Freshwater, Brackishwater and Marine resources - Lockdown Study Material

1 Freshwater, Brackishwater and Marine
resources

Types
of Fisheries:

Fisheries are of two types based on type of
organisms.

a. Fin
Fisheries: It deals with the organisms possessing Fins. ie.
Fishes.

b. Shell Fisheries: It
deals with the aquatic organisms other than fish. These organisms contain shell
on their surface. This includes, prawns, crabs, oysters, mussels, lobsters etc.

Fisheries are also classified into 2
types based on mode of their exploitation

a.       
Capture fisheries: Fishes/prawns/crabs etc. are captured
from their natural habitats by using various crafts and gears.  This is carried out in seas, rivers, lakes or
reservoirs etc. over fishing destroys the fish stock (total number of
organisms). Hence fishing holiday is recommended during the breeding season of
fishes.   The catches include both
desirable and undesirable species.

b.       Culture
fisheries:  Culture
fishery includes culture of economically important fish/prawn/crab in a
confined area with proper care.  The seed
is stocked, nursed, fed and harvested. 
Culture fishery is carried out in freshwater, brackish water or marine
water.

Types
of culture systems:

Aquaculture
is defined as the rearing of aquatic organisms under controlled
conditions.  Based on type of water,
aquaculture is of three types

a.       
Freshwater Aquaculture: In
this the organisms are cultured in Freshwater eg. Catla catla, Labeo rohitha
etc

b.       Brachish
water Aquaculture:  in this the
Organisms are cultured in Brachish water eg. Mullets, Latescalcarifer etc.

c.       
Marine water Aquaculture:
organisms are cultured in sea water.

Based
on the stocking of the cultivable species aquaculture is devided into

a.       
Mono culture: 
only single species is cultured

b.       Polyculture:  more than one species is cultured

c.       
Integrated culture: 
fishes are cultured along with other animals or agriculture

Based
on intensity of the culture system, aquaculture is classified as

a.       
Traditional culture:  it is the simplest and oldest practice.  No selection of species, no fertilization, no
feed is given.  It gives less produce.

b.       Extensive
culture:  it is an
improved system of traditional culture. 
Species are selected.  The
cultured organisms feed on natural food available in the pond.  Fertilisers are used to increase the natural
food in the pond

c.       
intensive culture: 
it is highly advanced culture system. 
Here species are selected, stocked at high rates.  Given feed, medicines and water quality is
maintained with extra care.  It gives
good yields.

d.       Hyper
intensive culture:  the stocking density
is higher than intensive system. 
Continuous water exchanges takes place through biological filter
systems.  Constant aeration and pelleted
feed is given.  Very good yields are
achieved.

Marine
fisheries:

Marine Fisheries contributes to food security and
provides direct employment to over 1.5 mn fisher people besides others
indirectly dependent on the sector.

According
to the CMFRI Census 2010, there are 3,288 marine fishing villages and 1,511
marine fish landing centres . The total marine fisherfolk population was about
4 million

The
bulk of the Marine catch comprises oil sardines, followed by penaeid and
non-penaeid shrimp, Indian mackerel, Bombay duck, croakers, smaller quantities
of cephalopods, other sardines and threadfin breams.(CMFRI 2008).

Inland
Fisheries

India’s freshwater resources consists of rivers and
canals (197,024 km), reservoirs (3.15 million ha), ponds and tanks (235 million
ha),  lakes  (1.3 million ha), brackishwaters (1.24
million ha) and estuaries (0.29 million ha).

The inland capture fish production has increased from
192,000 tonnes in 1950 to 781,846 tonnes in 2007, the major species being
cyprinids, siluroids and murrels.

Leading
fish producing states in India, 2007–2008

Rank    State   
Total production (metric tonnes)

1          Andhra Pradesh                        1,010,830

2          Gujarat                                       721,910

3          Kerala                         667,330

4          Tamil Nadu                                559,360

5          Maharashtra                              556,450

6          West Bengal                              349,480

7          Uttar Pradesh 
                          325,950

8          Bihar                                           319,100

9          Karnataka                   297,690

The region wise distribution of the fishery landings
are like this.  North east region (West
Bengal and orissa) 13%, south East region (Andhra pradesh, Tamilnadu)
contribute 22%, West coast (Maharastra and Gujarath ) contribute 30% where as
south west region (Kerala karnataka ) contribute to the maximum of 35% of the
total fishery landings of India.