LAUSR

Chilika, a Ramsar site and the largest brackish water lagoon in Asia, is situated in East Coast of India, endowed with rich fisheries resources. In this study, SARIMAX fisheries forecasting model was developed by using seasonal ARIMA (Auto Regressive Integrated Moving Average) model with three external physicochemical factors (factor 1 was dominated by the combined effect of salinity and temperature and factor 2 and factor 3 were dominated by alkalinity and transparency) in Chilika. Monthly fish catch data and physico-chemical parameters of water from 2001–2002 to 2015–2016 was used to develop model. The results showed SARIMAX model; SARIMA (1,0,0)(2,0,0)12 with factor 1, factor 2 and factor 3 was the best fitted model for the fish catch in Chilika. The factor 1 was found to be positive influence on catch at 10% level of significance (p = 0.089) while, factor 2 and factor 3 were found to be insignificant. The developed SARIMAX model was validated with actual annual fish catch for the years 2011–2015 with prediction error 3–7%. Further, the developed SARIMAX model was used to forecast fish catch for the period April 2016 to March 2018 indicating increasing 10% present catch in the lagoon. The developed SARIMAX model in the present case study is of the first time to forecast and visualise the positive influence of salinity and temperature on the fish catch in the Chilika lagoon.