Knots and Rigs for Hapuku

Grumpy McMurdo Fishing Tips

Hapuku or groper and bass are the deepwater kings of sportfishing in New Zealand.

These two closely related species grow to large sizes and are available to anglers right around the country, though they’re nowhere as common as they were formerly.

Commercially and recreationally, hapuku (Polyprion oxygeneios) and bass (Polyprion americanus) are often caught with bluenose (Hyperoglyphe Antarctica), a type of warehou unrelated to the other big boys, but often sold as ‘groper’ and equally good to eat. It, too, grows to a large size and is caught using the same gear and techniques as hapuku/bass.

Hapuku and bass belong to a family of fishes with the common name of wreckfish. Hapuku are commonly called bass in southern parts of the country and the Maori name for bass is moeone, which is still used in places.

All three species occur over deep reefs with bass and bluenose generally found in deeper water than hapuku. However, all three species can be caught at some locations.

Hapuku favour reefs in 80-200m of water, but are caught in much shallower water at times, as well as deeper. In the past they were relatively common inshore, but are now rare. In a few isolated spots it’s still possible to catch them from the shore.

Bass and bluenose are usually found in water over 200m deep and as far down as 500m. Bass become increasingly common in northern waters.

Larger groper and bass are almost always associated with reef structure; smaller fisher may be caught out in the open over mud or sand. Fish found in the open tend to be smaller specimens (‘pups’ or ‘schoolies’ and are usually hapuku. Bass seldom feed in the open, but both hapuku and bass have pelagic juvenile phases with small fish associating with floating objects.

Bluenose also prefer rough ground, but also school in deep water over open ground where they are targeted by trawlers. Bluenose eat a lot of invertebrates, but like hapuku and bass also eat fishes, so they’re easily caught using conventional baits.

All three ‘gropers’ grow to large sizes and all are good eating fresh or frozen. Hapuku can reach 1.8m in length and weigh 80kg or more; bass get even bigger: 2m and 100kg-plus. Average sizes are similar for both at around a metre with the stouter bass weighing heavier for its length. School fish are generally less than 15kg in weight and ‘pups’ under 10kg.

Bluenose are on average smaller – 60-100cm – with a maximum of 1.3m and 50kg.

Hapuku and bass look very alike, but are easy to tell apart when placed side by side. Hapuku are greyer in colour – blue when young – shading abruptly to almost white on the belly. They are generally slighter and more elongated than bass and have a noticeably longer lower jaw, giving them an underslung look.

Bass are more heavily built and have a shorter, more rounded head with a lower jaw which projects only slightly. They tend to be darker brown in colour grading gradually in grey-brown on the belly. Juvenile fish have pale bands or mottling.

Bluenose look quite different and are much more laterally compressed. Their plump bodies are solid and deep with large, blunt heads, large eyes and relatively small mouths compared to hapuku and bass, although large for fish in the warehou family. They’re blue-grey above, shading to grey and silver on the sides and belly. Once caught, the skin exudes a lot of slime.

Food for all three species includes a wide range of crustaceans, invertebrates and fishes, some large. Big groper have large appetites and their capacious mouths can accommodate large prey items, which they engulf by opening their jaws and sucking in the prey.

Little is known about the spawning habits of any of these species, but it is assumed hapuku and bass free-spawn in coastal waters, with bluenose doing the same in deep coastal waters. Seasonal migrations between shallow and deep water is a feature of the lifecycles of all three, thought to be related to spawning activity.

Juvenile groper and bass are sometimes caught over shallow reefs and young fish may well inhabit inshore areas for some years. All three species are slow-growing and long lived, making them vulnerable to overfishing.

Hapuku and bass are part of a five-fish limit with kingfish in most places, of which no more than three may be kingfish. Bluenose are part of a 20-fish finfish limit, except in the southern fishery zone where the bluenose limit is 30.

Best Rigs
Various groper species are most often caught on set-lines (‘groper/hapuku droppers’) or by rod and line fishing using large fish flesh or squid baits.

