Similar to P/B ratios, experts uncertainty ranges for Q/B were variable with individual expert assessments ranging from 0—100 for all scenarios (Figure D2). The PB combination (7.5, 15.15, 27.02) for silver carp given silver carp only invasion was characterized by a higher median value, but narrower uncertainty range than the EQ combination (0.534, 9.048, 59.81) (Figure D2a). The PB combination for the bighead given bighead only invasion Q/B ratio were identical to that of the silver carp given silver carp only scenario, and the EQ combination was only slightly different than the silver carp EQ combination (Figure D2b). Q/B estimates for silver or bighead were essentially unchanged under the scenario where both species invade (Figure D2c,d). To estimate Q/B ratios, most experts again referred to the published literature. All panels of Figure D2 include vertical colored lines that refer to the published values of Q/B that some experts used to estimate their responses. Some experts based responses on combinations of Q/B values estimated for other Lake Erie species such as gizzard shad. Two experts used their estimated P/B ratios (given in the previous section) to derive Q/B ratios, and one expert his estimates on the published literature and adjusted those values based on personally conducted experimental observations and published measurements of Lake Erie productivity. Three experts estimated identical Q/B ratios for silver and bighead carp, however 8 of 11 experts estimated that Q/B estimates for silver carp will be higher than bighead carp because of differing feeding strategies (e.g., detrivory by silver carp) and food assimilation efficiencies. Discussion of P/B and Q/B Ratios While expert estimates of fish biomass may quantify the magnitude of impact of Asian carp populations in Lake Erie, understanding the ecological mechanisms behind the establishment of an invasive species may provide further insight to the potential impacts on trophic structure and ecosystem functioning. An
Similar to P/B ratios, experts uncertainty ranges for Q/B were variable with individual expert assessments ranging from 0—100 for all scenarios (Figure D2). The PB combination (7.5, 15.15, 27.02) for silver carp given silver carp only invasion was characterized by a higher median value, but narrower uncertainty range than the EQ combination (0.534, 9.048, 59.81) (Figure D2a). The PB combination for the bighead given bighead only invasion Q/B ratio were identical to that of the silver carp given silver carp only scenario, and the EQ combination was only slightly different than the silver carp EQ combination (Figure D2b). Q/B estimates for silver or bighead were essentially unchanged under the scenario where both species invade (Figure D2c,d). To estimate Q/B ratios, most experts again referred to the published literature. All panels of Figure D2 include vertical colored lines that refer to the published values of Q/B that some experts used to estimate their responses. Some experts based responses on combinations of Q/B values estimated for other Lake Erie species such as gizzard shad. Two experts used their estimated P/B ratios (given in the previous section) to derive Q/B ratios, and one expert his estimates on the published literature and adjusted those values based on personally conducted experimental observations and published measurements of Lake Erie productivity. Three experts estimated identical Q/B ratios for silver and bighead carp, however 8 of 11 experts estimated that Q/B estimates for silver carp will be higher than bighead carp because of differing feeding strategies (e.g., detrivory by silver carp) and food assimilation efficiencies. Discussion of P/B and Q/B Ratios While expert estimates of fish biomass may quantify the magnitude of impact of Asian carp populations in Lake Erie, understanding the ecological mechanisms behind the establishment of an invasive species may provide further insight to the potential impacts on trophic structure and ecosystem functioning. An
ConsBio_SOM_D_PB_QB_Rationales.docx