Use by juvenile barramundi, Lates calcarifer (Bloch), and other fishes of temporary supralittoral habitats in a tropical estuary in Northern Australia

Abstract

Use by fishes of temporary pools created by high seasonal tides, which occur each year from October until April, on the saltpans and littorals adjacent to the Norman River estuary in northern Queensland was investigated. Fish entering the pools were sampled with one-way tidal traps placed in inlet gutters, and fish in the pools were poisoned using rotenone. Recruitment to the pools by fish occurred soon after the initial tidal inundation. Juvenile fish of 37 species, including the commercially important food fish L. calcarifer, used the pools. The first barramundi were found 8 weeks after initial inundation and for the remainder of the study they continually migrated into these habitats. The total length of the smallest L. calcarifer sampled was 9.5 mm. Salinities in pools containing fish ranged from 94 × 10^-3 to less than 1 × 10^-3 and temperatures reached 36ºC.