Periphytic Algae Research Articles

Interaction Between Climate Change Scenarios and Biological Invasion Reveals Complex Cascading Effects in Freshwater Ecosystems.

Climate change often facilitates biological invasions, leading to potential interactive impacts of these global drivers on freshwater ecosystems. Although climatic mitigation efforts may reduce the magnitude of these interactive impacts, we are still missing experimental evidence for such effects under multiple climate change scenarios within a multi-trophic framework. To address this knowledge gap, we experimentally compared the independent and interactive effects of two climate change scenarios (mitigation and business-as-usual) and biological invasion on the biomass of major freshwater trophic groups (phytoplankton, zooplankton, periphyton, macroinvertebrates, and a native macrophyte) and the decomposition rate of allochthonous material. Among the independent effects, we found that the business-as-usual climate treatment resulted in lower native macrophyte biomass and higher periphyton biomass compared to the climatic baseline and mitigation treatments. This indicates the potential of climate change to alter the relative dominance of different freshwater producers and demonstrates that climate mitigation efforts can counteract these effects. Biological invasion alone increased the biomass of chironomids, a dominant macroinvertebrate group in tropical freshwater ecosystems, demonstrating a compensatory effect on climate change. Climate change and biological invasion interactively reduced the decomposition rate of allochthonous detritus, likely mediated by the feeding preference of abundant chironomids for periphytic algae associated with the presence of non-native macrophytes. We concluded that (i) climatic mitigation can maintain climate baseline conditions in freshwater ecosystems, and (ii) the interactive effects between future climate scenarios and biological invasion are related to complex cascading interactions among trophic groups on ecosystem processes.

On the taxonomic richness, evenness and divergence of periphytic algae in Amazon streams

On the taxonomic richness, evenness and divergence of periphytic algae in Amazon streams

Differences in seasonal dynamics, ecological driving factors and assembly mechanisms of planktonic and periphytic algae in the highly urban Fenhe River

BackgroundAlgae play important roles in urban river ecosystems and are the cornerstones of most water quality monitoring programs. Thus, a better understanding of algal community dynamics is needed to support sustainable management of water resources in urban rivers.ResultsIn this study, we quantified the seasonal variations in planktonic and periphytic algal community structure in the highly urban Fenhe River and identified environmental factors affecting algal community structure and diversity. We monitored planktonic (drifting) and periphytic (attached) algal communities in the Taiyuan section of the Fenhe River over one year. The results indicated that Cyanophyta was the dominant phylum in both communities, followed by Bacillariophyta and Chlorophyta. Significant differences were observed in the composition of the planktonic and periphytic algal communities. In particular, the periphytic algal community was more diverse than the planktonic community. Water temperature and pH were the main environmental factors affecting planktonic and periphytic algal community structure, respectively, while nutrients were the most significant factor affecting planktonic and periphytic algal diversity. Ecological modeling indicated that the variations in the algal communities of the Fenhe River are mainly driven by stochastic processes. A co-occurrence network developed for the communities displayed positive interactions between the planktonic and periphytic algae.ConclusionsThese findings deepen our understanding of the seasonal interaction between planktonic and periphytic algae and the driving factors affecting community structure in the Fenhe River. They also provide a theoretical basis for the managing and protecting water resources in urban river ecosystems.

The effect of ship-induced wave trains on periphytic algal communities in the littoral zone of a large regulated river (River Danube, Austria)

Riverine ecosystems are profoundly influenced by hydrological dynamics and natural flow regimes, which dictate the temporal variability of water levels and the amplitude of fluctuations. Human activities, particularly navigation and hydropower generation, have significantly altered these natural patterns, leading to detrimental impacts on the physical, chemical, and biological integrity of river ecosystems. The littoral zone, in particular, is highly susceptible to anthropogenic disturbances, experiencing disruptions in biological activity and biogeochemical processes. This study evaluates the effects of ship-induced wave trains on the structural and functional properties of periphytic algal communities in a regulated river environment. Using data from the Austrian Danube River, periphytic algae's immediate and long-term responses to wave events generated by different types of ships were investigated. Immediate reactions of periphytic algae to wave trains were characterized by reductions in the effective quantum yield of PS II, indicating stress-induced down-regulation of photosystem II photochemistry. Abrasion and remobilization of periphytic algae due to wave action led to increased resuspension of chlorophyll-a into the water column. Furthermore, ship-induced wave trains influenced the pigment composition of periphyton, with photoprotective mechanisms being activated in response to fluctuating light conditions. Long-term effects of wave impact on periphytic algae biomass varied depending on water depth and exposure to aerial stress. While wave action mitigated desiccation stress in shallow areas, it resulted in biomass reduction and alterations in community composition in deeper zones. Notably, the occurrence of diatoms decreased in wave-impacted areas, potentially shifting the community towards Chlorophyceae dominance. Overall, this study underscores the complexity of ship-induced wave impacts on riverine ecosystems and highlights the importance of considering both immediate and long-term responses of periphytic algal communities. Understanding these dynamics is crucial for informing sustainable management strategies aimed at mitigating the adverse effects of navigation activities on riverine biodiversity and ecosystem functioning.

