Ecosim Beth Fulton 2012

Time dynamic Ecopath = initial conditions Define Duration Environmental drivers Contaminants option Fleet dynamics option ECOPATH, ECOSIM and ECOSPACE Ecosim

Basic equation ECOPATH, ECOSIM and ECOSPACE Ecosim

Flow-control: (top-down to bottom-up) Sensitive parameter check with sensitivity analysis, time series fitting, two- model comparison, Bunfished/B 0, F max /M) Feeding time adjustment rate Predator effect on feeding time 1.0 = stop feeding if predation risk high 0.0 = ignore predation risk high Other mortality (top predators sensitive to this) Catchability Environmental tolerances Ecosim – Group info

ECOPATH, ECOSIM and ECOSPACE Ecosim – Group info

Ontogenetic changes (growth vs reproduction, egg production) Feeding related changes (diets, feeding time, handling time) Trophic effects (predator/prey dynamics) ECOPATH, ECOSIM and ECOSPACE Ecosim Covers…

Forcing functions (seasonal, long-term, environmental, productivity…) ECOPATH, ECOSIM and ECOSPACE Ecosim – Forcing functions

Drawn or imported Apply to different groups / interactions on Apply FF Primary productivity over time (apply to primary producers or their interactions) ECOPATH, ECOSIM and ECOSPACE Ecosim Covers…

Mediation effects ECOPATH, ECOSIM and ECOSPACE Ecosim - Mediation

How you put in non-trophic interactions done in very similar way to forcing (apply usingApply FF sheet but select mediation option) Ecosim - Mediation

Vulnerability = rate become vulnerable to predators ECOPATH, ECOSIM and ECOSPACE Ecosim – vulnerabilties

Parameterise which wins out hunger or fear Depending on parameterisation can create many alternative functional responses (LV, Holling types, ratio dependent etc) ECOPATH, ECOSIM and ECOSPACE Ecosim – vulnerabilties

Unavailable prey B-V Unavailable prey B-V Available prey V Available prey V B = Total prey biomass; V = Vulnerable prey biomass; v = Behavioral exchange rate; P = Total predator biomass; a = Predator rate of search. B = Total prey biomass; V = Vulnerable prey biomass; v = Behavioral exchange rate; P = Total predator biomass; a = Predator rate of search. v(B-V) vV Fast equilibration between B-V and V implies V=vB/(2v+aP) Predator P Predator P aVP Ecosim – vulnerabilties Vulnerable prey

Fishing effort over time Biomass/original biomass Ecosim – forecasts fishing effects

Output Run Ecosim is everything flat (or changing according to the Biomass Accumulation)? if wild look at balance, small plankton, discard effects ECOPATH, ECOSIM and ECOSPACE Ecosim – check Ecopath

ECOPATH, ECOSIM and ECOSPACE Input Fishing rate pick fleet sketch a disturbance (fishing rate change) Ecosim – check Ecopath

Go to Output and rerun if everything OK the trajectories come back to initial value (eventually) are all groups reacting at the speed you expect them to? Ecosim – check Ecopath

Relative or absolute biomasses Mortality rates, F, Z, catches Effort data Forcing factors (primary productivity) Incorporates goodness of fit measure (weighted SS) Anomaly fitting (productivity, recruitment) Fit to data Similar to single species assessment Ecosim – using past time series

Compare time series

Group info parameters Vulnerabilities high v = Lotka-Volterra like with small perturbations = top-down low v = bottom-up explore settings to edge of stability fit to data Ecosim – sensitivity analysis

Remove fishery check system evolution should maintain all species recheck vulnerabilities (higher less stable) fit to data Ecosim – sensitivity analysis

Fisheries policy search (economic, social, biological objectives) Ecosim Extras

Management Strategy Cycle (reproducing management cycle) Ecosim Extras - MSE

Enter options, regulations etc Ecosim Extras - MSE

Multiple runs to see probability of outcomes Ecosim Extras - MSE

Ecosim Example

Catch and effects at different levels of depletion Ecosim Example

Compared to other models Example

Thank you