what do you know about trout movements? [Archive] - Fly Fishing Forum

: what do you know about trout movements?

03-05-2004, 12:06 PM
I am wondering if I can get a handle on trout movements and population delineation by gathering your collective knowledge as observant fly fishers.

Do you think that trout in streams and rivers are more migratory than trout in lakes? What sort of reasoning and/or observations make you think it may or may not be true. I am wondering what would be the effect on trout populations if say a management measure was brought in to make all moving waters (streams, rivers) catch and release fly fishing only while allowing multiple gear type catch and kill in some or even most lakes. That would be a management measure over a very large area, e.g. an entire state or a large area well defined by geographical features. Would this make fishing better in both moving waters and lakes? If the trout in streams tend to have a more migratory behaviour then could they be important as seed stock for areas where populations are depleted like the lakes where catch and kill is occuring? I am speculating that making streams catch and release fly fishing only, would protect an important component of populations that are more migratory and do help seed other populations. Also, because trout in streams tend to be more confined they are often more vulnerable to having a larger proportion of their populations removed by fishing than are trout in lakes suggesting that they need greater protection regardless.

Does anyone know of a fisheries management plan that uses this sort of reasoning?

Putting aside the problems of implementation at the moment, I am interested if just the basic assumption of migration and separate sub-population holds for stream fish.


03-05-2004, 12:22 PM
This is probably an over simplistic answer, based upon 'my .02 cents only.'

My guess is (leaving spawning out this) fish in moving water have their food 'coming to them.' Find a nice 'lane' and settle in; the bigger fish get the best lanes, etc.

Still water the fish have to 'hunt' for their food, ergo the major reason for movement (leaving water temp preferences out of this).


John Desjardins
03-05-2004, 01:13 PM
From what little I've seen on the topic of trout migration it is worthy of multiple doctoral theses.

I could swear that in the past couple of weeks I saw an article or news release on a comparison of steelhead that stayed as residents of a stream vs going to sea on several west coast rivers. From memory it showed that no 2 rivers acted alike.

Sorry I haven't been more help.

Dble Haul
03-05-2004, 01:27 PM
The problem with generalities....

It has been well documented that many trout hold in their protective lies during off feeding hours and then travel as much as a few miles to occupy their low light feeding lanes. So we can't make an assumption that trout in moving waters are more static; they may be at particular times of day, but overall they might travel just as much or more so than their stillwater counterparts.

Trout in still water may move to hunt their food, but they still tend to relate to structure as they do so. If the structure is a weedbed that's only 100 feet long and a trout makes a dozen passes along it during its hunt, then it doesn't even come close to the travels of the aforementioned river fish who might travel a few miles for the same thing. So in many cases, stillwater trout that relate to structure, thermoclines, etc. may be more static on average then trout in moving water.

There are no hard and fast rules with this, and that's where the troubles begin when trying to manage a situation based on fish behavior. There is no catch all. I wish I could remember the source of the data for the river trout daily migration patterns, but it escapes me.

Good luck with your search.