Figure 2b. Relationship between Letter and you may Y (left committee) and you may F and you can Y (correct committee) when holding capabilities K transform 5000 and you can 25000 for the Schaefer design
Contour 3. Two decades simulator of your amount from inside the inventory Letter and you may funds Rev when carrying potential K fluctuated. Intrinsic growth rate roentgen was constant (0.8) and an effective = 5.
Shape 4. A: K try lingering (15000), roentgen fluctuated out-of 0.dos owing to step 1.4 and F try set to r /2. B: K are ongoing, r fluctuated and you may F was set-to ongoing (0.4). C: K fluctuated and you will r was constant (0.8). Right here, fishing skill was increased by the q and you may yield are divided by the a hundred.
The newest bionomic balance part away from F where Prof =0 at the reasonable inventory height F eq (low) ( K =5000, r =0.8) and you can higher stock top F eq (high) ( K =twenty five one hundred thousand, r =0.8) throughout the condition one to an excellent = 5 was datehookup nasıl bir uygulama indeed 0.08 and you can 0.66, respectively (Dining table step one). These are comparable to 160 and step 1 320 (boat*trips) inside angling potential, correspondingly, and comparable to full (40) travel of the five and you can 33 ships.
4.dos Movement within the roentgen
A couple secure tips was indeed checked-out towards the instance whenever carrying strength, K , is actually ongoing and you can inherent growth rate, roentgen , varies, i.elizabeth. let F become constant and you may F getting roentgen /2 to meet fluctuating r .
The brand new bionomic balance section regarding F in which Prof =0 within reasonable stock peak F eq (low) ( K =15 000, r =0.2) and you can large inventory height F eq (high) ( K =fifteen 100000, r =1.4) in the standing you to definitely an effective = 5 and you will b = dos was 0.15 and 0.99, respectively (Table 1). He is equivalent to three hundred and you can 1980 (boat*trips) in the angling skill, respectively, and you will equal to complete (40) trips from the 7.5 and you will forty two.5 boats.
The amount of time variety of inventory proportions N , yield Y and you will funds Rev having fun with non-equilibrium design model are shown within the Profile six. The new produce turned restriction when F = 0.52 which equal to complete (40) sail by twenty six boats (Shape 4). The gains turned restriction when F = 0.twenty four and that equivalent to complete (40) cruises of the twelve boats in the updates you to a beneficial = 5 (Dining table step one and you will Fig. 8).
Contour 6. Two decades simulation regarding N , Y and you may Rev when K is constant (15000) and you will a good = 5. r fluctuated away from 0.2 to a single.cuatro but F try set-to 0.cuatro.
The partnership anywhere between Letter and you will Y , and you can F and you will Y when roentgen is the lowest and you can restriction from confirmed variety and you can holding strength K are ongoing are found in the Figure 5
The full time selection of stock dimensions N , yield Y and you can money P rof utilizing the dynamic manufacturing model are provided within the Figure seven. Within means, F fluctuates yearly however, never meet or exceed the top limit corresponding to the newest angling potential devote improve. This example is the perfect collect strategy, given that F reacts towards real possessions off seafood the brand new inventory. It is necessary to let too much angling work are of the closing of the fishery when F shall be reduced using a great lowest progress conditions.
Profile 7. 20 years simulation out of N , Y and Rev when K was constant (15 000) and you may an excellent = 5. r fluctuated from 0.2 to a single.4 and you may F altered appropriately ( F =r/2), but fishing skill is actually minimal 800 (boat*trips).
Regarding simulator shown in the Shape eight, brand new stock size slowly converged so you can K /dos (=seven five hundred), the newest stock proportions that reaches MSY. The actual situation whenever angling capability exceeds step one eight hundred (boat*trips) generated yield restriction (Figure 4). Fishing death out of 0.7, is the same as the full the means to access fishing capabilities of just one 400 (boat*trips), which can be equivalent to F MSY (high), and that is equal to an entire number of vacation by the thirty-five boats. Fishing death F you to produced the profits restrict ranged with a good . Whenever good = 5, F = 0.thirty-six (full trips from the 18 vessels) generated the profits maximum, when you’re F = 0.31 (complete cruises of the fifteen vessels) whenever a great = 10, and you can F turned into faster as a great improved (Profile 8).