Table 1. Brackish water prawn farming areas and marine prawn landings in India.
State | Potential brackish water culture area (ha)a | Traditional farms (ha)a | Existing & planned farms (ha)b | 1984–85 prawn landings (Mg)c |
---|---|---|---|---|
Gujarat | 376,000 | 600 | 13,787 | |
Maharashtra | 81,000 | 100 | 45,416 | |
Karnataka | 8,000 | 5,000 | 50 | 5,547 |
Goa | 19,000 | 40 | 3,903 | |
Kerala | 243,000 | 5,000 | 200 | 37,168 |
Tamil Nadu | 80,000 | 250 | 12,567 | |
Andhra Pradesh | 200,000 | 500 | 7,647 | |
Orissa | 299,000 | 20,000 | 800 | 2,496 |
West Bengal | 405,000 | 400 | 1,034 | |
Pondicherry | - | 30 | 711 | |
Andamans | - | - | 199 | |
Larger trawlers | - | - | 58 | |
Total | 1,711,000 | 30,000 | 3,500 | 130,533 |
a Dandekar and Upare, 1985
b N.P.Bhakta, pers. comm.
c CMFRI, 1986
Criteria for Site Selection of Prawn Hatchery
Land availability
Hydrology
No heavy metals (if inshore well is used).
Topography
Protected from cyclones, storms and other wind and wave action.
Source of Broodstock and Spawners
Pond broodstock - farms.
Infrastructure
Freshwater supply (for hatchery and domestic needs).
Social services
Madhavapur (Gujarat) | Chandrabhagar (Orissa) | Gudlavanipalem (Andhra Pradesh) | Bimlipatam (Andhra Pradesh) | Valinokkam (Tamil Nadu) | |
---|---|---|---|---|---|
Location | 21°15'N, 69°57'E | 19°53'N, 86°5'E | 17°47'N, 83°23'E | 17°53'N, 83°27'E | 9°7'N, 78°30'E |
Climate type | I | IV (to serve type II also) | IV | IV | V |
Date & time of survey | 16-4-86, 0930 hr | 23-4-86, 1230 hr | 22-4-86, 0930 hr | 22-4-86, 1100 hr | 20-4-86, 0830 hr |
Salinity (ppt) | 33 a | 35 b | 35 b | 36 b | 36 b |
Temperature (oC) | 23 | 27 | 21 | 21 | 29 |
Veraval, 1985 | Puri, 1985 | ||||
min 14.5°C, Jan. | min 22.0°C, Jan | ||||
max 32.4°C, June | max 31.5°C, May | ||||
Water quality | Clear (sandy due to wave action) | Clear | Clear | Turbid (after rain) | Very clear |
Substratum | Sand & limestone rock | Sand | Sand | Sand | Sand |
Winds | ave. 50–40 kph (max. 150 kph) | ave. 60 kph (max. 160kph) | ave. 60 kph | ave. 60 kph | Protected by Sri Lanka Island and natural bay. |
Proposed seawater intake | Inshore well | Inshore well | Inshore well | Inshore well | Sea bottom pipe (intertidal area 30 m wide x 2 m high) |
Broodstock & spawner sources | Trawler(Veraval); staked gill net (Dwarka); future farma - Bulsar area | Trawlers; traditional gill nets; confined ponds (Chilka Lake) | Numerous trawlers & mechanised boats; bottom set gill nets | Trawlers & mechanised boats; bottom set gill nets | Trawlers; bottom set gill, nets |
1 | 2 | 3 | 4 | 5 | 6 |
Farms (existing & potential) in state | Singaoh salt ponds; Bulsar - planned | 300 ha Chilka Lake 440 ha proposed | 600 ha existing 1,000 ha planned 1986–87. | 600 ha existing 1,000 ha planned, 1986–87 | 50 ha existing 200 ha planned |
Electricity | Available | Available | Available | Available | Available |
Road | Accessible | To be extended 21 km | Accessible | Accessible | To be extended |
Freshwater supply | Dig shallow well | Dig shallow well | Dig shallow well | Dig shallow well | Dig shallow well |