Nutritional Quality of Basal Resource in Stream Food Webs Increased with Light Reduction—Implications for Riparian Revegetation

Biofilms are considered a basal resource with high nutritional quality in stream food webs, as periphytic algae are abundant of polyunsaturated fatty acids (PUFAs). PUFAs are essential for growth and reproduction of consumers who cannot or have very limited capacity to biosynthesize. Yet, how the nutritional quality based on PUFA of basal food sources changes with light intensity remains unclear. We conducted a manipulative experiment in mesocosms to explore the response and mechanisms of nutritional quality to shading, simulating riparian restoration. We found a significant increase in PUFA% (including arachidonic acid, ARA) under shading conditions. The increased PUFA is caused by the algal community succession from Cyanobacteria and Chlorophyta to Bacillariophyta which is abundant of PUFA (especially eicosapentaenoic acid, EPA; docosahexaenoic acid, DHA). On the other hand, shading increased PUFA via upregulating enzymes such as Δ12 desaturase (FAD2, EC:1.14.19.6) and 3-ketoacyl-CoA synthase (KCS, EC:2.3.1.199) in the biosynthesis of unsaturated fatty acid elongation pathways. Our findings imply that riparian reforestation by decreasing light intensity increases the nutritional quality of basal resources in streams, which may enhance transfer of good quality carbon to consumers in higher trophic levels through bottom-up effects.

Salamander loss alters montane stream ecosystem functioning and structure through top‐down effects

AbstractAmphibians are among the most endangered taxa worldwide, but little is known about how their disappearance can alter the functioning and structure of freshwater ecosystems, where they live as larval stages. This is particularly true for urodeles, which often are key predators in these ecosystems. The fire salamander (Salamandra salamandra) is a common predator in European fresh waters, but the species is declining due to habitat loss and the infection by fungal pathogens. We studied the consequences of fire salamander loss from three montane streams, by comparing two key ecosystem processes (periphyton accrual and leaf litter decomposition) and the structure of three communities (periphytic algae, aquatic hyphomycetes and invertebrates) using stream enclosures with and without salamander larvae. Salamander loss did not cause changes in invertebrate abundance or community structure, except for one stream where abundance increased in the absence of salamander larvae. However, salamander loss led to lower periphyton accrual, changes in algal community structure and slower leaf litter decomposition, with no associated changes in fungal communities or microbial decomposition. The changes observed may have been caused by release of salamander predatory pressure on invertebrates, which could have promoted their grazing on periphyton, in contrast to their preference for leaf shredding in the presence of salamander. Our study demonstrates an important role of salamander larvae in montane streams through top‐down control of lower trophic levels and thus in regulating key stream ecosystem processes. Our results highlight the need for improving protection measures for amphibians to prevent these alterations on ecosystem structure and function.

Revealing the response characteristics of periphyton biomass and community structure to sulfamethoxazole exposure in aquaculture water: The perspective of microbial network relationships

The widespread application of sulfonamide antibiotics in aquaculture has raised concerns about their adverse environmental impacts. Periphyton plays a crucial role in the aquatic ecosystem. In this study, we examined sulfamethoxazole (SMX) effects on the community structure and interactions of periphyton in simulated aquaculture water. Our findings indicated that the total biomass of periphyton decreased, while the biomass of periphytic algae and the secretion of extracellular polymeric substances (EPS) increased at 0.7 × 10−3 mg/L. Under higher SMX concentrations (5 mg/L and 10 mg/L), periphyton growth was severely inhibited, the microbial community structure of periphyton were sharply altered, characterized by the cyanobacteria growth suppression and decrease in the diversity index of community. Furthermore, elevated SMX concentrations (5 mg/L and 10 mg/L) increased the ratio of negative relationships from 45.4% to 49.4%, which suggested that high SMX concentrations promoted potential competition among microbes and disrupted the microbial food webs in periphyton. The absolute abundance of sul1 and sul2 genes in T2 and T3 groups were 2–3 orders of magnitude higher than those in control group after 30 days of SMX exposure, which elevated the risk of resistance gene enrichment and dissemination in the natural environment. The study contributes to our understanding of the detrimental effects of antibiotic pollution, which can induce changes in the structure and interaction relationship of microbial communities in aquaculture water.

