{"id":4998,"date":"2018-08-10T08:31:01","date_gmt":"2018-08-10T07:31:01","guid":{"rendered":"https:\/\/www.vtei.cz\/?p=4998"},"modified":"2024-07-16T14:29:58","modified_gmt":"2024-07-16T13:29:58","slug":"changes-in-chemistry-and-biology-of-the-mesotrophic-water-reservoir-after-an-extraordinary-level-decrease","status":"publish","type":"post","link":"https:\/\/www.vtei.cz\/en\/2018\/08\/changes-in-chemistry-and-biology-of-the-mesotrophic-water-reservoir-after-an-extraordinary-level-decrease\/","title":{"rendered":"Changes in chemistry and biology of the mesotrophic water reservoir after an extraordinary level decrease"},"content":{"rendered":"

<\/i> This article is available in Czech only. For translation or more information on this topic, please contact author.<\/h4>\n

 <\/p>\n

Souhrn<\/h2>\n

Vod\u00e1rensk\u00e1 n\u00e1dr\u017e Opatovice je v\u00fdznamn\u00fdm zdrojem pitn\u00e9 vody pro okresn\u00ed m\u011bsto Vy\u0161kov na ji\u017en\u00ed Morav\u011b severov\u00fdchodn\u011b od Brna. Po \u010d\u00e1ste\u010dn\u00e9m sn\u00ed\u017een\u00ed hladiny v\u00a0roce 2012 a\u00a0po v\u00fdznamn\u00e9m sn\u00ed\u017een\u00ed v\u00a0roce 2017 byly zaznamen\u00e1ny znateln\u00e9 zm\u011bny v\u00a0chemismu i\u00a0v\u00a0biologii n\u00e1dr\u017ee. Do\u0161lo ke zhor\u0161en\u00ed kysl\u00edkov\u00e9ho re\u017eimu, zv\u00fd\u0161en\u00ed koncentrace n\u011bkter\u00fdch l\u00e1tek a\u00a0hlavn\u011b k\u00a0tvorb\u011b pom\u011brn\u011b intenzivn\u00edho vodn\u00edho kv\u011btu v\u00a0pozdn\u011b letn\u00edm obdob\u00ed. Zvl\u00e1\u0161t\u011b nep\u0159\u00edjemn\u00fd je rozvoj problematick\u00e9ho rodu Microcystis<\/em>.<\/p>\n\"\"<\/a>\n

\u00davod<\/h2>\n

N\u00e1dr\u017e Opatovice zat\u00edm pat\u0159ila k\u00a0pom\u011brn\u011b kvalitn\u00edm jihomoravsk\u00fdm zdroj\u016fm pitn\u00e9 vody. Podle projev\u016f eutrofizace ji bylo mo\u017eno ozna\u010dit jako mezotrofn\u00ed a\u017e slab\u011b eutrofn\u00ed. Masov\u00fd sinicov\u00fd vodn\u00ed kv\u011bt se sporadicky n\u011bkolikr\u00e1t vyskytl po\u010d\u00e1tkem 90. let, posledn\u00edch minim\u00e1ln\u011b 10\u00a0let tvo\u0159ily sinice pouze men\u0161\u00ed \u010d\u00e1st biomasy fytoplanktonu a\u00a0hodnoty chlorofylu a<\/em>\u00a0v\u011bt\u0161inou nep\u0159esahovaly 20\u2008\u00b5g\/l.<\/p>\n

