Table 4.
Summary of results from GAMs to test for relationships between the focal taxa and environmental variables. Analyses were carried out separately for Björnöfjärden (BJO) and the reference site (REF), for data on abundance (CPUE) and biomass (WPUE) per unit effort. Values denote Chi2. For significant variables (p > 0.01), the direction of response is indicated as interpreted from partial response plots: + = positive,—= negative, * = unimodal. Double symbols denote p < 0.001. (ns) = not significant. NA = not applied. R2 = Adjusted R2, D2 = Deviance explained
| Response variable | Explanatory variables | Model statistics | ||||||
|---|---|---|---|---|---|---|---|---|
| Taxon SITE | Unit | Temp. during fishing | Temp. growth season | Oxygen | Turbidity | Tot-P | R2 | D2 |
|
Perch BJO |
CPUE | 336 (++) | (ns) | (ns) | (ns) | (ns) | 0.428 | 63.1 |
| WPUE | 60.3 (++) | (ns) | 9.8 (**) | (ns) | (ns) | 0.396 | 52.3 | |
|
Perch REF |
CPUE | 92.2 (++) | 8.8 (−−) | 14.2 (+ +) | 11.9 (−−) | (ns) | 0.554 | 62.1 |
| WPUE | 61.3 (++) | (ns) | (ns) | (ns) | (ns) | 0.435 | 58.0 | |
| Cyprinids BJO | CPUE | 180 (++) | (ns) | 15.7 (−−) | 3.9 ( +) | (ns) | 0.309 | 62.6 |
| WPUE | 70.7 (++) | (ns) | (ns) | 11.1 (+ +) | 5.5 (−−) | 0.402 | 58.1 | |
| Cyprinids REF | CPUE | 425 (++) | (ns) | (ns) | 14.9 (+ +) | (ns) | 0.374 | 58.7 |
| WPUE | 123 (++) | (ns) | (ns) | (ns) | (ns) | 0.348 | 58.4 | |
| Herring BJO | CPUE | 65.8 (**) | 3.5 (–) | (ns) | (ns) | (ns) | 0.339 | 35.1 |
| WPUE | 19.2 (**) | (ns) | (ns) | (ns) | (ns) | 0.346 | 31.1 | |
| Herring REF | CPUE | NA | NA | NA | NA | NA | 0.010 | 15.5 |
| WPUE | NA | NA | NA | NA | NA | < 0.01 | < 1.0 | |