The fisheries based in the estuaries of Western Australia are among the oldest commercial fisheries in the State. ⁴⁴ The fishery in the Swan Estuary was established as early as 1829, i.e., not long after settlement and was followed in the years up to 1930 by the development of fisheries in the Peel-Harvey, Leschenault Inlet and a number of estuaries along the south coast of the State. Prior to 1899, no distinction was made between commercial and recreational fishermen. ⁵⁴ Since 1899, those people who were catching fish for sale have been required to be licensed and thus became distinguished from recreational fishermen. ⁵⁴ The commercial estuarine fisheries were mainly established to provide fish for the populations that settled in the vicinity of those estuaries. ⁴⁴ Initially, these fisheries were small and prevented from expansion by the lack of infrastructure required to allow transport of the catch to the major population center of Perth.

The development of a commercial fishery for the western rock lobster (Panulirus cygnus) in marine waters in the 1950s provided the estuarine net fishermen with a market for the plentiful two mullet species and Perth herring as bait for this crustacean. The subsequent rapid expansion of the rock lobster fishery resulted in the commercial estuarine fisheries in the Peel-Harvey Estuary, Swan Estuary and Leschenault Inlet developing into large bait fisheries. These fisheries, together with those for Australian salmon (Arripis truttaceus) and Australian herring (Arripis georgianus) in inshore marine waters, provided the bulk of the rock lobster bait through to the late 1980s, when the importation of cheaper frozen bait led to a decline in the demand for locally caught bait. The decline in bait prices has resulted in the commercial estuarine fishermen turning to more valuable table species, such as crabs, prawns and cobbler, to help replace their loss of income from bait species. This change has the potential to bring commercial fishermen into conflict with the very large recreational fishing sector.

A study commissioned in 1969 suggested that there were more commercial fishermen operating in southwestern Australian estuaries than could be economically supported. ⁴⁴ The Western Australian Department of Fisheries recommended legislation to reduce the number of fishermen in some estuaries to a level at which individual licensed fishermen could be economically viable, and to prevent the movement of commercial fishermen between estuaries. ⁴⁴ This legislation was enacted in 1969 and has resulted in a steady reduction in the number of licensed fishermen in those estuaries.

Nineteen of the 42 estuaries in temperate Western Australia ace currently fished commercially. The most important are the Peel-Harvey Estuary, Swan Estuary and Leschenault Inlet, respectively. ^44,55 In 1991, these three estuaries contributed about 54% of the total commercial estuarine catch in Western Australia. ³⁹ The commercial estuarine fisheries of Western Australia accounted for 12.1% by weight of the total finfish catch in the state in the years between 1976 and 1984. ⁵⁵ During those years, the contribution made by species that are either resident in estuaries or use estuaries at some stage of their life cycles, represented 20.3% by weight of the total commercial finfish catch of the State. ⁵⁵

The commercial estuarine fisheries of Western Australia are typically multi-species and employ more than one type of fishing gear to catch fish. ^44,55 Gill and haul netting are used to catch teleosts and the blue manna crab, while beam tide nets are used to obtain the western king prawn. Commercial fishermen generally operate from outboard powered dinghies. ⁴⁴ The only changes in the way in which estuarine commercial fishermen have operated in Western Australia during the 1970s and 1980s have been the introduction of monofilament nets and the use of trailerized dinghies. The latter makes the fishermen more mobile and thus better able to follow the movements of fish.