Proximity to towns (services & amenities) | ½ km from Mangrol | 2 km from Konarak (10,000 pop.) | 3 km from Vishag (500,000 pop.) | Close to Bimlipatam town, 23 km from Vishag | 0.5 km from village (5,000 pop.) |
a Salinity-conductivity-temperature meter
b Atago S-100 hand refractometer
Tank | Stage a | Maturation/ hatching/ survival rate(%) | Stocking b | Total water vol°(m3) | Daily water exchange | Peak load | |||
---|---|---|---|---|---|---|---|---|---|
Initial No. | Final no. | Density | Rate(%) | Vol.(m3) | |||||
Maturation Tanks | IF to S/E | 70 | 270 | 189 | 2.5/m3 | 108 | 200 | 216 | 9 m3/hr: 0000 – 2100 hr |
(189 F/60 days = 47 F/15 days at 300 × 103 E = 14 × 106 E) | |||||||||
Spawning Tanks | E to N | 70 | 14 × 106 | 10 × 106 | 3,000/L | 8 | 100 | 8 | |
Larval Tanks | N to PL5 | 25 | 10 × 106 | 2.5 × 106 | 100/L | 100 | 30 | 30 | |
Postlarval Tanks | PL5 to PL20 | 50 | 2.5 × 106 | 1.25 × 106 | 5,000/m3 | 500 | 20 | 100 | a) 35 m3/hr: 0800 – 1200 hr |
Natural Food Tanks | 20 | (20) | |||||||
Training Tanks | 4 | 30 | 1.5 | b) 5 m3/hr: 1300 – 1700 hr | |||||
Broodstook Holding Tanks | 7 | 50 | 4 | ||||||
Total | 750 | 380 |
a IF - immature females, S-spawners, E-eggs, N-nauplii, PL-Post larvae
b One run, maturation tank = 60 day
larval tank = 15 days
post larval tank = 15 days
Tank | Dimensions | No. | Unit Vol. (m3) | Total Vol. (m3) | Shape | Material | Building | |
---|---|---|---|---|---|---|---|---|
A. | Maturation area: | |||||||
Maturation tanks | 4 m Æ × 1.2 m | 9 | 12 | 108 | Circular | Concrete | Dark roof, walls | |
Spawning tanks | 1 m Æ × 0.35 m | 40 | 0.2 | 8 | Conical | fibreglass wooden stand | ||
Broodstock | ||||||||
Holding tanks | 2 m × 1 m × 0.6 m | 7 | 1 | 7 | Oval | Oval | ||
B. | Larval rearing area: | |||||||
Larval tanks | 5 m × 1 m × 1 m | 20 | 5 | 100 | Rectangular | Concrete | 30% skylight, walls | |
Natural food | fiberglass | skylight, open | ||||||
Tanks | 2 m × 1 m × 0.6m | 20 | 1 | 20 | Oval | |||
Training tanks | 1 m Æ × 0.35 m | 20 | 0.2 | 4 | Conical | fiberglass with wooden stand | 30% skylight, walls | |
C. | Others: | |||||||
Post Larval Area: | ||||||||
Post Larval tanks | 5 m × 2 m × 1 m | 50 | 10 | 500 | Rectangular | Concrete | Skylight, open. |
Table 6 - Assumptions and Guidelines for Prawn Hatchery
Production level = 25 × 106 PL20/yr or 1.25 × 106 PL20/run
Operational period = 10 mo (2 mo for repairs & maintenance)/yr
1 run = 15 days or 2 run/mo
1 yr = 20 runs
Seawater intake
inshore well - Madhavapur, Chandrabhaga, Gudlavanipalem
bottom intake
pipe- Valinokkam
Seawater Supply
maturation tanks - direct pumping from well or sump pit or require reservoir of 20–50 cu.m. (depending on no.of hours pumping).
larval, postlarval and other tanks - require total reservoir capacity of 200 cu.m.
Seawater filtration
inshore well - no filter required if naturally filtered through sand.
sand filter - for sea bottom pipe (Valinokkam).
inline filters - to spawning, larval and algal tanks. (Cartridge etc)
Average air requirement of 0.35 m3/hr/1 m3 water (1 m depth).
Ratio by volume, 1 natural food/algal tank : 5 larval tanks 1 larval tank : 5 postlarval tanks.