Species Composition and Association of Periphyton on Ceratophyllum demersum L. and Vallisneria spiralis L. in Two Freshwater Ponds of Kavaledurga Fort, Central Western Ghats, Karnataka, India

The aim of the current research was to ascertain how the periphytic algae's species composition and diversity varied seasonally and how those changes related to the physico-chemical elements of two submerged macrophytes (<i>Ceratophyllum demersum, Vallisneria spiralis</i>) in the ponds of Kavaledurga Fort. Periphytic algal communities were highly diversified totalling 70 species, and limnological variables were measured in pond water samples over the three seasons of the study period from September 2020 to May 2021. Members of <i>Zygnematophyceae (n = </i>57) were found in water bodies with a high diversity and covering of macrophytes. <i>Ceratophyllum demersum (n =</i> 64) was an algae rich macrophyte when compared to <i>V. spiralis (n = </i>25). The main determining factors for this community variability were elevations in temperature, pH, DO, electrical conductivity and nutrients. The species richness and evenness of periphytic algae over the macrophytes were disclosed by diversity indices. From the similarity index, the results indicated a slight difference in populations of periphytic micro-algae between the studied ponds.

Spatial pattern of periphytic algae communities in major tributaries of the upper Jinsha River and the environmental drivers

Spatial pattern of periphytic algae communities in major tributaries of the upper Jinsha River and the environmental drivers

Response of periphytic algae community structure characteristics to hydrodynamic conditions in an open channel

Response of periphytic algae community structure characteristics to hydrodynamic conditions in an open channel

Diatoms Reduce Decomposition of and Fungal Abundance on Less Recalcitrant Leaf Litter via Negative Priming

Heterotrophic microbial decomposers colonize submerged leaf litter in close spatial proximity to periphytic algae that exude labile organic carbon during photosynthesis. These exudates are conjectured to affect microbial decomposers’ abundance, resulting in a stimulated (positive priming) or reduced (negative priming) leaf litter decomposition. Yet, the occurrence, direction, and intensity of priming associated with leaf material of differing recalcitrance remains poorly tested. To assess priming, we submerged leaf litter of differing recalcitrance (Alnus glutinosa [alder; less recalcitrant] and Fagus sylvatica [beech; more recalcitrant]) in microcosms and quantified bacterial, fungal, and diatom abundance as well as leaf litter decomposition over 30 days in absence and presence of light. Diatoms did not affect beech decomposition but reduced alder decomposition by 20% and alder-associated fungal abundance by 40% in the treatments including all microbial groups and light, thus showing negative priming. These results suggest that alder-associated heterotrophs acquired energy from diatom exudates rather than from leaf litter. Moreover, it is suggested that these heterotrophs have channeled energy to alternative (reproductive) pathways that may modify energy and nutrient availability for the remaining food web and result in carbon pools protected from decomposition in light-exposed stream sections.

<em>In situ</em> effects of arsenic, aluminium and chromium stresses on algal periphyton of the river Ganga at Varanasi, India

In situ effect of metal stress on periphytic algal communities of a river was studied using chemical diffusing substrates. The metal stress caused the inhibition of periphytic biomass in a concentration-dependent manner. The study indicated differential response of various periphytic groups to different metal treatments. Diatoms exhibited tolerance against arsenic (As) and aluminium (Al) treatment but displayed sensitivity against chromium (Cr) treatment. An increased abundance of cyanobacteria was noteworthy in Cr enrichment, but Al and As were hazardous to these organisms. The relative abundance of green algae also increased in all three test metals. The metal stress lowered the species richness and diversity of periphytic algae, apparently due to the elimination of some of the sensitive species followed by an increased abundance of tolerant forms. Periphytic taxa tolerant to one metal were not necessarily tolerant to other metals or metalloids, and vice versa. The metal-induced changes in algal community composition will lead to severe ecological consequences by affecting biological diversity and in turn productivity of aquatic systems. Since algae occupy the aquatic food web base, any harmful effect on these organisms would have repercussions at higher trophic levels. Thus, it seems urgent to incorporate biomonitoring practices and chemical analysis to monitor the river Ganga's ecological health.

