Using AVHRR sea surface temperature (SST) data in 1985 to 2005, along with hydrographic records at coastal stations and from cruises, we ever found that there might be a delayed ENSO (El Nin˜o Southern Oscillation) effect working as a major mechanism for the interannual variability of coastal upwelling in the western Taiwan Strait (TWS), which is expected to be associated with the variability of coastal blooms. Later, based on phytoplankton absorption data from MODIS in 2003-2009, we noticed that the year of minimum and maximum bloom intensity is in the midst of an El Nino ˜and a La Nina event, respectively, in a specific zone of the western TWS, where river plumes and coastal upwelling enhance surface nutrient loads. In addition, using records of spring algal bloom events released by the provincial monitoring agency, along with MODIS ocean color data in 2002-2020, we found a shift of spring blooms from the north to the south after 2009, while the Zhe-Min coastal current is found strengthening. Do these phenomena signal a potential turning point in the western TWS? Here in this study, we will use long term ocean color and SST data, in combination with chlorophyll and nutrients data from in situ surveys, to try seeking an answer to this question.