[hr]<\/p>\n
Metan znatno pridonosi globalnom zagrijavanju<\/strong><\/p>\n Nakon ugljikova dioksida, on je drugi najve\u0107i uzrok globalnog zagrijavanja izazvanog direktnim djelovanjem ljudi. Najve\u0107i biogeni izvori metana jesu mo\u010dvarna podru\u010dja i ostali slatkovodni sustavi, s naglaskom na staja\u0107icama.<\/p>\n Tijekom 2022. i 2023. godine Institut Ru\u0111er Bo\u0161kovi\u0107 proveo je istra\u017eivanje \u201eMetan u Visovcu \u2013 uloga biogeokemijskih procesa i dinamika mikrobnih zajednica \u2013 METVIS\u201c<\/strong> s ciljem utvr\u0111ivanja uloge i zna\u010daja mikrobnih zajednica u kru\u017eenju metana u jezeru Visovac.<\/p>\n Tijekom istra\u017eivanog razdoblja pra\u0107eni su fizikalno-kemijski parametri: prisutnost bakterija odgovornih za sintezu ili\/i razgradnju metana u vodenom stupcu i korelacija kemijskih parametara i koncentracije metana s bakterijskom zajednicom. Uporabom najnovijih metoda u istra\u017eivanju sastava mikrobnih zajednica (sekvencioniranja sljede\u0107e generacije) i povezivanjem tih zajednica s fizikalno-kemijskim parametrima, na dvjema odabranim to\u010dkama na jezeru Visovac istra\u017een je odnos bakterija i metana. Kako je u lipnju 2023. godine zabilje\u017eena iznimno velika koli\u010dina oborina, koja je uzrokovala mije\u0161anje vodenog stupca, on nije dalje obra\u0111ivan. Ipak, budu\u0107i da su obje to\u010dke na kojima je obavljeno uzorkovanje imale vrlo sli\u010dne rezultate, u budu\u0107nosti bi uzorkovanje sa samo jedne to\u010dke bilo dovoljno za pra\u0107enje koncentracije metana u jezeru.<\/p>\n Koncentracija kisika u vodenom stupcu opadala je od prolje\u0107a do jeseni. U pridnenom sloju utvr\u0111ena je anoksija (pomanjkanje koli\u010dine kisika u organizmima), na \u0161to je upu\u0107ivalo i pove\u0107anje sulfata u tom sloju. Na pojavu anoksije \u00a0najvi\u0161e utje\u010de porast temperature vode.<\/p>\n Metan je utvr\u0111en u svim uzorcima. Njegova koncentracija raste od prolje\u0107a prema jeseni, ali u granicama koje su i ina\u010de utvr\u0111ene u sli\u010dnim slatkovodnim ekosustavima. Svaka sezona oblikovala je svoju mikrobnu populaciju, a pojava anoksije najvi\u0161e je utjecala na njihov sastav. Najzna\u010dajnije grupe bakterija odgovorne za ciklus metana jesu Methylococcales<\/em> i Methanobacteriales\/Metanobacterium.<\/em><\/p>\n Da bi se dobila kompletna slika organskog optere\u0107enja jezerskog sustava, istra\u017eivanja trebaju osim Visovca obuhvatiti i jezero Brljan, a uzorkovanje se mora obavljati redovito. Zbog jake interakcije organskog optere\u0107enja i koncentracije metana, u budu\u0107nosti se mora realizirati i monitoring organskog optere\u0107enja ekosustava Krke.<\/p>\n \u00a0<\/p>\n \u00a0<\/p>\n [\/hr]<\/p>\n [en] After carbon dioxide, it is the second largest cause of global warming caused by direct human activity. The largest biogenic sources of methane are wetlands and other freshwater systems, with an emphasis on bodies of stagnant water.<\/p>\n During 2022 and 2023, the Ru\u0111er Bo\u0161kovi\u0107 Institute conducted the research project \u201cMethane at Visovac \u2013 the role of biogeochemical processes and the dynamics of microbial communities \u2013 METVIS\u201d<\/strong>, with the aim of determining the role and importance of microbial communities in the circulation of methane in Visovac Lake.<\/p>\n Physical-chemical parameters were monitored during the period of investigation; the presence of bacteria responsible for the synthesis and\/or decomposition of methane in the water column, and the correlation of chemical parameters and methane concentration with the bacterial community. By utilizing the latest methods in investigating the composition of microbial communities (next generation sequencing) and connecting them with physical-chemical parameters, the relationship between the bacteria and methane was investigated at two selected points at Visovac Lake. As an exceptionally large amount of precipitation was recorded during June 2023, which caused mixing of the water column, hence it was not investigated further, but both sampling points had very similar results, and in the future, one sampling point would be sufficient for monitoring the concentration of methane in the lake.<\/p>\n The concentration of oxygen in the water column decreased from spring to autumn, where anoxia was established in the lower \u00a0layer, while an increase in sulfate in the lower layer also indicated anoxia. Temperature is the factor that most significantly affects the appearance of anoxia.<\/p>\n Methane was documented in all samples, with an increase in concentration from spring to autumn, but within the limits that have otherwise been established in similar freshwater ecosystems. Each season shaped its own microbial population, but the occurrence of anoxia had the most significant impact on the composition. The most important groups of bacteria responsible for the methane cycle are: Methylococcales<\/em> and Methanobacteriales\/Metanobacterium.<\/em><\/p>\n In order to obtain a complete picture of the organic load of the lake system, investigation should include Brljan Lake, in addition to Visovac Lake, and regular sampling should continue. Also, due to the strong interaction of the organic load and methane concentration, it would be necessary in the future to implement monitoring of the organic load of the Krka River ecosystem. Metan znatno pridonosi globalnom zagrijavanju<\/p>\n","protected":false},"author":3,"featured_media":588,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[44],"tags":[],"class_list":["post-9459","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-research"],"_links":{"self":[{"href":"https:\/\/npkrka.hr\/hr\/wp-json\/wp\/v2\/posts\/9459","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/npkrka.hr\/hr\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/npkrka.hr\/hr\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/npkrka.hr\/hr\/wp-json\/wp\/v2\/users\/3"}],"replies":[{"embeddable":true,"href":"https:\/\/npkrka.hr\/hr\/wp-json\/wp\/v2\/comments?post=9459"}],"version-history":[{"count":4,"href":"https:\/\/npkrka.hr\/hr\/wp-json\/wp\/v2\/posts\/9459\/revisions"}],"predecessor-version":[{"id":14050,"href":"https:\/\/npkrka.hr\/hr\/wp-json\/wp\/v2\/posts\/9459\/revisions\/14050"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/npkrka.hr\/hr\/wp-json\/wp\/v2\/media\/588"}],"wp:attachment":[{"href":"https:\/\/npkrka.hr\/hr\/wp-json\/wp\/v2\/media?parent=9459"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/npkrka.hr\/hr\/wp-json\/wp\/v2\/categories?post=9459"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/npkrka.hr\/hr\/wp-json\/wp\/v2\/tags?post=9459"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}
\n\u201cMethane at Visovac \u2013 the role of biogeochemical processes and dynamics of microbial communities \u2013 METVIS\u201d<\/strong>
\nMethane contributes significantly to global warming<\/strong><\/p>\n
\n[\/en]<\/p>\n","protected":false},"excerpt":{"rendered":"