An nuna cewa canje-canjen da yanayi ke haifarwa a cikin ruwan sha sun shafi tsarin da aikin halittun bakin teku. Mun kimanta canje-canje a tasirin kwararar koguna a kan tsarin bakin teku na Arewa maso Yammacin Patagonia (NWP) a cikin 'yan shekarun nan (1993–2021) ta hanyar haɗakar nazarin jerin lokutan kwararar ruwa na dogon lokaci, kwaikwayon ruwa, bayanai daga tauraron dan adam da sake nazarin yanayin saman teku (zafin jiki, turbidity, da gishiri). An bayyana raguwar kwararar ruwa mai mahimmanci a cikin yankin da ya mamaye manyan kwaruruka shida a ma'aunin mako-mako, wata-wata, da yanayi. Waɗannan canje-canjen sun fi bayyana a cikin kwaruruka na arewa masu gauraye (misali, Kogin Puelo) amma da alama suna ci gaba zuwa kudu zuwa koguna waɗanda tsarin ruwa ke siffantawa. A cikin teku mai matakai biyu na ciki da ke kusa, raguwar shigar ruwa mai tsafta ya yi daidai da halocline mai zurfi da karuwar yanayin zafi a fadin arewacin Patagonia. Sakamakonmu yana nuna tasirin da koguna ke samu cikin sauri akan magudanar ruwa da ruwan bakin teku da ke makwabtaka da su a cikin NWP. Mun nuna buƙatar lura da yanayin muhalli, hasashen yanayi, rage tasirinsa da kuma dabarun daidaitawa a cikin sauyin yanayi, tare da kula da tsarin da ke samar da kwararar ruwa zuwa ruwan teku na bakin teku.
Koguna su ne babban tushen shigar da ruwan sha na nahiyar zuwa tekuna1. A cikin tsarin bakin teku mai kewaye, koguna muhimmin abin da ke haifar da hanyoyin zagayawa2 da kuma gadar da ke tsakanin yanayin halittu na ƙasa da na ruwa, jigilar abubuwan gina jiki, abubuwan halitta, da laka waɗanda ke ƙara wa waɗanda ke cikin tekuna da kuma buɗe. Nazarin da aka yi kwanan nan ya ba da rahoton canje-canje a cikin girma da lokacin shigar da ruwan sha zuwa tekun bakin teku4. Binciken jerin lokaci da samfuran ruwa sun nuna nau'ikan yanayi daban-daban5, misali, daga ƙaruwa mai ƙarfi a fitar da ruwan sha a manyan latitudes6 - saboda ƙaruwar narkewar kankara - zuwa raguwar yanayin a tsakiyar latitudes saboda ƙaruwar fari na ruwa7. Ko da kuwa alkibla da girman yanayin da aka ruwaito kwanan nan, an gano canjin yanayi a matsayin babban abin da ke haifar da canjin tsarin ruwa8, yayin da har yanzu ba a tantance da fahimtar tasirin da ke kan ruwan bakin teku da yanayin halittu da suke tallafawa ba9. Canje-canje na ɗan lokaci a kwararar ruwa, waɗanda sauyin yanayi (canjin yanayin hazo da hauhawar yanayin zafi) da matsin lamba na ɗan adam kamar madatsun ruwa ko ma'ajiyar ruwa10,11, karkatar da ban ruwa, da canje-canjen amfani da ƙasa12, suna haifar da ƙalubale wajen nazarin yanayin shigar ruwa mai tsafta13,14. Misali, bincike da dama sun nuna cewa yankunan da ke da yawan bambancin dazuzzuka suna nuna juriya ga yanayin ƙasa a lokacin fari fiye da waɗanda gonakin daji ko noma suka mamaye15,16. A tsakiyar latitudes, fahimtar tasirin sauyin yanayi na gaba a kan tekun bakin teku ta hanyar kawar da tasirin sauyin yanayi da rikice-rikicen ɗan adam na gida yana buƙatar lura daga tsarin tunani tare da ɗan canji mai iyaka don a iya raba canje-canje a tsarin ruwa daga rikice-rikicen ɗan adam na gida.
Yammacin Patagonia (> 41°S a gabar tekun Pacific na Kudancin Amurka) ya fito a matsayin ɗaya daga cikin waɗannan yankuna da aka kiyaye sosai, inda bincike mai gudana yana da mahimmanci don sa ido da kare waɗannan halittu. A wannan yanki, koguna masu gudana kyauta suna hulɗa da ilimin yanayin ƙasa mai rikitarwa na bakin teku don tsara ɗaya daga cikin manyan macro-estuaries a duniya17,18. Saboda nisan da suke da shi, kwarurukan kogunan Patagonia sun kasance ba tare da wata matsala ba, tare da babban katangar daji na asali19, ƙarancin yawan jama'a na ɗan adam, kuma gabaɗaya ba su da madatsun ruwa, tafkuna, da kayayyakin aikin ban ruwa. Rashin lafiyar waɗannan halittun bakin teku ga canje-canjen muhalli ya dogara ne kawai, ta hanyar faɗaɗawa, akan hulɗarsu da maɓuɓɓugan ruwa masu tsabta. Ruwan sabo yana shiga cikin ruwan bakin teku na Arewa maso Yamma Patagonia (NWP; 41–46 ºS), gami da ruwan sama kai tsaye da kwararar kogi, yana hulɗa da tarin ruwan teku, musamman Ruwan Subantarctic mai yawan gishiri (SAAW). Wannan, bi da bi, yana tasiri ga tsarin zagayawar jini, sabunta ruwa, da kuma iska20 ta hanyar samar da ƙarfin gishiri, tare da babban matakin bambancin yanayi da bambancin sarari a cikin halocline21. Hulɗar da ke tsakanin waɗannan hanyoyin ruwa guda biyu kuma tana tasiri ga tsarin al'ummomin planktonic22, yana shafar raguwar haske23, kuma yana haifar da narkewar yawan Nitrogen da Phosphorus a cikin SAAW24 da haɓaka wadatar orthosilicate a cikin layin saman25,26. Bugu da ƙari, shigar da ruwan sha yana haifar da ƙarfin tsayuwar oxygen mai narkewa (DO) a tsaye a cikin waɗannan ruwan estuarine, tare da saman Layer gabaɗaya yana nuna babban yawan DO (6-8 mL L−1)27.
