Here are my "selective techniques" for June chinook. This is how I (an knowledgeable angler in a variety of techniques) do it. I am not saying it is the best technique, the right technique or the only technique, but it works for me. This maximizes chinook catches and too date has not caught me 1 early sockeye (over the past 15 years):
1. bottom bouncing with leader lenghs as short as 6 feet and as long as 20 feet
2. select a gravel bar where current is relatively fast
3. fish at the top of the bar; that is where current is fast and chinook hang out; socks like the bottom of the bar
4. cast as far out as possible- that is were the chinook travel; sockeye travel close to shore; this involves heavy weight- at least 4 oz
5. anchor your boat in about 6 feet of water; this increases my casting distance; you will need a heavy anchor in June to stay still
6. cast to a position of 11 o clock and let drift to about 2 o clock; all my chinook are caught in this zone; most socks are caught close to shore; performing this technique will also reduce snagging the bottom and losing leaders this technique is important
7. heavy action rod with 60 lb mainline and 30 lb leader; allows me to bring whatever is on my line in quickly
8. play the fish heavy; helps keep the fish on the line with barbless hooks; if you hook a sock, the hook should pull out as they have extremely soft mouths; when socks are open I will play them very lite to maximize landing ratios
9. Use a larger coacky and at least 5 pieces of yarn; socks don't like large profile lures
10. When your weight hits the water, ensure you reel at least 10 times; this mends out your leader for your short drift = 11 o clock to 2 o clock; this is another important point
These are some other selective techniques which I have not yet used, but will work:
A) if I know socks are in the area or see any being hooked, I would select a different bar; this creates problems for those who do not own a boat; if you have a boat there are many "chinook bars"
B) if I catch a sock, quickly reef it in and release it; I would hope pulling hard would cause the hook to pull out
C) I have a releasing tool which I use on Skeena chinook and socks in August; it is a gaff which has been cut and bent; it allows me to quickly release the fish without touching it
D) shorten my leader if I catch a sock
Hopes this helps some of you. Others will be opposed, but each of us have there own views.