Do roku 2012 se v\u00fd\u0161ka hladiny pohybovala kolem k\u00f3ty 333\u2008m n. m. Po zji\u0161t\u011bn\u00ed skute\u010dnosti, \u017ee j\u00edlov\u00e9 j\u00e1dro hr\u00e1ze sesych\u00e1 a\u00a0kles\u00e1, byla v\u00a0roce 2012 z\u00a0bezpe\u010dnostn\u00edch d\u016fvod\u016f sn\u00ed\u017eena hladina zhruba o\u00a0dva metry pod k\u00f3tu 331\u2008m n. m. Na ja\u0159e 2017 byla hladina sn\u00ed\u017eena je\u0161t\u011b v\u00edce kv\u016fli rekonstrukci hr\u00e1ze a\u017e na k\u00f3tu 319\u2008m\u00a0n.\u00a0m., co\u017e je o\u00a014 metr\u016f proti p\u016fvodn\u00edmu stavu. Celkov\u00fd objem zadr\u017een\u00e9 vody poklesl z\u00a0p\u0159ibli\u017en\u011b 9\u2008mil. m3 <\/sup>na hodnoty kolem 300\u00a0000\u2008<\/sup>m3<\/sup>!<\/p>\n

Pon\u011bvad\u017e jsou takov\u00e9to z\u00e1sahy prov\u00e1zeny v\u011bt\u0161inou negativn\u00edmi zm\u011bnami v\u00a0chemismu i\u00a0biologii, byly vyhodnoceny zm\u011bny v\u00a0okysli\u010den\u00ed, teplot\u011b, slo\u017een\u00ed \u017eivin i\u00a0n\u011bkter\u00fdch kov\u016f a\u00a0tak\u00e9 zm\u011bny biologick\u00e9, u\u00a0kter\u00fdch jsme se zam\u011b\u0159ili mimo zm\u011bn kvantitativn\u00edch zvl\u00e1\u0161t\u011b na slo\u017een\u00ed fytoplanktonu a\u00a0p\u0159\u00edtomnost nebo absenci a\u00a0p\u0159\u00edpadn\u00fd rozsah vodn\u00edho sinicov\u00e9ho kv\u011btu.<\/p>\n

Parametry a\u00a0charakteristika n\u00e1dr\u017ee<\/h2>\n

N\u00e1dr\u017e se nach\u00e1z\u00ed na \u0159\u00ed\u010dce Mal\u00e1 Han\u00e1 v\u00a0bl\u00edzkosti okresn\u00edho m\u011bsta Vy\u0161kov v\u00a0Jihomoravsk\u00e9m kraji. Jej\u00edm hlavn\u00edm \u00fa\u010delem je akumulace vody pro skupinov\u00fd vodovod Vy\u0161kov a\u00a0Bu\u010dovice, d\u00e1le zaji\u0161t\u011bn\u00ed minim\u00e1ln\u00edho pr\u016ftoku a\u00a0sn\u00ed\u017een\u00ed pr\u016ftok\u016f povod\u0148ov\u00fdch. Vodn\u00ed n\u00e1dr\u017e Opatovice m\u00e1 celkovou d\u00e9lku 2,3\u2008km, maxim\u00e1ln\u00ed hloubku 33\u2008m, z\u00e1sobn\u00ed objem 7,784\u00a0mil.\u00a0m3<\/sup> a\u00a0celkov\u00fd objem 9,867\u00a0mil.\u00a0m3<\/sup>. Zatopen\u00e1 plocha je 70,51\u2008ha a\u00a0plocha nevelk\u00e9ho a\u00a0pom\u011brn\u011b zalesn\u011bn\u00e9ho povod\u00ed je 43,24\u2008km2<\/sup>. V\u00a0povod\u00ed jsou v\u00fdznamn\u011b zastoupeny listnat\u00e9 d\u0159eviny. Pr\u016fm\u011brn\u00fd ro\u010dn\u00ed pr\u016ftok je 0,190\u2008m3<\/sup>\u2219s-1<\/sup>. Jedn\u00e1 se o\u00a0vod\u00e1renskou p\u0159ehradu s\u00a0nejv\u00edce dendritick\u00fdm charakterem (tzn. vn\u011bj\u0161\u00ed \u010dlenitost\u00ed) v\u00a0cel\u00e9m povod\u00ed Moravy. N\u00e1dr\u017e byla uvedena do provozu v\u00a0roce 1972.<\/p>\n

