Deep Sea/ Trench Biomes

Adding Deep Sea Biomes to Minecraft would enhance underwater exploration and take full advantage of the expanded vertical limits introduced in the Caves and Cliffs update. These biomes could include the Abyssal Plains, and/or Trenches. Structures like Hydrothermal Vents could generate.

These biomes could introduce darker, more mysterious underwater environments with unique blocks, such as deep-sea corals, bioluminescent plants, and new ores. Players could encounter new mobs like deep-sea fish or giant squids. (It would also be funny if the giant squid was just an oversized version of the regular squid)

It would also be a great opportunity to add new light source blocks.