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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.
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.
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.
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
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.
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.
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.
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.
Contact Don Bishop at:
Fukui North America
110-B Bonnechere St.W.
Eganville, Ontario K0J 1T0
CANADA
**NEW**Fax: 613-432-9494
Email: don@bishopaquatic.com or don@bishopaquatic.com
Copyright © 1999-2004 Fukui North America. All rights reserved.