fish, algae (also supplements) salt contain toxic?

ok so im really concern about toxin (mercury , etc) in fishes (omega supplement, etc) and algae (chlorella, spirulina, fucoidan, kelp) as you can see those are really necessary for us because it contains many beneficial nutritients in it that our body need to maintain health and combat our health issues. but now im worried about taking them and confused wether i should still taking them or not. im sure many of you already heard about this.
therefore i thought eating farm raised fishes was safer as an alternative to that but i read that its harmful too research found that fish farms produce protein with high concentrations of Antibiotics , pesticides and lower levels of healthy nutrients. dioxins impair the endocrine, immune, nervous and reproductive systems and are carcinogens.u can read it more about it if you google it.
flax seed, other seeds, etc also not really a good choice since its high in anti nutritient which is bad for your health. and there are no alternatives to algae. so whats your opinion about it?
nb: salt from ocean also contaminated with mercury. how great is that. Tweet