水質監(jiān)控技術-Water quality monitori

水質監(jiān)控技術Waterqualitymonitoringtechnology--水質監(jiān)控技術課程組WaterqualitymonitoringTechnologyCoursegroup養(yǎng)殖水質亞硝酸鹽氮的檢測與調控Detectionandregulationofnitritenitrogeninaquaculturewater《水質監(jiān)控技術》課程WaterQualityMonitoringTechnology水體中亞硝酸鹽氮對養(yǎng)殖生物的毒性及影響因素

Toxicityandinfluencingfactorsofnitritenitrogeninwatertoaquacultureorganisms

學習目標Learningobjective掌握水體亞硝酸鹽氮的毒性機理和養(yǎng)殖生物的中毒表現；Tounderstandthetoxicmechanismofnitritenitrogeninwaterandthetoxicmanifestationsofaquacultureorganisms;掌握水體亞硝酸鹽氮毒性的影響因素。Tounderstandtheinfluencingfactorsofnitritenitrogentoxicityinwater.學習目標1.Learningobjective1學習目標2.Learningobjective2水體亞硝酸鹽氮的毒性機理Toxicitymechanismofnitritenitrogeninwater.亞硝酸鹽會影響魚蝦蛙等動物體內抗氧化酶的活性，同時也影響溶菌酶的活力，從而降低動物的免疫能力；Nitritecanaffecttheactivityofantioxidantenzymesandlysozymeinfish,shrimp,frogandotheranimals,thusreducingtheimmunityofanimals.養(yǎng)殖水體亞硝酸鹽濃度過高時，可通過魚蝦類體表的滲透與吸收作用進入血液，使血液中的亞鐵血紅蛋白被氧化成高鐵血紅蛋白，由于高鐵血紅蛋白不能與氧氣結合，從而導致血液載氧能力下降甚至喪失。Whentheconcentrationofnitriteinaquaculturewateristoohigh,itcanenterthebloodthroughtheinfiltrationandabsorptionofthebodysurfaceoffishandshrimp,sothattheferrohemoglobininthebloodisoxidizedtomethemoglobin.Becausemethemoglobincannotcombinewithoxygen,theoxygencarryingcapacityofthebloodisreducedorevenlost.不同濃度的亞硝酸鹽對魚蝦的影響Effectsofdifferentconcentrationsofnitriteonfishandshrimp.0~0.1㎎/L(以氮計)(innitrogen)正常養(yǎng)殖水體的亞硝酸鹽濃度低于0.1㎎/L，魚蝦水生動物在此條件下，能夠正常自由地生活，不會造成任何健康損害。Theconcentrationofnitriteinnormalaquaculturewaterislowerthan0.1㎎/L,andaquaticanimalsoffishandshrimpcanlivenormallyandfreelyundersuchconditionswithoutcausinganyhealthdamage.不同濃度的亞硝酸鹽對魚蝦的影響Effectsofdifferentconcentrationsofnitriteonfishandshrimp.0.1~0.5㎎/L(以氮計)(innitrogen)

養(yǎng)殖對象的生理功能紊亂，影響其生長或引起其他疾病的發(fā)生，造成魚、蝦慢性亞硝酸鹽中毒，表現為攝食量下降，生長不明顯，活動力減弱，鰓及鰓蓋內表面血管呈暗紫紅色，呼吸困難，游動緩慢，騷動不安或反應遲鈍，同時體表呈現不正常的色澤。Thephysiologicaldisordersoftheculturedobjectsaffecttheirgrowthorcausetheoccurrenceofotherdiseases,resultinginchronicnitritepoisoningoffishandshrimp,whichismanifestedasdecreasedfoodintake,insignificantgrowth,weakenedactivity,darkpurpleredbloodvesselsontheinnersurfaceofthegillsandgillcovers,dyspnea,slowswimming,agitationorslowresponse,andabnormalcoloronthebodysurface.

