Blue Cod – Parapercis colias
Other names: Rawaru, patutuki
by Allan Burgess
Blue Cod – Parapercis colias – are caught all around the coast of New Zealand including the Three Kings Island in the far north, and the Chatham Islands. More abundant and larger around the South Island. Very large blue cod around Fiordland and Southland. Perhaps the most popular table fish sort after by anglers around southern New Zealand. They aren’t actually a true cod at all but come from the family of fishes known as Mugiloididae or sand perches.
They are prone to be fished out in some areas where there is a lot of fishing pressure. One such area is the Marlborough Sounds where the only cod caught nowadays tend to be smaller juvenile fish. While other less accessible locations such as Fiordland still produce large fish up to 5 or 6kg.
The best places to fish for them are definitely the distant reefs off Southland and Fiordland.
Yellow cod look very similar but are a colourful creamy-yellow colour. Although they look very similar they are a different species and are a smaller fish.
Marlborough Sounds Fishing Rules
Nowadays there are not the numbers of blue cod in the Marlborough Sounds that there were just a few decades ago. The fishery in the sounds is under considerable stress. The Marlborough Sounds are closed for blue cod fishing from September 1 until 20 December. This measure is aimed at reducing disruption to spawning fish. When the Marlborough Sounds blue cod fishery is open the minimum length fishers are permitted to keep is 33cm and over. The daily bag limited in the Marlborough Sounds is two fish.
In the Southland Area, for example, the bag limit is 20 fish per angler per day. Anglers fishing unfamiliar parts of New Zealand need to pay very careful attention to the fishing rules by reading and understanding the brochures and information put out by Fisheries New Zealand. Here is a link to the Challenger Area Fishing Rules – Fisheries New Zealand. Never assume the rules will be the same as they are back home!
Fiordland Fishing Rules
In Doubtful, Thompson, Bradshaw Sounds internal waters the maximum daily limit of blue cod is just one fish per angler. Fiordland Area Fishing Rules. There are actually three different bag limits for blue cod in Fiordland depending on where you are fishing. Again you must study the Area Fishing Rules and not just guess, or assume they are the same as they were at some time in the past.
When fishing in Fiordland one is struck by the comparative size of the blue cod together with their considerable abundance. They are voracious feeders often being the first species caught when baited hooks are lowered to the bottom in any new fishing spot. This perhaps goes a long way to explaining why they are so easily fished out by recreational anglers from certain localities!
This species is found mostly over foul ground from a few metres down to about 150m. The Pegasus Canyon off Canterbury produces some very big blue cod, as does the Kaikoura coast and Motunau Beach. Many anglers nowadays fish with multi-hook flasher rigs. When these are used you can often catch as many as four or five cod from just one drop. In this situation, it is important to limit your catch and return unwanted fish unharmed to the water as quickly as possible. If you are hauling up small blue cod on every hook you are best to change to a rig with fewer but larger hooks. Check the rules on how many hooks you are permitted to fish with on your terminal rig. This also differs in different parts of New Zealand.
Cod are such voracious feeders that they will take almost any bait you care to use though I am sure that fresh-cut fish baits like yellow-eyed mullet are the best. I have caught quite a few blue cod on soft plastic worms. Having a few of these soft plastics in your tackle box will get you started if you have no other bait available.
The best hook sizes are 3/0 to 5/0 depending on the area you are fishing. I have tried using quite large hooks to limit the catch of smaller cod but this has had limited success as even the smallest fish seem determined to get themselves hooked anyway. Circle style long-line hooks are an advantage as they almost always hook the blue cod in the corner of the mouth making it easier to release smaller fish unharmed.
This is one of the best-eating fish in the sea. This is especially so in the South Island where anglers don’t get many snapper!
Blue cod have firm pinkish-white fillets suitable for frying, baking and smoking. Smoked, they are a southern New Zealand delicacy!
Blue cod are almost exclusively found over around rocky coastline especially in and around kelp beds. They can be caught on rod and line from shore in quite shallow water provided there is plenty of kelp for cover. However, as experienced anglers know fishing near kelp tends to result in plenty of lost sinkers and rigs.
They are a beautiful brilliant shimmering blue and green colour when first caught but like most fish, their colours fade after capture. They become drab and almost black.
Adult blue cod generally measure 30-40cm and weigh between 1-3kg. The largest specimen seen by David H. Graham caught in Otago measured 24 inches in length (60cm) and weighed 12 pounds (5.4kg).
Sex Changing Hermaphrodites
All members of the Pinguipedidae (sand perches) family are sex-changing hermaphrodites. Like spotties, blue cod all start out as females initially, before some change into males. Graham found the roes of a late-maturing three and a half pound specimen contained about a million eggs. Males are known to defend a territory from other males where they “collect” a group of females.
