Periphyton In Lakes Research Articles

Shifts in periphyton research themes over the past three decades.

It has been well documented that periphyton communities play a key role in primary productivity, nutrient cycling, and food web interactions. However, a worldwide overview of research on the key themes, current situation, and major trends within the field is lacking. In this study, we applied the machine learning technique (latent Dirichlet allocation, LDA) to analyze the abstracts of 6690 publications related to periphyton from 1991 to 2020 based on the Web of Science database. The relative frequency of classical and basic research on periphyton related to colonization, biomass, growth rate, and habitats has been clearly decreasing. The increasing trends of research on periphyton are embodied in the periphyton function in freshwater ecosystems (e.g., application as ecological indicators, function in the removal of nutrients, and application in paleolimnology), the research at macroscales (e.g., spatial-temporal variation, and functional and taxonomic diversity), and the anthropogenic themes (e.g., climate warming, response to multiple stressors, and land use type). The keyword and title analysis showed that the periphyton studies are concentrated mainly on diatom aspects, especially with respect to streams relative to lakes. The thematic space based on non-metric multidimensional scaling (NMDS) showed that the classical themes such as growth rate, colonization, and environmental factors (e.g., multiple stressors and climate warming) were most linked to other research themes. We proposed that future trends in the periphyton should focus on the function of periphyton in lakes and their response to multiple environmental pressures with the increasingly extensive eutrophication in lakes and the increasingly significant change in the climate.

Factors regulating lake periphyton biomass and nutrient limitation status across a large trophic gradient

Abstract Because of the historical focus of limnology on pelagic processes, the factors controlling lake periphyton growth and nutrient limitation are understudied compared to the phytoplankton. We deployed nutrient‐diffusing substrata at 28 sites spanning a wide trophic status gradient in Lakes Superior and Michigan to assess periphyton biomass accrual on control substrata and the response of periphyton to single and combined phosphorus (P) and nitrogen (N) additions. Periphyton growth was unimodally related to a composite metric of site trophic status, with highest biomass at mesotrophic sites and lower growth at oligotrophic and highly eutrophic sites. Contrary to expectations, P limitation was rare. Instead, several lines of evidence pointed to primary N or N + P co‐limitation of periphyton. Limitation extent was negatively related to site trophic status, with stronger nutrient limitation at oligotrophic sites. Our results support the hypothesis that phytoplankton and periphyton biomass respond differently to nutrient enrichment and suggest that different nutrients may limit pelagic and benthic primary production, even in the same system. Our findings also support the use of periphyton as an early warning indicator of nutrient pollution and help explain why large, oligotrophic lakes may be especially susceptible to localised benthic algal blooms.

Mercury methylation and demethylation by periphyton biofilms and their host in a fluvial wetland of the St. Lawrence River (QC, Canada)

Wetlands in large rivers are important sites of production of the neurotoxin methylmercury (MeHg), and the periphyton growing on wetland macrophytes are increasingly recognized as key players in this production and transfer in food webs. Information is lacking about mercury methylation (Km) and demethylation (Kd) rates in periphytic biofilms from the Northern Hemisphere, as well as about the drivers of net MeHg production, hampering ecosystem modeling of Hg cycling. Mercury methylation and demethylation rates were measured in periphytic biofilms growing on submerged plants in a shallow fluvial lake located in a temperate cold region (St. Lawrence River, Quebec, Canada). Incubations were performed in situ within macrophyte beds using low-level spikes of 199HgO and Me200Hg stable isotopes as tracers. A direct relationship was observed between Km (0.002 to 0.137d−1) and [MeHg] in periphyton. A similar relationship was found between Kd (0.096 to 0.334d−1) and [inorganic Hg]. Periphyton of Lake St. Pierre reached high levels of net MeHg production that were two orders of magnitude higher than those found in local sediment. This production varied through the plant growing season and was mainly driven by environmental variables such as depth of growth, available light, dissolved oxygen, temperature, plant community structure, and productivity of the habitat.

Lake benthic algae: toward an understanding of their ecology

AbstractLake phytoplankton studies outnumber studies on lake periphyton by an order of magnitude, and most periphyton research has been done in streams. Most benthic algal taxa found in lakes also can be found in lotic systems, but assemblages and taxa differ in a number of ways. The ecological characteristics of some lake benthic algae reflect habitat coupling. Littoral zones (benthic areas above the light compensation depth) are areas of high productivity and biodiversity. The proportion of benthic and planktonic primary production (autotrophic structure) is a key ecosystem property. The distribution of lake benthic algae is markedly influenced by the depth gradient and substratum, and assemblages change with depth from epilithic and epiphytic rheobionts to epipsammic and epipelic limnobionts. At shallow depths, periphyton must cope with the effects of high radiation, water-level fluctuations, wave action (e.g., desiccation, ultraviolet radiation exposure, shear stress), and seasonal shifts in temperatu...

