A roe sac, roe bag, is a piece of roe or cluster of salmon eggs tied together in a mesh. This is used for salmon, steelhead, trout and white sturgeon fishing in British Columbia.
Roe can be used without being tied in a sac but they can fall off after awhile. A roe sac keeps your bait together even after many casts or being pecked by small fish in the water.
The size of the roe sac depends on your target species. When targeting trout, a couple of eggs in a sac is sufficient enough. For salmon and steelhead, a sac that is the size of a penny maybe needed. When fishing for white sturgeon in the Fraser River, much larger chunk of roe tied into a sac is necessary.
The mesh material used for a roe sac can be purchased from your local tackle store. Old nylon stocking is also a good alternative for the mesh material. Thin, stretchy elastic lines are used to tie the sac.
Before using roe sacs, you should be sure that they are allowed. Roe sacs are prohibited in fisheries that have a bait ban in effect.