Oceanic Races

Oceanic races are a subset of the sentient races of the Eighth Realm which dwell primarily or totally within the seas. These races all share common features, such as the ability to breathe underwater as well as bodies adapted to the conditions of the ocean instead of land. Notably, the oceanic races do not include other acquatic races which may dwell in rivers or lakes. Therefore, the races included in this definition are the Merfolk, Tritons, Rodyalkas, Terraderm, Sea Elves, Water Elementia, and Nephrods. Out of these races, the Merfolk are by far the most dominant, spreading far across the seas, including both tidal regions and open oceans within their zone of habitation.

Living underwater has much different challenges to living on land; namely that light begins to drop off quite sharply as one descends into the depths. Although it may vary depending on the local water conditions, only about 1% of light actually penetrates to 100 meters deep. This creates quite the issue for any race, as plants can only grow within this "photic", or sunlight, zone, found from 0-100 meters of depth. Although technically some light may persist as far as 1000 meters below the surface, 100 meters is generally known as the practical limit. While the photic zone extends, in many parts of the open ocean, to 200 meters instead of 100 meters, this is of little practical use to any oceanic race as they are not filter feeders. Since no ocean race is a filter feeder, any plant life they consume must be able to grow from the ocean floor, thus limiting all oceanic races to either a nomadic lifestyle or one in which they are rather close to the coastline of one of the continents. The few places in which continental shelf extends dramatically are generally hotspots for oceanic races, as these form wide plains where they can develop agricultural societies.

While the plant issue is perhaps more important for forming a civilization, the much more critical factor to light levels is the ability to see. Although each oceanic race has distinct levels of vision both above and below the ocean surface, they all have hard limits as to the depth at which they can functionally see.