on the freshwater fishes of the western ghatswgbis.ces.iisc.ernet.in/energy/lake2006/programme...on...

On the Freshwater On the Freshwater fishes of the fishes of the

Western GhatsWestern Ghats

An experience from Aghanashini River, Central Western Ghats, India

Influences on the fish species richness in forest streams

Sreekantha

EWRG, CES, IISc, Bangalore

sreekantha@ces.iisc.ernet.in

Why Aghanashini?

Represents one of the pristine ecosystems of the Western Ghats

The river is not dammed

No discharge of industrial/domestic effluentsinto the river

However;

An example for variety of disturbances and catchment degradation at micro level

Photograph: Gururaja K VPhotograph: Gururaja K V

Western Ghats FishesWestern Ghats Fishes

Over 320 speciesOver 320 species

43.1% (138 species) endemism43.1% (138 species) endemism

27 critically endangered27 critically endangered

55 endangered55 endangered

130 are data deficient 130 are data deficient

Human induced threats to the Western Human induced threats to the Western Ghats fishesGhats fishes

Habitat destructionDeforestationStream fragmentationStream diversionClearance of riparian vegetation

Damming the riversAgricultural activitiesUncontrolled and destructive fishingExotic species introductionInterlinking of river basins

Rainfall and river flow patterns in the Rainfall and river flow patterns in the Western GhatsWestern Ghats

On an average 5000 mm annually

80% during four months of monsoon

Streams - perennial, intermittent and ephemeral

DroughtsDroughts

Photograph: Gururaja K VPhotograph: Gururaja K V

Natural threatsNatural threats

Floods Floods

It’s a challenging freshwater life !

An yearly cycle of flooding and drying

Harsher habitat conditions

Environmental pressures

Sampling approachMonthly data collection for five dry monthsSampling in 11 localitiesSampling with gill nets, cast nets, and drag netsOpportunistic collection Equal effort and covering all microhabitats

Photograph: Photograph: SudhiraSudhira H SH S

Photograph: Photograph: SameerSameer AliAli

Outcomes of the study

1064 individuals and 25 speciesWestern Ghats endemics – 32%Distributed throughout India – 68%Endangered – 20%Vulnerable – 8%Data deficient – 20%Lower risk – 52%

Schistura sp

Glyptothorax lonah

Ompok malabaricus

Syciopterus griseus

Chelenodon patoca

Puntius setnai

Puntius jerdoni

Microphis cuncalus

Accidental Encounters!

Schistura sharavathiensis

Schistura nagodiensis

Relationship between species richness and catchment attributes

Stream order Evidence of fishing

Stream Width Evidence of fish poisoning

Type of stream substrate No. of months of water flow

Canopy Cover Availability of refuge

Riparian vegetation Simpson's dominance

Catchment forest type Shannon's index

Broad land-use within 50m Pielou's index

Types of microhabitats Species richness

Number of microhabitats

Species richness and Stream order

Stre

am O

rder

Type

of

subs

trate

Veg

etat

ion

cove

r

Ripa

rian

vege

tatio

n

Fore

st ty

pe

Type

s of

mic

roha

bita

ts

Num

ber o

f m

icro

habi

tats

Fish

poi

sons

Rive

r flo

w

Ava

ilabi

lity

of

Refu

gia

Type of substrate 0.58 Vegetation cover 0.48 0.14 Riparian vegetation 0.52 0.18 0.87 Forest type 0.32 -0.07 0.74 0.80 Types of microhabitats 0.26 0.82 -0.23 -0.21 -0.42 Number of microhabitats 0.47 0.66 -0.24 -0.03 -0.20 0.61 Fish poisons 0.04 0.21 -0.24 -0.41 -0.35 0.12 0.53 River flow 0.33 0.68 -0.48 -0.34 -0.44 0.64 0.79 0.41 Availability of Refugia 0.27 0.57 -0.58 -0.54 0.71 0.73 0.66 0.29 0.85 Species richness 0.64 0.57 -0.03 0.01 -0.26 0.34 0.48 0.45 0.69 0.65

Species richness and River flow period

Stre

am O

rder

Type

of

subs

trate

Veg

etat

ion

cove

r

Ripa

rian

vege

tatio

n

Fore

st ty

pe

Type

s of

mic

roha

bita

ts

Num

ber o

f m

icro

habi

tats

Fish

poi

sons

Rive

r flo

w

Ava

ilabi

lity

of

Refu

gia

Type of substrate 0.58 Vegetation cover 0.48 0.14 Riparian vegetation 0.52 0.18 0.87 Forest type 0.32 -0.07 0.74 0.80 Types of microhabitats 0.26 0.82 -0.23 -0.21 -0.42 Number of microhabitats 0.47 0.66 -0.24 -0.03 -0.20 0.61 Fish poisons 0.04 0.21 -0.24 -0.41 -0.35 0.12 0.53 River flow 0.33 0.68 -0.48 -0.34 -0.44 0.64 0.79 0.41 Availability of Refugia 0.27 0.57 -0.58 -0.54 0.71 0.73 0.66 0.29 0.85 Species richness 0.64 0.57 -0.03 0.01 -0.26 0.34 0.48 0.45 0.69 0.65

