There is probably no more divisive thing in the fishing world than how anglers handle their catch and what they decide to keep. I have seen message board and social media posts burst into flames as the shamers and shamees go at it with one another. This post will explore some of the science behind catch and release (C&R) angling, fish harvest, and how fish populations and size structure can be affected by angling. This is in no way meant to be comprehensive review of the science behind C&R fishing. I'm saving that for later.
My quick thoughts, which I'll expand upon below, are:
Catch and release angling is very effective and under the right conditions mortality is generally quite low. There are simple things that can be done to increase the already high odds that a fish lives to swim another day.
We owe it to our catch to handle them properly, whether we are keeping or releasing them.
Keeping fish is a personal choice and we shouldn't shame people for doing it. Nor should those that want to keep fish troll social media by posting piles of dead fish all over the place.
Keeping fish has an affect on fish population dynamics, in particular size structure.
Catch and Release Angling is Effective (and more so when fish are handled with care)
First, as someone that has handled hundreds of thousands of fishes in my life; they are tougher than we give them credit for but handling absolutely does matter. Factors that have shown some effect on trout survival rates are how long the fish was out of the water, water temperature, how and where the fish was hooked, and angling / fish handling experience.
Mortality rates for trout are generally quite low. Estimates for fly caught fishes are as low as a few tenths of a percent in some C&R studies and range to 5-10% in studies showing higher mortality rates, generally in caged studies or when testing poor conditions. Mortality of bait caught fish are generally an order to several orders of magnitude higher, up to 25% is a reasonable estimate. Of course, mortality of kept fishes is 100%...
Some simple guidelines for reducing C&R mortality are:
Keep the fish and your hands wet as much as possible. Air exposure is one of the leading causes of C&R mortality. "Need" to get a photograph? Be prepared to take a quick photograph. Keep the fish near the water so if it does fall, no damage is done to the fish.
Probably the single biggest thing that can be done to reduce C&R mortality are to take stream temperatures when streams are likely to be warm (>65F). Fishing is likely to be crap anyway - move upstream or fish for warmwater species.
Support your catch. Letting fish hang vertically is really not good for them nor is the "bass here" hinged jaw pose. This is particularly problematic for long fishes like Muskellunge and Northern Pike.
Play the fish as quickly as is reasonable. I am always amazed to see videos of musky anglers landing their fish in a few seconds. Using a net helps with not overplaying them. The less that they are consuming a lot of oxygen and creating lactic acid in their muscles, the quicker they'll be able to recover.
If possible, keep them wet. It is pretty easy to release fish without even having to touch them. For more information, visit: https://www.keepfishwet.org/
I'll do a more detailed scientific inquiry into C&R mortality rates over the winter.
Handling Your Catch with Respect
The section above goes into C&R fish handling, in this section, I want to talk a bit about how to handle those fish you are keeping.
I have to admit I cringe a bit when I see fish that are being kept that are handled poorly. For me, keeping fish for dinner is a rarity but I do keep a few every year (and probably should keep more in some of the streams I fish - yet another new post...) and want those to be as high of quality as they can be. If I plan to keep fish, having ice available is a necessity and I am going to try to get that fish on ice as quickly as I can to preserve its quality.
You wouldn't buy a fish at the grocery store if you knew it was carried around in the sun for a few hours, would you? I want the fishes I consume to be a delicacy so I'll put in the effort to handle them with respect after I dispatch of them. Which leads me to a second point - kill your fish humanely after deciding to keep them with a knock or two to the head. It's a lot more humane and it preserves the fish better than allowing them to die a slow, suffocating death. I do not carry a priest around (no, not that kind, this kind of priest) so a rock or the butt of a rod works just fine.
No Shaming / No Trolling
The internet often brings out the worst in people. I mean, not in any of you, but in everyone else...The C&R police versus the trolls looking to get rises out of the C&R police is an internet mainstay. And it is not new but social media (Facebook, Twitter, and Instagram) have made it a whole lot easier - and much more annoying. It's the nature of the beast, I suppose.
People are funny and the internet makes intent difficult to decipher. Yes, there are anglers that appreciate (unrequested) advice about how to handle fish. Some anglers lack the experience or knowledge of how to properly handle fish. However more often than not, they generally are not asking for your advice and too often that advice is given in a manner that is judgmental and not likely to be received well. The only thing worse than the C&R police might be the guys (it is ALWAY guys) that are trolling for the C&R police.
So what to do? I honestly do not really know. I don't comment despite the fact, at times, I'd like to. I hate seeing fish treated poorly and it can so easily be avoided. I wish more social media fishing pages had criteria for posting fish pictures and guidelines for C&R that were clearly stated and pinned to the top once in a while. I think this would do a lot to make people think about what they're posting and why. If the shamers stopped shaming the trolls would get bored and crawl back under their bridges. A guy can dream, right.
Size Structure and Keeping Fish
This deserves a lot more attention than it is going to get here. Angling CAN have an impact on fish populations and some fishes are much more susceptible to overharvest than others. Even in areas as large as our oceans, overfishing is an important ecological and sociological problem. If we can overfish some species, particularly the larger and longer lived ones, in the ocean, we can certainly see that in lakes, ponds, and streams. That said, in my corner of the world, Wisconsin's Driftless Area, I would suggest that streams would benefit from some increased level of intelligent harvest.
What do I mean my intelligent harvest? First, the smaller fishes are more numerous and more "expendable". To me - and this is personal choice - I prefer to keep trout less than 13 inches or so in our Driftless Area streams. If we want there to be 18 inch browns, we need there to be 15 inch browns first. Second, these decisions are complex and it depends upon where you are. I remember eating a 22 inch Brown Trout cooked over a campfire that was absolutely delicious. It came from a northern Wisconsin spring pond where native Brook Trout are "supposed" to be the only trout species there. He didn't feel bad keeping the fish nor did we mind helping him eat the brookie killer.
Sources used to support this blog post: