{"id":"https://openalex.org/W2525299142","doi":"https://doi.org/10.1127/lr/18/2008/25","title":"Long-term and seasonal changes of nutrients, seston and phytoplankton concentrations in the Lower Danube (Bulgarian-Romanian stretch)","display_name":"Long-term and seasonal changes of nutrients, seston and phytoplankton concentrations in the Lower Danube (Bulgarian-Romanian stretch)","publication_year":2008,"publication_date":"2008-05-21","ids":{"openalex":"https://openalex.org/W2525299142","doi":"https://doi.org/10.1127/lr/18/2008/25","mag":"2525299142"},"language":"en","primary_location":{"id":"doi:10.1127/lr/18/2008/25","doi":"https://doi.org/10.1127/lr/18/2008/25","is_oa":false,"landing_page_url":"https://doi.org/10.1127/lr/18/2008/25","pdf_url":null,"source":{"id":"https://openalex.org/S67052599","display_name":"River Systems","issn_l":"1868-5749","issn":["1868-5749","2363-7137"],"is_oa":false,"is_in_doaj":false,"is_core":true,"listed_in":["cwts-core"],"host_organization":null,"host_organization_name":null,"host_organization_lineage":[],"host_organization_lineage_names":[],"type":"journal"},"license":null,"license_id":null,"version":"publishedVersion","is_accepted":true,"is_published":true,"raw_source_name":"River Systems","raw_type":"journal-article"},"volume":null,"type":"article","indexed_in":["crossref"],"open_access":{"is_oa":false,"oa_status":"closed","oa_url":null,"any_repository_has_fulltext":false},"authorships":[{"author_position":"first","author":{"id":"https://openalex.org/A5045402561","display_name":"Roumen Kalchev","orcid":"https://orcid.org/0000-0002-1879-8589","observed_orcids":["https://orcid.org/0000-0002-1879-8589"]},"institutions":[],"countries":[],"is_corresponding":false,"raw_author_name":"R Kalchev","raw_affiliation_strings":[],"raw_orcid":null,"affiliations":[]},{"author_position":"middle","author":{"id":"https://openalex.org/A5004511341","display_name":"Doina Ionica","orcid":null,"observed_orcids":[]},"institutions":[],"countries":[],"is_corresponding":false,"raw_author_name":"D Ionica","raw_affiliation_strings":[],"raw_orcid":null,"affiliations":[]},{"author_position":"middle","author":{"id":"https://openalex.org/A5005949044","display_name":"Mihaela Beshkova","orcid":"https://orcid.org/0000-0001-8259-5260","observed_orcids":["https://orcid.org/0000-0001-8259-5260"]},"institutions":[],"countries":[],"is_corresponding":false,"raw_author_name":"M Beshkova","raw_affiliation_strings":[],"raw_orcid":null,"affiliations":[]},{"author_position":"middle","author":{"id":"https://openalex.org/A5019304694","display_name":"Ivan Botev","orcid":null,"observed_orcids":[]},"institutions":[],"countries":[],"is_corresponding":false,"raw_author_name":"I Botev","raw_affiliation_strings":[],"raw_orcid":null,"affiliations":[]},{"author_position":"last","author":{"id":"https://openalex.org/A5113022673","display_name":"Cristina Sandu","orcid":null,"observed_orcids":[]},"institutions":[],"countries":[],"is_corresponding":false,"raw_author_name":"C Sandu","raw_affiliation_strings":[],"raw_orcid":null,"affiliations":[]}],"institutions":[],"countries_distinct_count":0,"institutions_distinct_count":0,"corresponding_author_ids":[],"corresponding_institution_ids":[],"apc_list":null,"apc_paid":null,"fwci":0.7261,"has_fulltext":false,"cited_by_count":6,"citation_normalized_percentile":{"value":0.72164948,"is_in_top_1_percent":false,"is_in_top_10_percent":false},"cited_by_percentile_year":{"min":95,"max":96},"biblio":{"volume":"18","issue":"1-2","first_page":"25","last_page":"43"},"is_retracted":false,"is_paratext":false,"is_xpac":false,"primary_topic":{"id":"https://openalex.org/T10236","display_name":"Aquatic