I think one of the major problems with your question is the use of the word "Good". What is the subject that the word good is being applied to? Good for whom? Good for what? For example, I could do something that is good for myself but perhaps it is not good for the planet or perhaps society in general. Or to put it on a more simplistic level, I could do something that is good for myself but bad for my neighbor.
That salmon example is a horrible one, because it implies that the salmon sacrifices itself with the intent to feed the young. How can you actually make that claim? I highly doubt that is what motivates the salmon to be honest. I could be wrong but every salmon does that? Seems suspect. I think something more simplistic is happening that does not include any intention on the part of the salmon. What could that be? Well perhaps there is something biologically happening within the salmon itself, such as when it becomes time to spawn it's other biological habits such as feeding are in some ways effected which become detrimental to the organism itself. So the salmon dies from this result. That is only an example, I am not trying to claim that this is what actually happens but my point is, making a claim that a salmon self sacrifices to feed the young is a bit outlandish of a claim without something to actually back it up with. There are other possible reasons why the result happens that can do without any sort of conscious intention behind it's actions.
I personally do not see the world in such a way that everything happens for good reasons or good intentions. I think that is looking too narrow when examining to the world to be honest. How so? Just look at what you do to survive? If you are a consumer of meat, just ask the cow or the chicken who is getting the better part of the deal and you will see what I mean.
So when you use the word good, you have to give a context otherwise the use of the word is so relative that it becomes meaningless.