Seasonal Variations in the Abundance of Clupeidae, Scainidae and Mugilidae in Forcados River Estuary

Abstract The Forcados River Estuary, found in the Niger Delta region of Nigeria, is home to numerous economically important fish species, including Clupeidae (sardines and herrings), Sciaenidae (croakers), and Mugilidae (mullets). However, it has been observed that season has a significant impact on fish fauna composition in the tropics. This study was carried out to determine the seasonal variations in the composition of some economically important fish species in the Forcados River estuary with the aim of understanding the impacts of some environmental variables on their populations. Fish samples were collected between January 2017 and January 2018 using a combination of seine nets, gillnets, and hook-and-line gear. Environmental parameters including salinity, air temperature, pH, and water temperature were also measured. Samples were sorted, classified, and counted in the laboratory. A total of 4511 individuals were collected during the sampling period. During the dry season, a total of 2684 (59%) were recorded. On the other hand, a total of 1827 accounting for 41% were recorded during the wet season. Mugilidae dominated the rainy season catch, while the dry season catch was dominated by Clupeidae and Scainidae. The Forcados River Estuary is rich in fish species with an interesting seasonal twist. The canonical correlation indicated a perfect linear relationship between the first canonical components of the environmental parameters and fish abundance. The t-test revealed significant differences between the data recorded for the dry and wet seasons. Further research along this line is encouraged to improve data reliability and insights, optimal food production, and conservation.