Ecosystems and Phytoplankton Dynamics","score":0.8901000022888184,"subfield":{"id":"https://openalex.org/subfields/2304","display_name":"Environmental Chemistry"},"field":{"id":"https://openalex.org/fields/23","display_name":"Environmental Science"},"domain":{"id":"https://openalex.org/domains/3","display_name":"Physical Sciences"}},"topics":[{"id":"https://openalex.org/T10236","display_name":"Aquatic Ecosystems and Phytoplankton Dynamics","score":0.8901000022888184,"subfield":{"id":"https://openalex.org/subfields/2304","display_name":"Environmental Chemistry"},"field":{"id":"https://openalex.org/fields/23","display_name":"Environmental Science"},"domain":{"id":"https://openalex.org/domains/3","display_name":"Physical Sciences"}},{"id":"https://openalex.org/T11311","display_name":"Soil and Water Nutrient Dynamics","score":0.07509999722242355,"subfield":{"id":"https://openalex.org/subfields/2304","display_name":"Environmental Chemistry"},"field":{"id":"https://openalex.org/fields/23","display_name":"Environmental Science"},"domain":{"id":"https://openalex.org/domains/3","display_name":"Physical Sciences"}},{"id":"https://openalex.org/T10032","display_name":"Marine and coastal ecosystems","score":0.013399999588727951,"subfield":{"id":"https://openalex.org/subfields/1910","display_name":"Oceanography"},"field":{"id":"https://openalex.org/fields/19","display_name":"Earth and Planetary Sciences"},"domain":{"id":"https://openalex.org/domains/3","display_name":"Physical Sciences"}}],"keywords":[{"id":"https://openalex.org/keywords/lower-danube-river","display_name":"Lower Danube River","score":0.9750000238418579},{"id":"https://openalex.org/keywords/nutrient-loading","display_name":"nutrient loading","score":0.699999988079071},{"id":"https://openalex.org/keywords/suspended-particulate-matter","display_name":"suspended particulate matter","score":0.7739999890327454},{"id":"https://openalex.org/keywords/phytoplankton-abundance","display_name":"phytoplankton abundance","score":0.9179999828338623},{"id":"https://openalex.org/keywords/seston","display_name":"seston","score":0.8009999990463257},{"id":"https://openalex.org/keywords/long-term-trends","display_name":"long-term trends","score":0.7319999933242798},{"id":"https://openalex.org/keywords/seasonal-variation","display_name":"seasonal variation","score":0.7329999804496765},{"id":"https://openalex.org/keywords/dissolved-inorganic-nitrogen","display_name":"dissolved inorganic nitrogen","score":0.8650000095367432},{"id":"https://openalex.org/keywords/phosphate","display_name":"phosphate","score":0.6269999742507935},{"id":"https://openalex.org/keywords/trophic-state","display_name":"trophic state","score":0.8330000042915344},{"id":"https://openalex.org/keywords/river-water-quality","display_name":"river water quality","score":0.5569999814033508},{"id":"https://openalex.org/keywords/nutrient-dilution","display_name":"nutrient dilution","score":0.5580000281333923},{"id":"https://openalex.org/keywords/eutrophication","display_name":"eutrophication","score":0.6669999957084656},{"id":"https://openalex.org/keywords/danube-delta","display_name":"Danube Delta","score":0.49399998784065247},{"id":"https://openalex.org/keywords/danube-delta-biosphere-reserve","display_name":"Danube Delta Biosphere