Sea Mullet

A sea mullet is a grey-blue to olive-brown fish, silvery-white below, with a dark bluish spot at the base of the pectoral fin. Fishes of Australia says ocean fish are bluish-grey on the back and estuary fish are olive-brown. NSW DPIRD gives a maximum of about 75 centimetres and 8 kilograms; Fishes of Australia says most are around 40 centimetres. It lives in the sea, the estuaries and the lower fresh reaches of coastal rivers, and it tolerates a wide range of salinity.

Fly anglers rarely target them. Where they do, the approach is small and slow, and the best-written accounts come from overseas.

Almost the whole coast. Fishes of Australia gives far northern Queensland around southern Australia to the Kimberley in Western Australia, including the Bass Strait area of Tasmania. NSW DPIRD says sea mullet are particularly abundant in the estuaries and coastal waters of New South Wales.

What counts as a sea mullet is changing. Fishes of Australia notes that genetic studies show the fish long called Mugil cephalus is a complex of separate species, and the Status of Australian Fish Stocks report for 2023 says sea mullet on the west and east coasts of Australia are regarded as distinct species. The same report says tagging studies point to a single east-coast stock running from central Queensland to eastern Victoria.

In this guide sea mullet have been recorded in the Snowy River between 1975 and 2018, in the Merri River between 1980 and 1983, and in the Colo River in 2007. These are survey records, not fisheries.

Fishes of Australia describes sea mullet as fish of tropical and temperate coastal and estuarine water that often enter the lower freshwater reaches of rivers and move into lagoons, lakes and the upper estuary. They usually stay in water shallower than ten metres.

They live in schools and they move. Mature fish, Fishes of Australia says, migrate along the coast or gather in estuaries before spawning offshore, so the schools at an estuary mouth from late summer through autumn may be fish on their way out.

The 2023 stock report gives east-coast sea mullet a lifespan of up to 16 years, with half of males mature at 30 centimetres and half of females at 33.

Several mullet share Australian estuaries.

Sea mullet are a net fish commercially; the 2023 stock report lists beach seines, haul seines and gillnets among the methods. A fly angler who wants one is working against the fish’s diet.

The fly method worth reading is from France. Writing for the JP Ross fly rod company’s blog from the estuaries of Brittany, one angler describes small nymphs that imitate tiny crustaceans, green flies fished just below the surface to suggest weed, and all-marabou nymphs, fished on the incoming tide in calm, shallow water where the fish can be seen. The writer’s warning is the useful part: a mullet’s mouth is sensitive and quickly detects anything wrong with what it has taken. That is a different species in a different country, so treat it as a starting point and expect to work it out.

Small flies and fine tippets suit the method. The scuds and shrimp page covers the crustacean flies, and polaroiding covers finding fish that are feeding rather than just travelling.

Sea mullet share the estuary flats with fish that take a fly more readily, such as the dusky flathead, and a mullet that refuses everything is no reason to leave a good flat.

Autumn and winter, offshore. Fishes of Australia says mature fish migrate along the coast or gather in estuaries and then spawn offshore between February and September, depending on location, and that a female produces between 300,000 and 7.2 million floating eggs. The eggs float, and drift in open water.

Sea mullet carry a minimum size in both eastern states. Check the current guide before you keep one.

The 2023 stock report assessed both the east-coast and Western Australian stocks as sustainable.

Rarely, and usually only a very small one fished slowly in front of a fish that is feeding. Fishes of Australia describes a bottom-feeding detritivore, and that is the problem: most of what it eats does not look like a fly.

Look at the eye and the base of the pectoral fin. A yelloweye has a golden eye and no dark spot at the pectoral base. A sea mullet has a dark eye and a dark bluish spot.