Threshers are hard work to find in my experience with many hours spent in the pursuit of one but hopefully the following will help you target them, it’s taken me years of effort to finally be successful on my own boat earlier this year but I’ll try to relate what I found worked on this occasion for me.

Threshers can grow absolutely huge in our waters. The largest recorded got caught up in a squid net off Cornwall and was 32ft long and weighed a massive 1250lbs, so you really can’t skimp on the tackle, everything needs to be up to scratch! The other point about threshers is that they are roughly half tail, this translates to a potential for incredible speed, strength and stamina so I didn’t want to attempt this shot under-gunned.

Generally accepted wisdom is that they migrate east from the west, beginning in June, along a relatively narrow corridor. They then seem to congregate mainly around the Isle of Wight for a while with a few heading further east before the whole lot move back out to the west around September.  Threshers are slightly unusual in that they will free jump-I’ll never forget the first one I saw, for me it’s the most amazing and impressive thing I’ve ever seen at sea.  They also have a reputation for jumping and porpoising during the fight, this means there is the potential for them to land on your line and snap you off so needs guarding against where possible. Most years small threshers are taken on mackerel feathers and absolute monsters are seen jumping all within the same general area at similar times so it would seem the size classes mix.

Hanging a bait over the side you really have no idea what will take your bait and my approach to this means gearing up for the biggest fish you may sensibly encounter.

My local waters are Lyme Bay and it’s obvious that threshers move through here in both directions as they head toward and back from the IOW grounds.  I’ve targeted them for a few years in this area but never had a hookup despite some decent information.  With the list of 100lb species getting shorter I finally got over my hangup about catching one from my home port and headed to the areas where they are traditionally found in order to tick one off the list.

Thresher shark biology-

I’ll keep this short and pertinent to catching them, so in that respect threshers are very similar to porbeagles and should be treated in the same way as far as rigs and tackle are concerned. I’ve described my porbeagle approach in detail in a previous article so please refer back to that. (https://hookpoint.co.uk/pursuing-porbeagles). Both are pelagic and feed on similar prey fish; both give birth to live young and both occur to their maximum known potential size in our waters. I’ve heard several times that threshers have a small mouth and relative to the size of them this might be true but they are still a big fish that is capable of taking a fish of a few pounds and therefore a relatively big hook won’t do any harm.

Threshers have been filmed using their amazing tail to flick over their bodies and kill and injure fish before leisurely swimming back round to pick up the dead and injured. This needs considering as I have had experience of them hitting a bait under the boat with their tail before taking it so if the first bite seems too fast to be true it may well be, don’t delay the strike too long but at the same time don’t strike as soon as the reel goes off it‘s a really quick scream.


The free jumping phenomenon is difficult to accurately attribute to a cause as by their nature they can’t tell us why they are doing it.  For anyone who hasn’t seen it they will occasionally leap vertically clear of the water and crash back in sideways-an amazing sight.  The first time I saw this I happened to be looking in the right direction when a fish did exactly this around a mile away, it then did it again straight away-it looked like a bomb had gone off in the water.  My advice would be if you see it, mark it on your plotter with a rough bearing and distance as fish are obviously holding over that ground and it may come in useful on another day for a different drift. I’m speculating here, but I think it might be a mating display as seen and filmed from drones observing black-tip sharks in Florida, if I’m right I also think that jumpers are not necessarily takers.  If their minds are on displaying to the opposite sex they won’t have feeding at the forefront of their thoughts, however, after the jumping period they will have expended a fair bit of energy and be hungry.

This theory seemed to stack up when I look back at catches this year and last, lots of jumping seen and few catches, then jumping stopped and catches increased markedly but as I say it’s only a theory and my own observations.


Luckily for people looking for them threshers respond to chum and noise so can be attracted towards a boat on the drift, this is the recognised way of trying for them as with so many other sharks.  Another technique not often tried over here is trolling – this often causes a by-catch in areas such as California, unfortunately it also may mean hooking in the tail due to their tendency to use it in the strike which can mean dragging the shark backwards during the fight and drowning it so is best suited to targeting other shark species.


