Juvenile and subadult bluefin trevally have been recorded in estuaries in several locations, and generally occupy large, open estuaries up to the middle reaches of the system. These estuaries are often lined by mudflats and mangroves, however the species rarely enters these shallow waters. Individuals of between 40 and 170 mm have been recorded in South African estuaries, where they are the least tolerant carangid to the brackish and freshwater conditions of these systems.
Young and immature bluefin trevally have been observed in various estuaries, and typically occupy large, open waterways up to the middle sections. These estuaries often feature mudflats and mangroves along their edges, but the species rarely ventures into the shallow waters. Individuals of 40-170 mm have been recorded in South African estuaries, where they are the most sensitive carangid to the mix of salt and freshwater conditions.