Unless I'm missing something, it doesn't seem like aquavoltaics is actually a real thing like agrivoltaics.
With agrivoltaics, you get benefits to the agriculture (shade helps some crops), and the solar panels (less need for weeding between panels, transpiration cooling panels for higher efficiency). Obviously, probably the biggest benefit is monetary; the money per land area goes up, enabling different crops to be profitably grown, or grown on land that would otherwise be too expensive for agriculture.
With aquavoltaics, it doesn't seem like they specify a benefit other than "sticking solar panels on 'unused' land makes the land use more profitable"; there's no interaction. I suppose there is still the effect of making aquaculture profitable where it otherwise might not be, and allowing for different species that may be otherwise unprofitable.
Still though, it doesn't seem like there's an "interaction" unless I'm missing something. Maybe if the panels were literally over the water, you could keep the water (and the panels) cooler and grow different species?
I feel like if it's just the money piece, we could coin a whole bunch of other "-voltaics".