Fish eat algae...eat algae for EFA's. The concentrations are much smaller but algae like spirulina for example, is a complete food offering a plethora of nutrients that work synergistically.
Also, hemp oil or oil blends (preferably by the tea/tablespoon vs capsule) can actually make noticable improvements. Especially in cases where you have never given your body an "oil change".

Fish are sacred. If we are debating whether we should eat them because we have made them toxic, then the question answers itself, we need to let them heal and live. There is access to so much information and resource that enable quality health for human beings, without killing the animals we already make suffer.
I know this sounds potently intense. As a holistic nutritionist I believe human health involves a sensitive relationship of give and take with animals (ie including whole animal foods in the diet) but perhaps at a different time, in a future we have made sacrifices for.

And for those of us right now, those sacrifices can be minimal...

Algae, hemp oil and other sources of vegetal superfood supplementation are in abundance. You can; from my own experiences, experience adequate health transformations by supplying the human body with vegetal sources *alone.

* I personally include moderate amounts of organic cow or goat milk. Like human breastmilk: there are EFA's in the milks of these beings who offer to mother us along with their own young. Cultivate reverence for their offerings and recieve mother loving nourishment from them. I am fully aware of how these animals can be exhausted by our demands, so tread as lightly as possible, with caution and be prepared to let such go, when the intuitive notion arises...

[Blessings of good health for all beings]

Rji