一般來說，九孔的鹽度適應範圍屬於較高鹽度32-34ppt(楊，陳1984)與較狹鹽性，但在種貝的培育上可在30-33ppt下進行，因此在雨季時或是大雨後池水鹽度常會降到偏低而致使九孔損失，為解決這方面問題，擬以漸進改變鹽度的方式培育較低鹽度的種貝或種苗，使在鹽度較低的養殖地區也能發展九孔養殖業。
The mass mortality of abalone were suffered due to the acute salinity change duringrain fall. The study was conducted to select the breeding stock of abalone being tolerablefor lower salinty.