ruwa Mai gishiri shine tsari na kwararar gishiri da ke gurɓata yanayin ruwa, wanda zai iya cutar da nau'in ruwa a wasu adadi kuma yana lalata ruwan sha . Sau da yawa ana auna shi ta hanyar ƙara yawan adadin ma'adanai da aka narkar da fiye da abin da aka yi la'akari da shi na al'ada don yankin da ake kallo. Ana kiran salinization na halitta a matsayin salinization na farko; wannan ya hada da ruwan sama, yanayin dutse, kutsawar ruwan teku, da ma'adinan iska. Salinization da ɗan adam ya haifar ana kiransa salinization na biyu, tare da yin amfani da gishirin hanya mai ƙazantawa a matsayin mafi yawan nau'in zubar da ruwa. Kimanin kusan kashi 37% na magudanar ruwa a Amurka an yi su ne ta hanyar salinization a cikin ƙarni da suka gabata. EPA ta ayyana kofa biyu don ingantaccen matakan salinity a cikin muhallin ruwan ruwa: 230 mg/L Cl - don matsakaicin matakan salinity da 860 mg/L Cl - don shigarwar gaggawa. Salinity plays a major role in a freshwater organism's attempts to maintain an osmotic balance between ion concentration and their internal fluids.