You can choose to treat dynamics of fleet sizes and resulting fishing effort as unregulated and subject to fisher investment and operating decisions. The models are described in detail in the introductory material.<\/p>\r\n
If you wish to use the fleet\/effort dynamics model, you should check the 'fleet\/effort response' box on the Ecosim parameters form. When this box is checked, Ecosim erases all previously entered time patterns for fishing efforts and fishing rates, (e.g., from the sketch pad or from the time series data file), and replaces these with simulated values generated as each simulation proceeds.<\/p>\r\n
In this model, there are two time scales of fisher response:<\/p>\r\n\r\n
You need to set two parameters for the short time response model (\u2018Effort response power\u2019 and \u2018Initial effort\/capital capacity\u2019) and two for the longer time model (\u2018Capital depreciation rate\u2019 and \u2018Initial capital growth rate\u2019).<\/p>\r\n\r\n
Use \u2018Effort response power\u2019 to set the parameter p<\/em>, which represents a \u201cheterogeneity\u201d parameter for fishers: high p<\/em> values imply all fishers \u201csee\u201d income (I<\/em>) opportunity similarly, while low p<\/em> values imply fishers \u201cturn on\u201d their effort over a wide range of mean incomes (see figure 1).<\/p>\r\n\r\n This parameter is the ratio of initial fishing effort to fleet capacity (i.e., the proportion of maximum effort deployed in the first time step). It is used to set the initial fleet capacity Kg,1<\/sub><\/em> as well as the income level needed for half the maximum effort to be deployed (Ihg<\/sub><\/em>).<\/p>\r\n Calculating Kg,1<\/sub><\/em>: For each fleet, initial fleet capacity K1<\/sub><\/em> is calculated as the inverse of \u2018Initial effort\/capital capacity\u2019 (initial effort is scaled to be 1 at Ecopath base condition), i.e., if \u2018Initial effort\/capital capacity\u2019 is set at 0.5, then the fleet capacity will be set to 2 because half of the maximum effort is deployed. Kg,t<\/sub><\/em> is updated at each time step using the slow time response model.<\/p>\r\n Calculating Ihg<\/sub><\/em>: \u2018Initial effort\/capital capacity\u2019\u00a0 is also used to calculate Ihg<\/sub><\/em>. When the ratio is set at the 0.5 default value, Ihg<\/sub><\/em> is set to the initial income (summed over pools of Ecopath base catches x prices for each fleet).<\/p>\r\n\r\n Set the rate of capital depreciation here. Capital depreciation rates for fishing fleets are typically in the range 0.04 to 0.10 (equipment lasts 10-25 years), although will vary on a fleet by fleet basis.<\/p>\r\n\r\n Set the initial rate of annual capital growth here. A value of zero would represent a fleet with no growth (e.g., at bionomic equilibrium). For rapidly growing fleets, set the value at 0.5\u00a0 or higher. If you have data on the maximum effort deployed for a number of years before and after the Ecopath base year, you can estimate this parameter empirically.<\/p>","rendered":" You can choose to treat dynamics of fleet sizes and resulting fishing effort as unregulated and subject to fisher investment and operating decisions. The models are described in detail in the introductory material.<\/p>\n If you wish to use the fleet\/effort dynamics model, you should check the ‘fleet\/effort response’ box on the Ecosim parameters form. When this box is checked, Ecosim erases all previously entered time patterns for fishing efforts and fishing rates, (e.g., from the sketch pad or from the time series data file), and replaces these with simulated values generated as each simulation proceeds.<\/p>\n In this model, there are two time scales of fisher response:<\/p>\n You need to set two parameters for the short time response model (\u2018Effort response power\u2019 and \u2018Initial effort\/capital capacity\u2019) and two for the longer time model (\u2018Capital depreciation rate\u2019 and \u2018Initial capital growth rate\u2019).