Tsarin da aka yi amfani da shi wajen magance matsalar karancin ruwa a yankin Patagonia ya bambanta da yadda ake amfani da bakin teku sosai, musamman ma masana'antar kiwon kifi, wani muhimmin fannin tattalin arziki a Chile. A halin yanzu ana sanya shi a cikin manyan masu samar da kifin ruwa a duniya, Chile ita ce ta biyu mafi girma wajen fitar da kifin salmon da kifi, kuma ita ce mafi girma wajen fitar da kifin mussels28. Noman kifin salmon da mussels, wanda a halin yanzu ke da wuraren da aka raba kusan 2300 tare da jimillar fadin kifin hekta 24,000 a yankin, yana samar da muhimmiyar darajar tattalin arziki a kudancin Chile29. Wannan ci gaban ba shi da tasirin muhalli, musamman a fannin noman kifin salmon, wani aiki da ke ba da gudummawa ga abubuwan gina jiki na waje ga waɗannan halittu30. An kuma nuna cewa yana da matukar rauni ga canje-canjen da suka shafi yanayi31,32.
A cikin 'yan shekarun nan, binciken da aka gudanar a NWP ya ba da rahoton raguwar shigar ruwa cikin ruwa33 kuma ya yi hasashen raguwar kwararar ruwa a lokacin bazara da kaka34, da kuma tsawaita fari a cikin ruwa35. Waɗannan canje-canje a cikin shigar ruwa cikin ruwa suna tasiri ga sigogin muhalli nan take kuma suna da tasirin gaske akan yanayin halittu masu faɗi. Misali, yanayi mai tsauri a cikin ruwan saman bakin teku a lokacin fari na bazara-kaka ya zama ruwan dare, kuma, a wasu lokuta, sun shafi masana'antar kiwon kamun kifi ta hanyar hypoxia36, ƙaruwar parasitism, da kuma furen algae masu cutarwa32,37,38 (HABs).
A cikin 'yan shekarun nan, binciken da aka gudanar a NWP ya ba da rahoton raguwar shigar ruwa cikin ruwa33 kuma ya yi hasashen raguwar kwararar ruwa a lokacin bazara da kaka34, da kuma tsawaita fari a cikin ruwa35. Waɗannan canje-canje a cikin shigar ruwa cikin ruwa suna tasiri ga sigogin muhalli nan take kuma suna da tasirin gaske akan yanayin halittu masu faɗi. Misali, yanayi mai tsauri a cikin ruwan saman bakin teku a lokacin fari na bazara-kaka ya zama ruwan dare, kuma, a wasu lokuta, sun shafi masana'antar kiwon kamun kifi ta hanyar hypoxia36, ƙaruwar parasitism, da kuma furen algae masu cutarwa32,37,38 (HABs).
Sanin da ake da shi a yanzu game da raguwar shigar da ruwa a cikin ruwa a fadin NWP ya dogara ne akan nazarin ma'aunin ruwa39, wanda ke bayyana halayen ƙididdiga ko na canzawa na jerin bayanan ruwa da aka samo daga ƙarancin adadin bayanan dogon lokaci da ƙarancin ɗaukar sararin samaniya. Dangane da yanayin ruwa mai dacewa a cikin ruwan kogin NWP ko tekun bakin teku da ke kusa, babu bayanan da ke akwai na dogon lokaci a cikin wurin. Ganin raunin ayyukan zamantakewa da tattalin arziki na bakin teku ga tasirin sauyin yanayi, ɗaukar cikakkiyar hanyar haɗin ƙasa da teku don gudanarwa da daidaitawa ga sauyin yanayi yana da mahimmanci40. Don magance wannan ƙalubalen, mun haɗa ƙirar ruwa (1990-2020) tare da bayanan da aka samo daga tauraron ɗan adam da sake nazarin yanayin saman teku (1993-2020). Wannan hanyar tana da manyan manufofi guda biyu: (1) don tantance yanayin tarihi a cikin ma'aunin ruwa a sikelin yanki da kuma (2) don bincika tasirin waɗannan canje-canje ga tsarin bakin teku da ke kusa, musamman game da gishirin saman teku, zafin jiki, da turbidity.
Za mu iya samar da nau'ikan na'urori masu auna sigina daban-daban don sa ido kan ilimin ruwa da ingancin ruwa, barka da zuwa tuntuɓar mu.
Lokacin Saƙo: Satumba-18-2024