Some will argue that fish migrate and that poaching methods are more advanced than they used to be in Cahora Bassa and perhaps further upstream as well. But the scientific argument still remains in that there was no need for a tigerfish to migrate large distances before the construction of the dams. Surely then there must always be a healthy permanent fish population in the Lower Zambezi at any given point in time? Let us assume that there is and focus on those fish.
To ensure a sustainable and productive fishery in the long term, careful and well considered management is paramount. One need only consider the continued prosperity of the Hydrocynus Tanzaniae fisheries for evidence of this. It is a place that I am yet to visit but judging from all accounts it is well protected and will remain a fishing paradise for years to come. Protections include limitations on the number of fishermen and the regularity with which they fish certain sections of water, an insistence on fly fishing and spinning, and careful catch and release practices. If that weren't enough, the prices ensure that only those genuinely passionate about sport fishing will ever have the chance to go there. Whether the Lower Zambezi goes in that direction is a discussion for another day but the readers of this magazine can certainly take a moment to examine their fishing conduct.
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Circle Hooks: Saving the Tigers of Africa
By James Blevin
I have seen the Lower Zambezi on both sides of the divide, that being before and after the birth of all the fishing lodges and camps. When I speak of the Lower Zambezi I mean the stretch of river from the Chongwe confluence all the way down to, and including most of the Mupata Gorge. Indeed, there was a time when you could drift down the river for days on end without encountering another boat. Fishing methods were no more complex than drift baiting with a chessa cutlet, normally with handsome success. But things have changed and the question exists as to why. There has been a tendency in some articles to exact blame primarily on poaching, perhaps because it is a convenient scapegoat. The Lower Zambezi for the most part is well protected from poachers and in those areas where it isn't, poaching has been a factor for decades. It is not a new phenomenon. Why then has the fishing experience declined since the inception of the fishing lodges and camps?
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According to IFGA, recent studies have shown the best release techniques are often species-specific. A study published in Transactions of the American Fisheries Society in 2003, research compared respiratory responses in largemouth bass (Micropterus salmoides) and smallmouth bass (M.dolomieu) in situations with restricted oxygen levels – called hypoxia. Their findings concluded smallmouth bass are far more sensitive to hypoxia than largemouth bass, and the study suggests the ecological differences between the fish could be related to the differences in their physiological responses to hypoxia. Largemouth bass are lie-and-wait predators found in warmer shallow waters with lower dissolved oxygen levels, while smallmouth bass are more active and prefer deeper, colder waters higher in dissolved oxygen.
Tigerfish, like smallmouths, are more sensitive to hypoxia as evidenced by their high mortality if fought too long, not handled properly and released quickly, or if kept out of the water for any length of time. They do not generally survive in live wells, and react badly to any kind of handling out of the water. The most efficient way to release tiger is to keep them submerged close to the boat while removing the lure, and then simply allowing them to swim away.
There is no doubt that bait fishing targets larger hen fish and this is the major reason why it is not permitted in the Tanzanian fishery. In fact I have fished in many locations around the world where for certain periods during the year, bait fishing is prohibited. But the appeal of the Lower Zambezi will be diminished somewhat should potential visitors be told that they could not target a trophy fish. So a compromise must be reached. Circle hooks are a proven entity and must become the norm. When used correctly they only ever set in either the skin of the mouth or the side plating thus aiding a quick release once landed. Furthermore fishermen should be encouraged to set the hook early, rather than wait for the tiger to swallow the bait. The propensity for fishermen to do this developed through a desire to hook and land every bite, a simpler and less challenging task when the hook is in the gut rather than the mouth. Not only is this practice unsporting, but it is irresponsible in that it is harming the fishery at large.
A hen hooked in the gut is difficult to release and every one that dies takes thousands of eggs with her. When this happens enough, the fish population can be negatively affected. Another issue to address is the utilisation of light tackle. Again, the decision to use light tackle is an ill-considered one given that the fish has to do battle for longer thus diminishing its chances of successful recovery and release. A successful release is also contingent upon various other factors. The first is the method for landing the fish. A Boga Grip should used to secure the head of the fish in conjunction with wet mutton cloth to secure the tail. The fish's weight is then reasonably well supported before removal from the water. The combination of the Boga and mutton grip then allows for swift hook removal and photo opportunities before the fish is returned to the water. There is no reason why this whole process should take more than a minute. Upon returning the fish to the water it is a good idea to gently hold the tail itself and wait until the fish swims out of your grasp. This is an indication that the fish has recovered sufficiently well to survive.
