Complex sentence: Athapums are also phumdis in circular shape built by the villagers as the fishing enclosures cultured artificially for catching fish practiced presently, which has caused proliferation of the phumdis in the lake.
Split into simpler sentences: Athapums are also phumdis in circular shape built by the villagers used as fishing enclosures for culture fishing. Its present practice has caused proliferation of the phumdis in the lake.