Browsing by Subject "kasviplankton"

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  • Hällfors, Guy (Vesihallitus. National Board of Waters, 1979)
    Vesientutkimuslaitoksen julkaisuja 34, 3-24
    Tiivistelmä: Alustava pohjoisen Itämeren kasviplanktonluettelo.
  • Sörenson, Eva; Bertos-Fortis, Mireia; Farnelid, Hanna; Kremp, Anke; Krüger, Karen; Lindehoff, Elin; Legrand, Catherine (Wiley & Sons, 2019)
    Environmental Microbiology Reports, 11: 425-433
    Phytoplankton and bacteria interactions have a significant role in aquatic ecosystem functioning. Associations can range from mutualistic to parasitic, shaping biogeochemical cycles and having a direct influence on phytoplankton growth. How variations in phenotype and sampling location, affect the phytoplankton microbiome is largely unknown. A high-resolution characterization of the bacterial community in cultures of the dinoflagellate Alexandrium was performed on strains isolated from different geographical locations and at varying anthropogenic impact levels. Microbiomes of Baltic Sea Alexandrium ostenfeldii isolates were dominated by Betaproteobacteria and were consistent over phenotypic and genotypic Alexandrium strain variation, resulting in identification of an A. ostenfeldii core microbiome. Comparisons with in situ bacterial communities showed that taxa found in this A. ostenfeldii core were specifically associated to dinoflagellate dynamics in the Baltic Sea. Microbiomes of Alexandrium tamarense and minutum, isolated from the Mediterranean Sea, differed from those of A. ostenfeldii in bacterial diversity and composition but displayed high consistency, and a core set of bacterial taxa was identified. This indicates that Alexandrium isolates with diverse phenotypes host predictable, species-specific, core microbiomes reflecting the abiotic conditions from which they were isolated. These findings enable in-depth studies of potential interactions occurring between Alexandrium and specific bacterial taxa.
  • Vuorio, Kristiina; Mäki, Anita; Salmi, Pauliina; Aalto, Sanni L.; Tiirola, Marja (Frontiers Media S.A., 2020)
    Frontiers in Microbiology 11 (2020) 96
    The composition of phytoplankton community is the basis for environmental monitoring and assessment of the ecological status of aquatic ecosystems. Community composition studies of phytoplankton have been based on time-consuming and expertise-demanding light microscopy analyses. Molecular methods have the potential to replace microscopy, but the high copy number variation of ribosomal genes and the lack of universal primers for simultaneous amplification of prokaryotic and eukaryotic genes complicate data interpretation. In this study, we used our previously developed directional primer-independent high-throughput sequencing (HTS) approach to analyze 16S and 18S rRNA community structures. Comparison of 83 boreal lake samples showed that the relative abundances of eukaryotic phytoplankton at class level and prokaryotic cyanobacteria at order level were consistent between HTS and microscopy results. At the genus level, the results had low correspondence, mainly due to lack of sequences in the reference library. HTS was superior to identify genera that are extensively represented in the reference databases but lack specific morphological characteristics. Targeted metatranscriptomics proved to be a feasible method to complement the microscopy analysis. The metatranscriptomics can also be applied without linking the sequences to taxonomy. However, direct indexing of the sequences to their environmental indicator values needs collections of more comprehensive sample sets, as long as the coverage of molecular barcodes of eukaryotic species remains insufficient.