Tackle and rigs-


I’d hate to one day hook a magic 1000lb fish and lose it due to not thinking things through beforehand so every small detail is considered well before a hookup of any species.  Threshers can beat you up if you don’t go equipped so make sure you do your research and make sure all your tackle is sound.  I’ve gone into this in previous articles so won’t dwell on it here but we’re talking strong razor sharp hooks, double crimping, ball bearing swivels, heat shrink tubing, heavy rods and reels as previously detailed.  I’ve said this before but I favour braid on my reels to give me capacity to deal with long runs along with a topshot that will absorb some of the shock of headshakes.

I may be overthinking this but the length of the tail on a Thresher concerned me during my research.  To combat this I went longer on my trace, increasing it to 20ft.  I also went all wire, including the rubbing trace which I had mixed feelings about, given mono is kinder on the tail of the fish during the fight, but with the potential overall length of something that may take the bait I’d also be uncomfortable using mono and then losing a fish with a hook in should the tail smash through the mono. The tail also caused me to avoid my normal use of a snap swivel to attach the bite trace to the rubbing leader – no chance of a tail hitting a swivel and opening it up if you crimp a standard heavy swivel on. 


Tide is an issue in the area I was fishing so I also used a drilled lead weight to prevent the kiting effect, another thing I’d noticed was that several photos of threshers caught included a muppet above the hook, muppets are great for slowing washout of baits and preventing them spinning so I added one in to my rig. To be fairly specific I had a 9/0 owner hook (barb removed), double crimped to 480lb 49 strand wire on a 4ft bite trace, a 9 inch muppet, 400lb ball bearing swivel, 16ft of wire and another 400lb swivel that was then crosslocked to my 480lb swivel at the rod.  This had a jam knot connecting it to a double of 80lbs mono, then a plait knot to absorb more shock before going to a 50 yard 80lbs topshot, the topshot was connected to 80lb braid by my own modified FG knot.

In terms of rods I’d taken delivery of a pair of Penn Battalion IGFA 30lb bent butts in the winter, due to lockdown I hadn’t had much chance to test them out.  Around 2 weeks before the thresher shot I’d taken them to Cornwall on the boat for a trip to try for blues – I had 9 in a day, tagging 4 and the rods performed great but I really wanted to try them on something stronger as it felt they had loads of power in reserve.


Tactics-


As we’ve already said, Threshers respond to a drift with chum, a standard technique that we’ve explored before.  Due to the limited time these fish are present along with lockdown and limited time off work due to pressure there I mixed my chum to be three times stronger than normal and leave no room for interpretation on the behalf of the sharks.  I also felt that I’d started a bit too early the previous year – I’d started when there was a chance of a fish but wanted to concentrate on the prime time this year to have the maximum chance on any trip.  Unfortunately last year this also included a failure that meant a tow in and a tow off the beach by Jason Gillespie – the sea can be a lonely place until you have some help from another boat!

I’d had some good tips from friends on areas threshers had been seen in and set my drift to head through areas I’d seen fish jumping in the previous year.  The intention was to fish a whole tide and end up somewhere near where I started if possible.  I also felt I’d started before the prime time in 2019 hence my Cornwall trip to tag a few fish two weeks before and make the most of my first shot this year.


It’s unclear to me how resident threshers may be and I’m not sure anyone really has the answer, my thinking is that they probably dwell in a general area or migrate through a corridor and as long as you are roughly in that area there is a chance of a hookup.  I generally fish alone but for this trip I had a friend along which proved really useful as we got lots of footage that I would never have had on my own.  The deal was that he caught the bait and if there was a second fish he had that strike.  The night before I’d said we’d be hooked up within an hour of the turn of the tide, and, as luck would have it we were.


