Minor detail, but I don't think FAO has been mentioned or defined before

I like the interaction, but I wonder if this could be shown as small multiples instead? The patterns are quite different for the different countries.

Hi Robert, for this visual, we have combined the previous visual and this one into one. To have a more drilled down view, we added a checkbox instead so that the user can filter out the countries on their own.

You may have tried this, but I wonder if connecting the points in temporal order with lines (i.e., a connected scatterplot) here would make this more readable than the error bands.

For this one, our analysis doesn't focus much on the time domain but instead with the relationship between annual sea surface temperature and ratio of marine production. To reduce the clutter, we also added a checkbox for this visual so that the user can choose the countries they want to look at. For the readability, would it be advisable to instead remove the error bands, keeping just the trend lines?

Very nice! This is much clearer than the previous chart IMHO.

I would add a little preview of the data you're about to show here, just to give people an idea of what to expect. The introduction is fairly general, perhaps you can also pick out a few numbers from what you're showing below as examples to make things a bit more concrete.