  • Suikkanen, Sanna; Uusitalo, Laura; Lehtinen, Sirpa; Lehtiniemi, Maiju; Kauppila, Pirkko; Mäkinen, Katja; Kuosa, Harri (Elsevier, 2021)
    Food Webs 28, e00202
    Blooms of cyanobacteria are recurrent phenomena in coastal estuaries. Their maximum abundance coincides with the productive period of zooplankton and pelagic fish. Experimental studies indicate that diazotrophic, i.e. dinitrogen (N2)-fixing cyanobacterial (taxonomic order Nostocales) blooms affect zooplankton, as well as other phytoplankton. We used multidecadal monitoring data from one archipelago station (1992–2013) and ten open sea stations (1979–2013) in the Baltic Sea to explore the potential bottom-up connections between diazotrophic and non-diazotrophic cyanobacteria and phyto- and zooplankton in natural plankton communities. Random forest regression, combined with linear regression analysis showed that the biomass of cyanobacteria (both diazotrophic and non-diazotrophic) was barely connected to any of the phytoplankton and zooplankton variables examined. Instead, physico-chemical variables (salinity, temperature, total phosphorus), as well as spatial and temporal variability seemed to have more significant connections to both phytoplankton and zooplankton variables. Zooplankton variables were also connected to the biomass of phytoplankton groups other than cyanobacteria (such as chrysophytes, cryptophytes and prymnesiophytes), and phytoplankton variables had connections with the biomass of different zooplankton groups, especially copepods. Overall, negative relationships between cyanobacteria and other plankton taxa were scarcer than expected based on previous experimental studies.
  • Hällfors, Guy; Melvasalo, Terttu; Niemi, Åke; Viljamaa, Hilkka (Vesihallitus. National Board of Waters, 1979)
    Vesientutkimuslaitoksen julkaisuja 34, 25-34
    Erilaisten säilöntäaineiden vaikutus kasviplanktonin laskentatuloksiin
  • Forsblom, Louise; Engström-öst, Jonna; Lehtinen, Sirpa; Lips, Inga; Lindén, Andreas (2019)
    Journal of Plankton Research 41 (6), 925–938
    Abiotic variables subject to global change are known to affect plankton biomasses, and these effects can be species-specific. Here, we investigate the environmental drivers of annual biomass using plankton data from the Gulf of Finland in the northern Baltic Sea, spanning years 1993–2016. We estimated annual biomass time-series of 31 nanoplankton and microplankton species and genera from day-level data, accounting for the average phenology and wind. We found wind effects on day-level biomass in 16 taxa. We subsequently used state-space models to connect the annual biomass changes with potential environmental drivers (temperature, salinity, stratification, ice cover and inorganic nutrients), simultaneously accounting for temporal trends. We found clear environmental effects influencing the annual biomasses of Dinobryon faculiferum, Eutreptiella spp., Protoperidinium bipes, Pseudopedinella spp., Snowella spp. and Thalassiosira baltica and indicative effects in 10 additional taxa. These effects mostly concerned temperature, salinity or stratification. Together, these 16 taxa represent two-thirds of the summer biomass in the sampled community. The inter-annual variability observed in salinity and temperature is relatively low compared to scenarios of predicted change in these variables. Therefore, the potential impacts of the presented effects on plankton biomasses are considerable.
  • Poikane, Sandra; Kelly, Martyn G.; Várbíró, Gábor; Borics, Gábor; Erős, Tibor; Hellsten, Seppo; Kolada, Agnieszka; Lukács, Balázs András; Lyche Solheim, Anne; Pahissa López, José; Willby, Nigel J.; Wolfram, Georg; Phillips, Geoff (Elsevier BV, 2022)
    Science of The Total Environment
    Nutrient targets based on pressure-response models are essential for defining ambitions and managing eutrophication. However, the scale of biogeographical variation in these pressure-response relationships is poorly understood, which may hinder eutrophication management in regions where lake ecology is less intensively studied. In this study, we derive ecology-based nutrient targets for five major ecoregions of Europe: Northern, Central-Baltic, Alpine, Mediterranean and Eastern Continental. As a first step, we developed regressions between nutrient concentrations and ecological quality ratios (EQR) based on phytoplankton and macrophyte communities. Significant relationships were established for 13 major lake types; in most cases, these relationships were stronger for phosphorus than for nitrogen, and stronger for phytoplankton than for macrophytes. Using these regressions, we estimated the total phosphorus (TP) and total nitrogen (TN) concentrations at which lakes of different types are likely to achieve good ecological status. However, in the very shallow lakes of the Eastern Continental region, relations between nutrient and biological communities were weak or non-significant. This can be attributed to high nutrient concentrations (in the asymptotic zone of phosphorus-phytoplankton models) suggesting other factors (light, grazing) limit primary production. However, we also show that fish stocking is a major pressure on Eastern Continental lakes, negatively affecting ecological status: lakes with low fish stocking show low chlorophyll-a concentrations and good ecological status despite high nutrient levels, while the lakes with high fish stocking show high chlorophyll-a and low ecological status. This study highlights the need to better understand lakes in biogeographic regions that have been, for historical reasons, less studied. This, in turn, helps reveal factors that challenge the dominant paradigms of lake assessment and management.
