A system for transporting bottom waste from a net cage 10 in a fish farming plant 16 to a common processing site removes waste from the bottom of the net cage and transports it through the net cage in a pipe. The pipe 14 from the bottom of each net cage is connected to a main pipe via a branch pipe 11 on a raft 15 arranged between rows of net cages. The raft comprises several branches of the main pipe to be connected to one or more pipes from net cages. Also provided is a farming plant comprising a number of net cages wherein each net cage has a pipe for removal of bottom waste from the bottom of the net cage, and where the pipes are connected to a common main pipe transporting the bottom waste to a main barge. The net cages are arranged in rows and the pipes for removal of bottom waste from each net cage is connected to a branch pipe of the main pipe on a raft. The main pipe for removing of waste from the net cages is running from the most distal raft to the main barge.