Metodika<\/h2>\n

Biologick\u00e9 i\u00a0chemick\u00e9 odb\u011bry v\u00a0n\u00e1dr\u017ei jsou dlouhodob\u011b prov\u00e1d\u011bny na nejhlub\u0161\u00ed svislici v\u00a0p\u0159ehrad\u011b naproti vod\u00e1rensk\u00e9mu odb\u011bru 7\u00d7 ro\u010dn\u011b v\u00a0pr\u016fb\u011bhu eta\u010dn\u00ed sezony, chemick\u00e9 odb\u011bry tak\u00e9 na p\u0159\u00edtoku v\u00a0\u00fast\u00ed \u0159\u00ed\u010dky Mal\u00e1 Han\u00e1. Pomoc\u00ed multiparametrick\u00e9 sondy YSI byly in situ <\/em>prom\u011b\u0159ov\u00e1ny n\u00e1sleduj\u00edc\u00ed parametry: teplota, pH, vodivost a\u00a0koncentrace O2<\/sub>. Pr\u016fhlednost je dlouhodob\u011b m\u011b\u0159ena hr\u00e1zn\u00fdm 1\u20132\u00d7 t\u00fddn\u011b. Chemick\u00e9 anal\u00fdzy provedla laborato\u0159 Povod\u00ed Moravy. Celkov\u00fd fosfor byl stanovov\u00e1n metodou ICP-MS, chlorofyl a<\/em>\u00a0metodou YSI 10260 (etanolovou extrakc\u00ed), \u0159asy a\u00a0sinice byly po\u010d\u00edt\u00e1ny v\u00a0sedimenta\u010dn\u00edch kom\u016frk\u00e1ch v\u00a0mikroskopu Leica DM-IL, p\u0159esn\u011bj\u0161\u00ed determinace byla prov\u00e1d\u011bna na mikroskopu Olympus BX-60 [1\u20133]. Byly prom\u011b\u0159eny hlavn\u00ed dominanty fytoplanktonu a\u00a0pro v\u00fdpo\u010det objemov\u00e9 biomasy byl pou\u017eit program FYTO\u2013HBU.<\/p>\n\"\"<\/a>\n

Obr. 1. Obsah celkov\u00e9ho manganu v surov\u00e9 vod\u011b odeb\u00edran\u00e9 z VN Opatovice na \u00fapravnu vody
\nFig. 1. The content of total manganese in raw water taken from the Opatovice Water Reservoir on the water treatment plant<\/h6>\n

Odb\u011br sm\u011bsn\u00e9ho vzorku byl prov\u00e1d\u011bn sm\u00edch\u00e1n\u00edm vzork\u016f vody v\u00a0hloubk\u00e1ch 0\u20134\u2008m po 0,5\u2008m. Odb\u011br surov\u00e9 vody byl prov\u00e1d\u011bn z\u00a0kohoutu odb\u011brn\u00e9ho potrub\u00ed, kter\u00e9 p\u0159iv\u00e1d\u00ed vodu na \u00fapravnu vody.<\/p>\n

V\u00fdsledky<\/h2>\n

V\u00fdvoj fyzik\u00e1ln\u011b-chemick\u00fdch podm\u00ednek v\u00a0n\u00e1dr\u017ei<\/h3>\n

