Periphytic Algal Community Research Articles

The effects of a pesticide mixture on aquatic ecosystems differing in trophic status: responses of the macrophyte Myriophyllum spicatum and the periphytic algal community

The effects of a pesticide mixture (asulam, fluazinam, lambda-cyhalothrin, and metamitron) on aquatic ecosystems were investigated in 20 outdoor aquatic microcosms. Ten of the microcosms simulated mesotrophic aquatic ecosystems dominated by submerged macrophytes ( Elodea). The others simulated eutrophic ecosystems with a high Lemna surface coverage ( Lemna). This paper describes the fate of the chemicals as well as their effects on the growth of Myriophyllum spicatum and the periphytic algal community. In the Elodea-dominated microcosms significant increase in the biomass and alterations of species composition of the periphytic algae were observed, but no effect on M. spicatum growth could be recorded in response to the treatment. The opposite was found in the Lemna-dominated microcosms, in which decreased growth of M. spicatum was observed but no alterations could be found in the periphytic community. In the Elodea-dominated microcosms the species composition of the periphytic algae diverged from that of the control following treatment with 0.5% spray drift emission of the label-recommended rate (5% for lambda-cyhalothrin), while reduced growth of M. spicatum in the Lemna-dominated microcosms was recorded at 2% drift (20% for lambda-cyhalothrin). This study shows that the structure of the ecosystem influences the final effect of pesticide exposure.

An Examination of the Effects of a Reservoir, Lake Ashtabula, on the Periphytic Algae in the Sheyenne River, North Dakota

AbstractThe Sheyenne River is a third order stream that drains a significant portion of central and eastern North Dakota. In 1950, the Baldhill Dam was built and as a result, the reservoir, Lake Ashtabula, was formed. The periphytic algae in this river were extensively studied from 1997 to 1999. During this research, the effects of differences in environmental variables on the algal communities were assessed with Canonical Correspondence Analysis (CCA). In this analysis, the periphytic algal communities in the downstream sites appeared to be quite different from those communities found upriver of Lake Ashtabula. Other research on different rivers has shown profound changes in the algal community after a dam was built along the river. Redundancy Analysis (RDA) was used to determine if the sites downstream are more statistically similar with Lake Ashtabula than with the upstream sites. Finally, CCA was used to examine which environmental variables explain the most variance in Lake Ashtabula and the downstream sites.

Dredging impact on an urbanized Florida bayou: effects on benthos and algal-periphyton

Environmental effects of dredging events have been uncommonly reported for shallow, residential estuaries characteristic of the Gulf of Mexico region. The objective of this study was to determine the impact of hydraulic dredging on an urbanized estuary. Physicochemical quality, benthic community composition, whole sediment toxicity, periphytic algal community composition and trace metal tissue quality were determined prior to and after dredging. The effects on surface water pH, dissolved oxygen, and temperature were negligible but photosynthetically active radiation was decreased at several stations. Dredging significantly reduced benthic diversity and density ( P<0.05). However, the sediments were not acutely toxic to the epibenthic, Americamysis bahia (formerly Mysidopsis bahia); survival averaged 93% (post-dredging) and to 98% (pre-dredging). There were several post-dredging taxonomic structural changes in the diatom-dominated, periphyton community but differences in mean density and three diversity indices were not significant. Trace metal concentrations in periphyton after dredging were reduced from an average of 4–65% and significantly for mercury, zinc and chromium in several areas. It was concluded that the environmental impact of small-scale dredging events in urbanized near-coastal areas, based on the selected parameters, are likely to be localized and of short-term environmental consequence. The choice of the target biota, response parameters and chemical analysis are important considerations in the environmental impact assessment of these periodic episodic events.

Periphyton and Sediment Bioassessment in North Florida Bay

Periphyton colonization and sediment bioassessment were used ina survey to compare the relative environmental condition ofsampling sites located in Florida Bay and four peripheral sloughareas during the summer of 1995. Periphyton biomass, pigmentcontent, tissue quality and community composition weredetermined. In addition, benthic community composition and thetoxicities of whole sediments and associated pore waters weredetermined for two species of rooted macrophytes, an epibenthicinvertebrate and bioluminescent bacteria. Several locational differences were observed for the response parameters.Periphyton biomass was significantly greater in the Taylor Riverand the least in Shell Creek (P < 0.05). Most sediments were notacutely toxic to mysid shrimp nor phytotoxic. However, sedimentsfrom the Taylor River were more phytostimulatory than others (P< 0.05). Contaminant bioresidues were similar at most sites,however, mercury, chromium and nickel concentrations weregreater for periphyton colonized in the Taylor River and TroutCreek areas. Structural characteristics of the periphytic algalcommunity usually were statistically similar but a consistenttrend of lower density and diversity was evident for ShellCreek. The benthic community was the least diverse and dense inthe Canal C-111. The results of this study provide an initialindication of differences in the role of several slough areas aspossible sources of bioavailable contaminants to Florida Baywhich warrants additional investigation.

