Catch and release: a users guide

Graz
Graz

Graz and I wrote a little thing for the paper on this not long ago. However, given we’ve got a blog, I’ve decided to go into a few things in a little more detail.

In Australia catch and release fishing has been growing in popularity over the decades. Anglers all over the country are realising the importance of healthy fish stocks. This change in attitude has probably been most drastic amongst keen native anglers, chasing Murray cod, bass, barramundi and the like. Many more anglers are realising that these amazing fish are simply too good to catch just once. This heightened awareness of conservation among anglers and a concerted effort to build fishways and re-snag rivers to improve habitat as well as stocking programs mean that hopefully Australia’s native freshwater fish should have a bright and positive future. It speaks volumes to how far we have come as a community that nowadays, killing a meter long barra or murray cod is more likely to bring cries of shame rather than pats on the back and congratulations.

Its great that catch and release fishing has grown in popularity and our native fish are finally getting the respect they deserve.  But from time to time everybody needs a refresher (myself included) on the best ways for you to ensure the post release survival of what you catch. While fish might swim off looking OK most of the time, depending on how fish are handled and where they were hooked mortality can eventually be quite high in some instances. Most fish won’t die immediately and thats something we need to remember as catch and release anglers, just because a fish swims off, doesn’t mean it is going to live a long and happy life forever after. We also need to take into account potential indirect mortality from sub lethal stress, such as potential increased predation or increased susceptibility to infection.

Hooks:

The science on barbless hooks generally points to them causing far less damage. How much better they are for the fish than barbed hooks depends a little on species. For some species there is strong evidence that using barbless hooks dramatically increases survival of released fish, while for other species, there doesn’t appear to be any effect on survival. For example, survival rates are greater in barramumdi and Australian bass caught using barbless hooks, on the flip side there is little or no effect on survival for dusky flathead. The rationale for going barbless is twofold. Firstly, they do less damage to the fish. Secondly and of primary importance is they can make handling the fish once you catch it far faster and easier. This is especially true when using treble hooks, which at times can be tricky to remove. Going barbless reduces the chances of complicated de-hooking procedures, meaning you can de-hook and release your fish faster. That in my mind is the primary benefit of barbless hooks when lure fishing for catch and release. It reduces the time you need to handle your fish meaning you can get it back in the water faster. So while the benefits vary from species to species (from large increases in survival to negligible or no increases in some species), as a general going barbless will increase the survival of the fish you release. They are also safer for anglers, which is a nice added bonus. Graz wrote a piece here which also suggests barbless hooks might turn more bites into hookups.

Similarly, if you do want to use barbs, consider moving to single hooks over trebles. Single hooks again are likely to do less damage and are easier to remove than trebles, whether they are barbed or not. For example, in this study on Tailor, the use of single hooks increased survival of the fish post release. If you are chasing aerobatic species that often throw hooks, single barbed hooks give you the extra insurance of a barb while also doing less damage and being easier to remove than treble hooks.

For bait fishermen, deep hooking is one of the primary concerns. Deep hooking is greatly reduced by the use of circle hooks. The use of larger hooks can also be effective. Lastly, if fish are deep hooked survival of fish is increased by simply cutting the line rather than trying to remove the hook, which does far more damage.

Fight time:

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As a rule the shorter the fight the better. Longer fight times are associated with more physiological stress, a build up of lactic acid and increased mortality in some species. This means choosing tackle that is appropriate to the fish you are targeting. Don’t go chasing Murray cod on 2lb for example, even if you are lucky enough to land one, that fish will probably been fought to death by the time you get a glimpse of it. Now this is likely to be a little controversial, but I think it illustrates the complexity of catch and release rather eloquently so here goes. I would argue that in some specific instances, there may be some benefit in slightly prolonging fight times. For example, sometimes, when catching Kingies, you’ll have little fish eat a few meters from the boat and it is possible to have the fish at the boat within 2-3 seconds. In these cases, the fish are HARD to handle and make the process of releasing them far more difficult than it usually is. In these circumstances, I usually don’t try and land the fish straight away, but let them have one run first before getting them to the boat. This makes an in water release far far easier. The issue here is that very green fish, can be very hard to handle and that can potentially increase handling time and the likelihood of injury during handling. Now I am only talking about prolonging fights by small amounts of time  and I bring it up mainly to illustrate that what we want to achieve as catch and release fishermen is limited harm and stress over the whole process from fighting, to release. There are potentially cases, where the the best practices in one area, might make best practice in another area harder. So while the over-riding point of reducing fight times is completely solid and backed up by lots of science, there are times where it may be a little more complex than that. So use a little common sense, don’t fight fish to exhaustion, but try to take into account that landing a fish that is too “green” may increase the chances of injury to the fish.

