An nuna canje-canjen da ke haifar da yanayi a cikin abubuwan shigar ruwa mai daɗi don yin tasiri ga tsari da aikin yanayin yanayin bakin teku. Mun kimanta canje-canje a cikin tasirin ruwan kogin a kan tsarin bakin teku na Arewa maso yammacin Patagonia (NWP) a cikin shekarun da suka gabata (1993-2021) ta hanyar haɗin bincike na jerin lokaci mai gudana na dogon lokaci, kwaikwaiyon ruwa, tauraron dan adam da aka samu da sake nazari akan yanayin saman teku (zazzabi, turbidity, da salinity). Mahimman raguwa a cikin mafi ƙarancin magudanar ruwa a cikin yankin da ke da manyan raƙuman ruwa shida ya bayyana a ma'auni na mako-mako, kowane wata, da na yanayi. Waɗannan sauye-sauyen sun fi bayyana a cikin gauraye masu rahusa na arewaci (misali, Kogin Puelo) amma da alama suna ci gaba zuwa kudu zuwa kogunan da ke da tsarin mulkin kama-karya. A cikin tekun ciki mai layi biyu na kusa, raguwar shigar ruwa mai kyau yayi daidai da madaidaicin halocline da kuma ƙarin yanayin zafi a arewacin Patagonia. Sakamakonmu yana nuna tasirin koguna da ke tasowa cikin sauri akan estuarine da kuma ruwan bakin teku a cikin NWP. Muna ba da haske game da buƙatun lura da ƙetaren muhalli, hasashen, ragewa da dabarun daidaitawa a cikin sauyin yanayi, tare da daidaitaccen tsarin kula da kwandon shara na tsarin da ke ba da kwararar ruwa zuwa ruwan tekun tekun.
Koguna su ne tushen tushen shigar ruwa na nahiyar zuwa tekuna1. A cikin rukunonin tsarin bakin teku, koguna suna da mahimmancin tafiyar matakai na wurare dabam dabam2 da gada tsakanin halittun ƙasa da na ruwa, jigilar abubuwan gina jiki, kwayoyin halitta, da matsuguni waɗanda ke haɓaka waɗanda ke bakin teku da buɗe teku3. Bincike na baya-bayan nan ya ba da rahoton sauye-sauye a cikin girma da lokacin shigar ruwa mai daɗi zuwa tekun bakin teku4. Nazari na jerin lokaci da ƙirar ruwa suna nuna nau'ikan yanayi daban-daban5, jere, alal misali, daga ƙaƙƙarfan haɓakar magudanar ruwa a manyan latitudes6-saboda ƙara narke kankara-zuwa raguwar abubuwan da ke faruwa a tsakiyar latitudes saboda karuwar fari na ruwa7. Ba tare da la’akari da alkibla da girman yanayin da aka ruwaito kwanan nan ba, an gano canjin yanayi a matsayin babban abin da ke haifar da sauye-sauyen gwamnatocin ruwa8, yayin da tasirin ruwan teku da kuma yanayin da suke tallafawa har yanzu ba a tantance da kuma fahimta ba9. Canje-canje na wucin gadi a cikin kwararar ruwa, tasirin canjin yanayi (canza yanayin hazo da hauhawar yanayin zafi) da matsin lamba na anthropogenic kamar madatsun ruwa na ruwa ko tafki10,11, karkatar da ruwa, da sauye-sauyen amfani da ƙasa12, suna haifar da ƙalubale don nazarin abubuwan da ke faruwa a cikin abubuwan shigar ruwa mai daɗi13,14. Alal misali, bincike da yawa sun nuna cewa yankunan da ke da ɗimbin gandun daji suna nuna juriyar yanayin muhalli yayin fari fiye da waɗanda noman daji ko noma ke mamayewa15,16. A tsakiyar latitudes, fahimtar tasirin canjin yanayi na gaba a kan tekun bakin teku ta hanyar kawar da tasirin sauyin yanayi da rikice-rikice na al'ada na gida yana buƙatar lura daga tsarin tunani tare da iyakanceccen canji ta yadda za a iya raba canje-canje a cikin tsarin tsarin ruwa daga rikicewar ɗan adam na gida.
Yammacin Patagonia (> 41 ° S a kan Tekun Pasifik na Kudancin Amirka) ya fito a matsayin ɗaya daga cikin waɗannan yankuna masu kyau, inda bincike mai gudana yana da mahimmanci don saka idanu da kiyaye waɗannan halittu. A cikin wannan yanki, koguna masu gudana kyauta suna hulɗa tare da hadaddun yanayin yanayin gabar teku don siffata ɗaya daga cikin mafi girman macro-estuaries a duniya17,18. Saboda nisan su, rafukan kogin Patagonia sun kasance babu damuwa sosai, tare da babban gandun daji na asali19, ƙarancin yawan jama'a, kuma gabaɗaya babu madatsun ruwa, tafki, da kayayyakin ban ruwa. Lalacewar waɗannan yanayin yanayin bakin teku ga sauye-sauyen muhalli ya dogara musamman, ta hanyar haɓaka, akan hulɗar su da tushen ruwan. Abubuwan shigar ruwa na ruwa a cikin tekun bakin teku na Arewa maso yammacin Patagonia (NWP; 41-46 ºS), gami da hazo kai tsaye da ruwan kogi, suna mu'amala da yawan ruwan teku, musamman ma babban ruwan Subantarctic Water (SAAW). Wannan, bi da bi, yana rinjayar yanayin wurare dabam dabam, sabuntawar ruwa, da samun iska20 ta hanyar samar da ƙarfin salinity gradients, tare da babban matsayi na bambancin yanayi da bambancin sararin samaniya a cikin halocline21. Haɗin kai tsakanin waɗannan maɓuɓɓugan ruwa guda biyu kuma yana tasiri abubuwan da ke tattare da al'ummomin planktonic22, yana rinjayar attenuation23 mai haske, kuma yana haifar da dilution na Nitrogen da phosphorus maida hankali a cikin SAAW24 da haɓaka samar da orthosilicate a saman Layer25,26. Bugu da ƙari, shigar da ruwa mai tsabta yana haifar da ƙaƙƙarfan gradient mai ƙarfi na narkar da iskar oxygen (DO) a cikin waɗannan ruwayen estuarine, tare da babban Layer gabaɗaya yana nuna babban taro na DO (6-8 ml L-1)27.