V\u00a0teplotn\u00edch a\u00a0kysl\u00edkov\u00fdch zonac\u00edch se projevil v\u00fdrazn\u011bji a\u017e rok 2017, kdy se objevila velmi brzy v\u00fdrazn\u00e1 anoxie u\u00a0dna v\u00a0profilu u\u00a0hr\u00e1ze. Ve vodn\u00edm sloupci redukovan\u00e9m na v\u00fd\u0161ku 22 metr\u016f z\u00a0p\u016fvodn\u00edch 33\u2008m byl u\u017e v\u00a0\u010dervnu obsah rozpu\u0161t\u011bn\u00e9ho kysl\u00edku pod 1\u2008mg\/l ve vrstv\u011b 10\u2008m nade dnem. Takto siln\u00fd pokles kysl\u00edku v\u00a0hypolimniu nebyl dosud na n\u00e1dr\u017ei zachycen (obr. 2<\/em>). V\u00a0d\u016fsledku toho v\u00fdrazn\u011b vzrostly koncentrace manganu v\u00a0cel\u00e9m vodn\u00edm sloupci, zejm\u00e9na v\u0161ak v\u00a0odeb\u00edran\u00e9 surov\u00e9 vod\u011b (obr. 1<\/em>). Spolu s\u00a0manganem v\u00a0surov\u00e9 vod\u011b v\u00fdrazn\u011b vzrostla i\u00a0koncentrace \u017eeleza a\u00a0amoniaku (obr. 3<\/em>).<\/p>\n\"\"<\/a>\n

Obr. 2. Dlouhodob\u00e1 stratifi kace rozpu\u0161t\u011bn\u00e9ho kysl\u00edku ve VN Opatovice
\nFig. 2. Long-term stratification of dissolved oxygen in the Opatovice Water Reservoir<\/h6>\n

Z\u00a0graf\u016f je patrn\u00e9, \u017ee uveden\u00e9 parametry nam\u011b\u0159en\u00e9 v\u00a0surov\u00e9 nebyly v\u00fdrazn\u011b ovlivn\u011bny poklesem v\u00a0roce 2012, ale pozorovateln\u00e9 zm\u011bny nastaly a\u017e v\u00a0roce 2017. Na odtoku z\u00a0n\u00e1dr\u017ee (obr. 4<\/em>) v\u0161ak u\u017e jsou patrn\u00e9, ne v\u0161ak pr\u016fkazn\u00e9 (na rozd\u00edl od koncentrac\u00ed v\u00a0surov\u00e9 vod\u011b), i\u00a0zm\u011bny tohoto prvn\u00edho upu\u0161t\u011bn\u00ed o\u00a0cca 2 metry. Odb\u011brn\u00fd objekt je toti\u017e situovan\u00fd v\u00fd\u0161e ne\u017e objekt v\u00fdpustn\u00ed, ve vod\u011b odt\u00e9kaj\u00edc\u00ed spodn\u00ed v\u00fdpust\u00ed se tedy projev\u00ed anoxie v\u00a0n\u00e1dr\u017ei siln\u011bji a\u00a0d\u0159\u00edve. V\u00a0parametru N-NH4<\/sub> byl dokonce n\u00e1r\u016fst v\u00a0roce 2012 v\u011bt\u0161\u00ed ne\u017e v\u00a0roce 2017. Na rozd\u00edl od surov\u00e9 vody jsou ve vod\u011b odt\u00e9kaj\u00edc\u00ed spodn\u00ed v\u00fdpust\u00ed vid\u011bt i\u00a0p\u0159edchoz\u00ed v\u00fdkyvy, kter\u00e9 byly zp\u016fsobeny z\u0159ejm\u011b po sn\u00ed\u017een\u00ed hladiny v\u00a0letech 2002 a\u00a02003. N\u00e1dr\u017e reaguje velmi citliv\u011b na obdob\u00ed s\u00a0v\u00fdrazn\u011bji sn\u00ed\u017eenou hladinou.<\/p>\n\"\"<\/a>\n

Obr. 3. Obsah celkov\u00e9ho \u017eeleza (naho\u0159e) a N-NH4<\/sub> (dole) v surov\u00e9 vod\u011b
\nFig. 3. Total iron content (above) and N-NH4<\/sub> (down) in raw water<\/h6>\n

