Oxygen din kwayoyin da ke narkar da ruwa ana kiransa narkar da iskar oxygen kuma yawanci ana yiwa lakabi da D0. Adadin narkar da iskar oxygen a cikin ruwan saman shine 5-10mg / L. Lokacin da aka sami iska mai ƙarfi da raƙuman ruwa, narkar da iskar oxygen a cikin ruwa na iya kaiwa 14mg/L. Narkar da jikewar iskar oxygen = ƙimar da aka auna ta narkar da iskar oxygen/narkar da iskar oxygen a ƙarƙashin yanayin da aka auna * 100%, wato, 90% da sama, ƙimar da aka auna yana sama da 7.5 mg/L, kuma mafi ƙarancin shine 2 mg/L.
Low-oxygenruwazai wuce ta cikin tsire-tsire kuma ya cire oxygen daga tushen tsarin. Hakanan, zai rage iskar oxygen a cikin ƙasa. Tsire-tsire masu lafiya da lafiyayyen flora na ƙasa suna buƙatar iskar oxygen a waɗannan sassa biyu.
Rashin narkar da iskar oxygen a cikin ruwa kuma na iya haifar da wasu matsaloli. Alal misali, nematodes kamar ƙasa hypoxic. Shuke-shuken ban ruwa tare da ruwa mai ƙarancin iskar oxygen zai kawo su kusa da saman kuma cikin sauƙin lalata tushen tsirrai.
Bincike ya nuna cewa rage yawan narkar da iskar oxygen a cikin tushen shuke-shuke zai rage karfin tsirran don sha nitrogen da ruwa. Rashin iskar oxygen na iya lalata tushen. A cikin aiwatar da daidaitawa zuwa ƙananan ƙarancin iskar oxygen da aka narkar da su, ƙwayar tsire-tsire ta canza. Hypoxia a cikin shuka ana kiransa hypoxia na ciki. Ɗayan sakamakon shine lalacewar sucrose, kuma tsire-tsire suna juya zuwa hanyoyin ceton makamashi don rama ƙarancin iskar oxygen.
Photosynthesis na phytoplankton shine babban tushen iskar oxygen a cikin tafkunan, yawanci yana lissafin 56% -80% na tushen iskar oxygen; sauran suna fitowa daga iska da raƙuman ruwa, ta yadda iskar oxygen da ke cikin iska ta narkar da kai tsaye a cikinruwa. Amfanin 12-14mg/L
Heilongjiang: 600-square-mitaTanning tafkin na iya ƙara yawan zafin jiki na ruwa da digiri 3 zuwa 4 kuma ya ƙara yawan hatsi da kashi 6%.