  • Raitanen, Henna (Helsingin yliopisto, 2020)
    In this study, the goal was to determine which nutrient, phosphorus or nitrogen, limits the phytoplankton growth at the Vanajavesi freshwater site. The aims were to detect spatial and temporal changes and find out if the wastewater treatment plant (hereafter, WWTP) located by the study site affects the nutrient concentrations and the limiting nutrient. The reliability of determining limiting nutrient by bioassays and measuring the phytoplankton response to different treatments as fluorescence was also evaluated. The study was conducted because knowledge of nutrient limitation is essential when allocating resources to reduce nutrient loading and planning other remediation practices in eutrophicated waterbodies. According to the EU Water Framework Directive, all waterbodies in the EU must be in a good ecological status by the year 2027. This goal is yet to be achieved in Vanajavesi; the ecological status of the river Vanajanreitti is poor and that of lake Vanajanselkä is moderate. The samples for bioassays were taken from five different locations. Three sampling sites were in the river and two by the lake. Based on the direction which the water flows, one of the sampling sites was before the outlet from the WWTP and the rest after it. The bioassays were carried out with the water and natural phytoplankton community taken from the study site. The experiment was conducted five times: in November, March, May, July and August. The temperature and light conditions in the incubation room were set to mimic those in Vanajavesi at each given time. Part of the preparations was to filter out the zooplankton using 50 μm plankton net. There were four different treatments: control without nutrient additions, nitrogen addition, phosphorus addition and nitrogen and phosphorus additions. Fluorescence from the 2 litre incubation bottles was measured every 1-3 days during each experiment. Chlorophyll a was determined in laboratory before and after the experiments. Nutrient concentrations were also determined before each experiment. Small seasonal and temporal changes were observed in the nutrient concentrations and the limiting nutrient. These changes were most likely due to changing seasons, effluent from the WWTP and denitrification at lake Vanajanselkä. Phosphorus limited phytoplankton growth year around at all places. At the end of the summer also nitrogen was limiting. In July co-limitation was detected in all sampling sites. In situations of co-limitation there was either no secondary limiting nutrient, or it was phosphorus. Only once, in August at the sampling point before the outlet from the WWTP, was the secondary limiting nutrient nitrogen. On average the nutrient concentrations were higher in the river than in the lake. Chlorophyll a concentrations and some nutrient concentrations were higher after the WWTP. However, no significant negative impact due to WWTP could be detected, especially at lake Vanajanselkä and the WWTP did not result in a change from phosphorus limitation to nitrogen limitation. Bioassays and the phytoplankton yield measured with a fluorometer was a reliable way of determining the limiting nutrient. Chlorophyll a concentrations verified the fluorescence results. The probe used in this study measured only the fluorescence of chlorophyll a. Even more accurate result of the phytoplankton biomass would have been obtained with a probe that measures also the fluorescence of phycocyanin, the photosynthetic pigment in cyanobacteria, because cyanobacteria has less chlorophyll a than other phytoplankton groups. As Vanajavesi is phosphorus limited or co-limited by phosphorus and nitrogen year around, reductions in phosphorus loading will likely improve the water quality. The main source of phosphorus to Vanajavesi is the nutrient loading from agricultural practises on the drainage basin. Efficient management of this diffuse loading will cause the phytoplankton biomass, especially the biomass of harmful cyanobacteria, to decrease. Nitrogen-fixing cyanobacteria is not dependent on the nitrogen concentrations in the water column, but the concentration of phosphorus. Significantly reducing the phosphorus loading is a prerequisite for the Vanajanreitti and Vanajavesi to be in a good ecological status by the year 2027.