Reserve","score":0.48899999260902405}],"concepts":[{"id":"https://openalex.org/C2780892065","wikidata":"https://www.wikidata.org/wiki/Q184755","display_name":"Phytoplankton","level":3,"score":0.8610864281654358},{"id":"https://openalex.org/C2776000122","wikidata":"https://www.wikidata.org/wiki/Q3180532","display_name":"Seston","level":4,"score":0.8059857487678528},{"id":"https://openalex.org/C142796444","wikidata":"https://www.wikidata.org/wiki/Q181394","display_name":"Nutrient","level":2,"score":0.6941394805908203},{"id":"https://openalex.org/C39432304","wikidata":"https://www.wikidata.org/wiki/Q188847","display_name":"Environmental science","level":0,"score":0.6149227619171143},{"id":"https://openalex.org/C140793950","wikidata":"https://www.wikidata.org/wiki/Q168091","display_name":"Animal science","level":1,"score":0.582442581653595},{"id":"https://openalex.org/C24245907","wikidata":"https://www.wikidata.org/wiki/Q498957","display_name":"Particulates","level":2,"score":0.5365216135978699},{"id":"https://openalex.org/C510538283","wikidata":"https://www.wikidata.org/wiki/Q674","display_name":"Phosphorus","level":2,"score":0.49627500772476196},{"id":"https://openalex.org/C77077793","wikidata":"https://www.wikidata.org/wiki/Q336019","display_name":"Abundance (ecology)","level":2,"score":0.4695340394973755},{"id":"https://openalex.org/C185592680","wikidata":"https://www.wikidata.org/wiki/Q2329","display_name":"Chemistry","level":0,"score":0.363860547542572},{"id":"https://openalex.org/C107872376","wikidata":"https://www.wikidata.org/wiki/Q321355","display_name":"Environmental chemistry","level":1,"score":0.33710765838623047},{"id":"https://openalex.org/C18903297","wikidata":"https://www.wikidata.org/wiki/Q7150","display_name":"Ecology","level":1,"score":0.3260628879070282},{"id":"https://openalex.org/C86803240","wikidata":"https://www.wikidata.org/wiki/Q420","display_name":"Biology","level":0,"score":0.1876606047153473},{"id":"https://openalex.org/C178790620","wikidata":"https://www.wikidata.org/wiki/Q11351","display_name":"Organic chemistry","level":1,"score":0.0}],"mesh":[],"locations_count":1,"locations":[{"id":"doi:10.1127/lr/18/2008/25","doi":"https://doi.org/10.1127/lr/18/2008/25","is_oa":false,"landing_page_url":"https://doi.org/10.1127/lr/18/2008/25","pdf_url":null,"source":{"id":"https://openalex.org/S67052599","display_name":"River Systems","issn_l":"1868-5749","issn":["1868-5749","2363-7137"],"is_oa":false,"is_in_doaj":false,"is_core":true,"listed_in":["cwts-core"],"host_organization":null,"host_organization_name":null,"host_organization_lineage":[],"host_organization_lineage_names":[],"type":"journal"},"license":null,"license_id":null,"version":"publishedVersion","is_accepted":true,"is_published":true,"raw_source_name":"River Systems","raw_type":"journal-article"}],"best_oa_location":null,"sustainable_development_goals":[{"display_name":"Clean water and sanitation","score":0.965499997138977,"id":"https://metadata.un.org/sdg/6"}],"study_designs":[],"awards":[],"funders":[],"has_content":{"pdf":false,"grobid_xml":false},"content_urls":null,"referenced_works_count":0,"referenced_works":[],"related_works":["https://openalex.org/W4285120170","https://openalex.org/W7097372344","https://openalex.org/W2478507915","https://openalex.org/W160873593","https://openalex.org/W7020387824","https://openalex.org/W1971929881","https://openalex.org/W3022754743","https://openalex.org/W192298720","https://openalex.org/W2302917291","https://openalex.org/W2078136782"],"abstract_inverted_index":{"Data":[0],"of":[1,27,102,119,137