Aquaculture, one of the fastest growing food-producing sectors that habitually develops in unutilized coastal areas, can face significant risks due to extreme weather events. Changing climates can increase the intensity and frequency of extreme weather events like cyclones and floods, and many coastal regions where shrimp farming takes place are often the worst affected.
The biggest cyclonic storm has created now, that cyclone might hit the coast of Myanmar on May 7th and is named as the AMPHAN and is moving towards the Andhra Pradesh location. It may hit Uttarandhra coast by May 9th or 10th.On May 4, low pressure will be created at the Bay of Bengal and on May 5th, the low pressure will become a depression.Within two days cyclone AMPHAN will power into a very severe cyclonic storm with a wind speed of 170 – 180 KMPH.
The current situation with cyclonic circulation over Southeast Bay and likely formation of a low-pressure area is conducive for heavy rains and strong winds over the chain of islands, particularly the Little Nicobar and Great Nicobar in the next 48 hours. Meanwhile, the cyclone warning center in Visakhapatnam cautioned the fishermen to not venture into the sea for the next 24 hours.
Recent Updates :
IMD’s (India Meteorological Department) latest observation reveals weakening signs of cyclone Amphan. It is DOWN but not OUT. Indian agency INCOIS and World’s top 2 models, ECMWF & US-GFS, predict revival on May 12.
The weakening signs become more apparent as the cloud top temperature of the low level closely circulated cloud clusters over the south Andaman sea dropped to around (-) 62℃ on May 6. The temperature on May 5 was (-)75℃ and was (-) 90℃ on May 3. The combined influence of these two could give rise to a significant weather system. The complete region, therefore, remains under observations over the next 4-5 days for any further development.
During and after cyclone
Hurricane/cyclone: Operational impacts include the disruption of power if farms and hatcheries are connected to a grid. It would cause the stoppage of operations in hatcheries the result of which would be the absence or shortage and higher cost of seed for the next crop; lack of seed would freeze operations. If the warning is not early enough harvest able crops could be lost. All standing crops would be damaged and the cropping timetable is derailed. Pearl oyster farms have suffered from the destruction of spat collection rigs and onshore structures. Cages and farm structures are usually damaged but especially to marine cages, pens and seaweed crops, as usually happen in the Visayas region in the Philippines when a typhoon blows through the area. A downstream operational impact is that the marketing timetable is upset, and transport to market is cut off or disrupted. On the other hand, a cyclone and adverse weather conditions that affect fishing as well as epidemics in the livestock and poultry sector could create a short–term higher demand and prices for cultured fish. A positive result, demonstrated by the changes in shrimp farmers practices in Nicaragua in the aftermath of Hurricane Mitch in November 1998, was the adoption of the closed circulation pond system to reduce the risk of pests and disease vectors entering the ponds with the water, reduce the need for pesticides and drugs, and minimise the discharge of effluent laden with pesticide and drugs into receiving waters.
IMPACT ON FISHERIES AND AQUACULTURE
1. Loss of habitat
2. Loss of juveniles and brood fishes
3. Loss of livelihoods of farmers and fishermen
4. Spread of diseases
5. Loss of capital assets
6. Loss of pens and cages
7. Loss of biodiversity
8. Tropical cyclones becoming more intense
9. Increased peak wind speeds
10. Higher mean and peak rainfall
11. Heavy rains create inland flooding
12. Damage to infrastructure
Most aqua farmers can efficiently manage extreme climate events to some extent, by modifying their farm designs and incorporating management measures to increase their operations’ resiliency. Many improvements to adapt to changing climate conditions could be achieved by incorporating the lessons from the history of climate extremes into the management needs and farm design.
Points to Remember :
1. Give continuous aeration throughout the day during rains/cyclones which will help to maintain stable DO levels.
2. Apply Agriculture lime according to the pond condition.