Din Posted October 25, 2007 Share Posted October 25, 2007 This is prolly a dumb question.....but here goes... Why is it that when salmon head up rivers to spawn they die, whereas steelhead don't (maybe they do, I really have no idea)? Been contemplating this while trying to learn accting...shows how productive that is going. please shed some light for me so i can study!!! Quote Link to comment Share on other sites More sharing options...
SteveM Posted October 25, 2007 Share Posted October 25, 2007 This is prolly a dumb question.....but here goes... Why is it that when salmon head up rivers to spawn they die, whereas steelhead don't (maybe they do, I really have no idea)? Been contemplating this while trying to learn accting...shows how productive that is going. please shed some light for me so i can study!!! It's simple, really. This is how the Creator of the universe decided it should be, so this is how it is. His ways are mysterious to us mere mortals; we are not meant to comprehend all. Just kidding! Seriously, though...not sure why it happens, but I've seen documentaries that show what a huge impact all the dead salmon have on the ecosystem- ginormous benefits. BTW, not all salmon die after spawning- Atlantic Salmon live to do the mating thing more than once. Quote Link to comment Share on other sites More sharing options...
admin Posted October 25, 2007 Share Posted October 25, 2007 Also note that the Atlantics don't always die and that they may spawn several times over their life. A lot of the salmon I have seen spend a lot of energy to get to the right spawning grounds. So much that they are pretty much dead by the time they get there. It's hard work swimming upstream in 4 inches of water. In rainbows (steelhead) they need to spawn and release their eggs / sperm or they can get eggbound. I've been told that this shorten's their life if they can't release. Part of the reason that some lakes in BC have installed spawning channels is to help the fish live longer / grow larger. Perhaps a biologist can better explain the reasons. Quote Link to comment Share on other sites More sharing options...
ladystrange Posted October 26, 2007 Share Posted October 26, 2007 correct me if i am wrong but here is the therory that has always been told to me... pacific salmon return to the fresh water at the end of its life cycle to die, which is approx 4 years. once they enter the fresh water they cant metabolize the oxygen through their gills as well as in salt water, they also stop eating. they colour change occurrs from lack of oxygen and the salmon basically has enough fat/engery stores built up to get to the part of the river where they need to spawn. once they get there, they cant get back, not enough O2 or energy stores as for steelhead. adaptation over time allowed for a fresh water fish to survive in salt water. i seem to remember reading somewhere that salt water has a higher O2 content - but dont quote me on that. so since the trout was already able to survive in fresh water with the lower O2 level, the transition to the ocean was neglegible. steelhead continue to feed once they return to spawn. it also seem to me that steelhead have a longer life cycle allowing for 2 or 3 spawns. or something like that when i'm not so zoned out and in need of sleep - i will go and research this topic Quote Link to comment Share on other sites More sharing options...
Din Posted October 26, 2007 Author Share Posted October 26, 2007 correct me if i am wrong but here is the therory that has always been told to me... pacific salmon return to the fresh water at the end of its life cycle to die, which is approx 4 years. once they enter the fresh water they cant metabolize the oxygen through their gills as well as in salt water, they also stop eating. they colour change occurrs from lack of oxygen and the salmon basically has enough fat/engery stores built up to get to the part of the river where they need to spawn. once they get there, they cant get back, not enough O2 or energy stores as for steelhead. adaptation over time allowed for a fresh water fish to survive in salt water. i seem to remember reading somewhere that salt water has a higher O2 content - but dont quote me on that. so since the trout was already able to survive in fresh water with the lower O2 level, the transition to the ocean was neglegible. steelhead continue to feed once they return to spawn. it also seem to me that steelhead have a longer life cycle allowing for 2 or 3 spawns. or something like that when i'm not so zoned out and in need of sleep - i will go and research this topic seems to make sense...better than the creator of the universe theory, lmao Quote Link to comment Share on other sites More sharing options...
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