|article: portland's threshers by geoff wilson
Dated: 12 December, 2008
|Bill and Mick with one of our thresher shark (Photo: Live Now! Fish to the Max).|
In December last, I Joined Mick Kollaris and Bill Athanasslies of Live Now! Fish to the Max at Portland where we caught and released six Thresher Shark, from an estimated 60 to 80 kg.
Following local fishing Guru Bob McPherson’s advice we began trolling with lures, a blue Rapala X-Rap and a gold coloured Shimano Stiffy, from the mouth of the Surrey River. Just slowly at around 2 knots, but enough to keep the lures working.
The depth at which we most often hooked up would have been around 10 metres and probably no more than a kilometer of the shore.
Both lures were taken at various times and usually the strike was totally unexpected, the thresher just belting the lure with its tail and becoming hooked in the tail by doing so.
|Bill with another (Photo: Live Now! Fish to the Max)|
The fact that Thresher Shark are often hooked in the tail raises a difficulty for the angler and crew because the fish is being brought in backwards.
Because it was our intention to release the fish we caught we used 50 lb Fireline on several different rods and reels, and made the most of its use with the application of pre-determined determined drag settings of 12 kg.
At that pressure the fight lasts about 20 minutes and the fish comes alongside quite tired, but in good condition for release. The use of the normal 8 kg drag pressure used with 24 kg tackle can allow the fight to go out to an hour or more with little chance that the hooked fish would survive.
High drag pressures of 12 kg can be handled quite OK by the average angler with a sound technique in good conditions, the biggest risk is that of pulling the hooks from the tail. If that happens while the lure is clear of the water, it can do some damage if it hits you. We had a near miss ourselves.
It was raining, and we’d all taken our glasses off. Not such a good move from a safety aspect. I had brought a very lively thresher close to the boat when the lure pulled free and we had to duck quick-smart. Luckily it didn’t hit anyone.
Interestingly, on the last of our three days at Portland, we decided to catch one more thresher for the table. They are probably the best eating of the local sharks. The weather had changed though and it was quite rough. It was also sunny and rather warm in contrast to the cold, rain and comparatively calm conditions we experienced over the previous two days.
In any event we had no strikes, and – unlike on the previous two days – we saw nobody else hook-up either, but that’s fishing for you.
|Julian Dickerson and Tim Clark with a thresher that was too far gone for release. It weighed 82 kg. (Photo: Bob McPherson)|
Thresher Shark (Alopias vulpinus)
References: Sharks and Rays of Australia by Last and Stevens.
Fishes of Southern Australia by Hutchins and Swainston.
Of the three known Thresher Sharks, pelagic thresher, big-eye thresher, and the common Thresher Shark, the latter grows largest, is most common, and is of most interest to anglers.
The Thresher Shark has a tail as long, sometimes longer than its body which is short and stout, almost barrel-like, retaining a good deal of weight to the base of its tail.
Its eyes are large and dark with no nictitating membrane and positioned well forward, about level with the front of the mouth which is surprisingly small in comparison with other sharks of similar size.
Colour is metallic grey with a striking lilac or mauve sheen, fading to white underneath with some blotchy markings low on the sides, particularly near the pectoral fins.
|A hooked thresher shark comes to the surface. (Photo: Bob McPherson).|
The Thresher Shark bears live young, small litters of only two to four pups at a time measuring up to 1.5 metres in length. Male threshers mature as small as 2.6 metres in length; females mature between 3.5 and 4 metres.
Like the great White Shark, mako shark and porbeagle, the Thresher Shark has a heat exchanging circulatory system enabling it to maintain body temperatures higher than that of the surrounding water.
Thresher Sharks grow large, weighing probably 400 kg or more and measuring well over five metres in length. Hutchins and Swainston, in Fishes of Southern Australia credits threshers growing to 6.1 metres. Captures on rod and reel have included several specimens over 300 kg, and would be truly awesome adversaries at this size.
|A hooked thresher shark jumps clear of the water off Narrawong Beach. (Photo: Bob McPherson)|
The Thresher Shark feeds mainly on small school fish, stunning them with its tail. Will also investigate, and pick up potentially edible items either floating on the surface or resting on the sea floor.
