You can simply go lakeside at Lake Dona and see the native merfolk positively aghast at these newcomers in their environment. They have no idea where they came from, but it seems Astoria (through some method or another) has quelled them into preventing them from murdering the other mermaids. Additionally, it seems the merfolk from Akvos are adapting fine to the Lake Dona environment, fresh water and all. Weird. It must be magic.

They'll accept jewelry and some of the neat land fruits, for the most part. They'll seemingly help the Akvos natives willingly (kin is kin, and all that) but they certainly won't be happy that these strangers are all up in their lilypads without any clue on how living in a deep lake works.

Also, Nessie loves the new mermaids. :) Just in case Vex was wondering.