the MCDM technique to assign a specific weight to each one. The economic criterion
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was thus found to be the most important one, although the criteria of efficiency (fish in-
423
fish out ratio) and omega-3 (which affects quality) are also taken into consideration (Luna
424
et al., 2019a).
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Criteria
Scenario 1
Economic Criteria
81.8%
Profit
81.8%
Environmental Criteria
9.1%
% Organic Feed
0.3%
Fish in-Fish out Ratio
3.2%
Total
Nitrogen
1.0%
Total Phosphorus
1,0%
Energy Use
1.8%
Global Warming Potential
1.8%
Quality Criteria
9.1%
% Fish origin feed
0.9%
Omega-3
8.2%
Table 2 - Producer preferences.
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In addition, from the very beginning and throughout the entire production process, many external
427
factors directly influence the results obtained for each candidate solution and hence the final plan
428
selected. First, the main variable affecting the biological model is the water temperature. In this
429
respect, the Mediterranean Sea is the most common place to farm gilthead seabream and so it was
430
chosen as the hypothetical location for the farm. The annual information on temperature was
431
obtained from the Spanish Port Authority’s network of oceanographic buoys in
a location close
432
to Tarragona (Fig. 3).
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Fig. 3 - Average Farm Temperature
434
Fish selling prices are estimated from the main Spanish wholesale market prices for the
435
commercial classes of seabream (300–400g, 400–600g, 600–1000g) for 2018
on a weekly basis,
436
and used as a proxy of the ex-farm price applying a reduction comprising the average wholesale-
437
producer margin, as stated by MAPAMA (2012). The price considered for organic aquaculture is
438
15% higher for the same period, based on the study carried out by Zander and Feucht (2018),
439
which shows that willingness to pay varies between 7% and 20%,
depending on attribute and
440
country. Moreover, in some cases the farm will have some commercial agreement.
441
Do'stlaringiz bilan baham: