fisheries.

As with most everyone who talks about aquaculture, the professor at Hólar also sees it as the way of the future in fisheries as technology improves. With cod at least, growing the fish completely in captivity is still often too tricky to do profitably: in 2007, farmed cod production will total about 1200 tons, but only 200 tons will have been raised entirely in captivity, with all the rest having been captured from the wild as juveniles. The most exciting thing I learned, though, was that some of the research at Hólar has been directed towards creating plant-based rather than fish-based meal and oil to feed farmed fish. I think this is really central to creating an aquaculture model that sustainably contributes fish to the world food supply rather than just fishing down the food chain. If cod are grown in captivity simply by feeding them on smaller fish that have to be caught wild, it will still place significant fishing pressure on ocean ecosystems by requiring large catches of pelagic fish like capelin, and furthermore is not a terribly efficient use of the available fish, since each level up the food chain is only able to convert a fraction of its food into usable energy. The concept of sustainably-grown food and eating foods from lower trophic levels has become increasingly important to me (also part of the reason that I’ve stopped eating meat other than fish), and this problem of cod being a piscivorous (fish-eating) fish fairly high in the food chain has been one of my major misgivings about cod aquaculture as a long-term trajectory for cod fisheries. So I was very excited to discover that the research at Hólar shows that soy and canola protein (ok, maybe not tofu) can mostly replace fish protein in fish feed – they’ve managed to develop effective salmon feed that has almost no fish meal and still maintain high levels of omega-3 fatty acids (which is supposed to be what makes fish a particularly healthy food) by only feeding them fish oil just before harvesting.

After the lecture about aquaculture, I wasn’t expecting to be as excited to talk about freshwater fisheries (after all, cod aren’t freshwater fish), but it turns out that studying freshwater fish in Iceland is all about geology! Well, not exactly all about. Freshwater fish in Iceland all have to be rather recent arrivals, since they have to have come to Iceland after the end of the last ice age 11,000 years ago, and therefore there are only a few major species, all of which are able to migrate between saltwater and freshwater, the main species being Atlantic salmon, brown trout, and Arctic charr. Turns out the best way to generally characterize where each of these species are found is based on river type which is, of course, geologically controlled. Glacial rivers, found on the oldest rocks in the country, are the most difficult rivers for fish to live in because they contain few nutrients and have highly variable discharge rates, so they mainly are home to the fish that make the fewest demands on their environment, the Arctic charr. Spring-fed rivers on the other hand, found in the youngest and most permeable rocks (able to maintain groundwater flow), have lots of dissolved nutrients and stable discharge rates throughout the year, making them home to the fish that require the most productivity to survive, the Atlantic salmon. And the “middle” river type, runoff rivers that drain rainwater and snow melt and are found on the middling age rocks, seem to have mostly brown trout, which demands less than the salmon but more than the charr. It’s cooler with pictures overlaying the lithologic types with the species distributions, or maybe just if you happen to get really excited about rocks and hydrogeology and fish, but I thought it was pretty cool.

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