Biomanipulation of Periphytic Algae in the Middle Route of South–North Water Diversion Project Canal: An In Situ Study in the Lushan Section

The biomanipulation technique has been developed and implemented for decades, yielding favorable results in various lakes both domestically and globally. This technology uses fish to reduce algae biomass, giving a natural and environmentally friendly solution to improve water quality. The effectiveness of biomanipulation technology in large-scale artificial water canals, on the other hand, has been unclear. To address this, from 15 December 2019 to 30 April 2020, an in situ experimental study on the biomanipulation of periphytic algae was conducted in the Lushan section of the main canal of the Middle Route of the South-to-North Water Diversion Project (MSNWDP). The study aimed to verify the control effect of fish on periphytic algae. Various combinations of Megalobrama terminalis and Xenocypris davidi were fixed on the canal with a triangular cylindrical cage, and their feeding effects on periphytic algae were observed. The results showed that the density of periphytic algae at the bottom of the cages was substantially lower than before the experiment, with a 68.75% average reduction. We graded the food-filling results based on the amount of digestive tract content, which was represented using Arabic numerals ranging from 0 to 5. The study discovered that M. terminalis had the best adaptability to the environment, with full intestines primarily composed of periphytic algae and a food-filling degree between grades 4 and 5. X. davidi, on the other hand, had a food-filling degree of 0. Furthermore, the weight of each M. terminalis increased significantly following the experiment, whereas the weight of each X. davidi decreased to varying degrees. Additionally, the study highlights the importance of selecting the appropriate fish species for biomanipulation, as different species may have varying levels of effectiveness in controlling periphytic algae. Overall, this study provides valuable insights into the potential of biomanipulation technology in large-scale artificial water canals and other water conservancy projects.

Periphyton in urban freshwater facilitates transformation of trace organic compounds: A case study on iodinated contrast media

Introduction: Due to urbanization and demographic change trace organic compounds (TrOCs), synthetic chemicals such as pharmaceuticals, personal care products or biocides are an increasing problem in waterbodies affected by treated sewage. This contamination is particularly relevant when surface water is used for drinking water production, either directly or by bank filtration. Removal and transformation of TrOCs are affected by a variety of processes, and we hypothesize that periphyton, the mixture of photo- and heterotrophic biota attached to submerged surfaces of aquatic ecosystems, can facilitate TrOC transformation. Here we experimentally tested the influence of periphyton on different substrates on the transformation of iodinated contrast media (ICM). These hydrophilic compounds are problematic due to their poor removal by conventional wastewater treatment and high persistence of the triiodinated benzoic acid within aquatic environments.Methods: We added 100 μg L-1 of three ICM, iopromide (IOP), iopamidol (IOM) and diatrizoate (DIA) to batch experiments containing periphyton on artificial substrates or on invasive quagga mussels and to a column experiment with periphyton, quagga mussels and sediment from a bank filtration site in a lake.Results: IOP concentrations were reduced by up to 93% after 30 days in batch experiments with periphyton on artificial substrates and completely in treatments with mussels and periphyton. In contrast, no concentration decrease was observed for IOM and DIA. IOP reduction was positively correlated with periphyton biomass ranging from 0.7 to 9.2 g dry weight m-2 and negatively correlated with oxygen saturation. 9 of 12 known aerobic IOP transformation products frequently occurring in treated wastewater were found.Discussion: We suggest that periphyton facilitated IOP transformation by providing substrate for bacterial growth and enhanced bacterial growth rates due to algal photosynthesis, a co-oxidation catalyzed by ammonia oxidizing bacteria and by a stimulatory influence of labile carbon produced by periphytic algae on the microbially mediated decomposition of IOP. Periphyton is facilitated by increased nutrient supply of dense mussel stands or by an increased surface area provided in dense macrophyte stands. Consequently, changes in the abundance of these littoral communities by invasion or management can affect TrOC transformation and thus water quality for drinking water production from urban freshwaters.

Deterministic processes dominate microbial community assembly in artificially bred Schizothorax wangchiachii juveniles after being released into wild.

