Table 1 Models of viability of the SRKW population for assessing current viability, sensitivity to anthropogenic threats, and responses to management.
From: Evaluating anthropogenic threats to endangered killer whales to inform effective recovery plans
Set | Scenario | Parameters varied | Population growth (r) |
|---|---|---|---|
Baseline | Baseline | Rates as observed 1976–2015 | −0.002 |
Sensitivity Tests | See Supplementary Information (S.I.) | See S.I. | |
Individual Threats | Current | Chinook = 1.0; Noise = 85%; PCB = 2 ppm/y | −0.001 |
Chinook | 0.6 to 1.3 × baseline | −0.038 to +0.025 | |
Noise | 0 to 100% of time | +0.017 to −0.004 | |
PCB | 0 to 5 ppm/y | +0.003 to −0.008 | |
Cumulative Threats | No Anthropogenic Threats | baseline Chinook; no noise, no PCB; no oil spills; no ship strikes | +0.019 |
Low Development | 25% decline in Chinook; 92.5% noise; low frequency oil spills and ship strikes (see Table 2) | −0.008 | |
High Development | 50% decline in Chinook; 100% noise; higher frequency oil spills and ship strikes (see Table 2) | −0.017 | |
Demographic Management | Fecundity | 1 to 1.5 × baseline |  + 0.016 |
Adult Mortality | 1 to 0.5 × baseline |  + 0.009 | |
Calf Mortality | 1 to 0.5 × baseline |  + 0.004 | |
Threat Management | Chinook | 1 to 1.3 × baseline |  + 0.025 |
Noise | 85% to 0% |  + 0.017 | |
PCB | 2 to 0 ppm/y |  + 0.004 | |
Chinook & Noise | 1 to 1.3 × Chinook; 42.5% Noise |  + 0.036 |
