Table 9. Comparison among alternative clam exploitation scenario, as set by Figure 4. The extreme scenarios, represented by full exploitation scenario (data and estimates from 1999) and no exploitation scenario (data, estimates), are compared with three intermediate scenarios: ScenMix1, ScenNat, ScenMix2, assuming a revenue of 50,000 euro/year/worker. Surface and employments parameters have been set at first, productivity, revenue and externalities have been computed using modeling results.

parameters/scenarios 1999 ScenMix1 ScenNat ScenMix2 Conservation
boats 1400 400 400 0
workers 2500 935 1288 1111 0
seeding tons (Natural)[tons] 0 800 2400 1600 0
Seeding tons (Hatchery) [tons] 0 1600 800 0
global surface fished/year [ha] 40,500 2160 2880 2520 0
sediment loss (from Orel et al. 2000) [m³] 405,000 21,600 27,600 21,600 0
Environ. externalities (1999 value) [million euro] 12.15 1.07 1.10 1.36 0
production [tons/year] 40,000 37,132 37,266 37,199 0
profits(20% premium price quality) [million euro] 64 47 64 56 0
% externalities 19% 1.5% 1.7% 1.6% 0