Tuesday, September 4, 2007

Nordnatur Days 4-6: In which I catch a lot of cod, eat a lot of fish, and become a celebrity

From Húsavík, we headed back east to Eyjafjörður, where we spent three days staying in a farm holiday house at Ytri Vik just north of Akureyri, and spent a lot of time on boats, largely catching a lot of cod. It wasn’t just catching cod, though: we went on three separate trips to catch cod to tag and re-release, one of the main ways of studying the cod’s behavior patterns. There are two major types of tags used for cod: external tags, which just identify the fish without recording information, and internal DSTs (digital storage tags). The external tags are fairly cheap and simple to use so they can be used on a large number of fish, but since the only information they provide is from when the fish is tagged and then again when it was caught without knowing anything about where the fish went in the intervening time, the amount that can be learned about fish behavior with external tags is limited. DSTs, on the other hand, are able to record information for up to a few years (depending on how often data points are taken – some are programmed to record every ten minutes whereas others only record once every six hours), providing continual information about where the fish goes between tagging and recapture. Right now, DSTs used for cod only record temperature and depth without recording an actual location, but since cod tend to spend a lot of time on the bottom, the tags often record tidal fluctuations, which can then be used to calculate a location. DSTs are expensive and require making and incision in the fish to insert the tag, which makes it much more difficult to use on large numbers of fish, but the information provided is much more extensive than with the external tags. All tagging experiment also require cooperation between scientists and fishermen, as the researchers who tagged the fish initially rely on the fishermen who catch them to record when and where it was caught and to return the tag, and sometimes also the fish (or at least the otolith). The fishermen are paid for returning the tags and also provided with the information about when and where the fish was tagged and, for DSTs, also sent a copy of the data the tag had collected, ideally helping the fishermen to also become invested in the research and more likely to return the tags. Of course, not all tags are ever recovered and sometimes the fishermen don’t return them (or forget to record where the fish was caught) – for internally-tagged cod, between a quarter and a third of the tags are generally recovered.

We had a chance to see the tagging method for both the external and internal tags over three days of fishing and tagging. Before tagging though, we had to catch the fish. We went out on the Níels Jónsson, and everyone did their best to catch cod for us to tag.

Any cod we caught, we put in a saltwater bin to keep alive for tagging, and everything else we threw back – although if a fish was caught so it was bleeding and wouldn’t live if thrown back (cod or anything else) we killed it to keep for dinner. We had pretty good luck with the fishing – we tagged 300 cod with external tags in just two three-hour trips, and also caught plenty to supply us with two days worth of dinners.

Loryane with her cod:

Teemo demonstrates Finnish fishing success (the Finnish guys were particularly avid fishermen, even bringing their own fishing rods and lures):

We also had a few unexpected catches. Here is Rasmus, the proud hunter, with his catch:

I only fished on one of the two trips since I wanted to mainly learn about the tagging, but I still managed to catch fourteen cod (one of which was 61 cm, pretty big for a handline catch), five blue whiting, one haddock, one rock (with exciting benthic fauna – pink calcareous algae and nifty tube worms), and two other people (though I didn’t actually pull them all the way up…). Despite setting out to spend a year studying fish, I had only been fishing once in my life before this summer, so this was really my first time doing any significant fishing. I was very proud.

Anyway, back to the science. For the external tags, the procedure was fairly simple: you calm the fish so it’s not moving too much (works to put a hand over its eyes), insert the tip of the tagging “gun” (think glue gun, not firearm) just below the first dorsal fin, then pull the trigger to release the tag and turn the gun and the tag is in place.

Before throwing the tagged fish back, we recorded the fish’s length and the time (to compare with the boat’s log from the trip and know the location) alongside the number the fish was tagged with.

The tag itself is just a small plastic T-bar (like the ones that hold on clothing tags) with a bright orange numbered tag that sticks out of the fish and ideally has as little effect as possible on the fish’s behavior (though it is possible for fouling organisms like barnacles to start growing on the tag, which then creates significantly more drag in the water).

