Figures & data
Figure 1. (A) Map of the global distribution of reports on the ecological effects of tilapia introduction by focal species in each publication. Locations were mapped to specific waterbodies when possible, or placed in the geographic center of the country or state/province where the study took place and offset to limit overlap. (B) Map of reported ecological effects (solid symbols) and mechanisms (hollow symbols) by region. Numbers within symbols indicate the total number of studies reporting that effect or mechanism, while the number in parenthesis indicates the number of studies which report that effect and use quantitative data, and controls or reference treatments.
Figure 2. The proportion of countries reporting ecological effects of tilapia introduction across all effect types by all species combined and by important species arranged in order of increasing power of inference in attributing ecological impacts to tilapia (see Methods for complete description of the bins, which represent increasing research effort). The numbers above the bars are the number of countries reporting ecological impacts of tilapia.
Figure 3. The number of papers categorized by perception of tilapia effects on ecosystem services for (a) particular species of tilapia and region; (b) different study designs (all reports compared to reports with quantitative data and controls); (c) and year of publication. Significant effects are indicated by (*) the best or (**) the second best ordinal regression model. O. aur = O. aureus, O. moss = O. mossambicus, O. nil = O. niloticus, Oreo = All other Oreochromis species, T. mar = T. mariae, T.S. = All other Tilapia or Sarotherodon species, T. zil = T. zilli, Afr = Africa, Eur = Europe, NeoTro = Neotropics, Ocn = Oceania, SrLka = Sri Lanka.
Table 1. The best ordinal regression models of the perceived benefit of tilapia introduction for all ecological effect categories combined. Summary model selection statistics, fixed, and random effects coefficients for species and regions. Items in parentheses indicate random effects. –LL = negative log likelihood, AIC = Akiake's information criteria, dAIC = difference in Akaike's information criteria to best model, Ctrl = presence or absence of control treatments, Yr = year of publication, Effects = presence or absence of ecological effects, GDP = Percent contribution of tilapia to GDP. and “na” indicates that GDP was not included in the model selection. Bold indicates statistically significant effects p < 0.05.
Figure 4. The number of papers categorized by perception of tilapia effects on ecosystem services and the reported occurrence of ecological effects in the same papers—including all effect types, species, and regions—(a) for all papers and (b) only for papers that consider quantitative data and include a control.
