Species: Achoerodus viridis

Bundjalung name: Jalum (fish)
Status (IUCN):  Near Threatened

Characteristics

• Length/size: 100cm and up to 50kg – these fish are actually wrasse, not gropers, but their large size is unusual for wrasse and probably why they are named for the larger gropers. 

• Colour: Varies and is characteristic of age / gender – adult males are vivid blue, females are reddish brown and juveniles can be green, grey, orange or brown. They also have yellow lines around the eyes and large fleshy lips. 

• Diet: Groper primarily eat molluscs, echinoderms & crustaceans, such as crabs, prawns, sea urchins and shellfish.

• Lifespan: The blue groper lives for at least 35 years, and likely much longer. Their close relative (the western blue groper) is said to live for 70 years, based on counting the rings in their otoliths (ear bones). 

• Breeding/reproduction: Fascinatingly, gropers are sequential hermaphrodites – they all start life as females but can potentially change to become a male after they grow big enough (over 60cm). Generally they live in harems, with one male, a few females and several juveniles. If the male dies, the dominant female can change sex and colour to take his place. The larvae start their life as drifting planktonic organisms before settling in seagrass beds. They reach sexual maturity at two or three years of age, and breed between July & September.

 

Habitat: Found on rocky reefs in shallow waters (down to 40m) along Australia’s east coast from southern QLD to southern Victoria. Juveniles often frequent estuarine seagrass beds. These characteristic fish are endemic to Australia and are found in the Byron Bay Hope Spot year round. They tend to be quite territorial, remaining in a similar location throughout their life. 

 

Threats: Their often friendly and curious behaviour sometimes makes these fish an easy target for spearfishing, and this has led to a decrease in populations in the past. In 1969 they were given total protection in NSW waters but since then regulations have varied and at times various methods of recreational and commercial fishing have been allowed. Currently there’s a 12 month trial of regulations prohibiting any fishing of this species (including line fishing) in NSW, aligning the regulations with Victoria (where the blue groper is completely protected). With quite a small range (less than 64,000 km²) and its slow-growing, long-lived nature, this population is at risk from our fishing activities.