ʻO ka Eastern Tropical North Pacific (ETNP) he wahi nui, hoʻomau, a hoʻoikaika ikaika i ka palena palena iki o ka oxygen (OMZ) e pili ana i ka hapalua o ka nui o nā OMZ honua. I loko o ke kumu OMZ (~ 350–700 m hohonu), ʻo ka oxygen dissolved ma kahi kokoke a ma lalo paha o ka palena ʻike analytical o nā mea ʻike hou (∼10 nM). ʻO nā ʻanuʻu oxygen kiʻekiʻe ma luna a ma lalo o ke kumu OMZ e alakaʻi i ka hoʻonohonoho ʻana o nā kaiāulu microbial e ʻokoʻa hoʻi ma waena o nā hakina nui e pili ana i ka particle (PA) a me ka noho manuahi (FL). Maʻaneʻi, hoʻohana mākou i ka 16S amplicon sequencing (iTags) e kālailai i ka ʻokoʻa a me ka puʻunaue ʻana o nā heluna prokaryotic ma waena o nā hakina nui FL a me PA a ma waena o nā kūlana redox ambient. ʻOkoʻa nā kūlana hydrographic ma kā mākou wahi aʻo mai nā mea i hōʻike mua ʻia ma ka ETNP a me nā OMZ ʻē aʻe, e like me ka ETSP. Loaʻa ka ʻike ʻana o ka oxygen (∼0.35 μM) i loko o ka OMZ core ma kā mākou wahi hoʻohālike. No laila, ʻaʻole i loaʻa nā hōʻiliʻili nitrite i hōʻike pinepine ʻia no nā cores OMZ e like me nā kaʻina no ka bacteria anammox (Brocadiales genus.CandidatusScalindua), i loaʻa maʻamau ma nā palena oxic-anoxic i nā ʻōnaehana ʻē aʻe. Eia nō naʻe, ka hāʻawi ʻana o ka ammonia-oxidizing bacteria (AOB) a me ka archaea (AOA) a me ka nui o ka nui o ka autotrophic carbon assimilation rate (1.4 μM C d.–1) i hui pū ʻia me ka haʻi ʻana o ka nui o ka ammonium ma kahi kokoke i ka piko o ka OMZ core. Eia kekahi, nā lālā o ka genusNitrospina, aia kekahi clade nitrite-oxidizing bacterial (NOB) nui e hōʻike ana i ka hiki ʻana o ka ammonia a me ka nitrite oxidation ma ka ʻike ʻana o ka oxygen. Ua hōʻike ʻia ka ʻikepili o ka hoʻāʻo like (ANOSIM) a me ka Non-metric Dimensional Scaling (nMDS) he ʻokoʻa loa nā hōʻike phylogenetic bacterial a archaeal ma waena o nā hakina nui. Ma muli o nā ʻaoʻao ANOSIM a me iTag, ʻoi aku ka liʻiliʻi o ka hoʻokumu ʻana o nā hui PA e ke aupuni biogeochemical hilinaʻi hohonu ma mua o ka hapa FL. Ma muli o ka loaʻa ʻana o ka AOA, NOB a me ka ʻike ʻana i ka oxygen i loko o ka OMZ core ke manaʻo nei mākou he hana ikaika ka nitrification i ka pōʻai nitrogen o kēia māhele o ka ETNP OMZ.
Hoʻolauna
I ka pane ʻana i ka hoʻololi ʻana o ke aniau a me nā hana kanaka kūloko, ua emi ka nui o ka oxygen dissolved i ka moana ākea a me nā ʻōnaehana kai kai (Breitburg et al., 2018). Ua manaʻo ʻia ka nalowale o ka oxygen mai ka moana ākea i nā makahiki 60 i hala aku nei ma mua o 2% (Schmidtko et al., 2017), ka hoʻokumu ʻana i nā hopohopo e pili ana i nā hopena o ka hoʻonui ʻia ʻana o ka oxygen-depleted zone (ʻO Paulmier lāua ʻo Ruiz-Pino, 2009). Hoʻokumu ʻia nā OMZ o ka moana i ka wā e hoʻoulu ai ka hana mua o ka ʻili kiʻekiʻe i ka koi o ka oxygen biological i loko o nā wai lalo i ʻoi aku ma mua o ka nui o ka ea kino i ka hohonu. Hiki ke loaʻa i nā kolamu wai o OMZ i nā ʻanuʻu kiʻekiʻe (oxycline) ma luna a ma lalo o ke kumu i hoʻopau ʻia ka oxygen e hana ana i ka hypoxic (maʻamau ma waena o 2 a ~ 90 μM), suboxic (<2 μM) a me anoxic (ma lalo o ka palena ʻike (∼10 nM) nā ʻāpana like ʻole (ʻO Bertagnolli lāua ʻo Stewart, 2018). Ke alakaʻi nei nā gradients oxygen i ka hoʻonohonoho ʻana o nā metazoan a me nā kaiāulu microbial a me nā kaʻina biogeochemical ma kēia mau oxyclines nui (Belmar et al., 2011).
Ua hoʻopaʻa ʻia kekahi o nā helu kiʻekiʻe loa o ka nalowale o ka nitrogen ma OMZ o ka Eastern Tropical North Pacific (ETNP) a me South Pacific (ETSP) (Callbeck et al., 2017;Penn et al., 2019), ke kahua paʻa paʻa ʻo Cariaco Basin (ʻO Montes et al., 2013), ke kai ʻArabia (Ward et al., 2009), a me ka OMZ o ka ʻōnaehana upwelling Benguela (Kuypers et al., 2005). I loko o kēia mau ʻōnaehana, ʻo nā kaʻina microbial o ka denitrification canonical (hoʻemi heterotrophic o ka nitrate i nā intermediates nitrogen a pinepine i ke kinoea dinitrogen) a me anammox (anaerobic ammonium oxidation) alakaʻi i nā poho nitrogen i hiki ke kaupalena i ka hana mua (Ward et al., 2007). Eia kekahi, ua manaʻo ʻia ka hoʻokuʻu ʻia ʻana o ka nitrous oxide o ka moana (he kinoea hoʻomaʻemaʻe ikaika) mai ka microbial denitrification i hana ʻia ma OMZs e helu ʻia ma kahi o hoʻokahi hapakolu o nā hoʻoiho nitrous oxide kūlohelohe honua (Naqvi et al., 2010).
ʻO ka ETNP OMZ kahi ʻāpana liʻiliʻi o ka oxygen nui, hoʻomau, a hoʻoikaika ʻia e kokoke ana i ka hapalua o ka nui o nā OMZ honua, aia ma waena o 0-25°N latitu a me 75 a me 180°W longitude (ʻO Paulmier lāua ʻo Ruiz-Pino, 2009;Schmidtko et al., 2017). Ma muli o ko lākou koʻikoʻi kaiaola, ua aʻo ikaika ʻia ka biogeochemistry a me ka microbial diversity o nā ʻāpana ETNP OMZ like ʻole (e laʻa,ʻO Beman lāua ʻo Carolan, 2013;Duret et al., 2015;ʻO Ganesh et al., 2015;Chronopoulou et al., 2017;Pack et al., 2015;Peng et al., 2015). Hōʻike nā haʻawina mua e pili ana i ka oxygen dissolved i kēia OMZ core (∼250–750 m hohonu) ma kahi kokoke a ma lalo paha o nā palena ʻike analytical (∼10 nM) (Tiano et al., 2014;Garcia-Robledo et al., 2017). Eia nō naʻe, ma ka ʻaoʻao ʻākau o ka ETNP's OMZ (kahi kahua aʻo ~ 22°N) ka nui o ka oxygen ma 500 m hiki ke hiki i nā awelika makahiki ma waena o 10 a me 20 μM (ʻO Paulmier lāua ʻo Ruiz-Pino, 2009; ʻIkepili mai ka World Ocean Atlas 2013)1. I ka wā o ka hoʻolaha kahua i hōʻike ʻia ma ʻaneʻi, ua ana mākou i ka oxygen i loko o ka OMZ core i ka lawa ʻana (0.35 μM) no ke kākoʻo ʻana i nā kaʻina microbial aerobic, e like me ka ammonium a me ka nitrite oxidation, a me ka pale ʻana i nā kaʻina microbial anaerobic koʻikoʻi. Ua ʻike mua ʻia nā kaʻina hana microbial aerobic i nā ʻāpana subboxic a i ʻole anoxic o ka ETNP OMZ (Peng et al., 2015;Garcia-Robledo et al., 2017;Penn et al., 2019). Eia nō naʻe, ʻaʻole maopopo loa nā mea e hoʻomalu ana i ka hāʻawi ʻana a me nā hana o nā pūʻulu hana kūikawā o nā microorganism i OMZ.
ʻO ka hiki ʻana o nā nitrifiers kahi i ʻike ʻole ʻia ai ka oxygen i loko o kahi OMZ hiki ke wehewehe ʻia e nā neʻe hou i ke kūlana kūpaʻa o ka oxycline ma muli o ka episodic vertical oxygen ventilation, hiki ke alakaʻi i nā pae oxygen trace ephemeral i loko o nā cores OMZ (Muller-Karger et al., 2001;Ulloa et al., 2012;Garcia-Robledo et al., 2017). Hiki ke hoʻohana ʻia kēlā mau kūlana transient e ka lehulehu aerobic a microaerophilic, me nā nitrifiers. Eia kekahi, hiki ke loaʻa nā ʻāpana o ka epipelagic (nā pūnaewele hui ʻia, nā pellets fecal, a me nā mea kūlohelohe paʻakikī) ke loaʻa i nā pae o ka oxygen (ʻO Ganesh et al., 2014). No laila, hiki ke lawe ʻia ka oxygen a me nā microbes aerobic i nā wai anoxic ʻē aʻe, e ʻae i ka manawa e hiki ai i nā metabolism aerobic e hui pū me nā ʻāpana. Ua ʻike ʻia nā ʻāpana he mau wahi wela o ka paikikala biogeochemical microbial (Simon et al., 2002;ʻO Ganesh et al., 2014) a hiki ke kākoʻo i nā kaʻina hana ʻokoʻa anaerobic a i ʻole aerobic microbial i ʻike ʻole ʻia ma ke kūlana noho manuahi (Alldredge a me Cohen, 1987;Wright et al., 2012;Suter et al., 2018).
Ma ke aʻo ʻana i kēia manawa, ke noiʻi nei mākou i nā kaiāulu prokaryotic e noho ana ma ka ʻaoʻao ʻākau o ka OMZ o ka ETNP a me nā mea pili i ke kaiapuni e hoʻohuli i kā lākou puʻupuʻu kū i ka hoʻohana ʻana i ka 16S amplicon sequencing (iTags) i hui pū ʻia me nā helu helu multivariate. Ua nānā mākou i ʻelua mau hakina nui; ka hakina ola manuahi (0.2–2.7 μm), a me ka hakina pili pili (>2.7 μm, hopu i nā ʻāpana a me nā pūnana protistan) ma nā hohonu he nui ma ka oxycline e pili ana i nā kūlana redox ʻokoʻa.
Hiki iā mākou ke hāʻawi i nā sensor oxygen dissolved me nā ʻokoʻa like ʻole, i hiki ke nānā ʻia ka ʻike molekala i ka manawa maoli. Welina mai e kūkākūkā
https://www.alibaba.com/product-detail/Wifi-4G-Gprs-RS485-4-20mA_1600559098578.html?spm=a2747.product_manager.0.0.169671d29scvEu
https://www.alibaba.com/product-detail/Maintenance-Free-Fluorescence-Optical-Water-Dissolved_1600257132247.html?spm=a2747.product_manager.0.0.169671d29scvEu
Ka manawa hoʻouna: Jul-05-2024