Consider the following scenario:
It's early March. You and a buddy are drift fishing for winter steelhead on one of Oregon's many coastal rivers. You hook six steelhead, land four and released all of them because most of the fish in the system at this time of year are in fact wild. Three of the steelhead you landed, you hooked drifting a pearl/pink corkie with a single hook and one of the steelhead was hooked after you threaded a sandshrimp under the corkie rig. The water is high and off-color making it difficult to find a place to step to shore. So, for every fish hooked, you had to fight them longer than usual because the swift current made it difficult to bring the fish alongside the boat. Each fish hung in the current downstream from the bow until it was exhausted. In fact, that is when you lost the other two. You were certain they were ready, but they made one last turn away from the boat, towards the shore and the direction of pull on the line changed. The hook pulled free and those two got away---But not the other four. After three attempts, your buddy slides a net under the steelhead and hauls it into the boat. It flops around a bit but you eventually unhooked the size 1 bait hook from the corner of its mouth. You hold the steelhead up for a picture or two and then slide the fish over the side. You hold it upright for a moment because that's what they say you should do to revive a tired fish, but it kicks out of your hand and swims off. Let's just say the four steelhead you landed responded similarly. From your perspective, it would be reasonable to assume that all of the steelhead survived after release because they did in fact swim off on their own.
Could you believe that the opposite might be true? More than likely, all four steelhead died from a long-term, delayed mortality, a truth difficult for the angler to confirm because in most instances, death occurs hours, if not days later.
In the previous scenario, you, the angler, made specific choices that directly affected the overall mortality of catch and release fishing. What we do once the hook is set has more bearing on a wild fish's survival than the gear we choose. Whether we fly fish only or pinch the barbs on our favorite plugs, equipment has little statistical impact on the overall percentage of mortality associated with catch and release. It is widely promoted that a fish hooked in the corner of the mouth or outside the mouth experiences a 3% chance of mortality if it is landed promptly, kept in the water and released quickly. The use of barbed or barbless hooks doesn't seem to change that percentage significantly. Mortality is determined greatly by our behavior, or habits, not our equipment.
Dr. Bruce Tufts is a professor of biology at Queens University in Kingston, Ontario, Canada. He has studied the physiological effects of catch and release fishing since the late 1980's. The findings from his research have helped shape catch and release regulations throughout North America.
According to Tufts, factors such as time out of water and length of fight combine to determine a released fish's chance of survival. In his study, "Physiological Effect of Brief Air Exposure in Exhaustively Exercised Rainbow Trout: Implications for "Catch and Release" Fisheries", Tufts studied the effect of time out of water periods of zero, 30 and 60 seconds for rainbow trout after exhaustive exercise. In 57-degree water, after 12 hours of recovery time, the control group-- fish that were held in captivity but not exercised--experienced no mortality. The group not exposed to air immediately after exercise experienced 12% mortality. The group exposed to air for 30 seconds after exercise experienced 38% mortality, and the group exposed to air for 60 seconds after exercise experience 72% mortality. 7 out of 10 trout died after 12 hours when exposed to air for 60 seconds.
Tufts concluded, "...the brief period of air exposure which occurs in many "catch and release" fisheries is a significant additional stress which may ultimately influence whether a released fish survives". According to Tufts' study, any exposure to air significantly decreases a salmon, trout, or steelhead's chance for survival.
In the above fishing scenario, how long would it take you to clear the net, unhook the fish, take the pictures and then put the fish back into the river? It is very, very difficult do it in less than a minute. I've timed numerous anglers trying to do exactly what I have described and in most instances, it takes two minutes or more once the fish is brought on board. So one might conclude that if 7 out of 10 rainbow trout die after an air exposure of 60 seconds, then 3 of the 4 steelhead netted and brought into the drift boat, died within 12 hours after release.
Tufts states in a 2004, In-Fisherman, article, "When you remove a fish from water the secondary lamellae in the gills collapse, inhibiting gas exchange". Tufts and I use similar analogies when trying to explain how detrimental it is to hold a fish out of water for long periods of time after landing it. Imagine running 100 meters as fast as you can and when you cross the finish line someone grabs you my the back of the head and forces it underwater for a minute. What's your chance of mortality? Salmon, trout and steelhead breathe air about as well as we breathe water.
Tufts states in an article published in, Atlantic Salmon Journal, Spring 2001, "There's No Excuse Not to Stop Killing Salmon" that, "the studies have documented (delayed mortality) in salmon and other species...it is not something that occurs immediately after the period of exhaustive exercise...therefore not something that would be apparent to an angler releasing a fish. Delayed mortality can occur in fish that appear absolutely normal at the start of the recovery period."
60 seconds out of the water and you've killed 7 out of 10 fish. This is somber news.
