Leeches on Trout

 Have you ever caught trout with leeches on them? It doesn't seem to be a common occurrence for one reason or another, and one wouldn't expect it to be frankly. Most environments salmonidae occupy aren't particularly leech filled, nor do trout and salmon make themselves easy targets for mud and leaf-litter dwelling leeches even when they do exist in the same water in large numbers. I can remember one brook trout, caught in a far eastern Maine beaver pond, that had a couple leeches at the base of its ventral fin. The beaver pond factor made that less than shocking. In fact, when I was done fishing there I picked a few leeches off my legs, and later at the hotel more still that had made it into my boots and through my socks. Leeches are perhaps more expected in beaver ponds than even brook trout, so the two in tandem isn't exactly a shock. But I'd never caught a trout in CT with a leech on it. That is, until a few weeks ago. 

I've been paying semi-regular visits to a classic small CT brown trout stream that I know has the potential to kick out some high quality fish. It's a tricky stream to negotiate, at least the stretch I've come to prefer. Tangles of felled trees make fantastic and necessary habitat. They're also great at keeping anglers out of a lot of water, doubly excellent. I love crawling under, climbing over and clambering through fallen trees and thick brush to explore streams. It destroys waders and other clothes and does a little damage to the skin sometimes too, but I feel it's worthwhile. After negotiating my way through the maze one morning in mid January, I worked the water for a little while before a brown took my streamer. When I got it to hand, I could see that it had some small leeches on its tail and ventral fin. This was the first of three trout I'd catch that day that had leeches on them. One other fish didn't have any. Given the notable absence of leeches on trout anywhere else I'd fished in CT, I found that noteworthy. 

So what does it mean? Well, I don't know. It likely speaks to the nutrient levels of the stream, and certainly to the substrate. A lot of the stream bed there is fine sediments and mud, goods habitat for some leech species. Whether the leeches are having any notable impact on the trout themselves, I'm not sure. The easy leap is that parasite=bad; but that isn't completely accurate. The trout these leeches were on were no worse for wear. If there are more leeches in this stream than is typical they may in fact make up a substantial portion of their diet. But really, I'm not sure. All I can say is I don't generally find leeches on trout so to see so many on a high percentage of the fish I caught in one day seemed interesting. What do you think?

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