The 41st U.S. - Japan Natural Resources (UJNR) Panel on Aquaculture Science Symposium
and a Field Tour to a Kelp Processing House
Well, this posting has been languishing for a long time, but I finally got around to it. Back in October of 2013, I got a chance to participate in the UJNR meeting, in Hakkodate, Japan. My role was to present a long-term view of the stock enhancement and aquaculture work with sea scallops in Maine, work that had a direct origin in an earlier trip to Aomori, in 1999. Most of the other presenters were doing work on finfish physiology, feeds and similar topics, so my shellfish focus was a little bit of an outlier, but the whole thing was fascinating. Below is a snippet from the tour, and it constituted a site report from me, regarding one of the highlights (it was for me, anyway), and some general background. Background first:
The UJNR is one of the oldest and most effective cooperative bilateral agreements between Japan and the United States. Having been in effect since 1964, the Aquaculture Panel is currently represented by NOAA and the Japanese Fisheries Research Agency. The Panel is composed of United States and Japanese scientists who meet annually to conduct business meetings and hold a science symposium to share research on selected scientific topics in the field of aquaculture. Business meetings and science symposia are followed by field trips to research institutes, universities, fish farming centers and commercial farms. Meetings alternate annually between nations. The visit to the kelp farm described here was one of the field tour sites visited by the UNJR Panel following the 41st Science Symposium held from October 9-12, 2013 on the northern island of Hokkaido.
Site Visit with Mr. Takahiko Yamada
Hakodate, Hokkaido, Japan
October 12, 2013
The U.S. and Japanese delegations were fortunate to make a couple of stops in Hakodate, the first being a visit to the Usujiri Fisheries Station, and meet with its’ director, Dr. Hiroyuki Munehara. Dr. Munehara oversees work in reproductive and molecular ecology, and is a leading expert in biogeography and speciation of greenling. The station welcomes visiting scientists and students, and has a range of facilities to field and laboratory research.
|Mr. Yamada (white overalls) explaining his operation||to the delegation|
His wife is an integral part of the company, though his son did not want to enter the business, preferring to go to college, and Mr. Yamada noted that his farm production of about 100,000 blades of mature kelp at final harvest, plus other products - is tailored partly so that he can assist with his son’s education.
|Mr. Yamada at the motorized cutting wheel; his wife at the cutting table and stacked bundles of dried kombu behind.|
At the time of our visit, they were processing the harvest, which had been completed in July. The kelp blades had been dried and bundled. They were then to be rehydrated, rolled flat and dried again, and then trimmed, cut to length and packaged. A motorized trimming machine allowed them to remove the thin outer fringe of the kelp (kombu). The blades were then passed to his wife, who had a bench equipped with a cutting handle, probably taken from a paper cutter.
The kombu itself was quite substantial; about 7-8 inches wide when whole/dried, but trimmed to about 5 inches in width, to capture the thickest part of the blade. Any stipe still attached to the blade was quite short, only a few inches. When harvested, the remainder of the raw stipe is cut and pickled. The trimmings from the blades are used as well; they are bundled and pressed together into a block; the block is then sliced thinly, though he didn’t say what the sliced trimmings were used for.
Trimmings of the dried stipe themselves are used in traditional children’s medicine to treat coughing and colds. It was clear that Mr. Yamada has a use for all the biomass coming off the farm; they have a diverse set of products and markets they sell to, so everything is used.
|A trimmed piece of stipe (right) and a piece from the center blade.|
Seed for his operation is produced at the local kelp cooperative. His farm uses 2km of seed line. For 2km he pays an estimated $3800 (we assumed it was estimated in $USD), or roughly $1900 per km (ca. $1.90/m, or ca. $0.65/ft). Seed line comes wrapped on a PVC tube. Instead of spiraling the seed string around the growout line (as we have learned to do in the U.S.), they cut it into pieces about 1.5-2 inches long. These short pieces are inserted into the growout line, which is a 3-strand soft lay rope of Japanese manufacture.
We did not see the vessel(s) he uses to service the farm, so we can’t speculate on their size, arrangement or equipment aboard. We were informed however that he will thin the lines two or three times during the growing season; the plants coming from the farm during thinning are used for other products.
Growout lines are laid out in the shape of a ladder, laid flat. The seeded lines are about 8 feet in length, and these run horizontally (the ‘rungs of the ladder’) between two longlines (the long sections of the ladder); the longlines are ca. 22mm hard-laid line (e.g. polysteel). Each seeded line terminates in a loop, and from the loop is a short length of ~5mm hollow-braid twine; the twine is attached to the longline with either a rolling hitch on a bight or a clove hitch on a bight - that way the seeded line can be untied from the backline quickly, with one quick tug on the free end.
|Seed string, inserted into the soft-lay rope of the growout line.|
The mature plants we saw were about 8 feet in length. They presumably are brought wet into his drying house. One location for drying was a sort of shed, in which he had hung racks overhead and clips to hold the kelps. In addition, he now has a drying house proper, approximately 30’x15’, which is equipped with racks that raise and lower on pulleys. These racks are also outfitted with many hooks, and there is an oil-fired heater in the shed - I think he said he dries the kelps at approximately 85deg F. The plants we saw were a rich brown color, and not green, which would indicate drying at too high a heat.
|One of Mr. Yamada's kelp-drying facilities is a roofed shed: the racks above move up and down on pulleys, and carry many clips for holding onto the kelp plants. Photo: Steve Eddy|
In addition, we were shown a kelp cleaner; an enclosed box equipped with a water spray, and both rubber and brush heads. We did not see the unit in operation (it is variable speed however), but it was to clean the kelp from fouling (we saw a small amount of bryozoans on some of the kelps). The brand of cleaner is no longer in manufacture, but we suspect that other companies produce such machinery, and it should be possible to find such equipment.
|Kelp washer; the functional parts; rubber wheel for grabbing/moving the kelp and a brushed roller for scrubbing.|
|Kelp washer manufacturer identification: Mohkas, model MB-6?.|
Although this photo does not give a good representation, Mr. Yamada had a re-hydration tent set up in the room next to his processing space. The ‘tent’ appeared made of the same material as a plastic tarpaulin, and had a zipper in the side - the whole arrangement being about 10 feet square, and hanging from the drying clips that were also in the room. Dried kelp plants were placed in here, and a humidifier was placed inside. After a short time (minutes, we believe) the kelp softens enough so that it can be placed in a homemade press: this resulted in the flat, dried kelp blades that we observed the Yamada’s processing. This room is also used to ensure that kelp ready for packaging is fully dried by using a dehumidifier to remove any ambient moisture.
Top view of the rehydration tent; showing the zipper and how it's simply hung from the clips otherwise used for drying.
The inside of the tent was pretty bare when we saw it, but would have had a humidifier present when re-hydrating seaweed. Photo: Steve Eddy.