Fish artificial breeding and release is an important method to restore wild populations of endemic fish species around the world. Schizothorax wangchiachii (SW) is an endemic fish in the upper Yangtze River and is one of the most important species for the artificial breeding and release program implemented in the Yalong River drainage system in China. It is unclear how artificially bred SW adapts to the changeable wild environment post-release, after being in a controlled and very different artificial environment. Thus, the gut samples were collected and analyzed for food composition and microbial 16S rRNA in artificially bred SW juveniles at day 0 (before release), 5, 10, 15, 20, 25, and 30 after release to the lower reaches of the Yalong River. The results indicated that SW began to ingest periphytic algae from the natural habitat before day 5, and this feeding habit is gradually stabilized at day 15. Prior to release, Fusobacteria are the dominant bacteria in the gut microbiota of SW, while Proteobacteria and Cyanobacteria generally are the dominant bacteria after release. The results of microbial assembly mechanisms illustrated that deterministic processes played a more prominent role than stochastic processes in the gut microbial community of artificially bred SW juveniles after releasing into the wild. Overall, the present study integrates the macroscopic and microscopic methods to provide an insight into the food and gut microbial reorganization in the released SW. This study will be an important research direction to explore the ecological adaptability of artificially bred fish after releasing into the wild.

Environmental Driving Factors and Assessment on the Aquatic Ecosystem of Periphytic Algae of Six Inflow Rivers in Yangtze River Basin

Phytoplankton is frequently utilized in the assessment of water ecological health, and a great number of related studies have been conducted in China; however, most of them are limited in scope. A phytoplankton survey was carried out at the basin scale in this study. A total of 139 sampling sites were set up in crucial locations of the main stream, from the Yangtze River's source region to the estuary, as well as the eight primary tributaries and the Three Gorges' tributaries. In the Yangtze River Basin, phytoplankton was found in seven phyla and 82 taxa, with Cryptophyta, Cyanophyta, and Bacillariophyta being the dominant species. To begin, the composition of phytoplankton communities in various sections of the Yangtze River Basin was studied, and LEfSe was utilized to identify highly enriched species in different regions. The association between phytoplankton communities and environmental factors in different sections of the Yangtze River Basin was then investigated using CCA. The generalized linear model demonstrated that TN and TP were strongly positively linked with phytoplankton density at the basin scale, whereas TITAN analysis identified the environmental indicator species and their corresponding optimal growth threshold range. Finally, the study assessed each Yangtze River Basin Region in terms of biotic and abiotic factors. Although the results of the two aspects were incongruent, the analysis of all indicators using the random forest method can yield comprehensive and objective ecological evaluation results for each section of the Yangtze River Basin.

Influence of River Disconnection on Floodplain Periphyton Assemblages

The Atchafalaya River Basin (ARB) in southcentral Louisiana, USA, is a structurally and biotically diverse floodplain of Atchafalaya River (AR), which is the largest distributary of the Mississippi River. Annual floodplain inundation facilitates the exchange of nutrients and organic material between the AR and its floodplain, giving rise to the high productivity of the river-floodplain system. Production within the ARB is driven by periphytic algae, phytoplankton, and aquatic macrophytes, however, very little is known about periphytic algal assemblages in floodplain systems or how loss of annual flooding impacts these assemblages. In this study, we use artificial substrates to sample periphytic algae bi-weekly (January 2019 – September 2019) from ARB sites with active river connections and from a permanently-isolated floodplain system (Lake Verret). Our results showed that connection to the river caused spatiotemporal shifts in periphytic algal assemblages in the ARB. Overall, ARB sites had a higher density of algal cells compared with non-ARB sites, and for ARB sites with more active river connections, total algal density was greater nearer to river inputs, particularly for cyanobacteria and centric diatoms, with diatoms dominating periphyton assemblages year-round. In contrast, the river-isolated system was dominated largely by chlorophytes. In both isolated and connected systems, sites with heavy macrophyte cover showed increased densities of euglenoids, chrysophytes, and xanthophytes. Shifts in periphytic algal assemblages due to floodplain alterations, such as the disconnection of a floodplain from its river source, could impact higher trophic levels and should be considered in future wetland management decisions.