COLONIZATION OF PERIPHYTIC ALGAE ON ARTIFICIAL SUBSTRATES IN A TROPICAL STREAM

Standard periphyton samplers were used to examine the colonization pattern of periphytic algae on an artificial substrate (glass slides) in the Lam Tsuen River, Hong Kong, between October 1995 and August 1996. Changes in the taxonomic composition, species diversity (Shannon-Wiener diversity index), total standing crop, as well as the abundance of individual algal species were monitored over a six-week period in each season. Diatoms were most dominant in terms of cell density and biovolume, while green algae were important in terms of cell biovolume in autumn and summer. Of the 81 algal species observed, the pennate diatoms were most abundant. Dominant algal species included Achnanthes minutissima, Gomphonema parvulum, G. angustatum, G. rhombicum, Synedra rumpens var. familiaris, Nitzschia palea, Cocconeis placentula, Mougeotia spp., Spirogyra spp., Stigeoclonium aestivale and Schizothrix calcicola. A maximum algal density of 3.45 × 106 cells per cm2 was observed after a 4-week field incubation in spring (April and May), while maximum algal biovolume (1.20 × 106 μm3 cm−2) was recorded after a 6-week field incubation in summer (July and August). In general, the standing crop reached its maximum at week 4. Seasonal variations in the succession patterns of the periphytic algal communities are described.

Effects of Microscale Water Level Fluctuations and Altered Ultraviolet Radiation on Periphytic Microbiota.

Abstract Microscale fluctuations in water level (1-20 mm) are common on a diurnal basis in shallow (<5-10 cm) wetlands, coupled to evapotranspiration losses during the daytime in excess of groundwater resupply. These depth variations alter the intensity of UV irradiance reaching attached periphytic algal and bacterial microbial communities. Effects of alterations of UV irradiance by micro-changes in water level on periphytic microbiota were examined experimentally. Attached microbial communities, grown on glass fiber filters in situ in a natural wetland, were exposed experimentally to near-natural levels of UV irradiance of differing spectral quality. UV intensity was altered by varying the distance of the communities from the light source, changes in UV-attenuating natural dissolved organic matter (DOM), and small changes in water level (2 or 4 mm). Algal productivity and photosynthetic oxygen production were significantly reduced by small enhancements of UV-B radiation, by decreased water levels of only 2 mm, and by reductions in concentrations of DOM. UV-B had only small short-term effects on chlorophyll a, although small increases in water depth and DOM concentration reduced pigment damage. Experimental removal of UV-B during in situ growth indicated that algae could adapt to UV radiation during growth in natural environments. Microbial oxygen consumption and bacterial productivity and biomass were also lowered significantly by UV-B exposure, and damage decreased with small (2 mm) increases in water depth or in DOM concentration. Selective inhibitors of algal photosynthesis and production of released extracellular organic substrates caused a concomitant reduction in bacterial productivity and a significant increase in magnitude of UV-B damage to bacterial biomass. These effects suggested that metabolic interactions between the periphytic autotrophs and heterotrophs altered community responses to UV-B radiation. Microscale water level reductions, common on a diurnal basis in shallow wetlands, and associated increased UV intensity can result in rapid alterations in periphytic metabolism.http://link.springer-ny.com/link/service/journals/00248/bibs/38n3p253.html</hea

Temporal variation in the structure of periphytic algal communities on an artificial substrate in the Jurumirim Reservoir, S.R, Brazil

(1998). Temporal variation in the structure of periphytic algal communities on an artificial substrate in the Jurumirim Reservoir, S.R, Brazil. SIL Proceedings, 1922-2010: Vol. 26, No. 4, pp. 1758-1763.

