Resource enhancement in Inland waterbodies

1. AEM – 507
Management of
inland aquatic
ecosystems
Resource
enhancement
Presenter name
Meenatchi S
FRM-MB0-02

2. • Technical interventions in existing aquatic resource systems, which can substantially alter the
environment, institutional and economic attributes of the system
• ‘culture-based fisheries (stock and recapture)’
• ‘stock enhancement (enhanced capture fisheries)’
• ‘species enhancement (introduction of species)’
• ‘environmental enhancement (fertilizing water bodies)’
• ‘management enhancement (introducing new management options)’
• ‘enhancement through new culture systems (cage culture, pen culture, FADs, etc.)’
• The two most common forms of enhancement suitable for and followed in Indian reservoirs
are:
• culture-based fisheries
• stock enhancement
• Culture-based fishery is the most common mode of enhancement being followed in inland
water bodies in India
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Enhancement

3. 3
Culture based fisheries increase
production in natural environments by
controlling a part of the life history of
certain species and transplanting or
releasing their seed or fry into open
waters

4. Species enhancement
• Inducting new species to broaden the catch
structure
• Stocking of right species at appropriate
proportion- key factor
• Plays very important role for the
augmentation of fish production from
reservoirs
• The combination and composition of species
to be selected is based on the available food
niche
• Species introductions into a reservoir system
area controversial issue on account of the
competition offered by the introduced species
at various levels to the endemic fishes of the
system
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• Catla, rohu performed better in terms of
yield
• Transplanted catla established a breeding
population in most of the reservoirs
• High proportion of catla & rohu are
recommended for stocking in reservoirs
with high density of phytoplankton and
zooplankton
• The % 0f mrigal should be determined
based on benthic food niche and detritus
load

5. Species enhancement scenario of Indian reservoirs
Common carp-
suitable to many
reservoirs of
karnataka & tamil
nadu
Small reservoirs-
catfish fishery
ICAR-CIFRI promotes
the stocking of
freshwater prawn, in
small productive
reservoirs
Grass carps & silver
carp- unfavourable for
stocking in south
indian reservoirs
Ompok pabda,
O.bimaculatus, Mystus
cavasius – karnataka
reservoirs
Indian reservoirs are
mostly being stocked
with carps
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6. Stock enhancement
Stock enhancement may be done either
by altering the species itself or by
altering the relative stock density
Types of stock enhancement:
• Single species enhancement
• Multiple species enhancement
• Predator enhancement
• Predator control
• Multispecies enhancement strategy
is usually applied across India
• Non-predator introductions in
reservoirs could be related to the
plasticity in feeding niches
• This would allow a greater degree of
niche-packing and restricts effects on
long-term stability of existing
communities
• Predator enhancement- to control
weed fish (tried in Tungabhadra
reservoir)

7. Environmental
enhancement
• Edaphic enhancement
• Nutrient enhancement
• Temperature dependent enhancement
• Hydrological enhancement
• Habitat enhancement

9. Pen culture
• Pens are portions of waterbody cordoned off by erecting a fence like
structure
• Hybrid between cage and pond culture
• Suitable for waterbodies with depth not more than 1.2 m
• Muddy clayed loamy soil- best utilised bottom
• Different shapes of pens:
• polygonal
• rectangular
• square
• circular
• Rectangular shaped pens were widely used in India