Additionally, Tufts does not take into account the cumulative effects of removing a fish's protective slime by netting and bringing the fish on board, increasing the chance of bacterial growth on the skin after release and the accompanying increased stress levels. Nor does he address the mortality impacts of hook placement and the increased blood loss from the most vital organ, the gills, when a fish is hooked inside the mouth on a delicate gill rake. Some states have made laws requiring anglers to use single barbless hooks and to keep fish in the water at all times if it is to be released to reduce the chance for post release mortality.
Whether the capture of wild salmon and steelhead is intentional or accidental, catch and release fishing causes mortality at a rate higher than most well intended anglers could ever imagine. It is possible that the angler who chooses to target wild fish, kills more wild steelhead, salmon or trout than the equally effective angler who chooses his angling opportunities according to the run timing of specific hatchery returns and kills every legal hatchery fish he or she catches. If I catch 20 wild steelhead in four days of fishing and handle them carelessly, it is possible that I might have killed 14 of them. That's six more than the eight fish, four day limit of the angler whacking and stacking hatchery fish. One has to ask, whose behavior is better for the resource?
So, considering the previous angling scenario, the high water day from the drift boat, what could you have done differently to increase the chance of survival for those four wild fish you released?
---First, wear waders if you can. Hip boots are fine. An angler has to get down into the water to properly release a fish. If the water is in fact too high and there is no accessible shore, pull anchor and find calmer water to land the fish.
---Use a net with a rubber or soft mesh. Hard nylon is too hard on the fish. If you can get to shore, slide the fish into the net but leave it in the water. Don't reef up on the handle and haul it out onto shore. If you net the fish from the boat, don't bring the fish into the boat. Leave it hanging over the side.
---The fish must stay in the water. Make sure its head is submerged. Get down on your knees, wait for the fish to calm down, and reach in carefully to remove the hook with a pair of pliers.
---Don't rip the hook out of the mouth. Gently back it out, the direction it went in. Even with a barb, if the hook is lodged in the corner of the mouth or lips, the hook should come out easily with a soft tug.
---If the hook is buried in a gill rake, down in the gullet or buried in the tongue, don't remove it. The fish's chances of survival with such a hook placement are reduced as it is. Removing a barbed hook from these areas will certainly kill it. Clip the leader, leaving at least 18 inches trailing outside the mouth and do your best to revive the fish. The old myth that the hook will dissolve over time can be questioned when one uses stainless steel or chrome hooks designed not to rust. (How many shiny hooks have you found hanging in the shoreline brush long after the mono has rotted away?)
---When you are ready to release the fish, gently hold it upright in the current. Don't move it back and forth. This drives water and sediments under the gill plate from the wrong direction inhibiting the all important gas exchange, effectively smothering the fish.
---When the fish seems ready to go, hold on to it a little longer. Its fins should be erect and its movements positive. Most fish will bolt from the hand out of fear when they start to get their senses back but haven't recovered enough to hold themselves upright in the current. If allowed to swim away, they often roll over and die under a rock somewhere downstream. This is the "not apparent" part of the delayed mortality Tufts refers to. Yeah they swim off, but some of them die.
---Don't touch the gills. The angler who puts his fingers into the gills of a fish they plan to release, for whatever reason, has probably killed that fish by damaging the delicate lamellae needed for gas exchange (breathing).
If you want to take a picture of the fish, hold it gently at the wrist of the tail while supporting the girth under the pectoral fins. Keep the head in the water while the photographer focuses and sets the exposure. Only when the photographer is ready, when they say so, should you lift the fish out of the water an inch or two. Take the picture and immediately place it back into the water. Reset and repeat if you like. Don't stand up and hold it out. Stay low. If you drop the fish, it's close to the water and won't be injured. How many times have you seen someone drop a squirming fish onto the rocks or into the bottom of the boat? All bad. I can always tell if a fish has been out of the water for a long period of time by the amount of water running off its body. Sadly, most fish are bone dry when pics are taken.
Unfortunately, ego and pride often overtake common sense in those exciting moments when a big wild fish works us over. Taking a fish out of the water is purely a convenience for the angler or guide. Yeah, we want that baby. Gotta get a picture of that bad boy. But, if you fish with the intent of releasing the wild ones, why wouldn't you, in good conscience, do everything you can to ensure that the trophy you plan to release, realizes its purpose? Go buy the right net. Pinch your barbs. Get out of the boat if you can. Don't use divers and bait during the wild run. (Gut and gill hooked fish experience 68-80% mortality depending on which study you use) Keep the fish in the water at all times. Fight the fish quickly.
The wild ones are amazing creatures and should be released unharmed to spawn and provide future angling opportunities. It's our responsibility as stewards and primary users of the resource to make sure that happens. I know that some habits die hard and the processes we've used for years are often second nature. But taking additional care when releasing wild fish is just plain ole' common sense that doesn't compromise the experience, so why not try? We will all benefit from your effort as will the fish.