If you think you are done with fishing after your journey to find the eel, know that it is not over yet! The Sturgeon is a pretty shy fish that doesn't show up everywhere and to receive the rewards from Meath's Offering Altar in Assassin's Creed Valhalla: Wrath of the Druids, you're going to have to go looking for it.
How to get Sturgeon
In Ireland
If you don't want to make a quick trip to England, be aware that the Sturgeon will be found in salt water, if we are to believe what the owner of the Fishing Hut in Ravensthorpe tells us. No Fishing Huts are available in Ireland, so it is quite complicated to know the location of this one, but we found a place full of Sturgeon.
At the Ulster border when you are on the coasts of Dublin, you may find Sturgeon. Do not hesitate to use Odin's Sight to be sure to stumble upon the fish. It is relatively large and expansive, so if you are still in doubt, dip a head in the water and see if the fish has small whiskers much like the Catfish.
In England
If you are not afraid to take a little trip to England, know that you can find Sturgeon in salt water, but also in the rivers of Cent, Suthsexe and Hamtunscire. To return to England, go to your map and interact with the "Atlas" key. You will have the choice between Norway and England.
How to fish for Sturgeon
If you haven't already, go to Ravensthorpe to create the Fishing Hut which is located right at the entrance to the harbor. This will allow you to have a net that will help you catch fish on any stream in Norway, England or Ireland. Unlike Ireland, you will need primary resources to build the Shack, and you can get these resources from Plunder on English Lands.
If you already have the net, use the shortcut wheel to find the tool and throw the hook into the water where a school of fish spurts out.
Meath Offering Altar Reward
In exchange for 5 large Sturgeons, you will be able to benefit from an additional skill point.