when i think selective desaturation I think of the little girl in the pink dress in schindler's list. See there the color was extremely meaning full and was used to draw in your attention. This is not doing that for me.
Keep in mind why Spielberg decided to selective color (desaturate, whatever you want to call it) the girl in the movie. In all reality, it was so we would remember her later. When you see the colored coat on the cart being hauled away later, you remember the little girl, so full of life, just minutes earlier.
If you're going to use SC, think about what it does to the image. Coloring (in a BW backdrop) will draw your attention. You will ignore almost everything else in the frame in the immediate. So to do it well, you need to have a reason to want your viewer to ignore most of your photo and focus only on what's colored. My critique here, then, will be some questions. These are mostly rhetorical as I'd like you to think about them.
1. What are you trying to convey by drawing my attention to a chunk of lead hanging from a fishing hook?
2. If your viewer weren't a fisherman (and I personally happen to be one), would they be able to figure out what's in the image? (It is fairly abstract, even if I do know what I'm looking at)
3. Why put the weight hanging from the hook, as this isn't how one would normally set up fishing gear? Is it for compositions sake? Would there be a way to set up the shot that would use a more realistic setup? (I'm not saying it's wrong, so don't misunderstand, but as a fisherman, I wonder why a weight is hanging from the hook)
This is just a start. think about things like this while you're shooting