人工基物上に形成される付着藻類相に与える下水処理水の影響

Effects of sewage effluent on periphytic algae in the River Tsunaki were surveyed using artificial substrata in weekly during summer in 1996. The artificial substrata were settled at 2m upper and 2m downstream site of the discharging point. After two weeks they were exchanged to clarify the influence of sewage on the periphytic algal community succession. Water quality were surveyed at three stations, artificial substrata settling sites and discharging point.The average concentrations of BOD were 0.7 (downstream site), 0.8 (sewage effluent) and 1.1mg/l (upstream site) . The many nutrient concentrations were constantly high at downstream site by the sewage effluent.Different algal communities were formed on artificial substrata at the upper and down site. Of fifty algae recorded, Nitzschia amphibia (at the upper site) and Stigeoclonium spp. (at the down site) were dominant.Nitzschia amphibia is eurysaprobic species and Stigeoclonium spp.is a tolerant species for pollution. It was found that after forming the stable periphytic algal communitiy the sewage didn't influence the algal succession on artificial substrata. The successions of algal periphytic community on artificial substrata exchanged between the upper and down sites after two weeks reflected the enviromnent before the exchange. But the diversity index of them were down by the sewage eflluent.

Seasonal dynamics of aufwuchs Naididae (Oligochaeta) on Phragmites australis in a eutrophic lake

The Oligochaeta and Aphanoneura in the aufwuchs on Phragmites australis in a eutrophic hardwater lake were studied at two sites over a period of one year, in order to elucidate the structure and dynamics of this assemblage. The naidids Chaetogaster diastrophus, Nais spp., and Stylaria lacustris dominated the assemblage at any season. At both sites these taxa showed the same distinct pattern of successive population maxima in spring and summer: Chaetogaster diastrophus reached its peak density first, followed by Nais species, and eventually by Stylaria lacustris. Differences in temporal dynamics between sites were small apart from a second Stylaria maximum which was only observed at one site. Total naidid densities reached peak values of 3.8 individuals per cm2 reed stem surface area. With mean individual biomass of 2.2 µg dry mass for Chaetogaster diastrophus, 13.3 µg for Nais, and 86 µg for Stylaria lacustris, respectively, maximum total naidid biomass on reed stems was 44 µg dry mass per cm2. The biomass peak occurred later than that of total naidid density because in summer larger naidids dominated the assemblage. The observed succession appears to be consistent with seasonal changes in periphytic algal communities on the reed stems.

下水処理場流出水の河川生物相に与える影響

Effects of effluent from sewage treatment plant on periphytic algae were surveyed five times in the Rivers Tsunaki and Hirose during 1993-1994.The River Hirose is a symbolic river flowing through Sendai City and the River Tsunaki is a branch of that. In the sewage treatment plant an ozone treatment (injection rate: 4mg/l) is used for disinfection of effluents, the sewerage flowing into the River Tsunaki.The periphytic algae and water quality were surveyed at three stations in both rivers. At all the stations the bacillariophytes were major, especially Cymbella minuta, Navicula lanceolata and Navicula gregaria were observed at most stations.And Nistzschia palea, which needs continuously elevated concentrations of organically bound nitrogen, appeared at the down stream stadons of discharging point. On the other hand the diversity index of periphytic algal communities receiving other sewage became higher than before. This indicates that the effluent from sewage treatment plant improved the periphytic algal communities at polluted places.

Effects of self-purification on periphytic algal communities in lotic systems

Effects of self-purification on periphytic algal communities in lotic systems

Factors regulating periphytic algal biomass

To assess the principal factors regulating periphytic algal communities, I conducted a field study along a productivity gradient of Swedish and Antarctic lakes ranging from extremely low productivity meltwater to highly productive lakes. Because the Antarctic lakes lack fish, as well as molluscs and insect larvae, the data set provides considerable variation in food web composition, offering a rare opportunity to evaluate the importance of these factors in determining the biomass of periphytic algae. Among the possible factors investigated, water temperature, substrate characteristics, and food web composition seem to be of minor importance. Instead, there was a curvlinear relationship between the biomass of sediment‐associated periphytic algae and lake productivity, suggesting a shift from nutrient limitation to light limitation caused by phytoplankton. A temporal study in the littoral zone of one of the lakes included in the spatial study showed that the temporal variation in periphyton biomass within the lake was low compared to the variation between lakes. The temporal study also strengthened suggestions from the spatial study by pointing to nutrient availability as a major factor determining periphytic algal biomass.

