Everyone has a part to play

Catch and release, off course we do it! Do a google search on catch and release and you will find literary  thousands of people writing about it and a lot more people swearing by it. It seems most people these days understand the value of release all or some of your catch to maintain a good population of fish in the waters we fish. But do we understand the echo system that we help preserve?

Just one thing though, this is not another one of those articles that are to discuss the ethics on Catch and release, or “Limit your kill” or “Limit your catch” or “Take only what you can eat” or any other concept that seems to have emerged in the on going debate on Catch and release. No this is more to understand that every fish in every echo system is valuable, every fish count.

This past summer I saw a couple of very terrifying examples of how people still are surprisingly narrow minded in their thoughts. People who would gladly confess to killing every Pike they catch in their trout waters because they “steal the trot”. Now, I can comprehend that some people like to fish for certain species of fish, I really can. But I think that people need to be more enlighten on the how the different species function in an ecosystem.

As long as we are not talking about an intrusive species that are put there unnatural (like for example certain types of crayfish has been) either by human or in any other way then every fish in a water has its role to play in the echo system. So if there are a sudden increase or decrease of any species or any particular size of one species too that will have effect on the echo system and the water in which the live.

Clearly there are people who gives it their best to exterminate for example pike from trout waters because they want more trout there.

Narrow minded? Well, yes.

But, let’s play with the thought that they would succeed with it, that all the pike from their precious trout water was caught and killed on shore.

What would happen with the echo system in that water? At worst? First there will be more mid size and large trout, since those are the normal target for pikes. And as soon as there are more big trouts there are gonna be many more predatory fish; hunting and eating smaller fish instead of insects. One of their basic food source would of course be small trout and trout fry along with small bottom dwelling fish like Sculpin. Now one the main sources of food for trout fry and other fry is different plankton. Now there are different typed of plankton, one of the most common is Phytoplankton which if they get to occur in to large numbers can cause murky waters and in worst case algal blooms and in the end can drain an entire water from livehood and oxygen. This is worst case of course, but if you were to kill all pike and there would be an abnormal growth of large and mid size trouts which would devour too much of fry and small fish then it is a fact that the Phytoplankton will increase and the risk of major effects on your water will occur! We often think of over-fertilization as the only source of this but disturbances in the echo system can have just as big effects.

Another worst case scenario would of course be that since there are so many larger trout around there will be VERY hard for fry to survive to become large enough to no longer be food source for the bigger fish. Eventually, this could lead to that the population will diminish to only a few fish and in the end, no trout at all in the water?

You want more examples? Are you a fact of tests geek like me? Okay, here you go with a really good example from my home waters The Baltic sea that again shows how important fish of all sizes are in the echo system (*
Scientists at the Swedish board of fishery couldn’t really understand why there was such big amount of algal bloom in areas that was not affected by over-fertilization as much as other areas. They eventually conducted a field experiment together with scientists at Stockholm university outside the island of Askö here in Sweden.

Bigger sections of the bottom were sealed off so that bigger fishes couldn’t enter while other equally big sections was only roped up for reference. The study clearly showed that the sections that the bigger fish was not entering grew MUCH more alga much quicker. The reason for this is that the main eaters of alga is shrimps and small snails. Now in the sections where the big fish was closed out the small fish ate the shrimps and snails to such extend that they no longer fed on the alga in the way that was needed to keep it in place. In a normal echo system there is a healthy distribution of fish in all sizes.

The responsible scientist Alfred Sandström says:

“- You cannot forget the fish when you are managing an echo system, because it is all connected. Without good management of the fish the problem with over-fertilization can get much worse.”

Now mother nature has taken a serious beating over the last hundred years or so, we humans have really put her to a real strain and there are a lot of waters like my own precious Baltic sea who are in real bad shape today. A lot of lakes suffer from sourness and other environmental issues. But hey, she is a tough chick, she has ways of recovering if only we can change our way of treating her. What she don’t need is us doing stupid things just because we want to “have more” of our favorite species.

As you fish a water you become part of that waters echo system, think about that.

(* the entire article on this study are to be found here, but sorry only in Swedish: https://sottosalt.fiskeriverket.se/artiklar/nystudievisarpafiskarsbetydelseformangdenalger.5.28d9b61d126d6846f2980009990.html

About Ulf Hagström

Fly fishing, fly tying, family and going your own way; the way of the fly. View all posts by Ulf Hagström

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