  • Olli, Kalle; Nyman, Emil; Tamminen, Timo (Oxford University Press (OUP), 2022)
    Journal of Plankton Research
    We analyzed phytoplankton biodiversity trends in a 52 year (1967–2018) monitoring time-series from the archipelago of Helsinki, Gulf of Finland, the Baltic Sea. The community ordination revealed strong ordering of samples along the time axis (generalized additive model—gam fit: R2 = 0.9). Species richness increased in time and was the most influential alpha diversity descriptor related to the community structure (gam fit: R2 = 0.56–0.70). Changes in species richness accounted for 35–36% of the mean between-sample beta diversity. The remaining 64–65% was due to species turnover—the dominant component of the biodiversity trend. The temporal beta diversity trend reflected the eutrophication history of the geographically confined region, with a turning point in mid-1990s demarking the adaptation and recovery phases of the phytoplankton community. Trends in spatial beta diversity revealed homogenization of the communities in the outer archipelago zone, but not in the inner bays. The temporal decay of community similarity revealed high turnover rate, with 23.6 years halving time in the outer archipelago and 11.3 years in the inner bays, revealing the differences in eutrophication strength. The observed phytoplankton trends manifest the regional eutrophication history, and dispersal of new species to the unsaturated brackish species pool.
  • Karlson, Bengt; Andersen, Per; Arneborg, Lars; Cembella, Allan; Eikrem, Wenche; John, Uwe; West, Jennifer Joy; Klemm, Kerstin; Kobos, Justyna; Lehtinen, Sirpa; Lundholm, Nina; Mazur-Marzec, Hanna; Naustvoll, Lars; Poelman, Marnix; Provoost, Pieter; De Rijcke, Maarten; Suikkanen, Sanna (Elsevier, 2021)
    Harmful Algae 102 (2021), 101989
    Harmful algal blooms (HAB) are recurrent phenomena in northern Europe along the coasts of the Baltic Sea, Kattegat-Skagerrak, eastern North Sea, Norwegian Sea and the Barents Sea. These HABs have caused occasional massive losses for the aquaculture industry and have chronically affected socioeconomic interests in several ways. This status review gives an overview of historical HAB events and summarises reports to the Harmful Algae Event Database from 1986 to the end of year 2019 and observations made in long term monitoring programmes of potentially harmful phytoplankton and of phycotoxins in bivalve shellfish. Major HAB taxa causing fish mortalities in the region include blooms of the prymnesiophyte Chrysochromulina leadbeateri in northern Norway in 1991 and 2019, resulting in huge economic losses for fish farmers. A bloom of the prymesiophyte Prymnesium polylepis (syn. Chrysochromulina polylepis) in the Kattegat-Skagerrak in 1988 was ecosystem disruptive. Blooms of the prymnesiophyte Phaeocystis spp. have caused accumulations of foam on beaches in the southwestern North Sea and Wadden Sea coasts and shellfish mortality has been linked to their occurrence. Mortality of shellfish linked to HAB events has been observed in estuarine waters associated with influx of water from the southern North Sea. The first bloom of the dictyochophyte genus Pseudochattonella was observed in 1998, and since then such blooms have been observed in high cell densities in spring causing fish mortalities some years. Dinoflagellates, primarily Dinophysis spp., intermittently yield concentrations of Diarrhetic Shellfish Toxins (DST) in blue mussels, Mytilus edulis, above regulatory limits along the coasts of Norway, Denmark and the Swedish west coast. On average, DST levels in shellfish have decreased along the Swedish and Norwegian Skagerrak coasts since approximately 2006, coinciding with a decrease in the cell abundance of D. acuta. Among dinoflagellates, Alexandrium species are the major source of Paralytic Shellfish Toxins (PST) in the region. PST concentrations above regulatory levels were rare in the Skagerrak-Kattegat during the three decadal review period, but frequent and often abundant findings of Alexandrium resting cysts in surface sediments indicate a high potential risk for blooms. PST levels often above regulatory limits along the west coast of Norway are associated with