Sardinella lemuru is important species and only exists in Bali Strait. In recent years (1980-2019), the fishing condition in Bali Strait is highly volatile. This condition makes lemuru catching locations are challenging to predict. According to catch data, Sardinella lemuru has collapsed and dramatically vanished in 1999, 2011, and 2017. Here, we examined the collapse was due to the impact of IOD or ENSO. According to wavelet coherence analysis, there was a strong association between IOD or ENSO phenomenon with decrease or increase in lemuru catches occurred in 2007-2012 with power 0.6 for IOD and 0.5 for ENSO. After those years, the coherence shows a weak association. The result of wavelet coherency in this study found that the incidence of lemuru collapse in the years 2011 and 2017 was caused by different factors. In 2011 decrease of lemuru was strongly coherent with the occurrence of positive IOD and La Nina events, but in 2017 lemuru decreased was not coherent with IOD (positive/negative) or ENSO (El Nino/La Nina) event.
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