Damatac II & Santos: Possible Effects of El Niño on
Some Philippine Marine Fisheries Resources
Philippine Journal of Science
Vol. 145 No. 3, September 2016
waters from which the fisheries sector greatly benefits.
However, this rich marine biodiversity is also under threat
due to rapid degradation of marine habitat and coastal
waters (Myers et al. 2000; Roberts et al. 2002). Another
cause of biodiversity loss is climate change, that affects
the biology and movement of many organisms.
Over the past decades, one of the observed changes
in climate was the frequent and extreme episodes of
El Niño Southern Oscillation (ENSO),which has two
phases: the occurrence of warmer (El Niño) and cooler
(La Niña) climatic patterns with El Niño being the more
extreme phase (Gitay et al. 2002; Meuser et al. 2013) .
Studies on climate modeling show that the occurrence of
ENSO events is predicted to increase in the future due to
greenhouse warming (Timmermann et al. 1999; Cai et al,
2014). To date, many El Niño events have been measured
and classified as weak, moderate, or strong (Table 1).
Since 1950, the two strongest El Niño events occurred in
Table 1. El Niño Years and Intensities (Source: Null, 2014).
El Niño
Weak
Moderate
Strong
1952-1953
1953-1954
1958-1959
1969-1970
1976-1977
1977-1978
2004-2005
2006-2007
1951-1952
1963-1964
1968-1969
1986-1987
1991-1992
1994-1995
2002-2003
2009-2010
1957-1958
1965-1966
1972-1973
1982-1983
1987-1988
1997-1998
1982/1883 and 1997/1998, with the latter considered as
the strongest El Niño in history (McPhaden 1999; Garcia
et al. 2004; Meuser et al. 2013). This phenomenon has
lasting effects on global biodiversity particularly since
El Niño happens in the biodiversity hotspots of the
world including the Philippines (Figure 1) (Holmgren,
et al. 2006; Meuser et al. 2013). Such extreme climatic
changes may result to alteration of marine biodiversity
patterns in a hotspot like in Australia where there was a
change in community structure after a high-magnitude
warming event (Wernberg et al. 2012). However, it is still
important to note that increased El Niño events is just one
of the many threats to biodiversity. This event together
with anthropogenic activities such as deforestation, illegal
trade, and overfishing contribute to biodiversity loss such
as in the Philippines.
Perhaps the most obvious effect of El Niño in the
Philippines is the change in weather and climatic
patterns brought by modifications in ocean-atmosphere
interactions in the Western Pacific. Depending on the
intensity, Delos Reyes & David (2006) reported that past
El Niño events reduced the rainfall rate up to 50% resulting
to drought. Moreover, strong El Niño prevented tropical
cyclones while weak to moderate events had longer effects
on the weather. Strong El Niño takes five to eight months
to cover the country with drought and has strong but short
effect while weak to moderate events only require one to
four months and have milder but longer damage (Delos
Reyes & David 2006).
Figure 1. El Niño and Biodiversity. The most biodiverse areas (Myers et al., 2000) and areas affected during El
Niño (Allan et al., 1996) in the world (Source: Meuser et al., 2013; Figure redrawn by Michael Mendiola).
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