DST tags, however, have an internal device (about the size of a bottle cork) to measure and record data in addition to the external piece used to identify the tagged fish. This means that the procedure for tagging the fish is much trickier, requiring a basic surgical procedure on the underside of the fish. We couldn’t do this kind of tagging ourselves, but Villi Þorsteinsson, who I had talked with about his research on Iceland’s cod stocks using tagging data on my second day in Iceland, came with his wife in the middle of his summer holiday to show us how the tagging is done.

He set up his equipment for tagging the fish on the Einar i Nesi while we caught the fish for him – which had to be at least 50cm long to be able to accommodate the size of the tag – and then pulled up alongside our boat so we could watch while he performed and explained the tagging procedure.

To insert the tag, he made an incision with a scalpel, then threaded the tag through the incision and made another small break in the skin to pull through the external portion of the tag (necessary so fishermen realize they have caught a tagged fish). The tag itself remains inside the body cavity, far enough from the incision site itself that it should not interfere with the healing process. He then stitched the incision site using a thread that eventually dissolves after the fish has healed and gave the fish an antibiotic, which helps avoid infections in the open wound and also produces a distinct yellow ring on the fish’s otolith, useful in the analysis after the fish is re-captured because it shows the exact time in the fish’s life when it was tagged.

Here is Villi tagging one of the cod:

And an up-close view of the tagged cod as the incision is stitched:

Tagging procedures in Iceland are slightly different than in most other places in Europe where internal tagging is used for research. Most European animal research laws require that the fish be sedated using anesthesia before the incision can be made to insert the tag, whereas this is not required or used in Iceland. Instead, the fish is kept still during the procedure by using a method of animal hypnosis known as tonic immobility, whereby the fish is turned upside down and a steady flow of water is kept on its gills to maintain oxygen circulation. The cod that Villi tagged did seem to remain mostly still using this method, and he was adamant that requiring anesthesia – mostly based on pressure from animal welfare groups and often legislation written with marine mammals in mind – is both unnecessary and detrimental to the success of the tagging research. Since the goal is to observe fish behavior, tagged cod are ideally re-released as close to the time they were caught and in the same location so that they have a chance to rejoin the group of fish with which they were traveling. Since the process of reviving anesthetized fish is often difficult and time-consuming, in addition to producing severely disoriented fish (same as people who have been anesthetized for surgical procedures), Villi says that the chances that fish tagged using anesthesia will behave irregularly or never successfully recover are much higher than those tagged using tonic immobility. I haven’t heard the argument for using anesthesia so I can’t make an unbiased judgment, but it does seem rather ridiculous to “protect” cod from pain during research surgical procedures that are designed to study the fish for the purpose of better regulating the legal killing of those same fish in the commercial cod fishery.

I was particularly glad to get a chance to see how this is done, since I’ve talked with Dave Righton about working with some data from cod tagging with DSTs in the North Sea while I’m in the UK. This data (and also much of the DST tagging in Iceland) is part of a massive project called CODYSSEY, which began tagging fish in 2002 in the Baltic Sea, Barents Sea, North Sea, and Icelandic and Faroese waters in order to study “cod spatial dynamics and vertical movements in European waters and implications for fishery management.” I still only know the basics about the tagging procedure from talking with and watching Villi, but I think I could now feel more comfortable using the data (or learning about other people’s studies and conclusions using tagging data) with some knowledge about the procedure used to actually collect it.

We also got to see two of the aquaculture facilities in Eyjafjörður that, though very different and neither farming cod, in my mind illustrate quite a lot about Iceland’s approach to aquaculture – a halibut farm considered to be one of the most successful fish farms anywhere in the world, and a blue mussel farm just getting on its feet that has lots of potential but still feels like a back-of-the-garage operation. The first place we went was the Fiskey halibut farm at Hjalteyri, where the manager and the research director gave us a tour.

Even though this is a tiny town with little other than the Fiskey plant, this is the largest halibut farm in the world, producing 50% of the world’s farmed halibut juveniles – they export about half a million five gram halibut juveniles each year. The juveniles are bred from adult halibut stock kept in Dalvík and grown for six months before they are large enough export to other farms, mostly in Norway, that grow the halibut to the market size of about five kilograms. We got to look into the tanks of developing eggs, where some of the floating dots were just beginning to grow eyes, then at the tanks where they begin to move from a pelagic phase to become bottom fish (this is also the time that they grow their characteristic coloration and their eyes migrate so that both are on the top of their body). This picture is overlooking the tanks of the “finished product” – five gram halibut ready for export.

