For the Taiwan brook masu salmon, already landlocked and unable to interact with other groups of the same species, the subdivision of its living space by the sand retention dams means a further narrowing of the gene pool and a serious problem of inbreeding.
而原本被自然環境阻絕、族群缺乏交流的陸封性台灣鮭魚，生活範圍被攔砂壩截斷，基因交換機會更窄，近親交配嚴重。