Species richness and availability of Refugia

Stre

am O

rder

Type

of

subs

trate

Veg

etat

ion

cove

r

Ripa

rian

vege

tatio

n

Fore

st ty

pe

Type

s of

mic

roha

bita

ts

Num

ber o

f m

icro

habi

tats

Fish

poi

sons

Rive

r flo

w

Ava

ilabi

lity

of

Refu

gia

Type of substrate 0.58 Vegetation cover 0.48 0.14 Riparian vegetation 0.52 0.18 0.87 Forest type 0.32 -0.07 0.74 0.80 Types of microhabitats 0.26 0.82 -0.23 -0.21 -0.42 Number of microhabitats 0.47 0.66 -0.24 -0.03 -0.20 0.61 Fish poisons 0.04 0.21 -0.24 -0.41 -0.35 0.12 0.53 River flow 0.33 0.68 -0.48 -0.34 -0.44 0.64 0.79 0.41 Availability of Refugia 0.27 0.57 -0.58 -0.54 0.71 0.73 0.66 0.29 0.85 Species richness 0.64 0.57 -0.03 0.01 -0.26 0.34 0.48 0.45 0.69 0.65

Different types of Different types of RefugiaRefugia

Availability of Refugia, and Forest types, type of microhabitats, number of microhabitats, River flow

Stre

am O

rder

Type

of

subs

trate

Veg

etat

ion

cove

r

Ripa

rian

vege

tatio

n

Fore

st ty

pe

Type

s of

mic

roha

bita

ts

Num

ber o

f m

icro

habi

tats

Fish

poi

sons

Rive

r flo

w

Ava

ilabi

lity

of

Refu

gia

Type of substrate 0.58 Vegetation cover 0.48 0.14 Riparian vegetation 0.52 0.18 0.87 Forest type 0.32 -0.07 0.74 0.80 Types of microhabitats 0.26 0.82 -0.23 -0.21 -0.42 Number of microhabitats 0.47 0.66 -0.24 -0.03 -0.20 0.61 Fish poisons 0.04 0.21 -0.24 -0.41 -0.35 0.12 0.53 River flow 0.33 0.68 -0.48 -0.34 -0.44 0.64 0.79 0.41 Availability of Refugia 0.27 0.57 -0.58 -0.54 0.71 0.73 0.66 0.29 0.85 Species richness 0.64 0.57 -0.03 0.01 -0.26 0.34 0.48 0.45 0.69 0.65

River flow period, and type of stream substrate, Forest type, type of microhabitats, number of microhabitats

Stre

am O

rder

Type

of

subs

trate

Veg

etat

ion

cove

r

Ripa

rian

vege

tatio

n

Fore

st ty

pe

Type

s of

mic

roha

bita

ts

Num

ber o

f m

icro

habi

tats

Fish

poi

sons

Rive

r flo

w

Ava

ilabi

lity

of

Refu

gia

Type of substrate 0.58 Vegetation cover 0.48 0.14 Riparian vegetation 0.52 0.18 0.87 Forest type 0.32 -0.07 0.74 0.80 Types of microhabitats 0.26 0.82 -0.23 -0.21 -0.42 Number of microhabitats 0.47 0.66 -0.24 -0.03 -0.20 0.61 Fish poisons 0.04 0.21 -0.24 -0.41 -0.35 0.12 0.53 River flow 0.33 0.68 -0.48 -0.34 -0.44 0.64 0.79 0.41 Availability of Refugia 0.27 0.57 -0.58 -0.54 0.71 0.73 0.66 0.29 0.85 Species richness 0.64 0.57 -0.03 0.01 -0.26 0.34 0.48 0.45 0.69 0.65

Catchment area parameters and microhabitats

Stre

am O

rder

Type

of

subs

trate

Veg

etat

ion

cove

r

Ripa

rian

vege

tatio

n

Fore

st ty

pe

Type

s of

mic

roha

bita

ts

Num

ber o

f m

icro

habi

tats

Fish

poi

sons

Rive

r flo

w

Ava

ilabi

lity

of

Refu

gia

Type of substrate 0.58 Vegetation cover 0.48 0.14 Riparian vegetation 0.52 0.18 0.87 Forest type 0.32 -0.07 0.74 0.80 Types of microhabitats 0.26 0.82 -0.23 -0.21 -0.42 Number of microhabitats 0.47 0.66 -0.24 -0.03 -0.20 0.61 Fish poisons 0.04 0.21 -0.24 -0.41 -0.35 0.12 0.53 River flow 0.33 0.68 -0.48 -0.34 -0.44 0.64 0.79 0.41 Availability of Refugia 0.27 0.57 -0.58 -0.54 0.71 0.73 0.66 0.29 0.85 Species richness 0.64 0.57 -0.03 0.01 -0.26 0.34 0.48 0.45 0.69 0.65

Key findings

Habitat parameters play a key role in determining the fish species diversity in streams

Habitat parameters are governed by the quality of the catchment

Refugia plays a major role in the recovery of fish communities apart from providing relatively stable environment

Conservation plan for freshwater fishes of Western Ghats