Table 1 Reservoirs selected for the study and their physiological characteristics

1

Anuradhapura

Nuwara wewa

8°21′0″N, 80°25′0″E

Nuwara 1

Surface

33

8.48

2

Nu-M

Surface—Plankton net

33

8.48

3

AN 6

Bottom—1.5 m

28

8.60

4

AN 7

Bottom—11 m

28

8.43

5

Tissa wewa

8°20′0″N, 80°22′0″E

Tissa 1

Surface

30

8.71

6

AT2

Surface

28

8.34

7

AT3

Surface—Plankton net

28

8.35

8

AT4

Bottom—1.5 m

30

8.57

9

Jaya ganga

AJ2 W

Surface—Plankton net

31

8.02

10

AJJ2

Bottom—5 m

29

8.02

11

Kala wewa

8°1′0″N, 80°31′0″E

AKK1

Surface

29

8.45

12

AK2 W

Surface—Plankton net

32

8.68

13

AK 1

Bottom—15 m

27

8.48

14

Nachchaduwa wewa

8°15′0″N, 80°28′60″E

N-B/ASM1-A

Surface

31

8.48

15

N-B2/ASM1-A

Bottom—15 m

30

8.50

16

Girandurukotte (Badulla)

Henanigala Wewa

7°34′42″N, 81°3′49″E

GH1

Surface

28.5

7.76

17

GM2

Bottom—3 m

32

8.46

18

GH2

Soil

–

–

19

Ulhitiya Wewa

7°27′26″N, 81°4′2″E

GU

Surface

28

7.65

20

GUU1

Bottom—7 m

31

7.31

21

GUU2

Center—surface

31

7.84

22

GUU3

Surface

31

7.74

23

Ratkinda Wewa

7°30′49″N, 81°4′52″E

GR

Surface

28

7.51

24

GRR2

Surface

29

7.74

25

GRR1

Bottom—8.5 m

29

7.52

26

Minipe Ela

7°12′36″N, 80°58′50″E

GMMi2

Surface

29

7.66

27

GMR8

Center–Bottom—2 m

27

7.65

28

GMY6

Surface

29

7.49

29

Kurunegala

Nika wewa

7°52′60″N, 80°25′0″E

K/Nik

Surface

32

8.45

30

KN1

Bottom—7 m

31

8.48