I do not know. I am unaware of all sea products containing arsenic. Do you have a reference which shows that all sea products contain arsenic, I would be grateful to receive it.
It might be a good idea to avoid all sea products, but then again, the word "sea" is generic, and some seas products may be more tainted than others.
I don't have all the answers, but am willing to learn and would be grateful to receive info upon which you based your statement.
I am sad that our oceans are so polluted. I remember Cousteau being himself sad about it 30 years ago, things have gotten worse.