The diatom <i>Didymosphenia geminata</i>: distribution and mass occurrence in the Province of Trento (Northern Italy)

Beltrami, Maria Elena; Cappelletti, Cristina; Ciutti, F.; Hoffmann, Lucien; Éctor, Luc

doi:10.1080/03680770.2008.11902196

Cited by 5 publications

(9 citation statements)

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“…However, at least one earlier reference to mucilage and some of the accounts on the internet almost certainly result from confusion in linguistic translation. In the case of , the report of extracellular polysaccharide apparently refers to the stalks, while it is unclear whether Kociolek & Spaulding (2003), Coyne et al (2006), Beltrami et al (2008c) and McNyset & Julius (2006) mean anything more in their reports of mucilaginous mats, colonies or gelatinous masses. Individual colonies are hemispherical or more spread out, but increasing abundance leads to the formation of extensive mats.…”

Section: Growth and Seasonal Changes In Morphologymentioning

confidence: 90%

“…Records for northern Italy start with Brun (1880) and Bonardi (1888), but it was not mentioned in earlier reports from the Trentino Region where it now occurs (Beltrami et al, 2008c). Beltrami et al (2008b) quote other earlier records from Italy, including flowing waters in the 1920s (Giaj-Levra & Abate, 1994) and five major lakes in the north of the country between 1883 and 1925 (database quoted by authors).…”

Section: Europementioning

confidence: 91%

“…When a stream has masses of persistent stalks with few cells, it can appear to the public as if covered with sheep wool, as first noted by Hassall (1845). The Brusago stream in the Province of Trento, Italy, differs from this seasonal cycle in that the mats persist through the winter, being present in February even under ice layers (Beltrami et al, 2008c). Several other accounts (see Table 2) mention mats in winter, but it is unclear whether new stalks develop at this time.…”

Section: Growth and Seasonal Changes In Morphologymentioning

confidence: 98%

“…TIN:TP was 31:1 by mass (based on means of 0.350 mg L -1 N and 0.11 mg L -1 P). Similarly, it seems likely that phototrophs in some other sites are also P-limited, such as the Brusago stream in north Italy (Beltrami et al, 2008c), since the N:P ratio was 21:1 based on mean and 31.7 based on median values. In the case of the two saline sites on R. Wisła, Poland, reported by Kawecka & Sanecki (2003), the TIN:P ratio at the time of the spot measurements was very high, 29.1 and 125:1, though perhaps success here was also influenced by inocula from upstream.…”

Section: Nitrogen and N:p Ratiomentioning

confidence: 99%

“…Lindstrøm (2008) reported for Norway that D. geminata is pollution sensitive and tends to disappear when total P exceeds 20 lg L -1 and organic C exceeds 6.5 mg L -1 C. A survey (Løvstad, 2008) of rivers in the Oslo Region of Norway involving 100 samples in each of five TP classes found 23 records in the lowest (0-12.5 lg L -1 P), 5 in the next highest (12.5-25 lg L -1 P), but none in the others. The mean value for the five streams and rivers in Poland with D. tatrensis and D. geminata was 34 lg L -1 P (Mrozińska et al, 2006a: unclear whether FRP or TP), while that for streams with D. geminata in northern Italy was 42 lg L -1 TP (Beltrami et al, 2008c). Records for a number of inflow rivers were given by Tarasova & Mescheryakova (1992) based on data for 1983 and 1984.…”

Section: Calciummentioning

confidence: 99%

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Biology of the freshwater diatom Didymosphenia: a review

2009

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Features of the colonial diatom Didymosphenia are reviewed, especially D. geminata. Although there is a long record of its occurrence in north temperate regions, mass growths have been reported much more widely in recent years. Contrary to some statements in the literature, there are also reliable older records for the southern hemisphere, though the first report of mass growth was in New Zealand in 2004. The annual cycle of morphological changes in D. geminata in northern England, and probably elsewhere, includes a winter period when motile cells are attached to the substratum followed by spring when stalks start to develop. These raise cells into the water column and provide a site for phosphatase activity. Environmental factors associated with success include absence of extreme floods, high light, pH above neutral and nutrient chemistry. D. geminata often, but not always, occurs in waters where the N:P ratio is high for much of the year, but the key factor is the ratio of organic to inorganic phosphate. D. geminata thrives where organic P is predominant and the overall P concentration is low enough for organic P to be an important P source. It is unknown whether organic N can be used. Environmental changes increasing the relative importance of organic P are likely to favour D. geminata. Likely examples are increased N:P due to atmospheric N deposition and changes in form and seasonality of P release from organic-rich soils due to climatic warming. The nutrient chemistry of deep water released from dams to rivers also needs investigation. To what extent are genetic changes occurring in response to environmental changes and are new ecotypes spreading round the world? In spite of many adverse reports about D. geminata, such as detached mats blocking water pipes, there is still doubt about the extent to which it causes problems, particularly for fish. There have been few adverse effects on migratory salmonids in Europe and North America, but at least one report of harm to a brown trout population in USA. In New Zealand, it has caused serious problems for water sports, although it remains open to question how much adverse effect it has had on fish populations. If the presence of microcystins in or associated with D. geminata, as indicated recently for two populations, proves to be widespread and at sufficiently high concentration, their possible accumulation in fish requires study. Where control is required, this could Handling editor: Pierluigi Viaroli be achieved by enhancing the ratio of inorganic to organic phosphate in the water early in the growth season. Practical ways to achieve this are suggested.