Artificial aeration as a factor influencing the periphytic algal community of Beech Fork Lake

Artificial aeration as a factor influencing the periphytic algal community of Beech Fork Lake

Invertebrate grazer‐periphyton interactions in a eutrophic marsh pond

SUMMARY. 1. The effects of two different invertebrate grazer guilds on the periphytic algal community were studied in a marsh pond in Manitoba, Canada over one entire open‐water season.2. Microcrustaceans (cladocerans, copepods, ostracods), which were numerically dominant in the unperturbed grazer community, effectively reduced the periphytic algal biomass to a persistent, depauperate residual assemblage throughout the season.3. The perturbed grazer community, enclosed and treated with ro‐tenone, was composed primarily of chironomids and oligochaetes. This community permitted a more diverse algal community to develop except when grazer numbers peaked.4. When grazer numbers in the perturbed community were at a maximum, the algal assemblage appeared to be ‘overgrazed’. Algal biomass was reduced below the minimum characteristic of the unperturbed community.5. There was an inverse relationship between algal biomass and grazer numbers in both perturbed and unperturbed communities, but variation in degree of response was much greater in the perturbed system than in the unperturbed one.

Effects of a pulp and paper mill effluent on the structure and metabolism of periphytic algae in experimental streams

The impact of a pulp and paper mill effluent on periphytic algae growing under controlled conditions in experimental streams was manifested as a drop in species richness and diversity, and changes in the taxonomic structure of the algal community. The decrease in diatom density was compensated by the relative contribution of Chlorophyceae, which increased with increasing effluent concentration (0.5%, 2.5% and 10% v/v). The presence of effluent also led to a rise in heterotrophic biomass and activity. However, the stream with the highest effluent concentration (10% v/v) showed a greater autotrophic biomass, and had the lowest photosynthetic efficiency, suggesting that algal species which develop under such conditions exhibit important heterotrophic activity. This hypothesis was supported by micro-autoradiographic studies, which showed that Chlamydomonas sp. cells were very strongly marked after incubation in the presence of amino acids, while diatoms showed little or no radioactivity. This suggested that the dissolved organic carbon in the effluent acted as a eutrophication factor for periphytic algal communities.

Biomass and compositional changes in the periphytic community of an artificial stream in response to lowered pH

Two artificial streams simulating low-order, softwater streams of the Upper Peninsula of Michigan were employed to examine the effects of lowered pH on periphytic algae. The control stream contained water with a circumneutral pH whereas the pH of the water in the acidified stream was decreased to pH 4 with H2SO4. Chlorophyll a concentrations and cell densities in the periphytic algal communities were used to measure differences in biomass accumulations between the 2 streams over a 42-d, spring colonization period. Relative abundances of algal genera and Stander's similarity index (SIMI) were used to examine compositional differences between the control and acidified periphytic algal communities. These algal communities exhibited pronounced differences in their total biomasses and compositions indicating periphytic algal communities inhabiting low-order, softwater streams, such as those of the Upper Peninsula of Michigan, are vulnerable to acidic deposition. Decreased biomass accumulation under acidified conditions was believed to result primarily from decreased nutrient availability, and possibly secondarily from elevated aluminum and/or iron concentrations. The shift in community compositions was interpreted to be a more direct response to the lowered pH as acidophils and acid tolerant genera became favored, and thus more abundant.

Changes in periphytic algal community structure as a consequence of short herbicide exposures

Effects of the triazine herbicides simazine and terbutryn on total biovolume and community structure of haptobenthic periphytic algal communities within in situ marsh enclosures are described. Levels of biovolume inhibition in excess of 98% relative to an untreated control were observed at all levels of terbutryn tested (0.01, 0.1 and 1.0 mg l−1). No reduction in total biovolume was observed at 0.1 mg l−1 simazine, with increasing inhibition (to 98%) at 1.0 and 5.0 mg l−1. Following incidental enclosure flooding and removal of herbicide, increases in biovolume were observed in all but the highest treatment levels, with rates of colonization similar to that of the control.

The composition and ecology of periphyton communities in freshwaters

The surfaces of aquatic plants are not metabolically inert, yet much evidence seems to suggest that they exert little influence on the composition of the periphytic algal communities associated with them. Other evidence indicates a specificity of the algal communities to particular macrophyte species. Evidence is given here, from a variety of studies, that the influence of host type in determining periphyton community composition is greatest in infertile lakes, but, that in progressively more fertile water, external environmental factors become more important.