A couple of copy/pastes from a different forum, that I found useful:
1. ALWAYS, ALWAYS, ALWAYS bleed your fish! in the net, a rope over the side or in the cooler. to me the eggs are more valuable than the fish. you have to have top quality eggs if you want to catch more fish. blood on the eggs can cause them to turn bad quickly.wipe off the skeins with a paper towel, plain paper, no print on it. some ingredients in cures will react negatively with inks in paper towels and newspaper. after the blood is off and the skeins are cut into bait sized pieces let drain to get all the excess liquid off. NEVER WASH THE EGGS!!!!! after you have used your cure lay out to dry on a piece of old fiberglass screen set atop of pop cans or such to allow good air flow around to dry the eggs. proper care of eggs is most critical to consistently catch more fish. and do not let cured eggs come into contact with metal, most cures will react to the metal as well. good luck with the eggs blake, and remember, blood belongs in the boat, not the eggs!
2. to properly bleed fish, stab the fish with a knife right behind the gill plate and in front of the pectoral fin. the heart is on the right side, this will cut the main artery and allow the fish to bleed very thourghly.
as for the people who say it doesnt matter if you have bloody eggs or not, good eggs are the difference between catching a couple fish or catching a dozen fish, we have all seen it on the river. usually there is one guy who is outfishing everyone although it "appears" you are doing what he is... a lot of times its the bait.
never wash your eggs! if you notice when removing the eggs from the fish there is a thick liquid with the eggs. this is part of what makes the eggs milk and carry the scent of the eggs. why would anyone want to wash this off???
if you put a lot of time into your bait, it will pay off! as proof, last year i fished a small river for fall chinook thanksgiving morning. i walked about 1 mile of river bank and caught 4 chinook using my friends eggs and he caught 5. once back to the truck i grabbed my eggs and we headed back down to the river. we walked the same area and fished the same holes, he caught 9 and i caught 22... all but 2 were chinook! nothing changed but the bait. he now swears by my bait!
3. Theres a million online resources which emphasize the importance of bleeding fish immediately after landing them.
Commercial fishermen live by a standard that makes a huge difference in thier sales. It all boils down to quality of the flesh at market time.
Ive attempted to emphasize the importance of bleeding AND gutting fish here several times with different reactions both in agreement, and, the popular " I've never noticed a difference"
For those of you interested in finding out if theres a difference, take an interest in science for a minute. I'll put it in as close to laymans terms as possible.
Blood in a dead or dying fish goes through many changes chemicaly. Studies clearly show blood is comprised of protiens, oxygen, hydrogen etc and when a fish dies and this blood is left in the veins and arteries a chemical breakdown occurs and, to make a long story short. Protiens are attacked by enzymes and the resulting waste is ammonia as well as other undesirables. Enzymes are living organisms that need oxygen to stay alive. Once the oxygen in the blood is depleted these enzymes attack oxygen rich flesh and cause a further breakdown....its called death kids. enzymes die and create bacteria almost immediately. Bacteria is alive too.. The bottom line is, bleeding fish properly makes a HUGE difference in fish texture, flavor and SHELF LIFE!
How does this apply to salmon eggs?
Theres no doubt in my mind that eggs cured from properly bled and gutted fish will catch far more fish than eggs cured from an unbled fish. No doubt at all. I make this statement not because of experience on the water using eggs from a bled fish along side eggs from an unbled fish. I am sure of this due to knowing what happens chemicallyinside a fish that has not been properly bled and gutted.
If humans, with a fraction of the "smell" senses of a fish can sense a difference in odor, texture and taste of a salmon fillet that has not been bled and gutted and chilled properly...does anyone have any doubts a salmon, which smells in parts per million would also react negatively to improperly handled eggs presented as bait? Remember, salmon are assumed to use thier sense of small to travel thousands of miles returning to thier native waters to spawn and die. Think they cant smell a little bacteria or ammonia in your cured eggs?
Enzymes left to die in fish blood produce millions more bacteria than in bled fish... No question about it.
Bleed those fish immediately. Severing the artery at the tail is by far the best way to bleed a fish but its not easy.
Ripping the gills with your hands produces more surface damage and causes more effective hemoraging than a sharp knife or scissors. Bonk the fish to incapacitate it...not to kill it. Obviously you want the heart to continue beating.
Blood contains parasites that will also look for oxygen when the blood has been depleted of it. Get the blood out quiker and the microscopic parasites, protiens and powerful enzymes will go with it and make a HUGE difference in your table fare as well as you eggs used for bait.
Gutting a fish soon after it has bled makes a big difference too, though its not always practical or reasonable on the boat while you're fishing.
If you want to take the advice of commercial fish buyers who have studied all the techniques to obtian the "best quality fish" bleed them, gut them and find the main artery located at the base of the spine near the anal fin and remove the end of that artery which will always be full of blood. Put a running hose in the cavity for a while and youll never have to use a spoon again to clean the blood along the spine. The flesh and the eggs will be a perfect pink with no sign at all of blood.
Allowing fish to go into and come out of rigor is also very important when it comes to flavor and texture. Leave it in the fridge or on ice until it completely finishes the "stiff" cycle and is limp again. This doesnt always happen when a fish is filleted before rigor has started and ended. Ask any of the many people here Ive fished with, I have never once filleted a fish at a fish cleaning station after a successful day. Theres a good reason. Rigor can take up to 30 hours. Never bend or force "stiff" fish to straighten out. You'll regret it when it comes time to eat it. Freeze fish that is already COLD and youll never have a problem with freezer burn. Get it good and cold in the fridge on ice for a day and then freeze it. It DOES make a difference.
I guaranty, if you dont bleed your fish while its alive, and wait all day to gut it until you get back to the launch. your fish will spoil within three days left in the refrigerator.
Bleed it, gut it and ice it within 60 minutes and those fillets can sit in the fridge covered for 7 to 10 days before they start smelling even a little fishy.
Bleed them fish! You'll be glad you did. Better table fare and much better bait.