Árbók VFÍ/TFÍ - 01.06.1998, Blaðsíða 322

320 Ritrýndar greinar
Lbs Size: Smolt S1 0-2 S2 2-4 S3 4-6 S4 6-8 S5 8-10 10-12 S6 S7 12-14 S8 Shadow prices CAD/kg
Sep 16 1 0 0 0 0 0 173 126 201 500 -1,61
Oct 17 2 0 0 0 0 0 0 345 155 500 -0,59
Nov 18 3 0 0 0 0 0 0 368 133 501 0,00
Dec 19 4 0 0 0 74 0 47 239 340 700 0,37
Jan 20 5 0 0 0 0 0 156 341 203 700 0,99
Feb 21 6 0 0 0 681 0 0 19 0 700 0,63
Mar 22 7 0 0 0 3 569 5 19 104 700 1,10
Apr 23 8 0 0 0 3 0 229 18 450 700 2,04
May 24 9 0 0 0 0 0 181 324 196 700 2,40
Jun 25 10 0 0 0 0 266 283 0 150 700 2,37
Jul 26 11 0 0 0 0 165 413 0 122 700 2,59
Aug 27 12 0 0 0 0 1 0 517 182 700 3,02
Tons total 0 0 0 762 1001 1486 2316 2237 7801
Table 3: Tons harvested of eacli size class in each month, and tlie shadow prices of demand
restrictions, CAD/kg.
of importance to the company because usually some of the smolt is sold, and the prices
offered can be compared with the shadow prices.
The harvesting numbers in Table 2 indicate that smolt category p - 5 and 6, i.e. the
largest smolt, should be harvested early while category p - 3 and 4 come in later. It is inter-
esting to see that a great deal of categories p = 1 and 2 are harvested in February and March
(periods 21 and 22), and even in December (period 19), but not as would at first glance be
expected in the last periods. This is explained by the fact that, as Fig. 1 shows, the price
difference between size classes is smallest in periods 19 to 22. In other words, it does not
pay off to grow these smolt categories any longer compared to the relatively high price for
small fish in these periods.
Table 3 shows the tons harvested of each size class in each month, and the shadow prices
of demand restrictions. Again it can be seen that small fish is harvested and sold in Febru-
ary and March, and also in December. In October and November, and August, on the other
hand, Fig. 1 shows the significant price peaks for the biggest fish, resulting in the harvest of
only the two largest size classes in these periods.
The shadow prices in Table 3 for the demand restrictions can help the company to decide
how much could be spent in terms of CAD/kg on increasing market, or capacity, in each
month. This is clearly and understandably of most importance in the last periods. Also, it
can be seen how much could be spent in September and October on fulfdling the market by
buying fish from other sources. For example, up to 1.61 CAD/kg would be justified for this
purpose in September. Note that this is the acceptable loss, or how much buying price from
other sources could exceed selling price on markel.
The HS-model was tested by scheduling harvest from 6 pens or pen groups, one of each
smolt quality category. Here some additional data is required. The starting size distribution