You would have to read the fishing regulations. Hook and line are OK but using salmon eggs may not be allowed in some drainages. There is a good website - California fish and game.

Why not use flies instead of fish eggs? You could put a little bobber on the line (to help throw it out) and a fly on the end.

I doubt you would catch many fish this way. But, if you find the right location, it may work. Although the fish may seem not to be skittish, they may be quite fussy when a line is thrown in.

By the way, I fly fish, and ALL my fishing gear, rod, reel, knife, case, etc, only weighs 11 oz. I can then almost guarantee I can catch fish. My rod is old- there are lighter ones available now. I use a piece of foam pipe insulation for a case. I do not take a net. I only have the minimum length of line - no need for any more than I am able to cast (which is not that far LOL). A Tenkara system also weighs very little. In my opinion, if I pay the price of the fishing license, I want to be sure I can catch fish. I fish enough to cut food weight back enough ounces to make up for the weight of the fishing gear.