V\u00a0surov\u00e9 vod\u011b i\u00a0ve vod\u011b odt\u00e9kaj\u00edc\u00ed spodn\u00ed v\u00fdpust\u00ed byly roky 2003, 2012 a\u00a02017 extr\u00e9mn\u00ed n\u00edzk\u00fdmi koncentracemi dusi\u010dnan\u016f (obr. 5<\/em>). Zejm\u00e9na rok 2017 byl v\u00a0tomto ohledu mimo\u0159\u00e1dn\u00fd, do\u0161lo prakticky k\u00a0vy\u010derp\u00e1n\u00ed ve\u0161ker\u00fdch dusi\u010dnan\u016f v\u00a0hypolimniu.<\/p>\n

Jak p\u0159edchoz\u00ed m\u00edrn\u00e9 sn\u00ed\u017een\u00ed v\u00a0roce 2012 (a\u00a0pravd\u011bpodobn\u011b i\u00a0v\u00a0roce 2002), tak zejm\u00e9na odpu\u0161t\u011bn\u00ed n\u00e1dr\u017ee v\u00a0roce 2017 m\u011blo tedy v\u00fdrazn\u00fd vliv na fyzik\u00e1ln\u00ed parametry a\u00a0chemismus n\u00e1dr\u017ee. Toto pozorov\u00e1n\u00ed je v\u00a0souladu s\u00a0podobn\u00fdmi jevy na n\u00e1dr\u017ei Land\u0161tejn [4] a\u00a0Karolinka [5].<\/p>\n\"\"<\/a>\n

Obr. 4. Obsah celkov\u00e9ho manganu (naho\u0159e) a\u00a0N-NH4<\/sub> (dole) v\u00a0odtoku z\u00a0VN Opatovice
\nFig. 4. The content of total manganese (above) and N-NH4 <\/sub>(down) in the outflow from the Opatovice Water Reservoir<\/h6>\n

V\u00fdvoj fytoplanktonu<\/h3>\n

V\u00fdvoj fytoplanktonu zde hodnot\u00edme ve t\u0159ech rozd\u00edln\u00fdch obdob\u00edch: I. obdob\u00ed p\u0159ed sn\u00ed\u017een\u00edm hladiny na ja\u0159e 2012, II. obdob\u00ed 2012\u2013jaro 2016 a\u00a0III. obdob\u00ed\u00a0\u2013 vegeta\u010dn\u00ed sezona 2017.<\/p>\n

I. obdob\u00ed<\/h4>\n

V\u00a0jarn\u00edch m\u011bs\u00edc\u00edch nebyly mezi jednotliv\u00fdmi obdob\u00edmi v\u00fdrazn\u011bj\u0161\u00ed rozd\u00edly, v\u00a0dubnu obvykle p\u0159eva\u017eovaly drobn\u00e9 cetrick\u00e9 rozsivky (Stephanodiscus parvus<\/em>), r\u016fzn\u00e9 skryt\u011bnky nebo pen\u00e1tn\u00ed rozsivka Asterionella formosa<\/em>. V\u00a0kv\u011btnu t\u00e9m\u011b\u0159 v\u00fdhradn\u011b dominovala pro tuto p\u0159ehradu typick\u00e1 centrick\u00e1 rozsivka Cyclotella balatonis<\/em>, ve d\u0159\u00edv\u011bj\u0161\u00edch determina\u010dn\u00edch kl\u00ed\u010d\u00edch ozna\u010dov\u00e1na jako Cyclotella radiosa<\/em>. V\u00a0\u010dervnu se v\u00a0obdob\u00ed \u201eclear water\u201c<\/em> objevuj\u00ed prvn\u00ed vl\u00e1knit\u00e9 sinice rod\u016f Dolichospermum<\/em> a\u00a0Aphanizomenon<\/em>, schopn\u00e9 v\u00e1zat vzdu\u0161n\u00fd dus\u00edk. V l\u00e9t\u011b a\u00a0na podzim dominovaly fytoplanktonu hlavn\u011b sinice, nevytv\u00e1\u0159ely v\u0161ak vysokou biomasu a\u00a0rod Microcystis<\/em> byl zastoupen pouze p\u0159\u00eddatn\u011b.<\/p>\n\"\"<\/a>\n

