FISH TRAPS

A net is still, by far, the most effective method of catching fish and almost any animal; but nets require cordage-a lot of cordage.

Implementing a fish trap can also be a very effective strategy, in your quest to obtain animal food; after a disaster, and when you are in a real short term survival situation. However, many of us, for some unknown reason; perhaps to demonstrate our, cunning, intelligence, and superiority over other animals; attempt to build them in a far too complicated way.
For many, very good, reasons (not the least of which is conservation); in the every day world, under ordinary conditions, fish corrals, pens, and container traps are illegal; they are to be built ONLY under emergency conditions and MUST be dismantled, on your departure from the area.
But you are not in the military, or on some TV reality series--so you already know this--
you do--don't you--don't you? How could you not, afterall, you are a "survivor, and besides, you just read it is so?
The basket type fish trap is very effective, especially when used in a narrow, shallow brook, with an under-cut bank. Aboriginal Canadians (before they became extinct) and early European pioneers, did use them fairly often,(well soaked or steamed willow strips can be  and usually were, used in both the forming of the hoops, and to lash the ribs to them.), because, quite honestly, they just did not have cordage of the type, or amount, necessary to fashion a gill net. Crab and lobster traps were fashioned out of wood, for the same reason. 
You can construct one by lashing several willow, or other, long, narrow, sticks together into a funnel shape. Use fibre cordage, provided of course, that you have enough, readily available, but if such is the case; you would be better to fashion a gill net.You close the top and bottom of the trap; leaving a hole at the top of the trap large enough for the fish to swim in, but not out.

While the illustration does serve to show narrowing of the water channel in order to "guide fish into it--not really necessary, if, you follow my instructions below; the trap, shown in the middle illustration above, is much too complicated and labour intensive in the building to be at ALL practical otherwise.
Instead of driving piles or posts into the stream bed--which in Canada's Arctic will likely be coarse gravel, solid rock, or permafrost; and you are not likely to have a power pile-driver handy--Why would you want to anyway-and scare all fish and game from anywhere close to where YOU are? It would, obviously, be much better, easier, practical to built more like a beaver dam, (smart critters them beaver, maybe that is why they have SURVIVED for so long) out of branches, any available debris, logs, tundra, and even mud. The bottom illustration gives the idea. It is not necessary for you to stop water flow or to flood an area. Instead build this type of  trap in an area where the water forms a natural eddy or pool. Place the opening so that natural fish foods will be swept in to the trap. This will of course also bring the fish. The water will flow through or over this type of trap--the fish will not.© Al (Alex-Alexander) D Girvan. All rights reserved.