Even though the farm operates on land in a highly controlled environment, the director told us that the operations are still very location dependent and can’t be easily reproduced elsewhere – they tried to open a similar plant in Nova Scotia, but were not nearly so successful. It seems that a lot of it is time and experience – this halibut farm has been in operation for twenty years, providing a lot of time to work out the kinks of the operation and allow the staff to learn from their experience.

The day after touring Fiskey, we went to see the blue mussel farm based on the island of Hrísey, Norðurskel. Basically, the operation works by putting frayed ropes (to increase surface area) in the water about a week before the mussel larvae are ready to settle (when the larvae are 0.25mmm), which allows the larvae to settle on the ropes. They then just let the mussels grow on these ropes until they’re ready to be harvested.

Here’s Víðir, the company manager (the company only has three employees), pulling up some of the ropes of mussels onto the boat so we can look at them.

And here’s what the mussels look like up close.

The company started in 2000, but for the first five years didn’t have much money to expand the operation and had to run largely on guesswork. Two years ago, though, they found investors to support the company and now have support from the University of Akureyri and Memorial University in Newfoundland, which has enabled them to buy the mussel harvesting boat we went out on and a building on Hrísey that they are converting into a processing facility and begin testing the water so they can be more precise about when to put the ropes out and also testing for toxic algae blooms. The company still isn’t profitable, but it’s still in the developing stages and expects to begin making a profit in a few years. For now, it’s the only mussel farm in Iceland, so at least until others get started, they control the market price and supply mussels for the entire country. Even though the company is obviously making a lot of progress, it did seem rather like a shoestring operation – when we went though the new processing facility, for instance, the whole front area was taken up by cars in various state of repair, which apparently were someone’s project for the winter.

A small, flexible farm though is probably what makes the most sense on an island like Hrísey. Although they do have regular connection to the mainland through the ferry that runs between the island and Dalvík, it’s still a tiny town, with only 150 people living on the whole island.

It’s a small enough place that many people have opted to drive tractors to get around rather than cars, reminding me of the golf carts that everyone drives on Tangier Island in the Chesapeake Bay.

Most of the island’s residents work in the two cod processing plants in town, but since one of the companies sold a lot of its cod quota a few years back, half the town’s residents lost their jobs and had to leave. This makes the growing mussel farm even more important, since it provides another potential source of jobs to keep people on the island even as the cod quota drops and the fish-processing plants may again have to cut back.

Nearly everyone I’ve talked with seems to think that aquaculture is the way of the future for fisheries, and I pretty much agree. The question, of course, is how long it will take to develop aquaculture methods capable of meeting the world’s demand for fish. Ideally, aquaculture will provide fish that are cheap enough to provide a significant food source and free of contaminants so that they remain a nutritious food, but also operate without harming the environment or wild fish stocks. I’m not ready to figure out the key to the future of aquaculture and the world’s fisheries, but I am convinced that this is going to increasingly become one of the most important concerns both in the world of fisheries and in the world in general. As for what I saw at these two farms, I think they’re fairly representative of where Iceland is in the development of aquaculture – simultaneously at the forefront of world technology and still trying out new ideas from more of an independent tinkering-in-the-garage innovation approach.

In between the cod fishing, we also spent some time looking at the bottom environment in Eyjafjörður and touring local aquaculture facilities. To see what the bottom looks like, we both took sediment samples and used a nifty underwater camera just to look at what we could see. The sediment samples we collected from Einar i Nesi using a Shipek grab, which basically just scoops some sediment from the bottom:

Then we sieved the mud that came up and preserved the contents to be analyzed later.

The Shipek grab and sieving procedure were very familiar (I’ve spent plenty of time looking at sediments), but the actual purpose was to look at the benthic organisms rather than the sediment itself. Of course, I had lots of questions about what research had been done on the sediments, but it sounds like they’ve only done cursory research to classify the sediments in the fjord (and certainly nothing on pore water chemistry…) and even very little research on the benthic organisms – our samples were part of a very small project to collect annually from just a few sites, seemingly used more as a teaching exercise at the University of Akureyri more than as real research.