Obr. 5. Koncentrace dusi\u010dnanov\u00e9ho dus\u00edku v\u00a0surov\u00e9 vod\u011b (dole) a\u00a0v\u00a0odtoku z\u00a0n\u00e1dr\u017ee (naho\u0159e)
\nFig. 5. Concentration of nitrate nitrogen in raw water (down) and outflow from tank (above)<\/h6>\n

II. obdob\u00ed<\/h4>\n

Prvn\u00ed rozd\u00edly se projevily ji\u017e v\u00a0\u010dervenci, kdy se v\u00a0obdob\u00ed II. objevuje fytoplankton s\u00a0p\u0159eva\u017euj\u00edc\u00edmi sinicemi rodu Microcystis<\/em>. Tento rod preferuje vy\u0161\u0161\u00ed teplotu a\u00a0vysokou stabilitu epilimnia [6, 7]. V\u00a0I. obdob\u00ed d\u0159\u00edve zpravidla v\u00a0\u010dervenci n\u00e1sledoval rozvoj dus\u00edk fixuj\u00edc\u00edch sinic, kter\u00e9 ov\u0161em nedosahovaly vy\u0161\u0161\u00ed biomasy. V\u00a0srpnu ve v\u0161ech t\u0159ech uveden\u00fdch obdob\u00edch tyto sinice zpravidla dominovaly, ov\u0161em v\u00a0posledn\u00edch dvou obdob\u00edch doch\u00e1zelo k\u00a0v\u00fdrazn\u00e9mu zv\u00fd\u0161en\u00ed sinicov\u00e9 biomasy, nap\u0159. druhu Aphanizomenon flos aquae<\/em> v\u00a0roce 2014 nebo Limnococcus limneticus <\/em>v\u00a0roce 2016. V\u00a0letech 2012 se v\u00a0srpnu rovn\u011b\u017e rozvinula populace planktonn\u00ed rozsivky Fragilaria crotonensis<\/em>. V\u00a0z\u00e1\u0159\u00ed ji\u017e v\u00a0tomto obdob\u00ed doch\u00e1z\u00ed k\u00a0pravideln\u00e9mu siln\u00e9mu rozvoji sinic. V\u00fdrazn\u00fd vodn\u00ed kv\u011bt byl pozorov\u00e1n zvl\u00e1\u0161t\u011b v\u00a0letech 2013 a\u00a02017 a\u00a0odpov\u00eddal ji\u017e eutrofn\u00ed n\u00e1dr\u017ei.<\/p>\n

III. obdob\u00ed<\/h4>\n

V\u00a0roce 2017 byla zji\u0161t\u011bna vysok\u00e1 biomasa sinic rodu Microcystis<\/em> a\u00a0sou\u010dasn\u011b nejvy\u0161\u0161\u00ed koncentrace chlorofylu\u00a0a<\/em> v\u00a0pozdn\u011b letn\u00edm obdob\u00ed (srpen, z\u00e1\u0159\u00ed). V\u00a0srpnu do\u0161lo k\u00a0siln\u00e9mu rozvoji rozsivky Fragilaria crotonensis<\/em>. Zm\u011bny v\u00a0tomto obdob\u00ed byly tedy pouze kvantitativn\u00ed.<\/p>\n