New and poorly known coccoid species (Cyanoprokaryota) from the mid-depth and deep epilithon of a carbonate mountain lake

AbstractThe deep littoral zone hosts a unique but understudied subset of lake periphyton. We investigated epilithic cyanoprokaryotes in a carbonate meromictic lake (Lake Tovel, southeastern Alps) to obtain information on 2 poorly known, deep-dwelling coccoid species (one new to science) and to analyze their distribution in light of the current understanding of the depth distribution of lake periphyton. Cyanoprokaryotes in Lake Tovel have distinct depth distributions among 3 zones: shallow (0–4 m), mid-depth (6–12 m), and deep (15–24 m). The mid-depth and deep zones are characterized by high stability with favorable growth conditions and by severe light limitation, respectively. Both zones have unique taxa that frequently possess colorless sheaths or pink–red–violet cell contents. The 2 most poorly known cyanoprokaryotes found in Lake Tovel (both pink–red–violet) were a species of Geitleribactron new to science (Geitleribactron purpureum sp. nov. Cantonati et Komarek) and the rare Chlorogloea purpurea. We ...

Nematodes in the periphyton of lakes: Variations in diversity, species composition, age structure, and sex ratio

Temporal fluctuations in the diversity, sex ratio, age, and species composition of free‐living nematodes inhabiting the periphyton of stony hard‐substrates were determined in three Swedish lakes differing in trophic state. Over a two‐year sampling period, different temporal patterns were observed. In the oligotrophic lake, nematode diversity showed moderate fluctuations and peaked in early summer. Diversity in meso‐ and eutrophic lakes showed the opposite pattern. Species composition changed along seasons, enabling to identify typical early and late season assemblages. This succession was linked to different reproduction periods of dominant species. The age structure and sex ratio of periphytic nematode communities varied both temporally and between lakes according to species traits. As an example, the male/female ratio increased with increasing lake trophic state. This trend reflects the decrease of partenogenetically reproducing species with increasing lake trophic state, and may be further considered as an indicator of lake trophic state.

Methanogens: Principal Methylators of Mercury in Lake Periphyton

Mercury methylation and demethylation rates were measured in periphyton biofilms growing on submerged plants from a shallow fluvial lake located along the St. Lawrence River (Quebec, Canada). Incubations were performed in situ within macrophytes beds using low-level spikes of (199)HgO and Me(200)Hg stable isotopes as tracers. To determine which microbial guilds are playing a role in these processes, methylation/demethylation experiments were performed in the absence and presence of different metabolic inhibitors: chloramphenicol (general bacteriostatic inhibitor), molybdate (sodium molybdate, a sulfate reduction inhibitor), BESA (2-bromoethane sulfonic acid, a methanogenesis inhibitor), and DCMU (3-(3,4-dichlorophenyl)-1,1 dimethyl urea, a photosynthesis inhibitor). Active microbes of the periphytic consortium were also characterized using 16S rRNA gene sequencing. Methylation rates in the absence of inhibitors varied from 0.0015 to 0.0180 d(-1) while demethylation rates ranged from 0.083 to 0.217 d(-1), which corresponds to a net methylmercury balance of -0.51 to 1.28 ng gDW periphyton(-1) d(-1). Methylation rates were significantly decreased by half by DCMU and chloramphenicol, totally inhibited by BESA, and were highly stimulated by molybdate. This suggests that methanogens rather than sulfate reducing bacteria were likely the primary methylators in the periphyton of a temperate fluvial lake, a conclusion supported by the detection of 16S rRNA gene sequences that were closely related to those of methanogens. This first clear demonstration of methanogens' role in mercury methylation in environmental periphyton samples expands the known diversity of microbial guilds that contribute to the formation of the neurotoxic substance methylmercury.

Characterization of the light attenuation by periphyton in lakes of different trophic state