A. catenella (ribotype Group 1) as the main toxin producer. Other Alexandrium species, such as A. ostenfeldii and A. minutum, are capable of producing PST among some populations but are usually not associated with PSP events in the region. The cell abundance of A. pseudogonyaulax, a producer of the ichthyotoxin goniodomin (GD), has increased in the Skagerrak-Kattegat since 2010, and may constitute an emerging threat. The dinoflagellate Azadinium spp. have been unequivocally linked to the presence of azaspiracid toxins (AZT) responsible for Azaspiracid Shellfish Poisoning (AZP) in northern Europe. These toxins were detected in bivalve shellfish at concentrations above regulatory limits for the first time in Norway in blue mussels in 2005 and in Sweden in blue mussels and oysters (Ostrea edulis and Crassostrea gigas) in 2018. Certain members of the diatom genus Pseudo-nitzschia produce the neurotoxin domoic acid and analogs known as Amnesic Shellfish Toxins (AST). Blooms of Pseudo-nitzschia were common in the North Sea and the Skagerrak-Kattegat, but levels of AST in bivalve shellfish were rarely above regulatory limits during the review period. Summer cyanobacteria blooms in the Baltic Sea are a concern mainly for tourism by causing massive fouling of bathing water and beaches. Some of the cyanobacteria produce toxins, e.g. Nodularia spumigena, producer of nodularin, which may be a human health problem and cause occasional dog mortalities. Coastal and shelf sea regions in northern Europe provide a key supply of seafood, socioeconomic well-being and ecosystem services. Increasing anthropogenic influence and climate change create environmental stressors causing shifts in the biogeography and intensity of HABs. Continued monitoring of HAB and phycotoxins and the operation of historical databases such as HAEDAT provide not only an ongoing status report but also provide a way to interpret causes and mechanisms of HABs.
  • Goncalves-Araujo, Rafael; Roettgers, Ruediger; Haraguchi, Lumi; Brandini, Frederico Pereira (Frontiers Media S.A., 2019)
    Frontiers in Marine Science 6: 716
    The South Brazilian Bight (SBB) is a hydrographically dynamic environment with strong seasonality that sustains a diverse planktonic community involved in diverse biogeochemical processes. The inherent optical properties (IOPs; e.g., absorption and scattering coefficients) of optically actives constituents of water (OACs; phytoplankton, non-algal particles–NAP, and colored dissolved organic matter–CDOM) have been widely employed to retrieve information on biogeochemical parameters in the water. In this study conducted in the SBB, a cross-shelf transect was performed for biogeochemistry and hydrographic sampling during a summer expedition. Our research aimed to determine the distribution and amount of the OACs based on their spectral signature, in relation to the distribution of water masses in the region. That allows us to get insights into the biogeochemical processes within each water mass and in the boundaries between them. We observed a strong intrusion of South Atlantic Central Water (SACW) over the shelf, mainly driven by the wind action. With that, phytoplankton development was fueled by the input of nutrients, and increased chlorophyll-a (Chl-a) concentrations were observed within the shallowest stations. Colored dissolved organic matter did not follow the distribution of dissolved organic carbon (DOC). Both CDOM and DOC presented high values at the low salinity Coastal Water (CW), as an indication of the continental influence over the shelf. However, CDOM was inversely correlated with salinity and lowest values were observed within Tropical Water (TW), whereas DOC values within TW were as high as within CW, indicating an autochthonous DOM source. Additionally, a deep Chl-a maximum (DCM) was noticed in the boundary between the TW and SACW. Along with the DCM, we observed the production of fresh, non-colored DOM attributed to the microbial community. Finally, our results suggest that CDOM is photodegraded at the surface of CW. This is mainly due to the Ekman transport effect over the region that traps CW at the surface, making it longer exposed to solar radiation.
