Translation:There is one big island in this sea.
I don't think so. :/ In sentences indicating where something is situated, you need to use the "there is/are" construction.
Apparently the English natives (at least in the UK) may find it acceptable, but not in all contexts and I don't understand if there's any rule.
There were sentences with multiple reports like this. I think those were mostly like "In the room is a table" and similar...
Why is "There is one big island on this sea" wrong? Because i used "on" instead of "in"? But "on" is more normal in English, as an island is above the water.