Fig. 4. Phase space showing environmental benefits (Be) as a function of percent external phosphorus load reduction (LR), which is inversely related to production benefits (Bp), with no mussels (MEF = 1.00 and MCF = 1.00) and with added mussel excretory and consumptive effects (e.g., MEF > 1.00 and MCF = 1.25).

Note: Mussel effects were held constant at the specified levels over the entire 50 simulation yrs for each simulation. Individual data points (indicated by various symbols) show each of the 50 simulation yrs. Dotted lines illustrate the system’s trajectory with time. In each case, the system began at LR = 0 and LR increased with time until stakeholder compromise (i.e., social–ecological equilibrium) was achieved. We label these attractors for the various simulations by the letter “X” in bold. The trend in attractors illustrates the impact of decreasing ecosystem resistance (caused by increasing the magnitude of the mussel excretory impact) on system behavior.