Some field notes on Trolls, courtesy of T.H.I.S.
SeaClans: The six seaclans are Dolphin, Gull, Ray, Kraken, Shark, and SeaDragon. These totem animals serve as mascots rather than any deep symbol of the clan. These seafaring organizations are filled with land based saliors and fishermen. They ply the seas and deeper waterways. They function like guilds for ocean sailors
The clans have their own homeland. These people live on large floating rafts- human made islands, as well as vessels of all varieties docked to it. These wetfoots never set foot on land (or only do it for a few hours at most).
Rat Clan: This guild is nominally related to the seaclans. The Rats ply the rivers and marshes of the world, as well as do longshoreman work. The seaclans hold the self proclaimed "rat clan" in contempt and the officials see them as just a Guild of River saliors and longshoremen with a funny name. The Rats hold their title with pride and will take it out on anyone who gives them grief about it.