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 Contents Page
Fishes of Sydney Harbour
Sydney Harbour is the centrepiece of Australia's largest city. It functions as a port, a recreation area, a source of food and a dumping ground for the people of Sydney as well as a home for a wealth of marine life.
Sydney Harbour is an estuary with a wide, deep water entrance and rocky shoreline. An estuary is a semi-enclosed coastal body of water which has a connection with the open sea and within which seawater mixes with fresh water from associated rivers and creeks.
Sydney Harbour is one of the richest estuarine areas of the world with roughly 550 species of fishes and a surprising diversity of underwater habitats. The outer portion of the Harbour is dominated by an intertidal rocky shoreline and extensive rocky reef and kelp beds. The inner harbour contains seagrass beds and mangroves and provides shelter for many young fishes.
To give some idea of just how diverse Sydney's fish life is, there are approximately 200 species of fishes recorded from the whole of The United Kingdom. This counters the impression many people have of Sydney Harbour as a desolate underwater wasteland.
Two factors contribute to the richness of fish life in the Harbour:
Firstly, Sydney sits on the Australian coast at a point where the warm tropical waters from the north and cooler temperate waters from the south mix. Consequently, both tropical and temperate fish species occur in the Harbour. The pelagic (open-water-living) juveniles of tropical reef species are carried south by the East Australian Current - a warm tropical current flowing south from the warm equatorial top end of eastern Australia to the southern regions of Queensland, New South Wales and occasionally as far as Tasmania.
Secondly, the outer portion of the Harbour, where most of the fish species occur, is not a true estuarine habitat but resembles an open coastal habitat. This means that the Harbour offers more diverse habitats for more species of fish than a more typical estuary.
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Eastern Blue Groper
Achoerodus viridus
The Eastern Blue Groper is well known by Sydney divers and snorkellers for its inquisitive nature. Interestingly, this species is born female and may turn into a bright blue male later in life. This species was in danger of being over-fished until its complete protection in New South Wales in 1969. Today, this species can be caught with a hook and line, but is still protected from commercial fishing and spearfishing. As a result, it is once again a common sight on the rocky reefs of Sydney. The Eastern Blue Groper was also made the fish emblem for New South Wales in 1996.
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Weedy Seadragon
Phyllopteryx taeniolatus
The Weedy Seadragon is found only in the southern waters of Australia. It acquired its named from the weed-like appendages on its body which help to camouflage it in the kelp beds that are common in Sydney Harbour. Like seahorses, it is the male Weedy Seadragon that carries and cares for the eggs. Unlike seahorses that have a pouch in which they rear their young, the male Weedy Seadragon carries its bright pink eggs fixed to the underside of its tail.
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Port Jackson Shark
Heterodontus portusjacksoni
Port Jackson Sharks are attractive fish which are named after the original European name for Sydney Harbour ' Port Jackson. They are considered harmless to humans and spend most of their time on the bottom of the Harbour, often in caves. Port Jackson Sharks lay very distinctive egg cases which blend with the kelp beds where they are laid. After hatching, the Port Jackson Shark eggs are often washed up onto Sydney beaches and have become a common prize for beachcombers.
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Pineapplefish
Cleidopus gloriamaris
The Pineapplefish is one of Sydney's more unusual, lesser-known, nocturnal inhabitants. It obtained its name from its resemblance to a pineapple as it is bright yellow when alive. It has very thick scales with curving spines, making it a rather unattractive meal for predators. It has its very own lighting system in the form of a light organ on either side of the lower jaw to locate its prey at night.
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Old Wife
Enoplosus armatus
The Old Wife is found only in the southern waters of Australia and is a very common sight in Sydney Harbour. It has venomous dorsal spines which can cause a great deal of pain when not handled carefully. The rather unflattering common name of this species refers to the sound it makes by grinding its teeth when caught. Apparently, those who fished this species when it was named thought it sounded like a grumbling old woman. The Old Wife was scientifically described in 1790, making it one of the very first fish described from Sydney Harbour.
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Red Indianfish
Pataecus fronto
The Red Indianfish belongs to a family of fishes which are found only in Australia. This unusual fish ranges in color from scarlet and brick red to orange, enabling it to blend easily with the sponge gardens in which it lives. Despite the fact that the Red Indianfish is so striking and inhabits the waters of Australia's largest city, very little is known about the biology of this species.
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Striped Anglerfish
Antennarius striatus
The Striped Anglerfish is the less famous, shallow water namesake of the deep-sea anglerfishes. Anglerfishes acquired their name through their ability to attract their prey with specialised fishing lures. The lure of the Striped Anglerfish is baited with what looks like a cluster of worms. When 'fishing', the Striped Anglerfish sits very still on the bottom, beautifully camouflaged and uses its lure to attract small unsuspecting fish towards its very large mouth.
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Lionfish
Pterois volitans
The Lionfish, also known as the Red Firefish, Turkeyfish and Devilfish is an exquisitely beautiful but venomous tropical visitor to Sydney Harbour. The Lionfish is one of the best known of the many tropical fish species which are carried south each year as tiny larva by the East Australian Current. Their journey begins on the tropical reefs of Queensland and ends on the rocky temperate reefs of Sydney Harbour ' where they spend their adult lives.
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Images above from: George Evatt
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