Bear in mind that those vegetarian sources provide alpha-linoleic acid (ALA) - and what we need is both EPA and DHA. We can convert ALA to EPA/DHA, but there's a lot of variability in how well anyone in particular can do it. The issue is particularly dire for the conversion to DHA (the one your brain needs) and complicated by diet (conversion goes down as n-6 unsaturated fats replace saturated ones). Easier to just eat some fish - or other direct source of DHA/EPA like krill.

FWIW, krill are where the DHA/EPA in seafood comes from. It's concentrated as it moves up the food chain - and is why those researchers suggest 'wild caught'; farmed fish may or may not be part of that food chain, depending on what they're fed.

Also, if you find fish stinky, find another place to get fish - that's a sign that it's going bad.