Nets: 

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Nets are a great way to get control over fish once the fight is over. They allow you to keep the fish in the water while de-hooking and are generally a very useful tool to facilitate efficient catch and release. Unfortunately some nets e.g. the old knotted string nets, can cause damage to the fish, by dislodging scales and the protective slime that covers the fish. This can increase mortality, stress and susceptibility to infection. The best nets to use are ones that are going to cause the least amount of damage, e.g. environets, closed plastic or rubber nets.

Handling:

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As has been eluded to in the proceeding sections, some of the considerations on what hooks to use and fight time often come back to one thing. Reducing handling time. I have already written about the effects of air exposure on fish and the potential negative effects on survival here. Needless to say, the less you handle the fish you catch the greater chance they will survive to be caught again. When handling fish there are a few things to consider.

*Always wet your hands before handling fish- like nets, hands can also damage the protective slime on the fish.

*If you have to put your fish down on, don’t put it down on hard or hot surfaces (rocks, boat bottoms, sand etc etc). Used a wet towel, wet brag mat or similar. The slime on fish that protects it from infection is easily damaged, so always take care when putting your fish down onto any surface.

*reduce the time your fish spends out of the water. As discussed in the link above, there is increasing evidence of the negative effects of air exposure on survival of released fish. Try to limit time out of the water to under a minute. The less time out of the water the better.

*If possible de-hook and release your fish in the water, avoiding air exposure entirely.

*when handling fish, try to avoid holding the fish vertically or worse horizontally from the jaw without supporting the fishes weight. The horizontal one handed jaw hold, popularised by the US bass scene and has recently become more popular on our own native Aussie bass. The photos might looks cool, but it is bad for fish. Avoid it. For any fish over a few pounds, holding the fish vertically by the jaw without support can do damage to the bones and ligaments in the jaw, which in the worst case scenarios can lead to a long slow death from starvation. Many fish rely on the complex architecture of their jaws to feed efficiently (e.g. barramundi). ALWAYS support the weight of the fish when its out of the water, this is especially important for any fish of more than a few pounds.

*avoid lip grips where possible. I’ve written about lip grips in more detail in a previous post. They may be useful in some instances, but they can also do significant damage to some fish species. Where possible for fish like cod, bass, barramundi etc, a lip hold with a gloved hand is going to be safer for the fish. In some cases using lip grips may be justified (e.g toothy fish that are hard to handle and release quickly), but avoid using them if you can. If you do use them NEVER use them to lift fish out of the water or hold the fish without first supporting the weight of the fish with your other hand. While some lip grips have scales, DON’T use them unless you have attached them to a net and not the fishes jaw. It will potentially injure the fish and reduce its chances of survival post release.

Release:

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Lastly, fish handling doesn’t end when the fish gets back in the water. Don’t just chuck your fish back in and think that’s the end of it. While spearing (not chucking) your fish back into the water is OK when releasing small tuna and other pelagics, for most fish, its important to return them to the water gently and then allow them time to regain equilibrium. Fish released without regaining equilibrium have increased mortality and increased stress post release. Hold the fish upright in the water by the jaw or tail and wait for the fish to regain strength and equilibrium and kick off on its own accord. For most species, trying to force water through the gills by pulling the fish froward in the water has the potential to do more harm than good. The filaments in the gills are delicate and can be damaged doing this. Its best to just hold the fish there and let the fish regulate the amount of water going over its gills and let it recover in its own time.

Of course there is a more too it and I’m sure I’ve forgotten a few things (for example barotrauma, discussed in the NSW dpi catch and release handbook). This is simply a very broad guide. There will be species specific techniques and issues that I simply don’t have space to cover (this post is long enough as it is). In short, use your common sense and always try to have the fishes welfare in mind when handling fish. Catch and release is great, but its important as catch and release anglers we try and practice ethical catch and release as often as possible, that means handling fish well and doing what is best for the fish, not just what is best for the instagram or facebook accounts.

While this may seem a little preachy, its not meant to be, I am in no way perfect. I still make mistakes when catching/handling fish and don’t always practice best practice (over my 30 year long fishing career I’ve probably committed most of the “sins” listed above at one time or another). I think the main thing is trying to do the right thing as often as possible and that as anglers we continue to learn and update our catch an release practices over time. The science on many of the issues above is also always moving forward and there is every chance “best practice” will change as more data comes in and some of the things discussed with be superseded/change in the future. In some areas the science isn’t settled and best practice is up for debate.

Let us know your thoughts about catch and release practices and anything I’ve missed in the comments.

Good luck on the water and happy fishing 🙂

Cheers

Hamish

flickandflyjournal.com

Hamish Webb, Dan Firth, Graham Fifield and Lee Georgeson have been fishing the south-east Australian region since 1987. Since then they’ve become avid sportfishermen who are constantly looking for new ways to challenge themselves. They are all scientists and conservationists who are passionate about the long-term sustainability of the ecosystem in which they live. They promote understanding and appreciation of the complex socio-political, economic and environmental issues surrounding fish, fishing and fisheries, while never losing sight of the various motivations that keep them coming back. In English, that means they love all things fishing and have a damn good time on the water, and that’s all that really counts in the end!

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