亞硝酸鹽中毒的對蝦外表癥狀有黑鰓、黃鰓、肝胰臟模糊不清晰，解剖后顯微鏡觀察，鰓絲腫脹充水，甚至糜爛粘有污物，腸道充血發(fā)炎，肝胰臟空泡甚至糜爛。Theoutwardsymptomsofnitritepoisoningofshrimpincludeblackgills,yellowgillsandvaguehepatopancreas.Microscopicobservationafterdissectionshowsthatthegillfilamentsareswollenandfilledwithwater,andthereareevenfilamentsstickytoerosion,intestinalcongestionandinflammation,hepatopancreasvacuoleandevenerosion.黑鰓病不同濃度的亞硝酸鹽對魚蝦的影響Effectsofdifferentconcentrationsofnitriteonfishandshrimp.>0.5㎎/L(以氮計)(innitrogen)魚中毒癥狀繼續(xù)加劇，體力衰退，游泳無力，某些代謝器官功能衰竭，并大量死亡。Thesymptomsoffishpoisoningcontinuetoworsen,withphysicaldecline,inabilitytoswim,failureofcertainmetabolicorgans,andalargenumberofdeaths.亞硝酸鹽偏高的危害更主要是表現在對蝦蛻殼期。會引起蛻殼期的對蝦因為缺氧、中毒而蛻殼不遂，出現大量軟殼蝦，常常引起蛻殼期大量“偷死”。Theharmofhighnitriteismainlymanifestedinthemoultingperiodofprawn.Itwillcausetheshrimpsinthemoultingperiodtomoultbecauseofhypoxiaandpoisoning,andtherearealargenumberofsoft-shellshrimps,whichoftencausealargenumberof"stealingdeath"inthemoultingperiod.急性中毒和浮頭很相似，都呈現缺氧癥狀，但是兩者最大的區(qū)別是亞硝酸鹽中毒在太陽出來后魚還不下水，有時甚至整天都在水面活動，晴天也不例外。Acutepoisoningandfloatingheadareverysimilar,bothpresenthypoxiasymptoms,butthebiggestdifferencebetweenthetwoisthatnitritepoisoningfishdonotgointothewaterafterthesuncomesout,sometimesevenalldaylongonthesurfaceofthewater,evenonsunnydays.不同濃度的亞硝酸鹽對魚蝦的影響Effectsofdifferentconcentrationsofnitriteonfishandshrimp.亞硝酸鹽的安全濃度和致死濃度Safeandlethalconcentrationsofnitrite.品種variety安全濃度(mg/L)Safeconcentration品種variety致死濃度(mg/L)Lethalconcentration一般淡水魚Generalfreshwaterfish<1虹鱒Rainbowtrout0.24一般海水魚CommonMarinefish<1鯉魚carp2.6一般海水蝦Commonseashrimp0.25草魚Grasscarp4.6羅氏沼蝦Macrobrachium

rosenbergii0.1羅非魚tilapia16水生動物不同種類、品種及個體對亞硝酸鹽的耐受性不同，因而，對不同種類魚蝦蟹的安全密度差異很大。為確保魚蝦蟹的安全（尤其在育苗期），亞硝酸鹽含量應控制在0.1㎎/L以下。Differentkinds,varietiesandindividualsofaquaticanimalsTolerancetonitriteisdifferent,so,Thesafetydensityofdifferentkindsoffish,shrimpandcrabsispoorIt'sabigdifference.Toensurethesafetyoffish,shrimpandcrabs(especiallyIntheseedlingstage),nitritecontentshouldbecontrolledBelow0.1㎎/L.影響亞硝酸鹽毒性的因素Factorsinfluencingnitritetoxicity溶氧：

低氧會使動物受到高濃度亞硝酸鹽影響的風險增加Dissolvedoxygen:Lowoxygenputsanimalsatincreasedriskofhighconcentrationsofnitrite氨氮：氨氮濃度高會增加亞硝酸鹽的毒性Ammonianitrogen:Highconcentrationsofammonianitrogenincreasethetoxicityofnitrites氯化物：水中氯化物濃度高可阻止動物對亞硝酸鹽的吸收，降低毒性氯化物與亞硝酸鹽之比為10:1時可消除亞硝酸鹽對溝鯰的毒性Chloride:Highchlorideconcentrationinwatercanpreventtheabsorptionofnitritebyanimals,andreducethetoxicityofnitritetocatfishwhentheratio