,163,216,219,225,242,258,260,283,290,306],"nutrients,":[2],"seston":[3],"and":[4,10,13,23,36,39,54,69,77,90,108,166,265],"phytoplankton":[5,191,209,243,328],"abundance":[6,192],"compiled":[7],"from":[8,31,193,244,326],"literature":[9],"routine":[11],"monitoring":[12],"covering":[14],"the":[15,28,32,42,129,139,157,177,185,198,207,217,222,240,251,256,278,284,287,291,296,304,307],"last":[16],"55":[17],"years":[18,165],"were":[19,74],"analysed":[20],"for":[21],"long-term":[22],"seasonal":[24],"trends.":[25],"Most":[26],"data":[29],"originated":[30],"stretch":[33],"between":[34],"376":[35],"554":[37],"river-km":[38],"varied":[40,148],"in":[41,125,184,254,273,300,330],"following":[43],"approximate":[44],"ranges:":[45],"NH":[46],"4":[47,56,71,145,263,317],"-N":[48,52],"0.1-0.5,":[49],"NO":[50],"3":[51],"0.5-2.0,":[53],"PO":[55,70,144,262,316],"-P":[57,72,146,264,318],"0.025-0.25":[58],"g":[59,104],"m":[60,105],"-3":[61,106],".":[62],"The":[63,84,187],"calculated":[64],"dissolved":[65],"inorganic":[66],"nitrogen":[67],"(DIN)":[68],"loads":[73,267],"within":[75,172],"2-14":[76],"0.3-1.4":[78],"kg":[79,110],"s":[80,111],"-1":[81,112],"correspondingly.":[83],"SPM":[85,245,266],"(suspended":[86],"particulate":[87],"matter)":[88],"concentration":[89],"load":[91,115,147,152,319],"have":[92],"decreased":[93],"continuously":[94],"6-8":[95],"times":[96,155,169],"till":[97],"today":[98],"with":[99],"minmax":[100],"values":[101,171],"21-340":[103],"116-1875":[109],"DIN":[114,151],"showed":[116,205],"an":[117],"increase":[118,249],"about":[120,167,277],"50":[121],"%":[122],"on":[123],"average":[124],"1988-1998":[126],"compared":[127],"to":[128,189,214,229,248,275,280],"previous":[130,308],"1950-1985,":[131],"followed":[132],"by":[133,196,232,313],"a":[134,161,314],"slight":[135],"decrease":[136],"approximately":[138],"same":[140,178],"degree":[141,279],"during":[142,156,250],"2000-2005.":[143],"stronger":[149],"than":[150,183],"increasing":[153],"2-3":[154],"1990s.":[158,186],"Then":[159],"after":[160,303],"gap":[162],"5":[164],"2":[168],"lower":[170,327],"1995-1999":[173],"it":[174],"has":[175],"reached":[176],"or":[179],"little":[180],"higher":[181],"levels":[182],"attempt":[188],"compare":[190],"different":[194,199],"periods":[195],"converting":[197],"quantitative":[200],"measures":[201],"into":[202],"one":[203],"(biomass)":[204],"that":[206,239],"recent":[208],"concentrations":[210,227,302],"are":[211,236,271],"very":[212],"similar":[213],"those":[215],"end":[218],"1990s,":[220],"despite":[221],"temporary":[223],"reduction":[224],"nutrient":[226,301],"caused":[228],"great":[230],"extent":[231,257],"dilution.":[233],"Moreover,":[234],"there":[235],"some":[237],"indications":[238],"share":[241],"may":[246],"continue":[247],"2001-2005.":[252],"Bearing":[253],"mind":[255],"changes":[259],"DIN,":[261],"more":[268],"detailed":[269],"analyses":[270],"needed":[272],"order":[274],"decide":[276],"which":[281],"each":[282],"factors":[285],"influences":[286],"trophic":[288],"status":[289],"Lower":[292],"Danube":[293],"River.":[294],"Unfortunately":[295],"outlined":[297],"decreasing":[298],"tendency":[299],"90s":[305],"century":[309],"neither":[310],"is":[311],"sustained":[312],"permanent":[315],"decrease,":[320],"nor":[321],"could":[322],"he":[323],"supposed":[324],"indirectly":[325],"biomass":[329],"this":[331],"river":[332],"stretch.":[333]},"counts_by_year":[{"year":2022,"cited_by_count":3}],"updated_date":"2026-10-14T16:39:01.820549","created_date":"2016-10-07T00:00:00"}