Table 5 Summary results of meta-analyses using subsets of fish abundance effect sizes for Control/Impact studies, testing the influence of the given moderator variable

Waterbody type

77

N/A

Dam size

 Unmoderated model

77

104.05 (p = 0.018)

–

–

 Dam size

77

–

0.52 (p = 0.773)

98.22 (p = 0.031)

Hydropower operational regime

 Unmoderated model

77

104.05 (p = 0.018)

–

–

 Operational regime

77

-

2.85 (p = 0.241)

90.12 (p = 0.098)*

Direction of flow magnitude alteration

 Unmoderated model

76

103.24 (p = 0.017)

–

–

 Flow alteration

76

–

0.36 (p = 0.551)

92.12 (p = 0.076)*

Alterations to other flow components

 Unmoderated model

77

104.05 (p = 0.018)

–

–

 Other components

77

–

0.27 (p = 0.873)

99.31 (p = 0.027)

Sampling methods

 Unmoderated model

73

96.90 (p = 0.028)

–

–

 Sampling technique

73

–

0.07 (p = 0.789)

96.29 (p = 0.025)

Sampling season

 Unmoderated model

77

104.05 (p = 0.018)

–

–

 Sampling season

77

–

2.21 (p = 0.531)

94.90 (p = 0.044)

Type of comparator (spatial)

 Unmoderated model

76

97.46 (p = 0.042)

–

–

 Comparator site

76

–

2.04 (p = 0.153)

86.01 (p = 0.161)

Time since intervention

 Unmoderated model

77

104.05 (p = 0.018)

–

–

 Time since intervention

77

–

1.64 (p = 0.441)

88.06 (p = 0.126)

Monitoring duration

 Unmoderated model

75

97.46 (p = 0.035)

–

–

 Monitoring duration

75

–

3.88 (p = 0.143)

83.97 (p = 0.158)

Life stage

77

N/A