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Section: Growth and Seasonal Changes In Morphologymentioning

confidence: 90%

Section: Europementioning

confidence: 91%

Section: Growth and Seasonal Changes In Morphologymentioning

confidence: 98%

Section: Nitrogen and N:p Ratiomentioning

confidence: 99%

Section: Calciummentioning

confidence: 99%

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Biology of the freshwater diatom Didymosphenia: a review

2009

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ENVIRONMENTAL CONTROL OF STALK LENGTH IN THE BLOOM‐FORMING, FRESHWATER BENTHIC DIATOM DIDYMOSPHENIA GEMINATA (BACILLARIOPHYCEAE)¹

Kilroy

Bothwell

2011

Journal of Phycology

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Blooms of the freshwater stalked diatom Didymosphenia geminata (Lyngb.) M. Schmidt in A. Schmidt typically occur in oligotrophic, unshaded streams and rivers. Observations that proliferations comprise primarily stalk material composed of extracellular polymeric substances (EPS) led us to ask whether or not the production of excessive EPS is favored under nutrient-limited, high-light conditions. We conducted experiments in outdoor flumes colonized by D. geminata using water from the oligotrophic, D. geminata-affected Waitaki River, South Island, New Zealand, to determine the relationship between D. geminata stalk length, cell division rates, and light intensity under ambient and nutrient-enriched conditions. Stalk lengths were measured in situ, and cell division rates were estimated as the frequency of dividing cells (FDC). FDC responded positively to increasing light intensity and to nutrient additions (N+P and P). Under ambient conditions, stalk length increased as light level increased except at low ambient light levels and temperature. Nutrient enrichment resulted in decreased stalk length and negative correlations with FDC, with this effect most evident under high light. Our results are consistent with the hypothesis that extensive stalk production in D. geminata occurs when cell division rates are nutrient limited and light levels are high. Thus, photosynthetically driven EPS production in the form of stalks, under nutrient-limited conditions, may explain the development of very high biomass in this species in oligotrophic rivers. The responses of FDC and stalk length under nutrient-replete conditions are also consistent with occurrences of D. geminata as a nondominant component of mixed periphyton communities in high-nutrient streams.

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Community signals of the effect of Didymosphenia geminata (Lyngbye) M. Schmidt on benthic diatom communities in Chilean rivers

Pereira

Pérez

2019

Rev. Chil. de Hist. Nat.

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Background: Didymosphenia geminata (Lyngbye) M. Schmidt is a freshwater invasive benthic diatom native to oligotrophic systems of the Northern Hemisphere. Since 2010, freshwater systems of south-austral Chile, have experienced a progressive invasion of this species between 37°18′ S and 54°30′ S. This invaded area is characterized by biogeographic heterogeneity, anthropic pressure and lack of knowledge. The objective of this study was to analyze the effect of D. geminata on the community structure of benthic diatoms and the variability of this effect in Chilean rivers. Methods: The data were collected between 2010 and 2017 and pre-treated using fourth-root transformation to construct a Bray-Curtis similarity matrix and a Principal Coordinate Analysis to identify groups of sites. The α diversity and β diversity were estimated and compared using univariate indexes and the Mann-Whitney test, respectively. We used Permutational multivariate analyses of variance (PERMANOVA) and PERMDISP to estimate the spatial variation of communities, and an Analysis of Percentage Similarity (SIMPER) was performed to identify the species which contributed to the similarity between the groups of sites. Results: The results suggest significant differences between invaded and noninvaded rivers (54% of the total variation); the univariate indexes showed greater richness (S), greater diversity (H′), and less species turnover in invaded rivers. The PERMANOVA indicated significant interaction between D. geminata and the basins; there was also a significant effect on the internal dispersion in the basins. The SIMPER analysis showed that the groups composed exclusively of invaded sites had high mean similarity in all basins and small pedunculated benthic diatoms showed a significant response to the presence of D. geminata. Conclusion: We found high variability in the community structures, that determine a strong segregation between noninvaded and invaded sites by D. geminata, and that the main effect of D. geminata on diatoms benthic was the homogenization of the communities. This is reflected in the increase in density of small stalked diatoms and the reduction of species turnover among rivers in the same basin, leading to the loss of community heterogeneity that overcomes the spatial heterogeneity in the area invaded in Chile.

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The diatom Didymosphenia geminata: distribution and mass occurrence in the Province of Trento (Northern Italy)

Cited by 5 publications

References 4 publications

Biology of the freshwater diatom Didymosphenia: a review

Biology of the freshwater diatom Didymosphenia: a review

ENVIRONMENTAL CONTROL OF STALK LENGTH IN THE BLOOM‐FORMING, FRESHWATER BENTHIC DIATOM DIDYMOSPHENIA GEMINATA (BACILLARIOPHYCEAE)¹

Community signals of the effect of Didymosphenia geminata (Lyngbye) M. Schmidt on benthic diatom communities in Chilean rivers

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The diatom Didymosphenia geminata: distribution and mass occurrence in the Province of Trento (Northern Italy)

Cited by 5 publications

References 4 publications

Biology of the freshwater diatom Didymosphenia: a review

Biology of the freshwater diatom Didymosphenia: a review

ENVIRONMENTAL CONTROL OF STALK LENGTH IN THE BLOOM‐FORMING, FRESHWATER BENTHIC DIATOM DIDYMOSPHENIA GEMINATA (BACILLARIOPHYCEAE)1

Community signals of the effect of Didymosphenia geminata (Lyngbye) M. Schmidt on benthic diatom communities in Chilean rivers

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ENVIRONMENTAL CONTROL OF STALK LENGTH IN THE BLOOM‐FORMING, FRESHWATER BENTHIC DIATOM DIDYMOSPHENIA GEMINATA (BACILLARIOPHYCEAE)¹