I wish they wouldn't. Here's why: In reality it's a very delicate species to try and catch and release. I asked Bruce Dale, owner of Teak Tree,what makes it such a fragile fish to catch, even though it is an incredibly powerful hard fighting fish too. Here's what he told me.
1. The heart of the Arapaima is very close to its mouth. If it swallows the hook the heart can be damaged easily and you end up reeling in a dead fish.
2. There are lots of great photos showing sports fishermen with their prized Arapaima, lovingly displayed, alive and well. The link here shows Bruce with the headlamp....clearly this fish made it back to the water alive and well. Unfortunately this species has a critical vein (artery?) which runs the whole length of its body. If it thrashes around while being photographed the vein can burst causing the fish to die.
3. When unhooking the fish it has been known that its jaw can lock open. This will actually drown the fish as it can't use its gills properly with a locked open jaw.
At Teak Tree Lake there are lots of other great predatory species which I would love to have caught. None of them are delicate flowers like the Arapaima. The list includes the Alligator Gar, Amazon Red Tail Catfish (I did catch a few small ones), the Asian Red Tail Catfish, the Tiger Catfish, and the Chao Phraya Catfish (Bruce holds the World Record for this species) amongst others. These are amazing creatures and wonderful sports fish too, capable of putting up a tremendous fight but without expiring on the way in like the Arapaima is wont to do.
The predator rig I was given by Bruce consisted of a heavy lead weight and a very short "tail" (the line between the hook and the weight). This "tail" can't have been more than 14 inches long. The rig is designed to sink straight to the bottom of the lake and thus greatly reduce the chances of a "take" by some of the bigger predators which feed at surface and mid-water levels. The lead weight serves also to try and lip hook a taking fish before it can swallow the hook whole. In other words, Bruce is worried about the health of his prized Arapaimas, and understandably so. The rod is placed in a rod holder and a bite alarm is attached to the line. You then go about attending another fishing rod or have lunch or chat with your friends. If a fish takes the bait the alarm goes off. It's a bit of a lazy way to fish and without the short tail and heavy lead weight would probably result in a lot of swallowed hooks and dead Arapaima.
Next time I go to Teak Tree Lake I will ask Bruce to set me up with a predator rig which will actually catch predators. I'll fish for them between the hours of four and seven pm. I will hold the rod in my hand, no bite alarm. I'll need a light weight (if any), and a long hook length (tail) between the weight and the baited hook. I want to fish top and mid-water. And, because I'll be holding the rod I hope to avoid the possibility of a hungry Arapaima swallowing the hook before I can set it. To be perfectly honest I'd prefer not to catch one if the risk to the fish's life is so great.
Personally, I now wish the Arapaima was not valued as a sports fishing prize. They're just too delicate. There's a famous fishing venue near Bangkok called Bungsamran Fishing Park. Numerous world records have been broken there. Fishing there for the day is a very reasonable 1000 Thai Baht (about $33.00US) and you can catch some absolute MONSTER predators. But, if you want to catch an Arapaima you have to pay 20,000 Thai Baht - over $620.00US - ...this is because the attrition rate for the species is so high. And, that is for ONE Arapaima. Catch your first one by 9:00am and your fishing is done for the day unless you pony up some more cash. As mentioned, Arapaima caught often end up belly up dead and it costs a lot to replace them.
For a fan of "Catch and Release" sports fishing I can't see the point of going after them. It would haunt me for days if I caught one weighing 50 - 200lbs and it died as a result.
Amongst other things the short video above shows that Arapaima will take dead fish bait when it is presented on or near the surface.