Livebaits, jigs and large soft plastics also work well, but the tackle and techniques are rather specialised.

Most rod and line anglers fish two or three-hook dropper/ledger rigs with short branching traces tipped with large hooks. Hooks may be of the conventional J-type, or more usually are circle-types with recurving points.

Groper rigs are tied or crimped in heavy monofilament line – 200kg is usual – and the hooks can be as large as 14/0, though smaller hooks are better if average fish size is smaller.

Because most groper fishing is in deep water from a drifting boat, large sinkers are mandatory. Streamlined ‘torpedo’ or ‘bomb styles are best with weights up to kilo required in some places. Attaching the sinker via a short length of light nylon designed to break if the sinker fouls on the bottom can save a lot of frustration and re-rigging.

Commercially-tied rigs, some equipped with luminescent tubing, beads and/or rubber squids, are readily available from most tackle retailers.

These additions are designed to make the bait more attractive down in the dark depths and some anglers go a step further by attaching a light stick or battery powered light to their trace.

Check that the swivels, hooks and knots/crimps are of sufficient quality to handle large, heavy fish before purchasing a pre-tied rig.

Heavy rods and large reels spooled with at least 24kg line are the go when groper fishing. These days, serious anglers use superbraid lines, which allows the use of smaller reels and makes fishing a lot more fun. Bites can be felt, even several hundred metres below the boat, and the struggles of a hooked fish are transmitted all the way to the rod.

Some people believe hapuku/bass are just dead weights on the line; fish with superbraid and you’ll soon learn they are not. Good drags are essential, as are good knots, a gimbal belt and a stand-up harness; 300m is a long way to lift 40 or 50kg of struggling fish.

Unlike hapuku and bass, whose swim bladders inflate as they are drawn towards the surface, incapacitating them, bluenose fight all the way and are tougher in proportion o their size.

Large soft baits and jigs can be deployed on specialised deepwater jigging gear, or on conventional groper tackle, since high-speed retrieves are unnecessary. Jigs and softbaits can be ‘yo-yo-ed’ near the bottom to good effect. ‘Drop-shot’ soft plastic rigs with a large soft bait attached at right angles to the line above the sinker work well..

Best baits:
Almost any fish bait will take hapuku and bass. Live baits – mackerel, blue cod, tarakihi, or any other prey-size species – work very well, often taking larger fish.

Cut baits of tuna, kahawai, barracouta, cod or sea perch are good. Alternatively, use whole mackerel or other small fish as bait, or squid, provided they’re large enough and fresh (avoid pink-coloured squid –fish do, too).

Look for durability in a bait – there’s a lot of winding to check baits.

Make sure the baits are large enough to discourage pickers, but not so large as to impede the rig’s rapid descent. You need to be able to reach the bottom to catch these generally bottom hugging fishing.

Best spots:
Hapuku hotspots are generally well known by local fishers. Any moderately deep to deep reef, preferably with plenty of current, is a good bet, but bear in mind that fish may be present only seasonally. Some inshore reefs also hold fish at certain times and some of these are in surprisingly shallow water. Local knowledge helps.

Acknowledged hotspots include reefs and banks around the Three Kings Islands, White Island and the Ranfurly Banks, but there are thousands of rocks and reefs right around New Zealand that offer good hapuku and bass fishing. Off the west coast the edges of the continental shelf provide near limitless fishing opportunities. Some prospecting with a powerful sounder can bear dividends for the patient angler.

Best times:
Groper are most often targeted nat or around slack water. They favour ares of high current and in many locations, it’s only possible to fish for them over the turn of the tide.

Elsewhere, fishing is possible on any tide, but too much current can make staying in contact with the bottom all but impossible. If the drift is too fast, due to tide, wind or both, the fishing is poor because baits are not spending enough time in the strike zone.

In shallower waters, anchoring may be possible, but boat positioning can be critical to success. Berleying is seldom practiced, but deep berleying can pay dividends in shallow water (100m or less).