A blue marlin, estimated at 180kg, tagged and released by David Kenny on board Ata Rangi on February 21 this year. Photo / Supplied
A Northland game fishing club is calling on other clubs to change their tournament rules to encourage tag-and-release of marlin rather than killing them.
Jeff Douglas, president of the Bay of Islands Swordfish Club, said 75 per cent of marlin hooked by its members were tagged and released — the highest proportion in the country.
In 2022, the total number of marlin tagged was also the highest of any New Zealand club.
A key reason behind those statistics was the club’s tournament rules, which favoured tag-and-release over killing.
“The way most of our competitions work is that you get more points if you tag and release. We also have a voluntary rule that any marlin under 90kg is automatically tagged and not weighed. That gives them a chance to breed,” he said.
Typically marlin took about four years to grow to 90kg. By that time they were capable of breeding, which they did further north in the Pacific.
An experienced skipper could guess the weight of a marlin fairly accurately, though it was recorded as an estimate only.
However, Douglas said the weight of the fish made no difference to the number of points awarded.
“At most tournaments you get 500 points regardless of the weight. If you kill it and you’re using heavier tackle, you’ll get fewer points so you’re less likely to win. It’s another incentive to let these fish go.”
The club was, however, not planning to make tag-and-release mandatory.
Douglas said there were a number of reasons why some marlins were brought back to shore.
“I usually kill one fish a year because they’re great to eat. Other people may choose to have their photo taken with it, if it’s over 90kg, because it’s their first marlin or because it’s close to a record.
“We respect the right of people to take fish to eat, or a trophy fish, but we have to look after our fishery.”
The tags were a numbered plastic strip, usually inserted into the marlin’s shoulder and penetrating only a short distance into the animal’s tough skin.
They allowed scientists to trace marlin movements and understand where they bred.
Satellite tags could provide far more data but were expensive at several thousand dollars a pop.
The club’s non-gamefish tournaments, targeting species such as snapper and yellowtail kingfish, used a similar points system to encourage measure-and-release rather than killing of fish.
Douglas said the Russell-based club was now calling on the other 54 sports fishing clubs around the country to make tag-and-release, or measure-and-release, the preferred option in their tournament rules.
Another key element of the club’s sustainability policy was a requirement in tournaments to use non-offset circle hooks with all baits, dead or alive.
Studies had shown released fish had a much higher survival rate if they were caught using non-offset circle hooks instead of the more common ‘J’ hooks.
When a circle hook was used, the fish was almost always hooked in the mouth, Douglas said.
A marlin’s mouth was all cartilage, so the hook could be pulled out with minimal damage.
With a J hook, however, the fish could swallow the bait and became “gut hooked”, greatly reducing its odds of survival.
The club allowed the use of J hooks with lures because, unlike baits, they were rarely swallowed.
The reason Bay of Islands Swordfish Club had the country’s highest tag-and-release rate was partly historic, Douglas said.
Decades ago, club members lobbied the government to ban commercial marlin fishing within New Zealand waters.
In 1998, the then Minister of Agriculture and Fisheries agreed, with one condition.
“He said: ‘Yes, I’ll push the commercial boys out to the 200-mile limit, but you guys have to tag a minimum 50 per cent of your catch. That agreement has been honoured ever since”.
Before the ban, Japanese fishing boats caught tens of thousands of marlin along the New Zealand coast, he said.
“We may take 150 a year instead of many thousands.”
Asked why game fishing should continue at all, Douglas said: “Fishermen are fishermen”.
“There’s nothing more exciting than catching a marlin if you’re a fisherman. People say, ‘but they’re beautiful fish’, but all fish are beautiful in my opinion. These are just a bit bigger.”
■ A circle hook, as the name suggests, is shaped like a partial circle with the barb pointing back at the shank (or shaft) of the hook. A ‘J’ hook is shaped like the letter J with the barb pointing straight up. In a non-offset hook, the barb is in the same plane as the shank, rather than at an angle.