What is Pacifica?
Thousands of small uninhabited islands exist in the pacific ocean. Well, seemingly uninhabited. The islands and the ocean in between are home to a myriad of peoples and creatures, including mermen & merwomen, gill people, dolphins (The Dolphin Council), whales (The Whale Consortium), intelligent (talking) birds and land mammals (to be named later), and "regular" humans so far removed from land humans that their main language is long forgotten.
Mer people and Gill people understand and speak a variety of pacific rim languages (English, Japanese, Tagalog, Chinese) as well as Pacifica, dolphin and whale. they are the linguists of the sea. English is common to Pacifica and Atlantis, so that is the language that the two continents speak to each other in, although the King Merman speaks Atlantian as well. Mer and Gilly also have their own language.
As with Atlantis, the Pacificans have underwater cities which are "bubbled", ie are suitable for air breathers, but the difference is that the Pacifican cities are seperated by the ocean, not connected together in one big group. so the cities of Pacifica are smaller and closer to the surface than the major portions of Atlantis. Pacificas underwater dwellings are solar powered from nearby surface islands. All quite practical and no hint of "magic" (unless you consider the magical nature of some of their inhabitants.
The Pacificans (human) have their roots in North East Asian and North West Native American peoples (mongols and eskimos). The humans have a great stake at maintaining the bubbled cities, as the Mer people and Gillies don't need underwater air sources. Humans as a race are younger than Mer folk, and while they share common features, they do not share common genetic background (humans are "evolved" from apes and Merman are "evolved" from dolphins).
Gillies are mutants from the early atomic age and are essentially a "new" race in relation to other pacifican races. They are products of atomic testing in Siberia and the bombing of Hiroshima. It is also thought that German and American bomb testing also bred gillies, and they have all come together is one race, orphaned by their origins to the ocean. Their youth and inexperience in any other culture has made them essentially slaves to the Mer folk. Their genetic background is human.
Merfolk existed in the pacific ocean long before humans walked on earth, tracing their roots into the Mesozoic era, decended from the same species as the dolphins. They co-exist with their dophin brethern, and revere them as decendent from the gods. The King of the Mermen rules with their guidance.
The Dolphin Council are the ruling body over all of Pacifica. They are considered gods by the Merfolk and defer to their older wisdom. The humans and gillies do not worship the dolphins, but they afford them the proper respect as the ultimate authority.
The whales are the merchants of the sea. Nothing is bought or sold in all of pacifica that isn't approved by the Whale Consortium.