Institute of Environmental Science and Meteorology, College of Science, University of the Philippines Diliman,
Quezon City
Science and Society Program, College of Science, University of the Philippines Diliman, Quezon City
Corresponding author
bmvallejo1@up.edu.ph
The sixty-six (66)-year brackishwater pond production trends from 1952 to 2018 in the Philippines reflect low metric tonnage and low productivity per hectare despite increasing mangrove conversion to fishponds and increasing aquaculture intensification nationwide. These trends were related to yearly climatological means by graphical analysis and regression. Our analysis suggests that the likely cause of the sharp decline in production and productivity starting in 1993 is the 1991 Mt. Pinatubo eruption and other environmental stress factors, including a warming climate. Environmental stress factors have contributed to about 85,500 MT of production loss every year since 1993 and a slight yearly productivity decline between 0.04 kg ha-1 and 0.1 kg ha-1 since the early 1970s. Increases in mangrove conversion to fishponds did not increase production nor productivity. Despite aquaculture intensification and shifts in production modalities, the mean production of milkfish in 2018 is similar to records taken in the late 1980s. This implies unsustainability as a result of environmental changes and has serious implications for food security.