Blue cod belong to the Pinguipedidae family and are by far the most popular recreational target species in the South Island. Typically a slow-moving fish, blue cod swim mainly propelled by their pectoral fins in a distinctive sculling motion, but are capable of sudden bursts of speed using their tail when required. Blue cod are not a schooling fish but are fairly easy to hunt as they are very inquisitive by nature and do not spook easily. They are best hunted during October to March, but the main season is April to September.
The colour of blue cod changes with size; juveniles (5−15cm long) have a whitish body with two brown stripes running the entire length. Maturing fish darken to a rusty- brown and the stripes become barely distinguishable. Beyond 25cm both sexes change colour to a mottled grey, which lasts until about 30cm, when a further change to green or blue occurs. Larger fish then develop a green-blue head, wide stripes and a pale belly. Both sexes occur in these colour phases, so it is not possible to sex blue cod by colour. Blue cod can also change sex from male to female
AGE & GROWTH
Blue cod can live to 17 years and reach a length of 60cm and weigh up to 4kg but an average is ½ to 1kg. An adult may grow to 60 cm in length and weigh from one to three kg. Spawning takes place in spring once they reach 20-25cm around 3-5 years old.
Spawning occurs in coastal and outer continental shelf waters from late winter to early summer.
Blue cod are endemic to New Zealand and have medium-textured white flesh with a very low oil content. It is a plump fish which produces very delicious fillets and the smoked flesh of the blue cod is regarded as a delicacy. It can be served in numerous ways but most scrumptious when battered, crumbed and pan fried with a bit of lemon.
HABITAT AND FEEDING
Blue cod are exclusively found in New Zealand in shallow waters around the rocky coasts. Although they are wide spread, they are far more common south of Cook Strait and around the Chatham Islands where waters are colder.
They are also found in the Marlborough Sounds and off Wanganui. Most are now caught in cod pots. New Zealand’s blue cod fishery is managed by strict quotas, which allow only a set amount of blue cod to be taken commercially each year. The Minister of Fisheries has closed the enclosed Marlborough Sounds and Tory Channel to all recreational blue cod fishing from 1 October 2008 to 1 October 2012. Always keep updated with local regulations by visiting the MAF website.
Juveniles are often found in shallow water, whereas adults are found at depths of up to 150 metres. Despite this, they are predominately an inshore bottom-dwelling domestic fish commonly found near reefs and around rocky bottoms with patches of sand and weed. Adult cod eat almost any animal that comes their way -they are opportunistic carnivores with a voracious appetite for a wide variety of marine animals such as pilchards, sprats, mullet, rock cod, red pigfish, mussels and crabs.
In one area, 52 different prey species were identified as part of the blue cod diet.
Blue cod are incredibly inquisitive and extremely territorial and will often approach divers and nip their fingers.