Table 3 Mean similarity between samples for the same year and dissimilarity between samples from different years in the estuary (SIMPER analysis, Bray–Curtis coefficient). Species contributing at least 10% to the similarity or dissimilarity of years: Cc, C. crangon; Pl, P. longirostris; Pm, P. macrodactylus; Pk, Penaeus. kerathurus; Ps, P. serratus; Pv, P. varians. Significance levels: *p < 0.001, **p < 0.05 and NS: non-significant p > 0.05.

Similarity

1

64.9

Pl > Cc > Pv

2

73.1

Cc > Pl

3

69.8

Cc > Pl > Pm

4

66.4

Cc > Pl > Pm > Pv

5

70.8

Cc > Pl > Pm > Pv

6

73.1

Cc > Pl > Pm > Pv

7

71.4

Pm > Pl > Cc > Pv

8

76.1

Cc > Pl > Pm

9

71.1

Cc > Pm > Pl

Disimilarity

1–2

*

36.8

Cc > Pl > Pk > Pv > Ps

1–3

*

45.8

Cc > Pl > Pm > Pk > Ps

1–4

*

45.8

Pm > Pl > Cc

1–5

*

44.1

Pm > Cc > Pl

1–6

*

44.5

Pm > Cc > Pl > Pk

1–7

*

45.2

Pm > Cc > Pl > Pk

1–8

*

41.5

Pm > Cc > Pl

1–9

*

49.6

Cc > Pm > Pl > Ps > Pk

2–3

*

32.8

Cc > Pm > Pk > Pl > Ps

2–4

*

38.1

Cc > Pm > Pl > Pk > Ps

2–5

*

34.9

Pm > Cc > Pk > Pl > Ps

2–6

*

35.7

Pm > Cc > Pk

2–7

*

39.7

Pm > Cc > Pk

2–8

*

32.6

Pm > Cc > Pk > Pl > Ps

2–9

*

38.1

Pm > Cc > Pk > Ps > Pl

3–4

NS

32.7

Cc > Pk > Pl > Pm > Ps

3–5

NS

30.1

Cc > Pk > Pm > Ps > Pl

3–6

NS

30.5

Pk > Cc > Pm > Ps

3–7

*

35.2

Cc > Pm > Pk > Ps

3–8

**

29.2

Cc > Pm > Pk > Pl > Ps

3–9

NS

31.3

Cc > Pk > Pm > Ps

4–5

NS

30.7

Cc > Pl > Pk > Pm > Ps

4–6

NS

30.3

Cc > Pk > Pl > Pm > Ps

4–7

NS

32.2

Cc > Pm > Pk > Pl

4–8

NS

28.5

Cc > Pl > Pm > Pk > Ps

4–9

NS

32.8

Cc > Pk > Ps > Pl > Pm

5–6

NS

27.2

Pk > Cc > Pm > Ps

5–7

NS

30.8

Cc > Pm > Pk > Ps

5–8

NS

27.2

Cc > Pm > Pl > Pk > Ps

5–9

NS

29.8

Cc > Pk > Pm > Ps

6–7

NS

28.1

Cc > Pk > Pm

6–8

NS

26.8

Pk > Cc > Pl > Pm > Ps

6–9

NS

28.8

Cc > Pk > Ps > Pm

7–8

NS

28.3

Cc > Pm > Pk > Pl > Pv > Ps

7–9

**

32.1

Cc > Pk > Ps > Pm

8–9

*

30.7

Cc > Pl > Pm > Pk > Ps