What I found most exciting about looking at the bottom environment in the fjord was our attempt to look at the hydrothermal vents in the fjord. This isn’t terribly relevant to cod, although we did see some cod near the vent – fish like to hang out in areas where there is more complexity in the bottom environment – but most importantly, hydrothermal vents are just darned cool. Most hydrothermal vents are found very deep in the ocean and are thus difficult to study without expensive underwater vehicles, but there are two areas in Eyjafjörður with hydrothermal vents and chimneys of mineral deposits that are so shallow it’s easily possible to scuba dive around them – or, in our case, look at them with a camera lowered from a boat floating just above the vents. We went out on the Húni II, a wooden fishing boat built in Akureyri in 1962-63 that was preserved to use for tourist trips when it outlived its use for fishing (unlike most wooden boats, which are traditionally burned at New Years bonfires, not so good for historical preservation).

Normally Húni II is based in the harbor in downtown Akureyri as part of the Industrial Museum and occasionally takes tourists fishing, but we got to spend an afternoon using it as a base for our explorations with the underwater camera, particularly making use of the large-screen television below decks which we hooked up to the camera so we could watch on a large screen. Nobody had ever tried to look at the environment around the vents using a camera like this before – and, since it turned out not to be a terribly effective method, it may not be frequently used in the future either. Basically, all we did was lower the camera into the water while stopped at the right GPS coordinates and watch what we could see on the video screen.

Since it was fairly difficult to control what the camera was looking at, it was really hard to see the vent, although we did get a couple good views, in addition to looking at a lot of the “normal” bottom environment in the area too. On our last time finding the vent, the camera actually got stuck under a ledge on one of the chimney cones, and the camera lost both of its flashlights and broke the wire holding the camera angle steady before we managed to pull it back out. Whoops.

Despite our lack of actual discoveries, this was apparently news enough to actually make the news, and both a radio station and the local Akureyri television station, N4, sent reporters to watch and run stories on our experiment, which mostly goes to show that there’s not that much to fill the news in a town of 16,000 people. I didn’t expect anything to come of this, but it turned out that not only was our fiddling around with the camera worth sending a news crew, it was also worth a fifteen minute slot on the news the next week. So, I’m famous! By which I mean there was a minute-long interview with me on Icelandic television where I said something along the lines of “Iceland is really cool” (something about my project, though there was no way to explain it in a one-sentence sound byte, in answer to the question “So what are you doing here with all these Nordic students?” and something about how I liked going out on the shrimp survey and about how we were really close to the whales in Húsavík). The best part though was their Icelandic subtitling of my interview: I became a “Thomas J. Whatsson” fellow. Rather clever, actually, to apply the Icelandic patronymic naming system to the name Watson, though it must have seemed particularly ridiculous to any Icelander since it means Thomas J., the son of What.

Between all of this fishing and becoming famous, we still had time to relax and have some fun back at Ytri Vik (which was in a gorgeous location, right on the edge of the fjord – the first morning there was a harbor seal sunning itself on a rock right in front of the house!). Each day after we got back, we cooked the fish that we had kept rather than tagging or just throwing back (those that were badly hooked), which was more than enough fish to provide full meals for all of us. I got to sample Finnish and Norwegian and Danish fish cooking styles; we had grilled fish, fried fish, boiled fish, and baked fish. It was all very good, although by the end of three days of fish dinners, we were thankful to have pizza the next night….

Finnish fish frying:

Danish fish grilling:

Relaxing also meant sampling Icelandic beer and enjoying the hot tub on the porch behind the house, which provided an excellent view of the fjord and mountains.

In addition to sampling the standard Icelandic beers (with very Icelandic names like “Viking” and many brewed by a company named after Egil Skalagrimsson, a famous saga character noteworthy as a rather bloodthirsty Viking), we also went on a tour of the Kaldi brewery at Arskógssandur, just outside Dalvík.

Sabine (the German, of course), was very curious about the brewing process and asked lots of questions, while most of us just enjoyed our samples.

So just in case you thought being a Watson fellow is all work, you can rest assured that I’m also having a good time.

1 comment:

Aedd Karston said...

Thanks for such a great article.

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