Shrnut\u00ed a\u00a0z\u00e1v\u011br<\/h2>\n

Sni\u017eov\u00e1n\u00ed hladiny vody v\u00a0\u00fadoln\u00edch n\u00e1dr\u017e\u00edch vede obecn\u011b ke zm\u011bn\u00e1m chemismu i\u00a0biologie vody. Tyto zm\u011bny jsou v\u011bt\u0161inou nep\u0159\u00edzniv\u00e9 pro jej\u00ed kvalitu a\u00a0\u010dasto vedou k\u00a0zintenzivn\u011bn\u00ed projev\u016f eutrofizace, p\u0159\u00edpadn\u011b dokonce ke zm\u011bn\u011b trofick\u00e9ho statusu n\u00e1dr\u017ee. V\u00a0povod\u00ed Moravy jsou d\u016fsledky takov\u00fdch zm\u011bn pozorov\u00e1ny zvl\u00e1\u0161t\u011b siln\u011b a\u00a0negativn\u011b, nap\u0159. v\u00a0n\u00e1dr\u017e\u00edch Land\u0161tejn a\u00a0V\u00edr. V\u00a0n\u011bkter\u00fdch velmi specifick\u00fdch p\u0159\u00edpadech m\u016f\u017ee naopak sn\u00ed\u017een\u00ed vodn\u00ed hladiny p\u0159isp\u011bt k\u00a0uskute\u010dn\u011bn\u00ed opat\u0159en\u00ed, kter\u00e1 napom\u00e1haj\u00ed biologickou i\u00a0chemickou kvalitu vody zvy\u0161ovat.<\/p>\n\"\"<\/a>\n

Obr. 6. Koncentrace chlorofylu\u00a0a<\/em>\u00a0ve sm\u011bsn\u00e9m vzorku u\u00a0hr\u00e1ze VN Opatovice
\nFig. 6. Concentration of chlorophyll\u00a0a<\/em> in mixed sample at the dam of Opatovice Water Reservoir<\/h6>\n

V\u00a0p\u0159\u00edpad\u011b Opatovic do\u0161lo ke zm\u011bn\u00e1m v\u00a0chemismu ji\u017e po prvn\u00edm men\u0161\u00edm sn\u00ed\u017een\u00ed v\u00a0roce 2012, k\u00a0opravdu v\u00fdrazn\u00fdm zm\u011bn\u00e1m v\u0161ak do\u0161lo a\u017e po zapo\u010det\u00ed opravy hr\u00e1ze a\u00a0zaklesnut\u00ed o\u00a0dal\u0161\u00edch t\u00e9m\u011b\u0159 deset metr\u016f na ja\u0159e 2017. Naproti tomu v\u00fdrazn\u00e9 zhor\u0161en\u00ed biologick\u00e9 zapo\u010dalo ji\u017e po prvn\u00edm z\u00e1sahu a\u00a0v\u00a0roce 2017 do\u0161lo pouze k\u00a0ur\u010dit\u00e9mu zhor\u0161en\u00ed, kter\u00e9 se projevilo vy\u0161\u0161\u00edmi koncentracemi chlorofylu\u00a0a<\/em>\u00a0v\u00a0pozdn\u011b letn\u00edm obdob\u00ed. Slo\u017een\u00ed druh\u016f \u0159as a\u00a0sinic se v\u0161ak od roku 2012 p\u0159\u00edli\u0161 nezm\u011bnilo (obr. 6<\/em>).<\/em><\/p>\n

Od roku 2012 se n\u011bkolikr\u00e1t objevil pom\u011brn\u011b siln\u00fd vodn\u00ed kv\u011bt, kter\u00fd byl tvo\u0159en hlavn\u011b druhy Aphanizomenon flos aquae, Microcystis aeruginosa, M. wesenbergii a\u00a0Woronichinia naegeliana. <\/em>Tyto sinice vytv\u00e1\u0159ej\u00ed rozmanit\u00e9 toxiny a\u00a0p\u0159i sv\u00e9m p\u0159emno\u017een\u00ed mohou nav\u00edc p\u016fsobit organoleptick\u00e9 pot\u00ed\u017ee [8].<\/p>\n

