Árbók VFÍ/TFÍ - 01.06.1998, Page 321

Optimization Models of Aquaculture Operations 319
Results of test runs
The models presented above were tested with real life production data from a salmon farm-
ing company in Atlantic Canada. The price scenario for the Sales Prices S/t) in Fig. 1 is
based on an exponential forecasting model developed for this purpose. As mentioned earlier
Fig. 2 shows the variable cost for fish harvested at different times Cp(t). In these test runs
we included only the feeding cost and no distinction was made between smolt quality clases
p. The transition probabilities of the 6 growth models Pps(f), one sby t matrix for each smolt
quality class p, were estimated for each pen class and an example is given in Table 1 for p
= 1.
Other data for the Aggregate Planning Model is as follows:
Ws = Weight of fish in size class s is:
i= 12345678
smolt 0,5 1,4 2,3 3,2 4,1 5,0 5,9 kg/fish
Rpi(l) = Rp which represents the size (quality) distribution of smolt released in May:
p= ' 1 2 3 4 5 6
100 200 600 600 300 200 No. of fish x 1000
Dmm(t) and Dmax(t), the bounds on demand in tons in period t, where set at 500 and 700 tons per
month for all 12 months.
The results of these test runs with the AP-model are shown in Tables 2 and 3. Table 2 shows
the number of fish (1000 fish), of all sizes, harvested of each smolt quality category through
the harvesting year, and the shadow prices for smolt in CAD/fish. These can be interpreted
as the value of smolt of each category for the company at the beginning of the growing per-
iod. As could be expected the shadow prices increase with size of smolt. These results are
pi P2 P3 P4 P5 P6 Sum:
Sep 16 i 2 11 12 32 44 101
Oct 17 i 3 25 54 12 0 95
Nov 18 3 7 13 24 33 17 96
Dec 19 4 42 27 17 30 29 149
Jan 20 4 7 14 73 4 39 141
Feb 21 22 9 114 94 41 20 300
Mar 22 32 60 0 0 64 46 202
Ap 23 3 12 49 13 60 0 137
May 24 3 6 17 102 13 0 142
Jun 25 3 5 17 152 0 0 178
Jul 26 2 7 154 10 0 0 173
Aug 27 8 17 100 10 0 0 135
Sum: 85 177 542 562 288 195 1849
Shadow prices: 14,25 15,68 17,17 17,92 18,68 19,33 CAD/fish
Table 2: Number offtsli (1000ftsh) harvested ofeach smolt quality class through the harvesting
year, and the shadow prices for smolt, CAD/fsh.