Chlorophyll-a estimation and relationship analysis with sea surface temperature and fish diversity

Phytoplanktons are sensitive to temperature changes and can only thrive in certain sea surface temperatures (SST). To determine the relationship between the two variables, the Chlorophyll (Chl-a) in phytoplanktons around the Bidong Island, Terengganu was estimated using the Sentinel-2 Multispectral Instrument (MSI) running two algorithms - C2RCC and OC3M - between 2015 and 2016. The OC3M algorithm resulted in better Chl-a estimation values with RMSE of 0.05 and MAE of 0.049. The relationship analysis was done using linear regression between OC3M Chl-a and MODIS SST. The regression analysis found that the Chl-a variation in the area was only weakly affected by the SST, with highest negative correlation of -0.2867 in September 2016. Fish sampling in the study area showed that there was significant difference in the diversity of fish species between the years 2015 and 2016. Comparison with Chl-a distribution showed that high species diversity and abundance of fish reduces the amount of Chl-a = in the water. Thus, this research can be further explored for sustainable fish production in the future.