We ran out and set our drift up in the area I’d seen fish jumping the year before, feathers went down and straight away we were into scad with the occasional mackerel which was a good sign.

Since I’m really busy at work this year and fishing time is severely limited I’d mixed my normal trout chum but only added 1/3 the bran that I normally would have, my thinking was that I wanted any shark anywhere near me to be well aware of where I was so this chum ended up 3 times as oily as my normal mix.  I knew I’d have limited shots so I also took more than normal and really let it go from the bucket to create a big slick.  I set my drift and that was it for the day, no repeat drifting like Porbeagles, my approach for this is more like fishing for blues.


We started with frozen baits but as soon as we had fresh I changed them out.  We fished three baits and after a few hours we had caught several scad but the mackerel were thin on the ground.  The turn of the tide was just approaching and I wanted fresh baits out – we had just had a nice mackerel come aboard which I flappered and switched out on the middle rod – my favourite position.


No sooner had I stopped it in place and placed it in the holder than the float moved out of line and dipped.  “Tope” I said to my mate and left it.  We hadn’t seen any Tope that day but they can be a pain in the general area, ruining well presented baits meant for much bigger fish. The float continued to bob for a few more seconds along with a couple of clicks on the ratchet before I decided to pick up the rod and change out the now wasted prime mackerel.

I never completely write off any bite so wound down and struck, just in case.  The float disappeared and there was a half solid weight on the end but these Battalion rods have plenty of power so I would it straight to the boat with a bit of cranking.  Whatever it was started digging under the boat and I changed my thoughts to a small porbeagle as there was no real fight but just a better weight than you’d expect from a tope.  As it came directly underneath I saw it in the water as it emerged from under the boat – I said to my mate “ah it is a tope but a big one” as I saw a sandy back deep in the water and a thinner profile than the porbeagle I was expecting.  I was then blown away as what should have been the end of the tope just carried on appearing and I saw this enormous tail.


I wish I could now give you a story of a fight of epic proportions with jumps, porpoising, backing the boat down and nearly getting spooled but the honest truth is that it was nothing remarkable and in reality pretty disappointing.  Watching the footage back later I had the leader in hand in under 4 minutes after striking which doesn’t fit with what you hear about the way Threshers fight at all – the fish was tagged and released in around 20 minutes with most of the time spent with the swivel at the rod tip.  Once I wired it up the thing that struck me other than the tail (which they move with incredible dexterity) were the eyes – they weren’t the black holes of a porbeagle but had a definite pupil with a vertical slit.

I tagged it with a NOAA tag and it came out of the formula at 120lbs so my sixth species from the British Isles over 100lb, five of which have come on my own boat and I have caught single handed.  Measuring the length of it was hard work due to the difficulty of getting it to lay flat in the water so we were very conservative with this as we wanted to get it away safely, but I had made up a girth measuring tool which worked perfectly so we had a very accurate girth figure. If I hadn’t been able to measure it at all I would have guessed around the 150lb mark.  We got the tagging and release on film and to be fair one of the best things about such a short fight the fish was in absolutely immaculate condition despite my worries of using the all wire trace, the fish went away like a bullet.


In terms of fighting handling and releasing a thresher, regardless of what I have said about the individual I caught I would not take any chances and treat them exactly as you would a porbeagle – a more spirited individual than mine could easily do you some serious damage. Extra notice should be taken of the tail which can move incredibly fast, potentially breaking ribs or worse but obviously they have sharp teeth, immense power and could easily do you damage if you weren’t on the ball.  Wiring gloves are essential, especially with the all wire trace I have described; they aren’t cheap but I’d rather spend a bit on gloves and keep all my fingers.  Threshers have a reputation for long searing runs so gear up appropriately for them and be prepared to start the engine and back down on your fish as docile fish like mine seem to be by far the exception to the rule.


I’m still looking for a fish to put a serious bend in the new rods so watch this space…

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