In Hawaii, the juvenile to subadult giant trevally is the most common large carangid in the protected inshore waters, with all other species apparently preferring the outer, less protected reefs. It is also easily attracted to artificial reefs, where studies have found it to be one of the predominant species around these structures in Taiwan. Juvenile to subadult giant trevally are known to enter and inhabit estuaries, the upper reaches of rivers and coastal lakes in several locations, including South Africa, Solomon Islands, Philippines, India, Taiwan, Thailand, northern Australia, and Hawaii. In some of these locations, such as Australia, it is a common and relatively abundant inhabitant, while in others, including South Africa and Hawaii, it is much rarer in estuaries. The species has a wide salinity tolerance, as evident from the ranges from which juvenile and subadult fish in South African estuaries have been recorded; 0.5 to 38 parts per thousand (ppt), with other studies also showing tolerance levels of less than 1 ppt. In these estuaries, the giant trevally is known from both highly turbid, dirty water to clean, high visibility waters, but in most cases, the species prefers the turbid waters. Younger fish apparently actively seek out these turbid waters, and when no estuaries are present, they live in the turbid inshore waters of bays and beaches. These young fish eventually move to inshore reefs as they mature, before again moving to deeper outer reefs. In the Philippines, a population of giant trevally inhabit (and were once common in) the landlocked fresh waters of the formerly saltwater Taal Lake, and are referred to as "maliputo" to distinguish them from the marine variant (locally named "talakitok"). Along with Taal Volcano and Taal Lake, the "maliputo" is prominently featured on the reverse side of the newly redesigned Philippine 50 peso bill. The giant trevally is a solitary fish once it reaches sexual maturity, only schooling for the purposes of reproduction and more rarely for feeding. Juveniles and subadults commonly school, both in marine and estuarine environments. Observations from South African estuaries indicate the schools of smaller juveniles tend not to intermingle with schools of other species, but larger subadults are known to form mixed-species schools with the brassy trevally. Research has been conducted on the movements of larger fish around their habitats, as well as the movement between habitats as the species grows, to understand how marine reserves impact on the species.