Tilapia farming is in for a dire future – unless something is done about it.
And that’s what farmers, weather scientists and agriculturists are doing, preparing for what they see as the inevitable impact of a changing climate.
“The major tilapia producing regions in the Philippines are now experiencing significant impacts from the progressing negative effects of climate change,” according to a report prepared by the Bureau of Fisheries and Aquatic Resources (BFAR), Philippine Atmospheric, Geophysical and Astronomical Services Administration (PAGASA) and the United Nations Food and Agriculture Organization (FAO).
“Tilapia pond-aquaculture farmers are alarmed at the recurrent decline in farm productivity; mass mortality and fish kill brought about by prolonged dry season; increasing air and water temperatures; critical dry spell and drought; frequency of strong thunderstorms; and heavy rainfalls which induce flooding and overflows of aquaculture farms,” the report stated.
Citing the key findings of a Special Report on Emission Scenarios by the Intergovernmental Panel on Climate Change, the report projects that seasonal rainfall will generally increase and that temperature warming will occur for all seasons. “Extreme events are likely to increase in the period 2011-2040,” it said.
Global climate change affects aquaculture, bringing tropical storms, typhoons, cyclones, flooding, strong winds, tornados and extreme temperatures that impact off-shore and inland fish farms.
Climate change induces rise in temperature, changes in rainfall patterns and frequent typhoons with extreme flooding, together with change in wind direction that alters the characteristics of near-shore fish habitats, ocean circulation pattern, coral reef production and fish migration pattern.
It will be greatly felt in coastal areas through rising sea level which would flood low-lying wet and dry land areas, erode shorelines, worsen storm flooding, increase salinity of estuaries and threaten freshwater aquifer. Areas devoted to fishery will decrease in size while important fish species may move to other areas making it less available to fishers.
Tilapia production from freshwater and brackishwater ponds accounted for 716.4 tons out of the country’s fisheries output of 261,210.41 tons in 2015. Most tilapia pond operators follow semi-intensive system in producing marketable size tilapia for the local market.
With inputs from PAGASA and FAO, BFAR has issued an Aquaculture Bulletin that covers the dynamics between tilapia farming in relation to the impact of weather systems on day-to-day pond management and operations. It is based partly on a participatory workshop among farmers from major pond-based tilapia farming provinces, aquaculture scientists and weather and climate experts.
It complements tilapia technology guides and manuals, most of which assume conducive weather or climatic conditions that are not often the case.
The information promotes agricultural adaptation to climate change through climate smart farming and fisheries, and reducing disaster risk through the use of weather and climate information, said Dr. Vicente B. Malano, PAGASA administrator.
One weather system, for example, that immediately impacts on aquatic habitat is the northeast monsoon (Hanging Amihan). Cold winds blowing from the northeast direction cause cloud development and rainfall at the eastern section of the country; this normally occurs from November to February.
Amihan causes widespread cloudiness and heavy rainfall, low air temperature, flooding and cold wind while rain may reduce water temperature (less than 24 degrees Celsius) that is stressful to tilapia.