V\u00a0roce 2017 do\u0161lo hlavn\u011b k\u00a0prohlouben\u00ed kysl\u00edkov\u00fdch deficit\u016f, zv\u00fd\u0161en\u00ed koncentrace \u017eeleza, manganu i\u00a0amoniaku v\u00a0hypolimniu n\u00e1dr\u017ee, sou\u010dasn\u011b ov\u0161em k\u00a0t\u00e9m\u011b\u0159 kompletn\u00edmu vy\u010derp\u00e1n\u00ed dusi\u010dnan\u016f. K\u00a0v\u00fdrazn\u00e9mu vzr\u016fstu koncentrace celkov\u00e9ho fosforu do\u0161lo rovn\u011b\u017e v\u00a0tomto roce, nedo\u0161lo v\u0161ak zat\u00edm k\u00a0v\u00fdrazn\u00e9 biologick\u00e9 odezv\u011b.<\/p>\n

Pon\u011bvad\u017e hladina p\u0159ehrady bude sn\u00ed\u017eena je\u0161t\u011b minim\u00e1ln\u011b dv\u011b vegeta\u010dn\u00ed sezony, je nezbytn\u00e9 bedliv\u011b sledovat biologii i\u00a0chemismus a\u00a0v\u00a0tomto sledov\u00e1n\u00ed pokra\u010dovat i\u00a0po op\u011btovn\u00e9m napu\u0161t\u011bn\u00ed. S\u00a0nejvy\u0161\u0161\u00ed pravd\u011bpodobnost\u00ed m\u016f\u017eeme o\u010dek\u00e1vat dal\u0161\u00ed n\u00e1r\u016fst biomasy fytoplanktonu, jeho\u017e v\u00fdznamn\u00e1 \u010d\u00e1st bude pravd\u011bpodobn\u011b tvo\u0159ena sinicemi.<\/p>\n

 <\/p>\n

P\u0159\u00edsp\u011bvek byl publikov\u00e1n ve sborn\u00edku Vod\u00e1rensk\u00e1 biologie 2018, ISBN 978-80-88238-06-5.<\/p>\n","protected":false},"excerpt":{"rendered":"

Opatovice Water Reservoir is an important source of drinking water for the district town of Vy\u0161kov in South Moravia, northeast of Brno. After a\u00a0partial decrease in the level in 2012 and after a\u00a0significant reduction in 2017 there were marked changes in the chemistry and in the biology of the tank. <\/p>\n","protected":false},"author":8,"featured_media":4953,"comment_status":"closed","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"_acf_changed":false,"footnotes":""},"categories":[91],"tags":[1295,1294,290,1298,1297,1296],"coauthors":[1252,1253],"class_list":["post-4998","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-applied-ecology","tag-algal-blooms","tag-decrease-of-water-level","tag-drinking-water","tag-hypolimnetic-anoxia","tag-manganese","tag-phytoplankton-cell-count"],"acf":[],"_links":{"self":[{"href":"https:\/\/www.vtei.cz\/en\/wp-json\/wp\/v2\/posts\/4998","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.vtei.cz\/en\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.vtei.cz\/en\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.vtei.cz\/en\/wp-json\/wp\/v2\/users\/8"}],"replies":[{"embeddable":true,"href":"https:\/\/www.vtei.cz\/en\/wp-json\/wp\/v2\/comments?post=4998"}],"version-history":[{"count":2,"href":"https:\/\/www.vtei.cz\/en\/wp-json\/wp\/v2\/posts\/4998\/revisions"}],"predecessor-version":[{"id":30466,"href":"https:\/\/www.vtei.cz\/en\/wp-json\/wp\/v2\/posts\/4998\/revisions\/30466"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/www.vtei.cz\/en\/wp-json\/wp\/v2\/media\/4953"}],"wp:attachment":[{"href":"https:\/\/www.vtei.cz\/en\/wp-json\/wp\/v2\/media?parent=4998"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.vtei.cz\/en\/wp-json\/wp\/v2\/categories?post=4998"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.vtei.cz\/en\/wp-json\/wp\/v2\/tags?post=4998"},{"taxonomy":"author","embeddable":true,"href":"https:\/\/www.vtei.cz\/en\/wp-json\/wp\/v2\/coauthors?post=4998"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}