A final point worth considering is whether the angling experience has waned due to fish intelligence. Some of the premier barramundi fisheries in Australia are stocked with up to a million fingerlings every year and yet they are known as 'the fish of ten thousand casts'. The barramundi are there but they have grown wiser through the years as a result of fishing pressure. Surely this is then also a factor in the Lower Zambezi? It is only logical to draw that conclusion when you consider that in 1998 you were unfortunate if you saw another boat on that stretch in a whole day's fishing. Nowadays you are considered fortunate if you manage a count under twenty. When this fact is fully accepted and embraced, there will be a natural progression to more sporting fishing methods such as fly fishing and the use of artificial lures. This will be due to those methods being more effective in terms of inducing strikes. In turn, the fishery will be given a chance to recover as the decline in bait utilisation will mean both a healthier food chain and some respite for our beloved hen fish.
As stated, the use of Circle hooks and their benefits are significant. Many studies have shown that where a fish is hooked has a significant bearing on whether that fish will be successfully released after capture. Effective use of circles is dependent on a number of factors which I have outlined below.
A circle hook is one manufactured so that the hook point is turned perpendicularly back toward the shank, forming a generally circular shape, hence the name. Various studies have assessed their efficacy in terms of hooking and landing rates, and their worth as a conservation tool. Prior to circle hooks becoming popular with recreational fishermen in regions such as the USA, they were the reserve of commercial long liners. Coincidentally, the commercial fisheries’ penchant for using them is borne of that same desire recreational fishers have to retain fish on the line once hooked. Study after study has revealed that the science of a circle hook means that fish will almost always be hooked in either the jaw or maxillary, or the skin of the mouth, and deep hooking is rare. Secondarily, the incidence of by-catch mortality in commercial fisheries is markedly reduced when circles are predominantly used. Again, this is because by-catch species can be released due to fish usually being hooked in a non-lethal area of the body.
As I’ve mentioned, the progression toward the exclusive use of circles by recreational fishers seems logical but for rumours of circles not being as effective as J-hooks when it comes to actually hooking fish. There is no doubt that once a fish is hooked on a circle, it very rarely escapes. The fact that they are good enough for commercial industry should be evidence enough of this claim. But are they as effective during the actual hook up? That, I believe, is the burning question of many of the readers of this magazine. The answer is yes, if the correct technique is employed.
The effective use of circles involves some connoisseur technicalities and they are best illustrated using a step-by-step guide, which is as follows:
1. Hook size relative to the fish species is important. A 6/0 and 7/0 work best for tigerfish and larger catfish. Be careful however, as there is some variability in sizes between manufacturers so my recommendation would be to buy a few packs of varying hook sizes, and actually test them in the field to see which works.
2. Circle hooks rely on slow, but direct, application of pressure. The blunt force induced by a strike when angling with a normal J-Hook will not work with a circle. The important word in the first sentence is ‘direct’, which means that braided lines complement a circle better than monofilament lines. The reason for this is that there is far more stretch in the latter and often the hook won’t set well. If you are averse to using braid, fluorocarbon is another option as it also does not stretch.
3. Pursuant to that word ‘direct’ again, I prefer using a Snell knot to tie my hook to the trace or leader. I have illustrated how to tie this knot below. The use of this knot allows for direct pressure to be applied through the eye and shank of the hook. Importantly, the hook will always be in the correct position as there is no loop which would normally be the case if you were using conventional wire and crimps.
4. When rigging your bait, it is vital that the hook not be buried in the bait. There must always be daylight between the point of the hook and the shank and often a simple thread through the top of the bait will suffice. Naturally, a smaller bait will aid your hook up rate as it is likely that the fish will have all of the bait in its mouth.
5. Once you have cast your bait, remain vigilant about monitoring its movement. In an ideal world, your line should be extending directly outward from the end of the rod tip. I.e. there should be no angle between the rod tip and the line. If your bait moves to three o’clock, reel in the slack line and move your rod tip to three o’clock as well, thereby “straightening” the line.
6. We’ve arrived at the most crucial part of the method and there are two options here. You can fish with a free spool and wait for the strike, or you can fish with a set drag. In both scenarios you will be setting the hook early and trajectory of the rod should be approximately 45 degrees. If fishing with a free drag, count two or three seconds into the run, then raise the rod gently, set the drag, and watch your rod load up. Do not strike. Doing so will result in you pulling the hook right out of the fish’s mouth. The same applies when fishing with a set drag. Keep the rod at 45 degrees in the right direction and any fish that strikes should hook itself.
7. Once the fish is on, the normal rules of engagement apply. Keep tension in the line at all times and remember that although a jump is great for photos, it is an indication that you are pulling too hard on the fish.
The science does not lie and you will find that most fish you catch on circles will be hooked in the jaw or skin of the mouth. You’ll also find that your catch and release efforts will improve drastically and gone will be the days of cutting the trace and releasing a fish with a hook still embedded in its throat. Whoever came up with the notion that hooks dissolve quickly in freshwater, does not deserve to be fishing at all. Every effort should be made to ensure that a fish is released in the same condition it was in prior to ingesting your bait.
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