All through the generations we are told  " Eat your fish, it's brain food ", how much truth is in that?
And  why is say Sword Fish, Trout , Cod, Benificial , and plaice, kipper, etc not? Is it because the trout and sword fish have been around longer? Being a hunter .
And when cooking fish we normally bake it in the oven, served it with carrots etc. sometimes fish is fried in olive oil .  I know steamed fish is more heathy, but for me not as tasty . When I was in Austrailia one time I had some shark, no bones just pure white meat , very tasty. Sharks have been around for 100's of year, must be ok for hunters? And in Austrailia, they love to Barbaque there fish, Yummy .normally with a cold beer, but now I don't drink beer at all . I did wonder if Ginger beer is ok to drink? Or a weak shandy?

Many factors are considered in determining a foods rating. I do not think being around longer is one of the factors considered.

omega 3

brain needs fat

It is my understanding that the fat in fish is very good for the brain.

There are some 200 factors used in the rating for the individual in SWAMI.

I'm not sure that steamed fish is better than baked.  I like baked fish with vegetables.  Fried fish is OK, as long as the fat is on your good list and you don't get it too hot.

I can't help with the ginger beer question...

Quoted from Eagle Beach

I know steamed fish is more heathy, but for me not as tasty.

Whenever you do prefer to have the fish steamed, you may add parsley and cilantro (and other spices and veggies you like) to the boiling water beneath, this will turn the taste to something else. Also a drizzle of olive oil and fresh lemon juice makes it exciting, as it does fresh salads.  

Steaming makes the most delicate dish.

I bake or grill my fish.  I use herbs and spices.  I never steam my fish.

By the way, be careful not to eat those large fish very often.  They have higher mercury content than that smaller fish.  Limit your shark and swordfish if you want to limit your exposure to mercury.