In order to measure the attenuation of light by periphyton a method has been developed which assures that natural periphyton architecture and therefore its optical characteristics remain preserved. This method has been applied to analyze the transmittance of periphyton of four lakes of different tropic states situated in the Osterseen Lake District (Upper Bavaria, Germany). The seasonal variation of the periphyton's transmittance has been studied using standard microscope glass slides exposed 1 m beneath the water surface within macrophyte beds. The study ran from February to November 1997 in two eutrophic lakes (Lake Waschsee, Lake Sengsee) and from May to November 1997 in the meso-oligotrophic Lake Eishaussee and in the oligotrophic Lake Herrensee. Generally the exposure-period, the seasonality, and the tropic state of the habitat affected the transmittance spectra of the periphyton. In all lakes the attenuation by periphyton increased with longer colonization times but at a different time scale. The periphyton of the nutrient-rich and the nutrient-poor lakes differed clearly in composition and architecture. The eutrophic lakes were characterized by a relatively thick but loosely attached, unstable periphyton community, which was translucent to a certain degree even at the end of the growth period. The transmittance of this periphyton fluctuated considerably and high percentages of filamentous green algae in this periphyton contributed to attenuation maxima within the range 400–500 nm and 650–700 nm due to photosynthetic pigments. By contrast, the periphyton of the meso-oligotrophic and of the oligotrophic lake was quite compact and nearly impervious to light.

Monitoring periphyton in lakes experiencing shoreline development

Early detection of degradation is crucial in previously pristine lakes experiencing residential development along their shores. Despite suggestions that the littoral zone responds to anthropogenic disturbance before open water, the use of periphyton for monitoring lake trophic status has been hindered by the heterogeneous distribution of this community. We examined the response of periphyton growing on different natural substrata — rocks, wood, sediments, and macrophytes — as well as on introduced plastic strips along a gradient of residential development in the Laurentian lakes (Quebec). We measured periphyton biomass as chlorophyll a and as thickness estimated with a ruler with the goal to evaluate the best method to monitor the incipient degradation of these lakes. Our findings suggest that rocks are the best substratum to sample because they are ubiquitous, and epilithic algae show a stronger response to shoreline residential development than algae on other substrata. Measurement of epilithon thickness appears a fast and reliable tool for estimating epilithon biomass. If measurements of chlorophyll a require several field and laboratory manipulations that are not readily available for voluntary lake monitoring by residents, measurement of periphyton thickness on rocks may allow examining spatial and temporal changes in a large number of lakes.

Note: An efficient in situ method for sampling periphyton in lakes and streams

We present an efficient in situ sampling device that allows a simple and quantitative sampling of natural periphyton communities. The Brush Sampler is based on a previously developed sampler, which was improved by the addition of an external water supply, ball valve closing mechanism, and special exchangeable stiff brushes to solve previously reported problems of biomass overestimation and underestimation. The Brush Sampler was tested under ambient conditions in the field at four different sampling sites in a lentic and a lotic system and compared to the old sampler and control samples. The tests revealed a high inaccuracy of the old sampler and showed that biomass estimates (ash-free dry mass and chlorophyll-a content) obtained with the improved Brush Sampler did not significantly differ from biomass values determined from scrapings of control samples collected at the same sites. Therefore, our modified sampling device can be used as a tool for quantitative and qualitative epilithon community analyses.

Algal assemblage types of bog-lakes in Hungary and their relation to water chemistry, hydrological conditions and habitat diversity

Algal flora of 12 bog lakes was investigated during the period of March 1995 to August 1999 in Hungary. Of the 129 samples, 624 taxa of algae were identified. Species richness of individual samples ranged between 8 and 107 except the extraordinarily species rich Balata-to where 533 algal taxa were observed. Ordination of the samples resulted in five groups: (1) assemblages dominated by chlorococcalean algae and planktonic Cyanoprokaryota; (2) assemblages dominated by flagellates (Dinophyta, Cryptophyta, Euglenophyta, Chrysophyceae, Raphidophyceae); (3) chlorococcalean algae and cyanoprokaryotic assemblages with desmids, cryptophytes, dinoflagellates or euglenophytes as subdominants; (4) assemblages dominated by diatoms and (5) a group of samples where other taxa belonging to Xanthophyta and filamentous green algae dominated. The bogs were typically rich in inorganic N and P, moreover, their water chemical characteristics (including pH and conductivity) were rather uniform. Therefore, other factors than chemical properties were responsible for different flora. The above groups were characteristic to certain types of habitats. In the first group, plankton samples from relatively large pools with considerable open water can be found. The second group included samples taken from small bog pools. The third group contained the periphyton samples from macrophytes, living in bogs with constantly reliable water supply. Samples of group four and five comprised small bogs that occasionally dry up. Periphyton of lakes with Sphagnum belonged exclusively to the fifth group. This study has shown that small bog-pools are often inhabited by different species of flagellates and desmids are not as important as it has been widely believed. Hydrological properties and habitat diversity are the major factors influencing species richness of Hungarian bog-lakes.

Periphyton function in lake ecosystems.

