Species name: Eastern Blue Groper (Achoerodus viridis).

Description: A very charismatic fish, very well-known to divers.

Characteristics: Endemic to Australia, found primarily from southern QLD to Victoria.

Interesting fact: Actually a member of the wrasse (Labridae) family, not a grouper. As with most wrasses, they are hermaphrodites, all starting life as females (brown-reddish colouration), then most become males as they grow. When they're big and blue, they're male. Socially, they will often have a number of females attending a large male.

Behaviours: Can be known to be quite comfortable around divers, swimming very close to them. They can be known to as 'underwater puppy dogs'. One in particular divers call 'Lippy' has managed to survive many years, even though he has damage to his mouth.

Diet: Benthic carnivore (eats animals off the seafloor like crustaceans, mussels, and urchins). Can use their powerful jaws to break open urchins - this can often be heard by divers ('thwack' noises, which usually has a troop of fish following, to help clean up any remnants the gropers leave).

Size: Grow up to 1m

Habitat: In a wide range of habitats in south-eastern Australia, from sea grasses to rocky reefs, in shallow waters to 40 m depth. They can be found at Halifax, Fly Point and Little Beach marine parks (adults are really only in the sanctuary zone areas).

Lifespan: Up to 35 years.

Threats: Fishing. Their population was severely depleted by fishing decades ago, resulting in complete protection from all recreational and commercial fishing from 1969-1973. Now only recreational line fishing permitted (no commercial sale, bottom gill nets, or spear fishing allowed). Recreational fishing impacts still evident, as they are primarily found in sanctuary zones (only small juveniles found at fished sites e.g. the marina breakwall, Boat Harbour).

Protection listing: Near threatened.

To showcase the Port's incredible underwater world the Examiner is collaborating with divers and photographers on a new series that explores life Beneath the Surface.

Meryl Larkin is a Port Stephens marine scientist and PhD researcher at Southern Cross University.