  • Vuorio, Kristiina; Björklöf, Katarina; Hällfors, Heidi; Järvinen, Marko; Lehtinen, Sirpa; Kuosa, Harri; Oja, Johanna; Leivuori, Mirja; Ilmakunnas, Markku (Finnish Environment Institute, 2021)
    Reports of the Finnish Environment Institute 29/2021
    Proftest SYKE organized in 2020 the sixth virtual phytoplankton proficiency test based on filmed and preserved material. A total of 38 persons from 33 organizations and ten countries took part in the test. The test material represented phytoplankton typically occuring in boreal lakes and in the Baltic Sea. The test consisted of three parts: 1) identification of lake and/or Baltic Sea taxa, 2) phytoplankton counting and 3) measurement of cell dimensions. Most of the participants demonstrated satisfactory phytoplankton identification skills and proficiency to perform phytoplankton counts and measurements. Both in the lake and the Baltic Sea phytoplankton identification tests 86 % of the participants reached a satisfactory result. All participants performed the counting test successfully and 95 % of the participants performed the cell measurement test successfully.
  • Filla, Sara (Helsingin yliopisto, 2022)
    Kasvi- ja eläinplanktonia esiintyy käytännössä kaikissa boreaalisissa järvissä ja lammissa. Kasviplankton on koko järviekosysteemille tärkeä perustuottajaryhmä, kun taas eläinplankton on tärkeä kasviplanktonin kuluttajaryhmä. Ne siirtävät energiaa korkeammille trofiatasoille. Lisäksi ne toimivat ympäristöntilan indikaattoreina, sillä erityisesti kasviplankton reagoi herkästi elinympäristönsä muutoksiin. Tämän vuoksi kasvi- ja eläinplanktonin esiintymiseen ja levinneisyyteen vaikuttavien tekijöiden tunteminen on tärkeää. Tässä maisterintutkielmassa selvitettiin kasvi- ja eläinplanktonin levinneisyyttä boreaalisissa järvissä viidellä eri valuma-alueella Suomessa. Levinneisyyttä tarkasteltiin kolmen selittävän tekijän avulla, jotka olivat runsaus, ekolokeron koko ja lajipiirteet. Nämä selittävät muuttujat valittiin, koska kirjallisuuden perustella ne vaikuttavat merkittävästi lajin levinneisyyteen. Runsaus kuvaa lajin paikallista esiintymistä, ekolokeron koko puolestaan vuorovaikutusta muiden lajien kanssa ja lajipiirteet vaikuttavat pääasiassa leviämiskyvyn lisäksi saalistuspaineeseen. Tutkimuksen aineisto sisälsi yhteensä 100 järven kasvi- ja eläinplanktonlajien yksilöiden määrän kussakin järvessä sekä fysikaalis-kemiallisten ominaisuuksien mittaustulokset. Lajipiirteistä valittiin tutkittavaksi solukoko, jonka arvot pohjautuivat kirjallisuuteen. Levinneisyyden yhteyttä selittäviin muuttujiin tutkittiin regressioanalyysin avulla sekä tärkeimmille järvien fysikaalis-kemiallisille muuttujille tehtiin pääkomponenttianalyysi (PCA). Runsaus sekä ekolokeron koko korreloivat merkitsevästi levinneisyyden kanssa. Solukoolla ei havaittu lainkaan yhteyttä kasviplanktonin levinneisyyden kanssa. Eläinplanktonilla yhteys näiden muuttujien välillä havaittiin, mutta tulos ei ollut merkitsevä. Tulokset levinneisyyden ja solukoon välillä eivät kuitenkaan olleet luotettavia tai vertailukelpoisia, koska aineiston lajeilla oli liian pieni otanta. Aiempien tutkimusten perusteella voidaan kuitenkin sanoa, että solukoolla olisi käänteinen suhde levinneisyyden kanssa. Lajisto ja järvien fysikaalis-kemialliset olosuhteet olivat samankaltaisempia mitä lähempänä valuma-alueet olivat toisiaan.