Anglers fishing with fairly large baits for Snapper and the like, both offshore and in sheltered waters occasionally hook the thresher. However, few are landed because they fight powerfully and frequently bite through the line.
Hooked Thresher Sharks outperform all other sharks of comparable weight, including makos, by a wide margin and sometimes give aerobatic displays rivaling billfish.
Thresher Sharks may be found in tropical, temperate and cold waters. In Australia, they seem to be most common around the southern half of the continent but rare further north than 25 degrees of latitude.
Most threshers caught in southern waters range in size from 40 to 100 kg making them ideal targets for sportfishermen working from small boats. They readily take both live and dead baits, and lures as well.
|Close up of a thresher shark alongside. This one was hooked on a baitfish known as a red rocket. (Photo: Bob McPherson)|
One important point to be remembered is that baits for threshers should be relatively small. Large pilchards, garfish, slimy mackerel, small Barracouta and other small fish are ideal. Large chunky baits like slabs of tuna are unsuitable for threshers.
Threshers take live baits, either rigged under a float or balloon, or bridle rigged and trolled very slowly, either along the surface or down deep behind a downrigger. In fact, slow-trolling live baits could well be the most effective method of targeting threshers.
Threshers take lures, particularly sub surface swimmers. The Rapala X-Rap and the Shimano Stiffy have accounted for a number of threshers. Most of these have been foul-hooked because of the thresher's inclination to strike first with its tail.
|A hooked thresher shark comes alongside. (Photo: Bob McPherson)|
Game fishing tackle is preferred for threshers. Sizes 10 kg and 15 kg are both effective on fish to around 50 kg but heavier tackle is required to land mature specimens.
Sharp hooks are essential. Those made by Gamakatsu and Owner are favoured by light tackle enthusiasts because their hook-up ratio is very high and they drop very few fish.
Wire traces are also essential, because - like most other sharks - threshers have sharp teeth which will quickly severe monofilament and other fishing lines.
The wire trace need not be very long. In fact very long wire traces are a liability in small boats because they can foul fittings and cleats etc, when being retrieved. A one metre length of wire is long enough when used in conjunction with a heavy monofilament leader which can be wound in through the rod guides and onto the reel.
|Tim Clark and a companion bring a thresher shark aboard. (Photo: Bob McPherson)|
Choice of wire varies among shark fishing enthusiasts, but Sevenstrand leaders testing five to eight times the breaking strain of the line class being used will usually be adequate.
Forty nine strand wire traces are easier to handle but are not as tough as Sevenstrand. For this reason, choose traces testing, at the very least, five times the nominated line class when using Forty nine strand traces.
Anglers who spend a good deal of time fishing for Thresher Sharks usually indicate a preference for nylon covered wire, because - it is claimed - they get more strikes.
My limited use of nylon covered wire indicates this could indeed be the case for whatever reason. However, it is important to check coated wire regularly because a leaking sheath can promote corrosion of the wire inside.
Single strand wire is rarely used for shark fishing in this country, but it has accounted for many Thresher Shark captures world wide. Preferred diameter for tackle classes discussed would be .029” (0.7 mm) to .035” (0.9 mm). Single strand wire is a difficult product to work with requiring handling skills few anglers possess.
|Jamie Karamatic with a thresher shark of about 40 kg that he caught off Jan Juc. (Photo: Matt Grgic)|
Although wire traces need not be long, extended heavy monofilament leaders, which can be wound in through the rod guides are becoming very popular among the gamefishing fraternity.
Game fishing regulations allow an angler to use a combined double, leader trace and hook length of six metres for 10 kg tackle and twice that length for 15 kg tackle.
In the latter case, this would all allow a short Bimini double of say, half a metre or less to attach a nine and a half metre monofilament leader of say, 100 kg breaking strain to which in turn would be attached a two metre wire trace of 100 kg wire.
The meat of this shark is excellent, possibly the most palatable of all sharks. According to Sharks and Rays of Australia by Last and Stevens, a gillnet fishery has recently been developed for Thresher Sharks off southern California.
They are also taken as a bycatch of the Japanese tuna longline fishery in southern Australia for meat and fins which is significant because Japanese fishermen discard most other sharks after cutting off their fins.
Fishnet Pro Angler
Email : firstname.lastname@example.org
Fishing reports may be sent by e-mail, or mail to Geoff Wilson:
PO Box 384,