Table 1 Food web metrics before and after sea-ice breakup for ITU-webs (Trophic-functional variability), population-webs (intrapopulation variability) and taxonomic-webs (mean population variability).

Food web properties

 S (nodes)

130 (59)

120 (36)

71 (59)

50 (36)

71 (59)

49 (36)

 Trophic links (L)

482

398

725

389

304

176

 Basal level fraction

0.16

0.28

0.17

0.24

0.17

0.27

 Intermediate fraction

0.69

0.63

0.70

0.69

0.52

0.41

 Top fraction

0.15

0.09

0.13

0.06

0.31

0.33

 Trophic level

3.34 ± 0.14***^{, a}

2.69 ± 0.11^a

3.15 ± 0.14^a

2.91 ± 0.19^a

2.35 ± 0.09*^{, b}

2.01 ± 0.10^b

Link properties

 Linkage density (L/S)

3.71 ± 0.15^a

3.32 ± 2.24^a

10.21 ± 0.72***^{, b}

7.94 ± 0.77^b

4.28 ± 0.36^a

3.59 ± 0.39^a

 Connectance (2L/S²)

0.06

0.06

0.29

0.31

0.12

0.15

Chain properties

 N° chains

37,398***^{, a}

18,472

> 10⁵

> 10⁵

1563***^{, b}

361

 Mean chain length

6.67 ± 0.01

7.12 ± 0.01

–

–

4.05 ± 0.04

2.88 ± 0.07

Omnivory properties

 Degree of omnivory

0.77

0.59

0.82

0.73

0.66

0.61

 Degree of intraguild predation

0.10

0.07

0.39

0.41

0.00

0.00

Competition

 N of competitors

13.91 ± 0.47^a

13.29 ± 0.65^a

49.97 ± 0.98***^{, b}

32.81 ± 0.85^b

35.39 ± 1.52***^{, c}

24.83 ± 1.29^c

 Competition strength (α)

0.35 ± 0.01***^{, ab}

0.28 ± 0.09^a

0.32 ± 0.02^a

0.36 ± 0.02^b

0.33 ± 0.01^b

0.40 ± 0.03^c

Vulnerability to diversity loss

 Robustness***

0.35

0.39

0.44

0.43

0.17

0.24

Network properties

 Neighbourhood connectivity (NC)

8.39 ± 0.12***^{, a}

7.71 ± 0.14^a

23.36 ± 0.32***^{, b}

17.72 ± 0.40^b

14.07 ± 0.52***^{, c}

11.67 ± 0.60^c

 Compartmentalisation

0.03

0.03

0.18

0.20

0.10

0.13

Core link properties

 Linkage density (L/S)

1.26 ± 0.12^a

4.00 ± 0.41^b

2.11 ± 0.26^c

 Connectance (2L/S²)

0.03

0.20

0.09