  • Lehtinen, Sirpa (University of Helsinki, 2000)
  • Lau, Danny C. P.; Christoffersen, Kirsten S.; Erkinaro, Jaakko; Hayden, Brian; Heino, Jani; Hellsten, Seppo; Holmgren, Kerstin; Kahilainen, Kimmo K.; Kahlert, Maria; Karjalainen, Satu Maaria; Karlsson, Jan; Forsström, Laura; Lento, Jennifer; Mjelde, Marit; Ruuhijärvi, Jukka; Sandøy, Steinar; Schartau, Ann Kristin; Svenning, Martin‐A.; Vrede, Tobias; Goedkoop, Willem (Blackwell Scientific, 2022)
    Freshwater Biology
    1. Arctic and sub-Arctic lakes in northern Europe are increasingly threatened by climate change, which can affect their biodiversity directly by shifting thermal and hydrological regimes, and indirectly by altering landscape processes and catchment vegetation. Most previous studies of northern lake biodiversity responses to environmental changes have focused on only a single organismal group. Investigations at whole-lake scales that integrate different habitats and trophic levels are currently rare, but highly necessary for future lake monitoring and management. 2. We analysed spatial biodiversity patterns of 74 sub-Arctic lakes in Norway, Sweden, Finland, and the Faroe Islands with monitoring data for at least three biological focal ecosystem components (FECs)—benthic diatoms, macrophytes, phytoplankton, littoral benthic macroinvertebrates, zooplankton, and fish—that covered both pelagic and benthic habitats and multiple trophic levels. 3. We calculated the richnessrelative (i.e. taxon richness of a FEC in the lake divided by the total richness of that FEC in all 74 lakes) and the biodiversity metrics (i.e. taxon richness, inverse Simpson index (diversity), and taxon evenness) of individual FECs using presence–absence and abundance data, respectively. We then investigated whether the FEC richnessrelative and biodiversity metrics were correlated with lake abiotic and geospatial variables. We hypothesised that (1) individual FECs would be more diverse in a warmer and wetter climate (e.g. at lower latitudes and/or elevations), and in hydrobasins with greater forest cover that could enhance the supply of terrestrial organic matter and nutrients that stimulated lake productivity; and (2) patterns in FEC responses would be coupled among trophic levels. 4. Results from redundancy analyses showed that the richnessrelative of phytoplankton, macrophytes, and fish decreased, but those of the intermediate trophic levels (i.e. macroinvertebrates and zooplankton) increased with decreasing latitude and/or elevation. Fish richnessrelative and diversity increased with increasing temporal variation in climate (temperature and/or precipitation), ambient nutrient concentrations (e.g. total nitrogen) in lakes, and woody vegetation (e.g. taiga forest) cover in hydrobasins, whereas taxon richness of macroinvertebrates and zooplankton decreased with increasing temporal variation in climate. 5. The similar patterns detected for richnessrelative of fish, macrophytes, and phytoplankton could be caused by similar responses to the environmental descriptors, and/or the beneficial effects of macrophytes as habitat structure. By creating habitat, macrophytes may increase fish diversity and production, which in turn may promote higher densities and probably more diverse assemblages of phytoplankton through trophic cascades. Lakes with greater fish richnessrelative tended to have greater average richnessrelative among FECs, suggesting that fish are a potential indicator for overall lake biodiversity. 6. Overall, the biodiversity patterns observed along the environmental gradients were trophic-level specific, indicating that an integrated food-web perspective may lead to a more holistic understanding of ecosystem biodiversity in future monitoring and management of high-latitude lakes. In future, monitoring should also focus on collecting more abundance data for fish and lower trophic levels in both benthic and pelagic habitats. This may require more concentrated sampling effort on fewer lakes at smaller spatial scales, while continuing to sample lakes distributed along environmental gradients.