A PIONEERING research on the marine fisheries and climate change in India was conducted in 2008 by the Central Marine Fisheries Research Institute. It indicated that the success of pelagic fisheries depends on a delicate balance between the physical oceanographic factors that trigger the occurrence of alternating El Niño and La Niña phenomena, on the one hand, and the effects of fishing on the standing stock biomass (SSB), on the other. This could belie the contention that the decline in SSB and the corresponding catch is solely due to overfishing caused by high fishing efforts or the number of fishers.
The Philippine marine fish catch for both commercial and municipal fisheries reached its peak in 2010, during a moderate El Niño, at 2.4 million metric tons. But the catch declined significantly to 2.17 million MT (or by 10 percent) in 2011 mainly due to a moderate La Niña. It must be noted that almost 70 percent of the catch were composed of small pelagic fish such as the Indian sardine (tamban), anchovy (dilis), round scad (galunggong), Indian mackerel (alumahan); and of large pelagic fish such as skipjack (gulyasan), yellowfin tuna (bariles/ bankulis), and frigate tuna (tulingan).
These pelagic fish are interrelated through a food web whose foundation is the plankton (phytoplankton and zooplankton). The blooms of plankton during El Niño coincide with the abundant catch of small pelagic fish that feed on plankton; the large pelagic fish prey on the small pelagic fish.
During La Niña in 2011-2014, there were less plankton blooms, which coincided with the leveling off in fish catch; thereafter, it was expected that the change from the weak La Niña in 2014 to the strong El Niño in 2015-2016 would lead to increasing catch. But the catch declined by 6-7 percent, based on the first-quarter pelagic fish-catch data in 2014, 2015 and 2016, mainly due to overfishing.
The blog titled “The big freeze of 2017 and 2018” by Jan Theart (8/22/15) states that every major El Niño has been followed by a deep La Niña within two years. Hence, the change from strong El Niño in 2015-2016 to strong La Niña in 2016-2017 would cause less plankton blooms leading to a decrease in SSB and the corresponding catch. It is the municipal fishers who will continue to experience decreasing catch, while the commercial fishers could still enjoy slight increasing catch by venturing into distant offshore fishing grounds that are still abundant with fish.
As of 2002, there were 16,497 commercial fishers and 1.37 million municipal fishers, but the latter significantly increased to 1.6 million in 2012 mainly due to the migration of poor and landless farmers to coastal areas adjoining the vast expanse of marine water where the fisheries are open-access.
The Duterte administration in its first two years will have to deal with the tremendous challenge of mitigating the negative impact of and adapting to a strong La Niña, particularly in coastal communities where fisherfolk register the highest poverty incidence (39.2 percent compared to the 38.3 percent among farmers).
—EDMUNDO ENDEREZ, eenderez@gmail.com