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Fukui's Monthly News Letter

Submerged longlines


In a previous column (June 1999) I discussed the submerged long line technology used by Dr. John Bonardelli of GRT Aqua-Technologies. This is one of the farms that has taken the Quantity + Quality = Profits (Q+Q=P) equation, as discussed in previous columns, very seriously.
In October of this year a pilot friend of mine and I flew his pressurized Cessna 210 up to John's farm in Gaspé, Quebec. I had wanted to visit the farm for some time however the remote location and options of regular scheduled airline service at decent prices have been a hold back. Aside from seeing John and the farm, I was able to get some quality flying time in. It was a typical fall day in this area of the world with air temperature of 30C to 100C, light rain or drizzle with a bonus of very light wind.
John has two farms set up for GRT Aqua Technologies; one in Baie des Chaleurs, which is very open to the elements, and the other in Gaspé Bay which is relatively protected.

buoys marking submerged longlines

On both sites the lines are 200 meters, anchor to anchor, with a usable working length between 150 to 180 meters, dependent on water depth and the particular submerged longline geometry (see figures).
At the more exposed Baie des Chaleurs site, the long lines are 30' below the surface with 20 foot socking loops suspended below the long line. The site at Gaspé Bay has the lines 15' below the surface with 15-foot loops. According to Bonardelli, they have hundreds of these longlines deployed with approximately 1 kilometer or just over ˝ mile of socking per longline.
When you consider that there will be approximately 4 lbs. hauling longlines out of harvested mussels per foot x 3300' of socking, that means there are close to 13,000 lbs. of product per longline. This output multiplied by the hundreds of deployed long lines, certainly puts these farms in the quantity section of the Q+Q=P equation.
Like all well thought out applications, GRT's farms are just different enough to take advantage of different environmental conditions.
Accessible work time to sites is not normally considered when planning your scheduling of deployment, maintenance, and harvest. In the case of exposed areas or the presence of winter drift ice, these factors must be taken into consideration. Bonardelli's Baie des Chaleurs site is accessible only in the summer months, or 60% of the year, due to the winter drift ice that makes work unsafe. His Gaspé Bay site is accessible during the summer, and also in winter by working on the 2 to 4 foot thick ice for harvesting, which can only be done at that time of year due to summertime toxic algae. This means that harvestable time is available only for 40% of the year. equipment for deploying and harvesting mussels on longlines
It is the environmental conditions that somewhat determine the size of the farm, from the perspective of available time for equipment usage. What this means is that to fit within the time frame allotted by accessibility/access factor you will need either more or larger boats and more efficient equipment in order to service a larger farm.
The percentage of workable time also must include the daily hours bulk bag for handling mussels that are affected by local wind conditions. For instance during specific times of the year between 10 a.m. and 3 p.m. it may be too rough to tend the farm, therefore you plan to work early in the day as well as later in the evening. Or during sustained windy periods, you do not harvest or manipulate certain lines but work on empty lines so as not to lose any mussels.
With respect to quality, it is well known that after spawning mussels lose a lot of their meat yield. Since spawning is typically induced by increasing water temperature after successive food build up, having your crop in deep colder water, that has very little temperature variance, can reduce spawning from one large expulsion to that of many trickle spawns. The difference in meat yields are dramatic. The trickle spawn mussels can have a meat yield in excess of 40% during peak periods, compared to the 25% range for the large discharge spawns. Once buyers and consumers experience the difference, it is much easier for them to justify the higher quality purchase and to be repeat customers.
By having the two sites, John's operations management team is able to select, based on the time of year, his time of harvest and maintenance. Growout cycles in this area are between 2 to 3 years from larvae to harvest with harvestable seed (5 to 8 mm) ready for socking 4 to 5 months after setting. mussel operation Product is harvested dependant on market demands, usually at 2 ˝" or 20 - 25 count per pound.
During the summer months surface buoys are attached to allow quick identification and for ease of maintenance. As well, it is very handy to have lines identified at the surface to manage growth spurts that happen in the summer months. The surface floats can give visual reference to just how much weight is being added to each line.
This extra work is minimal since the lines have to be floated up in spring and sunk for the winter anyway, additional flotation must be added at those times. During the winter months the surface buoys are removed so that adverse conditions have no effect on the longlines.
longlines on sonar With the amount of lines at the GRT sites, thorough record-keeping is a must for good farm management, both for equipment inventory and for determining time to market. Each line has a recorded GPS identity, and with the use of sonar depth monitoring, lines can be located and or inspected electronically.
The advantage of being well organized, properly financed and adequately equipped was proven very evident while we were there.
A few weeks previous it was discovered that the collection lines had suffered a starfish larvae set after the mussels had set in June/July. It doesn't take a lot of starfish to strip a collector line of smaller mussels once they start feasting away. starfish on mussel longlines If traditional long lines with single collectors were used it would have been next to impossible to rid the line of the starfish due to the high labour cost. Under these conditions, each collector would have to be manipulated individually. With the level of mechanization that John's team works with, they were stripping the lines, grading the mussels and dipping both the mussels and starfish in a 30% brine solution for 30 minutes. The process killed the starfish and left the mussels, which in 30 seconds were ready to be re-socked.
Once a certain volume was treated, the equipment on the boat was rearranged from stripping and sorting to socking and deployment. This takes only about 15 minutes, and within a short time all the mussels, less the predator starfish, were re-deployed. John uses a modified New Zealand method of center core rope and dissolvable cotton socking at this time.
This was the first exposure for my pilot friend, who is from the finance industry, to the aquaculture industry. He was quite impressed with the level of business methodology that had been used and even with the higher up front capital investment compared to the apparent norms of the industry, the profitable return caused by less labour and high production output was substantial.

along the longlines


Contact Don Bishop at:
Fukui North America
PO Box 669
110-B Bonnechere St.W.
Eganville, Ontario K0J 1T0
CANADA
**NEW**Tel: 613-559-0075 or 613-628-5266
**NEW**Fax: 613-432-9494
Email: kate@fukuina.com or don@bishopaquatic.com

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