Matsakaicin matsakaicin tsaka-tsaki da ke nuna rafukan nahiyoyin Patagonia ya bambanta da yawan amfani da bakin teku, musamman ta masana'antar kiwo, wani muhimmin sashin tattalin arziki a Chile. A halin yanzu tana cikin manyan masu noman kiwo a duniya, Chile ita ce ta biyu mafi yawan fitar da kifin kifi da kifi, kuma ta fi kowacce fitar da mussels28. Salmon da kuma noman mussel, wanda a halin yanzu ya mamaye ca. 2300 concession sites tare da jimlar yanki ca. 24,000 ha a yankin, yana haifar da ƙimar tattalin arziki mai mahimmanci a kudancin Chile29. Wannan ci gaban ba yana tare da tasirin muhalli ba, musamman a yanayin noman salmon, wani aiki da ke ba da gudummawa tare da abubuwan gina jiki na waje ga waɗannan mahalli30. An kuma nuna cewa yana da rauni sosai ga sauye-sauyen yanayi31,32.
A cikin 'yan shekarun nan, binciken da aka gudanar a cikin NWP ya ba da rahoton raguwar abubuwan shigar ruwa33 da kuma hasashen raguwar kwararar ruwa a lokacin bazara da kaka34, da kuma tsawaita fari na ruwa35. Waɗannan canje-canje a cikin abubuwan shigar ruwa mai daɗi suna yin tasiri ga sigogin muhalli nan da nan kuma suna da tasiri mai fa'ida akan faɗuwar yanayin yanayin muhalli. Misali, matsananciyar yanayi a cikin ruwa na bakin teku a lokacin rani-kaka fari ya zama mai yawa, kuma, a wasu lokuta, sun yi tasiri ga masana'antar kiwo ta hanyar hypoxia36, karuwar parasitism, da cututtukan algal blooms32,37,38 (HABs).
A cikin 'yan shekarun nan, binciken da aka gudanar a cikin NWP ya ba da rahoton raguwar abubuwan shigar ruwa33 da kuma hasashen raguwar kwararar ruwa a lokacin bazara da kaka34, da kuma tsawaita fari na ruwa35. Waɗannan canje-canje a cikin abubuwan shigar ruwa mai daɗi suna yin tasiri ga sigogin muhalli nan da nan kuma suna da tasiri mai fa'ida akan faɗuwar yanayin yanayin muhalli. Misali, matsananciyar yanayi a cikin ruwa na bakin teku a lokacin rani-kaka fari ya zama mai yawa, kuma, a wasu lokuta, sun yi tasiri ga masana'antar kiwo ta hanyar hypoxia36, karuwar parasitism, da cututtukan algal blooms32,37,38 (HABs).
Ilimi na yanzu game da raguwar abubuwan shigar ruwa mai daɗi a cikin NWP ya dogara ne akan nazarin ma'aunin ruwa na ruwa39, wanda ke bayyana ƙididdiga ko ƙayyadaddun kaddarorin jerin bayanan hydrologic waɗanda aka samo daga ƙayyadaddun bayanai na dogon lokaci da ƙaramin ɗaukar hoto. Dangane da yanayin yanayin ruwa mai dacewa a cikin ruwan esturine na NWP ko kuma tekun da ke kusa da bakin teku, babu wasu bayanan da ke cikin wurin na dogon lokaci. Bisa la'akari da raunin ayyukan zamantakewa da tattalin arziki na bakin teku ga tasirin sauyin yanayi, ɗaukar cikakkiyar hanyar mu'amala ta ƙasa da teku don gudanarwa da daidaitawa ga canjin yanayi yana da mahimmanci40. Don magance wannan ƙalubalen, mun haɗa ƙirar ƙirar ruwa (1990-2020) tare da tauraron dan adam da aka samo da kuma sake nazarin bayanan yanayin saman teku (1993-2020). Wannan tsarin yana da manyan manufofi guda biyu: (1) don tantance yanayin tarihi a cikin ma'aunin ruwa a ma'aunin yanki da (2) don nazarin abubuwan da waɗannan canje-canjen ke haifarwa ga tsarin gabar tekun da ke kusa, musamman game da salinity na saman teku, zafin jiki, da turbidity.
Za mu iya samar da nau'ikan na'urori masu auna sigina daban-daban don saka idanu akan ilimin ruwa da ingancin ruwa, maraba don tuntuɓar.
Lokacin aikawa: Satumba-18-2024