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Japanese scallop cooperative model of farm efficiency

When I was in Northern Japan a few years ago, I met with the director of a scallop growout cooperative that had 80 farm members. During my flight I had read a report that, in 1993, Canada produced 14 metric tons (mt) of scallop meat from farm operations. Production in the US was similar. Through an interpreter I was told that the cooperative's 80 farmers had produced 800 mt of meats in 1994. I questioned those numbers. How could only 80 farmers and their staff produce so much more than the whole nations of Canada or the US? Their reply was also disbelief. With all the area for farms that we have in North America, why were we not producing more?
In the discussion that took place over the next few hours, I learned that this cooperative has been in operation for 27 years. It was explained that one of the important reasons for the high yields achieved by the members is that they maximize their growout area. They use equipment that enables them to work every cubic meter (about a yard) of growout area in their lease.
This is a very important point. In North America we have a general tendency to look at lease sites as level areas with a two-dimensional viewpoint. In fact, every cubic area of the water column is capable of growout.
If we look at the basic growout model, taking out consideration of the species, water properties, and climatic conditions, the following information can be duplicated anywhere in the world.

Shellfish model
The Japanese cooperative's lease is in a bay that is approximately six miles wide, shallow at one side and deep (180') on the other. Even though the site is looked at in a cubic context, the farmers of the cooperative have discovered over the years that some areas of their site are not efficient to use.
The "five meter rule" (15') is applied extensively by this group. The rule is that growout is not efficient with respect to labour cost and yield in the area where most fouling occurs, which is five meters below the surface. The cooperative members will not farm within 5 meters of the bottom, either, due to predation and fluctuating wave action that, in heavy seas, may cause their hanging cages to hit bottom.
A combination of four different growout methods are used by the Japanese farmers to maximize their cubic grow out area. The following description and diagram explain the shellfish model:
A)   Deep water cages, which are pearl nets tied in a line of up to 30 nets deep, are deployed starting at a mean depth of 50'. The pearl nets are less efficient than lantern cages. However, the experience of the farmers was that in deeper water, lantern cages, due to their greater vertical surface area, suffered from a pendulum effect caused by tidal or storm surge. That, in turn, crowded the animals to one side of the cage thus increasing mortalities.
The pendulum effect is reduced dramatically, to almost none, with pearl nets because of their design and the fact that they are independent of each other. So, even with the increased handling factors, this method is the most efficient for the Japanese farmers in deep water because the yield is maintained. They also have discovered that the weight and bulk of going with more than 30 pearl nets deep is counterproductive to labour efficiency.
B)    Shallow water cages, which are lantern cages, are deployed starting at mean depths of 35' using a five-level unit, 40' using a 10-level unit, and 45' using a 15-level cage. The surges at these depths are different enough that the cages are not affected as much as in the deeper water, thus the labour efficiency of the lantern cage proves itself. The farmers have found that cages of more than 15 levels become difficult to handle with the current equipment being used.
C)    Horizontal ear hanging is the next method employed by the Japanese framers in their efficient use of the water column within the site.
Using a special ear-drilling machine, a hole is drilled through one of the ears on the scallop shell. The shell is then laced onto a special loop cord and suspended horizontally in the water column between two anchor lines. This method is normally deployed at mean depths of 20' - 30'
D)    The final part of the efficiency model is to bottom-seed the area between the ear hanging and minimum depth at shore with year-old scallop seed (grown in pearl nets). When fully grown, the scallops are harvested in the traditional dragger method.

Use what's proven
While your own future site may not be like the one described here, you just may be able to duplicate some of the Japanese cooperative's success if you adapt some of these methods.
Aquaculture operations in Japan, as a rule, make the most efficient use of whatever they are working with, which is very evident with respect to scallop farming. The fact that in North America we have so much space for shellfish culture is no reason to forego proven methods.
If you want to make money in this business you need to follow the lead of those that are making money. With annual scallop meat production of 800 mt at current market prices, the Japanese farmers are certainly in the money.
It is also worth repeating one of the rules of aquaculture: "What you learned today will probably change tomorrow."
The introduction of the very high-speed ear drilling and automatic attachment machines, which are capable of rigging 3,600 scallops per hour, will certainly change the efficiencies of what is taking place in Japan and North America.

While only the well-organized larger farms or cooperatives are now able to take full advantage of this new technology, the caveat is that small to medium-size farms can become big producers in short order.

Contact Don Bishop at:
Fukui North America

110-B Bonnechere St.W.
Eganville, Ontario K0J 1T0
Email: don@bishopaquatic.com or call 613-639-3474

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