Kuo Chin-lau notes that between 1977 and 1978, "elderly" fish of seven or eight were still being caught (the life expectancy of a grey mullet is about eight years). By 1985, they were all less than four.
郭慶老指出，民國六十六、七年間，漁民還有捕獲七、八歲以上高齡魚（烏魚的壽命約為八歲）的紀錄，到了七十四年以後，則都是四歲以下。