Interesting, but in retrospect childhood nutrition having long term effects shouldn't be surprising.
That said, I'd hesitate to prescribe salmon for kids simply because what's sold today is more likely to be farmed - and omega-3 oils are the product of a food chain that farmed fish aren't likely to be part of - and the wild-caught are both more expensive and a bit less palatable than the farmed (the farmed have a higher fat content as you might expect of animals not swimming wild). So, supplements - including cod liver oil and wild-caught oily fish like bluefish, mackerel, and sardines.
I'd also mention that some of us are not-so-good at converting alpha-linoleic oil into EPA and DHA (at least two known polymorphisms; TMI: I have one - which is why I'm aware of it). Worth considering if you're a vegetarian parent of young children as giving them ‘vegetarian’ versions of omega-3s might not get converted. Krill have actual omega-3s, no conversion needed (they’re the ‘base’ of the animal pyramid concentrating it into oily fish).