Last time I looked the photos in the regs are no way clear enough for a beginner to ID fish at all stages of the migration/spawning cycle.
It is up to individuals to educate themselves regarding fish identification. If you want to fish responsibly the onus is on YOU to figure it out. If you can't identify one species from the next it's simple, you should not be fishing for them.
There are plenty of pictures available online to help beginners sort it out.
Don't be too hard on frozensalmon, he is obviously a beginner and needs guidance, not ridicule. Not one person has said what in those pictures would differentiate a coho from a pink. So frozensalmon, some things that would help you identify them as coho as compared to a pink would be:
shape of the tail... these fish have a very squared off tail, whereas a pink salmon has a "V" shape.
shape of the tail 2.... these fish have THICK caudal area (where the tail joins the body). A pink salmon is noticealby thinner in this area.
spotting.... difficult to tell from these pictures as you can't see the tails... but pinks have "weak" oval spotting, where coho have dark spotting on their backs that extends to the upper portion of their tail (but not lower).
SCALE SIZE.... this is an easy one. You can see, even from these photos, that the scales are quite large. A pink salmon has very small scales, making them far less pronounced.
The "hook" on the nose... also a giveaway. The males get a real "gonzo" nose to them.
Body shape and head shape are markedly different too, this is something you will be able to recognize once you've seen more of them.
hope that helps.