More Abundant Around the Lower South Island
The further south you go in New Zealand’s South Island the more abundant this species becomes. Stewart Island, Foveaux Strait, and along the Fiordland coast are well known blue cod fishing areas. There is also plenty of blue cod around the Chatham Islands. Spawning takes place in the spring.
Blue cod do not move about much. They tend to remain in the same local area. This makes them susceptible to overfishing. The larger fish are taken first. When mostly small specimens are being hauled up to the boat it is a sign that the fishery in that area is under stress. Hence the best fishing, particularly for larger fish, is over the more distant isolated reefs and places that are difficult for anglers to reach. Most commercial fishing for this species is done with pots similar to those used to catch crayfish. They are also taken commercially by longline. Blue cod – Parapercis colias – are only found in New Zealand waters.
Susceptible to Overfishing
According to David H. Graham in his excellent book A Treasury of New Zealand Fishes, he said, “They were caught outside the Otago heads in from 10 to 60 fathoms (18 to 108m), and in the harbour in the summer months. In 1930-34 they were plentiful, but less so than formerly, possibly through overfishing.”
Graham also said, “Very good catches were taken at Taieri Mouth. These blue cod were in my opinion larger and of better quality than those caught elsewhere; this was probably due to the fishing grounds not having been worked over before.”
In the early part of last century, this species was plentiful in Dunedin Harbour. They could easily be obtained around Goat and Quarantine Islands.
The blue cod fishery in the Marlborough Sounds and adjacent waters has taken a battering from overfishing. As you can see from David H. Graham’s observations dating back nearly 100 years ago overfishing of this species causes havoc and ruins the fishery locally. Big males are territorial and will be among the first fish caught. Eventually, the only cod being caught are small juveniles. It is very important that we all abide by the rules to give this species the chance to recover.
In an interesting development, scientists have managed to successfully breed blue cod for the first time, a milestone that will support the development of a new aquaculture industry for New Zealand. You can read about it here on the Plant and Food Research website.
Anglers will be interested to know that this species prefers water that is clean and transparent. They don’t like dirty water. When the seabed is stirred up by a storm or from a river in flood blue cod will make themselves scarce. They can be taken well offshore in places like the “hole” 27 nautical miles off Banks Peninsula, Canterbury, down to depths of 150m.
According to Graham, the effect of temperature was plainly seen by the movements of blue cod into and out of Otago Harbour. They came in when the water increased in temperature but once cold set in (usually about May) they migrated out again to deeper and warmer water outside the harbour. Blue cod spawn from late winter to early summer. They may live as long as 15-20 years.
What Do Blue Cod Eat
This species will eat just about anything. They will readily hit soft baits, sabiki flasher rigs, metal jigs, and practically anything used on a baited hook that comes within their striking range. Graham, who conducted research at the Portobello Marine Station (as it was then called) in Otago Harbour, kept live fish he had captured in large tanks where they could be observed. He said, “They would eat almost any kind of fish and feed freely on cut up pieces of Dogfish, Pig fish, red cod or even blue cod. Live cockabullies, Sucker-fish, crabs, shrimp and worms that are thrown into the aquarium are soon devoured by them. One would think that a fish of the smallness of a cockabully would be too nimble to be caught by a fish like the blue cod, but the speed the blue cod attained and agility in turning to catch these fish were surprising.”
As part of Graham’s research, he investigated the stomach contents of between 400-500 specimens and found 16 species of fish in their diet. These were: Pilchard, Sprat, Short-snouted Pipefish, Seahorse, Red Cod, Ahuru, Mullet, Blue cod, Opal fish, Cockabully, Sea-perch, Pig fish, Rock cod, Bastard red cod, Spotty and Rockfish. They had also been eating shellfish, Octopus and Squid. Also found were two species of Mussel, and five other hard-shelled molluscs. Plus four species of crabs, including the Swimming Crab, so they are feeding on the seafloor, round rocky platforms, and even at the surface.
Blue cod were also found to have been feeding on eight other types of crustaceans, such as crayfish, whale feed and shrimps. There were also 5 species of worms found in their stomachs all of which live on the bottom of the ocean. Strangely, at times their stomachs were also crammed to capacity with kelp, sea lettuce, Jellyfish and Sea-anemones.
It is interesting to note that blue cod have a well-known habit of regurgitating their stomach contents when caught. When taken on hooks they often spin and jerk which can cause them to fall off the hook when being lifted aboard.
In general, they will eat just about anything they can catch. As mentioned above they will stalk and eat small fish whole. At times blue cod a caught with their stomachs packed to overflowing with shrimps/whale feed or krill. They will also eat small octopus. Keep in mind that when fishing for this species that they live either on the bottom or close to it.
Best Bait for Blue Cod
Given their diet, you could truly say they will eat practically anything. Personally I prefer squid or octopus as it stays on the hook well. The most successful way to catch blue cod in my experience is to use a baited flasher rig – especially if fishing in deep water. If a reasonable heavy jig is used to take the flasher rig down rather than a sinker success is almost a certainty.