Composition of epilithic diatom and soft-algal assemblages in infralittoral zones of Tennessee reservoirs and correlations of composition to trophic state

Assemblages of infralittoral periphytic algae are understudied due partially to the historical emphasis on phytoplankton and other water-column characteristics to evaluate the integrity of lentic systems. We tested the null hypothesis that characteristics of epilithic algal assemblages at infralittoral sites in reservoirs of Middle and East Tennessee do not infer trophic state. One infralittoral site in five mesotrophic and five eutrophic reservoirs in Middle and East Tennessee was sampled to determine the relative abundance of the most common epilithic diatoms and soft algae, concentrations of epilithic chlorophyll (chl) a, and water concentrations of chl a, total phosphorus (TP), and total nitrogen (TN). The concentration of epilithic chl a correlates significantly to the concentration of TP but not to TN as determined by the probability values for Pearson’s correlation coefficients. The water concentration of chl a does not correlate significantly to concentrations of TP, TN, or epilithic chl a. Trophic-state indicator values for 162 epilithic diatom taxa and 102 epilithic soft-algal taxa are calculated as the abundance-weighted average of the concentration of epilithic chl a normalized between 0 and 100. The trophic-state indicator values indicate the relationship of the abundance of algal taxa to trophic state and contribute to our limited knowledge of the effects of eutrophication on infralittoral algal taxa. Trophic-state indices are calculated as the mean abundance-weighted average of trophic-state indicator values for algal taxa of an assemblage. The index values infer the trophic state of the sites and are the first to use epilithic concentrations of chl a as opposed to water-column characteristics to indicate trophic-state optima for periphytic algae of lentic systems. The indices are easy to calculate and provide novel tools to help evaluate and monitor the trophic state of infralittoral sites in reservoirs of Middle and East Tennessee.

Dynamic Characteristics of Periphytic Algae Communities on Different Substrates and the Host Response in Subtropical-Urban-Landscape Lakes

Outbreaks of periphytic algae, including filamentous algae, have been observed after submerged macrophyte restoration and are common in early stages. Dynamic changes in the periphytic algae community on Vallisneria natans and artificial V. natans were investigated in situ, and their characteristics were compared on the two substrates. The results showed that more periphytic algae species occurred on V. natans (77 taxa) than on artificial V. natans (66 taxa) (F = 2.089, p = 0.047). The cell density and chlorophyll a (Chl. a) content of periphytic algae were 3.42–202.62-fold and 2.07–15.50-fold higher on the artificial substrate than on V. natans, respectively. Except for Lyngbya perelagans (i.e., the only common dominant periphytic algae species on the two substrates), the dominant species on V. natans were Cocconeis placentula and Ulothrix tenerrima, while those on the artificial substrate were Stigeoclonium aestrivale, Oscillatoria tenuis and Achnanthes minutissima. The cell density of periphytic algae was significantly affected by the total phosphorus (TP) and NO3−-N and electric conductivity on V. natans, and by TP and NH4+-N on artificial V. natans. The malondialdehyde content of V. natans was significantly correlated with the periphytic algae biomass. V. natans was more affected by periphytic algae during its slow-growing period, and the contribution order of stress to V. natans was diatoms > cyanobacteria > green algae. Our findings might contribute to the understanding the effect of substrate specificity on periphytic algae communities, and have important implications for the restoration of submerged plants in eutrophic lakes.

Effects of Different Colored Polycarbonate Plastics on Growth and Community Structure of Periphytic Algae

Periphytic algae are important primary producers in water bodies, which play an important role in maintaining ecological function and water purification. Previous studies have shown that plastic is a good substrate for periphytic algae, and different plastic materials have different effects on the colonization of periphytic algae; however, there are few reports on the effects of plastic color on the growth of periphytic algae. In this study, polycarbonate plastic (PC) of various colors were used as the substrate to study the effects of different colors on the growth and community structure of periphytic algae by measuring the biomass, photosynthetic activity, and community composition. The results showed that the growth of periphytic algae was inhibited by the brown PC plastic, and the contents of chlorophyll a and dry weight in this group were significantly lower than those in other groups. Green PC plastic inhibited the photosynthetic activity of periphytic algae, and the actual photosynthetic efficiency (Yield) of the group was significantly lower than that of the other groups. The influence of PC plastic with different colors on periphytic algae occurred mainly in the early colonization/development stage but was not significant in the late community maturity stage. On day seven of the experiment, the community composition of periphytic algae was significantly different between the transparent PC plastic group and the green PC plastic group. By contrast, on days 25 and 40, there were no significant differences in the community structure of periphytic algae. In the early stage of the experiment, the dominant genus was Pseudoranea (Cyanophyta), and in the middle and mature stages, the dominant genus was Mougeotia (Chlorophyta). In this study, the effects of different colors of polycarbonate plastics on periphytic algae were investigated, which provided new insights for selecting suitable substrates for water pollution treatment by using periphyton biotechnology.