<\/p>\n Use \u2018Effort response power\u2019 to set the parameter p<\/em>, which represents a \u201cheterogeneity\u201d parameter for fishers: high p<\/em> values imply all fishers \u201csee\u201d income (I<\/em>) opportunity similarly, while low p<\/em> values imply fishers \u201cturn on\u201d their effort over a wide range of mean incomes (see figure 1).<\/p>\n This parameter is the ratio of initial fishing effort to fleet capacity (i.e., the proportion of maximum effort deployed in the first time step). It is used to set the initial fleet capacity Kg,1<\/sub><\/em> as well as the income level needed for half the maximum effort to be deployed (Ihg<\/sub><\/em>).<\/p>\n Calculating Kg,1<\/sub><\/em>: For each fleet, initial fleet capacity K1<\/sub><\/em> is calculated as the inverse of \u2018Initial effort\/capital capacity\u2019 (initial effort is scaled to be 1 at Ecopath base condition), i.e., if \u2018Initial effort\/capital capacity\u2019 is set at 0.5, then the fleet capacity will be set to 2 because half of the maximum effort is deployed. Kg,t<\/sub><\/em> is updated at each time step using the slow time response model.<\/p>\n Calculating Ihg<\/sub><\/em>: \u2018Initial effort\/capital capacity\u2019\u00a0 is also used to calculate Ihg<\/sub><\/em>. When the ratio is set at the 0.5 default value, Ihg<\/sub><\/em> is set to the initial income (summed over pools of Ecopath base catches x prices for each fleet).<\/p>\n Set the rate of capital depreciation here. Capital depreciation rates for fishing fleets are typically in the range 0.04 to 0.10 (equipment lasts 10-25 years), although will vary on a fleet by fleet basis.<\/p>\n Set the initial rate of annual capital growth here. A value of zero would represent a fleet with no growth (e.g., at bionomic equilibrium). For rapidly growing fleets, set the value at 0.5\u00a0 or higher. If you have data on the maximum effort deployed for a number of years before and after the Ecopath base year, you can estimate this parameter empirically.<\/p>\n","protected":false},"author":1909,"menu_order":15,"template":"","meta":{"pb_show_title":"on","pb_short_title":"","pb_subtitle":"","pb_authors":[],"pb_section_license":""},"chapter-type":[],"contributor":[],"license":[],"class_list":["post-483","chapter","type-chapter","status-publish","hentry"],"part":441,"_links":{"self":[{"href":"https:\/\/pressbooks.bccampus.ca\/eweguide\/wp-json\/pressbooks\/v2\/chapters\/483","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/pressbooks.bccampus.ca\/eweguide\/wp-json\/pressbooks\/v2\/chapters"}],"about":[{"href":"https:\/\/pressbooks.bccampus.ca\/eweguide\/wp-json\/wp\/v2\/types\/chapter"}],"author":[{"embeddable":true,"href":"https:\/\/pressbooks.bccampus.ca\/eweguide\/wp-json\/wp\/v2\/users\/1909"}],"version-history":[{"count":8,"href":"https:\/\/pressbooks.bccampus.ca\/eweguide\/wp-json\/pressbooks\/v2\/chapters\/483\/revisions"}],"predecessor-version":[{"id":1874,"href":"https:\/\/pressbooks.bccampus.ca\/eweguide\/wp-json\/pressbooks\/v2\/chapters\/483\/revisions\/1874"}],"part":[{"href":"https:\/\/pressbooks.bccampus.ca\/eweguide\/wp-json\/pressbooks\/v2\/parts\/441"}],"metadata":[{"href":"https:\/\/pressbooks.bccampus.ca\/eweguide\/wp-json\/pressbooks\/v2\/chapters\/483\/metadata\/"}],"wp:attachment":[{"href":"https:\/\/pressbooks.bccampus.ca\/eweguide\/wp-json\/wp\/v2\/media?parent=483"}],"wp:term":[{"taxonomy":"chapter-type","embeddable":true,"href":"https:\/\/pressbooks.bccampus.ca\/eweguide\/wp-json\/pressbooks\/v2\/chapter-type?post=483"},{"taxonomy":"contributor","embeddable":true,"href":"https:\/\/pressbooks.bccampus.ca\/eweguide\/wp-json\/wp\/v2\/contributor?post=483"},{"taxonomy":"license","embeddable":true,"href":"https:\/\/pressbooks.bccampus.ca\/eweguide\/wp-json\/wp\/v2\/license?post=483"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}Initial Effort \/ Capital Capacity<\/h1>\r\n
Capital Depreciation Rate<\/h1>\r\n
Initial Capital Growth Rate<\/h1>\r\n
Fleet Size Dynamics Implementation<\/h1>\n
\n
Effort Response Power<\/h1>\n
Initial Effort \/ Capital Capacity<\/h1>\n
Capital Depreciation Rate<\/h1>\n
Initial Capital Growth Rate<\/h1>\n