Harm Reduction Techniques in Catch and Release by Forrest A Young

Best practices around catch and release fishing have come a long way since the early days of our sport and most modern anglers have consciously adopted harm reduction techniques to mitigate angler impact. 

A recent example is the marketability and acceptance of the Keepemwet campaign. ‘Catch and release’ will forever be married to fly fishing, so it is wise to occasionally reevaluate our practices and continue to educate newer anglers.    

The practice of catch and release angling is usually but not exclusively practiced with a net and careful handling technique in order to remove the hook and let the fish swim away unharmed. 

While rubber nets have become the standard over coarse nylon, they may not be as harmless as we think. 

How do we know anything beyond the assertion that they work?

Moreover, is the fishing net the only thing that damages or are there other considerations to look at?  Landing nets in particular can be very damaging, but so can subsequent handling, length of fight, water conditions, the nature of the fish, and hooking depth, to name a few.

By my count, there are potentially five points of physical contact between angler and fish if we include photographing our catch. I have spent my entire career capturing fish used in zoos and aquarium displays, and I have seen the full impact of landing nets and other mishandlings.

So what happens after we land a fish with a net? 

We have only educated guesses backed by some scientific understanding.  It may surprise you to know that all nets will damage fish, but this is especially true of multi-strand nylon nets.

At minimum, the abrasive nylon causes significant abrasions, analogous to brush burns, which can become infected.  They also cause significant damage to the eyes, skin, and fins.  Some fish such as a largemouth bass, tarpon and bonefish are quite resistant to netting due to protective tough scales and a thick slime coat.

Other fish such as trout, steelhead, or a permit, have very small, thin scales, and few to no scales on the head. These fish are very sensitive to net impact.

In our own practice, those fish species that we capture by hook and line such as jacks, snappers, and other relatively small schooling fish, are never landed with a net.

After capture, we lift these species out of the water with the rod and remove the hook by grasping them firmly behind the head. In this manner, we can quickly and effectively handle sensitive fish that would otherwise be scarred or seriously injured by the landing net.

The fly angler can do this as well. Most fish have a softer spot right behind the head that you can hold to immobilize the fish while you take the hook out.

Conversely, certain fish species such as dolphin fish and tuna are so sensitive that merely touching them with your fingers is sure to cause large skin lesions. The septicemia that follows can kill the fish.

When we catch tuna and dolphin for a public aquarium, we never touch the fish. 

First, we use barbless hooks to catch them.  We then lift them into the boat with the rod and set them into the live well. Finally, we cut the line so the fish can swim freely in the live well.   The fish will then shake their heads and the hooks will fall out. 

When we get back to the dock, we use a heavy plastic bag to ‘net’ them out of the live well and put them into the aquarium treated with antibiotics to resolve any lingering contact issues from the plastic bags.

As a result, human hands or a net never, ever touches these sensitive fish species.

Fish skins can be that delicate and this handling technique is imperative if the fish is to survive captivity. Any fish that accidentally gets touched or dropPed onto the deck of the boat are either kept and eaten, or simply released back to sea. By releasing them it is our hope that the more sterile conditions of the open sea will heal the infections. Through many years of seeing this, I have become very cautious about the use of landing nets.

When I land a trout, I almost always beach them in water deep enough to cover their gills, grab them firmly behind the head, and remove the hook with my forceps. 

Alternatively, I simply remove the hook without ever touching the fish. Naturally, all my fish handling experience has trained me to use the proper amount of pressure to immobilize, but not damage the fish.  With practice, the careful fly angler can do this too.

I never net steelhead and salmon. 

Just like the smaller trout, I beach them in water deep enough to cover their gills and remove the hook with forceps. Beaching a big steelhead involves a little more play and increased risk of not getting a picture, but in my opinion that risk is well justified by a healthier released catch.

A tool that should be in the arsenal of every careful angler is a BogaGrip.  This is an ideal tool to immobilize a caught fish in order to remove the hook or to take pictures.  I highly recommend having one.

There are certain situations where using a net is essential, such as fishing from a boat. I understand and recognize that. Trying to handle the fish boat-side without netting is impractical at best. I would encourage you in this scenario to obtain a rubber net or the above-mentioned BogaGrip.

The one drawback to rubber nets is their strength when trying to land a 15- or 20-pound steelhead, snook, barracuda, or other game fish.  In these cases, the use of a heavy-duty multi-strand nylon net is really the only alternative.

What can you do to minimize the negative aspects of this type of net?  Work quickly and get the fish unhooked and back in the water.  Landing can take place while the fish is still in the water, but it is more difficult, and you are likely to get wet. 

Netting and releasing practices are just two variables that will determine a fish’s survival rate.  For instance, fighting a fish greatly reduces its energy budget.  When we release fish back to the river or sea, it simply does not have the energy reserves it had prior to us catching it. This is even truer if the fish is caught in warm water or fought for extended periods.  Anadromous species like salmon and steelhead become especially vulnerable to predators and other barriers during their spawning run. It is a wonder so many fish survive being caught, but we know from studies that they do.      

A few other factors can determine a fish’s survival rate. 

Severe bleeding from the gills and hook sets deep in the gut are a death sentence.  Any fish with severe bleeding-out of the gills is not going to survive. I have never seen a fish bleeding from the gills survive in captivity for any reasonable length of time.  

A minor bleed is potentially survivable if the remaining handling is careful, but if you plan to take any fish, it is a good idea to take those few that have bled from the gills. 

Gut hooks also have little chance for survival. 

Attempting to pullout a deeply hooked fish - unless you expertly use a custom de-hooking device – is futile.  This fish is best taken for the table if it is of legal size and an edible species.

Alternatively, you can cut the line close to the mouth of the fish and hope it recovers. We have fish with deeply set hooks survive for long periods in the aquarium. We have also seen fish hooked in the gills manage to expel those hooks after a short period in captivity. I have reached a reasonable conclusion that the same fish would survive in the wild.

Please consider the impact that we have upon the fish that we love to catch.  All human activity impacts nature, but the impact we have can be minimized by proper handling and resource management practices.

- written by Forrest A Young