Periphyton communities have received relatively little attention in lake ecosystems. However, evidence is increasing that they play a key role in primary productivity, nutrient cycling, and food web interactions. This review summarizes those findings and places them in a conceptual framework to evaluate the functional importance of periphyton in lakes. The role of periphyton is conceptualized based on a spatial hierarchy. At the coarsest scale, landscape properties such as lake morphometry, influence the amount of available habitat for periphyton growth. Watershed-related properties, such as loading of dissolved organic matter, nutrients, and sediments influence light availability and hence periphyton productivity. At the finer scale of within the lake, both habitat availability and habitat type affect periphyton growth and abundance. In addition, periphyton and phytoplankton compete for available resources at the within-lake scale. Our review indicates that periphyton plays an important functional role in lake nutrient cycles and food webs, especially under such conditions as relatively shallow depths, nutrient-poor conditions, or high water-column transparency. We recommend more studies assessing periphyton function across a spectrum of lake morphometry and trophic conditions.

Comparison of usefulness of three types of artificial substrata (glass, wood and plastic) when studying settlement patterns of periphyton in lakes of different trophic status

Usefulness of three types of artificial substrata (glass, wood and plastic) was tested when studying settlement patterns of periphyton in lakes of different trophic status. Strictly eu-, meso- and oligotrophic lakes in central Sweden were chosen as objects of the study. Glass slides, glass tubes, pieces of plastic (PVC) and pieces of wood of similar dimensions were placed for 9 weeks in July–August vertically 3 cm above bottom at a total depth of ca. 30 cm. Substrata were located at well-illuminated places without any other submerged objects (like macrophytes and stones), which could potentially affect colonisation patterns by algae. Periphyton communities, which colonised both the glass tubes and the pieces of wood tested, were specific enough to enable a clear classification of the lakes studied in eu-, meso- and oligotrophic. Glass tubes turned out to be the most favourable substratum when investigating settlement patterns of periphyton in this study. Although also colonised by periphytic species, wood did not support the same diversity and abundance of species as glass did. No algae were detected on the plastics studied. The plastics were covered entirely by a slime layer of bacteria. It is discussed if the nature of plastics could have some inhibitory effects on algal growth or the slime layer itself may have prevented settlement of algal spores.

Comparative analysis of Lake Periphyton communities using high performance liquid chromatography (HPLC) and light microscope counts

High performance liquid chromatography (HPLC) and light microscope counts were used to characterize the taxonomic composition of epiphyton and epipelon at seven locations in a subtropical lake. Both methods indicated that algae were dominated by diatoms and cyanobacteria. However, the methods often gave dramatically different estimates of relative biomass among algal divisions, and there was no consistent pattern of co-variation. Large differences in underwater irradiance may have caused variation in accessory pigment to chlorophyll a ratios, invalidating application of the generic HPLC-based model. In large heterogeneous lakes, it may be necessary to use a suite of models, tailored to site-specific environmental conditions, if HPLC is to be used for evaluation of algal community structure.

Periphyton in Lakes of Different Trophy

In a study of 10 lakes in the Eastern Townships (Quebec) periphyton biomass correlated less well with total P (TP) concentration in the water than did phytoplankton biomass. The relationship with TP was improved somewhat when periphyton biomass was estimated as cell volume rather than as chlorophyll or organic material. When the community was divided among various groups according to taxa, life form, and size, only the biomasses of greens, filamentous algae, and algae exceeding 10 000 μm3 were correlated with TP. The biomass of the smaller algae, which are more readily grazed by benthos, was about the same in all lakes whereas nuisance forms increased significantly with P enrichment. At more eutrophic sites, maximal periphyton biomasses were observed in midsummer, coinciding with peak recreational use of lakes, whereas at the other sites, maxima appeared earlier in the season.

The impact of atrazine on lake periphyton communities, including carbon uptake dynamics using track autoradiography

Chlorophyll a, freshweight biomass, ash-free dry weight, cell numbers, species richness, community carbon uptake and species-specific carbon uptake were used to monitor the impact of atrazine (2 chloro-4-ethylamino-6-isopropylamino- s-triazine) on an in situ, enclosed periphyton community. Atrazine concentrations ranging from 0·08 to 1·56 mg litre −1 were used during the 2 years of study. In both 1982 and 1983, there was a shift from a chlorophyte- to a diatom-dominated community. In 1982 the cyanobacterium Cylindrospermum stagnale and the chlorophyte Tetraspora cylindrica developed isolated colonies in the 1·56 mg litre −1 treatment, indicating resistance to atrazine at this concentration. After atrazine exposure, community productivity was reduced by 21% to 82% in the low to high exposures, respectively. After day 21 productivity returned to control levels. It was shown, using track autoradiography, that the productivities of the larger algae Mougeotia sp., Oedogonium sp., Tolypothrix limbata and Epithemia turgida were the most affected, with reductions of 74·3% to 93·1% that of the controls. All the biotic measures indicated reduced growth after herbicide exposure.