Big Blues; That's the hot topic this week in Exmouth. Lots of blue marlin have been raised, hooked and some tagged over the last week in waters surrounding Exmouth, with some boats tagging four in a day, others tagging both blues and striped marlin. Interestingly, this has been the lead up to the full-moon: a phase of the moon that has been considered by some anglers to be prime-time for chasing billfish. There are also plenty of sails and blacks about, so any lucky boat could possibly get a Super-Slam. What is a Super-Slam, do you ask? A Grand-Slam is three different species of billfish in one day, while a Super-Slam is four different species in one day, and a Fantasy-Slam is five different species in one day.
Rowan Smith was out fishing aboard the boat Fully Sic on Tuesday last week, the day of the full-moon. Rowan was fishing with Steve Moore, Matt Niikkula and James Roscic, who make up the same team that travelled all the way to Hawaii recently to target big blue marlin in a tournament. Interestingly, they travelled half way around the globe to chase fish that they then found right here in their own back yard?! Rowan hooked a massive blue marlin early in the day off the Muiron Islands on stand-up tackle with 37kg line. The fish jumped, and after careful consideration, the crew decided to bring the fish in to weigh. Several hours later the fish was finally brought on board the 7m centre console boat. The fish measured 3.3m short length (tip of lower jaw to the fork in the tail) and 4.2m total length with a 1.7m girth at the thickest point.
There is a formula for estimating the weight of such fish. The formula is this: multiply the square of the girth in inches by the short length in inches and divide by 800. This gives you an estimate in imperial pounds. So, if we exchange the metric for imperial measurements, and do the maths, we come up with (67×67) x130 = 583570 divided by 800 = 729.46lb. Now, 1 pound is 0.453kg, so 729.46 x 0.453 = 330.44 is the estimated weight according to the formula. The fish actually weighed in at 330.1kg. How accurate is that!!
It's important to note that the Exmouth Game Fishing Club encourage anglers to learn more about recreational fishing through education. In December the EGFC is holding the Network Power Solutions Heavy Tackle Tournament to target big billfish. The EGFC is purchasing specific rulers to assist with measuring the short length of a billfish while it is alongside the boat, so that anglers can easily estimate the weight of a fish. Rowan's fish will be a good tool to show anglers just how accurate measurements can be, for estimating the weight of a fish in a tournament.
Another interesting fact is that the blue marlin weighed is estimated to be about 8yrs old, according to recognised world authority on billfish, Dr Julian Pepperell. Many people don't understand that billfish can grow at such a rapid rate. They can grow from the size of a pinhead to 30kg in just one year!
Rowan's fish is the heaviest recreational billfish recorded by weight since March 1983. That original fish was caught by Sir Garrick Agnew off Rottnest Trench. The capture of this blue marlin by Rowan Smith in Exmouth will hopefully help educate people to have a better understanding of these fish. Many, many billfish are tagged for recreation and research in this area. The data retrieved assists us to understand more about these species, where they travel, how fast they grow etc.. However, when a fish of this calibre is brought in, the focus is far greater by the public. People talk, and we hope that this talk will broaden the understanding of billfish, and in particular, game fishing and the way in which anglers work to help conserve these species. The tourism benefits of targeting these types of fish for tag and release is larger than most people recognize.