Some clean-water mini biomes has hatch buried beneath lowest water tiles, this hatches dies (drowned) in a few first moment of the game and replaced with buried object – meat.
Missed one important step – hatches start drowning only after first game load. So you have a chance to save them – you have to dig into the pool and build one tile underwater right above them.
Ceterum censeo bugs involving loss of resources mass like pumps, plumbing, water going downhill by steps, airlock doors in a row and so on should be attended with priority as affecting fundamental aspects of the game.
Create new game -> Pause -> Check underwater tiles for hatch -> Unpause and watch what happens