Macrophyte

Zeekoevlei is the largest freshwater lake in
South Africa and has a century-long history of
anthropogenic impact that caused hyper-eutrophic
conditions. We used biomarkers (alkanes and pigments),
stable isotopes (d13C and d15N), rates of
primary palaeoproduction and total inorganic carbon
(TIC) accumulation rates in the lake sediments to
investigate changes in plankton and macrophyte
communities in response to anthropogenic activities
in this shallow lake. Specific alkanes and pigment
(chlorophyll a, b,b-carotene, echinenone, fucoxanthin
and zeaxanthin) concentrations in lake waters indicated
the present-day hyper-eutrophic condition and
seasonal fluctuations of cyanobacteria, zooplankton
and diatom populations. Eutrophic conditions were
initiated in the lake with the start of recreational
activities and construction of a sewage treatment plant
in the early 1920s. The lake transformed from a
eutrophic to a hyper-eutrophic waterbody following
damming, pondweed eradication and accelerated
catchment-derived nutrient input. The change in lake
trophic state was recorded by a sharp decline in the
terrestrial to aquatic ratio (TAR) of specific n-alkanes,
low carbon preference index (CPI) and increased d13C
values in the sediment core. In addition, the aquatic
macrophyte n-alkane proxy (Paq) values (1) indicated
a slow takeover by floating macrophytes after
the eradication of submerged pondweeds in 1951.
Elevated n-alkane, total alkane and pigment
(chlorophyll a, b,b-carotene, zeaxanthin and
zeaxanthin to b,b-carotene ratio) concentrations, low
d15N values and low TIC accumulation rates in the
upper middle section of the core indicated the
beginning of intense cyanobacterial blooms after the
dredging in 1983. Although the cyanobacterial population
has decreased in recent years, hyper-eutrophic
conditions are reflected by low CPI<0.04 and TAR<1
values at the top of the sediment core.

Herbivory is a fundamental process that controls primary producer abundance and regulates energy and nutrient flows to higher trophic levels. Despite the recent proliferation of small-scale studies on herbivore effects on aquatic plants, there remains limited understanding of the factors that control consumer regulation of vascular plants in aquatic ecosystems. Our current knowledge of the regulation of primary producers has hindered efforts to understand the structure and functioning of aquatic ecosystems, and to manage such ecosystems effectively. We conducted a global meta-analysis of the outcomes of plant–herbivore interactions using a data set comprised of 326 values from 163 studies, in order to test two mechanistic hypotheses: first, that greater negative changes in plant abundance would be associated with higher herbivore biomass densities; second, that the magnitude of changes in plant abundance would vary with herbivore taxonomic identity. We found evidence that plant abundance declined with increased herbivore density, with plants eliminated at high densities. Significant between-taxa differences in impact were detected, with insects associated with smaller reductions in plant abundance than all other taxa. Similarly, birds caused smaller reductions in plant abundance than echinoderms, fish, or molluscs. Furthermore, larger reductions in plant abundance were detected for fish relative to crustaceans. We found a positive relationship between herbivore species richness and change in plant abundance, with the strongest reductions in plant abundance reported for low herbivore species richness, suggesting that greater herbivore diversity may protect against large reductions in plant abundance. Finally, we found that herbivore–plant nativeness was a key factor affecting the magnitude of herbivore impacts on plant abundance across a wide range of species assemblages. Assemblages comprised of invasive herbivores and native plant assemblages were associated with greater reductions in plant abundance compared with invasive herbivores and invasive plants, native herbivores and invasive plants, native herbivores and mixed-nativeness plants, and native herbivores and native plants. By contrast, assemblages comprised of native herbivores and invasive plants were associated with lower reductions in plant abundance compared with both mixed-nativeness herbivores and native plants, and native herbivores and native plants. However, the effects of herbivore–plant nativeness on changes in plant abundance were reduced at high herbivore densities. Our mean reductions in aquatic plant abundance are greater than those reported in the literature for terrestrial plants, but lower than aquatic algae. Our findings highlight the need for a substantial shift in how biologists incorporate plant–herbivore interactions into theories of aquatic ecosystem structure and functioning. Currently, the failure to incorporate top-down effects continues to hinder our capacity to understand and manage the ecological dynamics of habitats that contain aquatic plants.

http://www.scribd.com/doc/74982961/; S. A. Ostroumov (С.А.Остроумов), G. M. Kolesov.
The Aquatic Macrophyte Ceratophyllum demersum Immobilizes Au Nanoparticles after Their Addition to Water. -
Doklady Biological Sciences, 2010, Vol. 431, pp. 124–127.
File in the author’s PC: D:\Публикации мои тексты\2010.DBS.Au\Гидробиология. новые факты. ключевые слова-золото, наноматериалы, водные макрофиты, роголистник.10DBS.Au.Abstract in English.Keywords.doc;
© Pleiades Publishing, Ltd., 2010. ISSN 00124966;
Original Russian Text © S.A. Ostroumov, G.M. Kolesov, 2010, published in Doklady Akademii Nauk, 2010, Vol. 431, No. 4, pp. 566–569.
DOI: 10.1134/S0012496610020158;
Presented by Academician M.A. Fedonkin July 31, 2009;
ABSTRACT: Study of biogenic migration of the chemical elements is an important line of the biosphere research [1–8]. Biogenic migration of the elements in aquatic ecosystems, both freshwater and saltwater ones, is important for water self- purification and water quality formation [9–11]. Data on element accumulation and binding by aquatic organisms, including macrophytes, are necessary for analyzing the organisms’ important role in biogenic migration of the elements in aquatic ecosystems. There were no published data on the gold (Au) content in Ceratophyllum demersum L. and on interaction between Au nanoparticles and aquatic macrophytes. The goal of this work was to study the immobilization of Au nanoparticles added to the water medium of microcosms in the presence of macrophyte C. demersum L. This study was the first to determine the concentration of Au and some other elements in C. demersum phytomass after incubation in microcosms containing Au nanosize particles (NSPs). Results of the experiments: (1) the first data have been obtained that demonstrate that a significant amount of Au NSPs may bind to live phytomass of an aquatic plant, C. demersum. As a result of binding and/or immobilization, the content of Au was greater than the background level by a factor of 430.3; (2) modification of NSPs with a protein (immunoglobulin) had no effect on the NSP immobilization by macrophytes. The results contribute to understanding the role of these organisms in biogenic migration of elements. These data enable us to estimate the participation of phytomass of the studied macrophyte species in element concentration (as exemplified by Au) in an aquatic system.
REFERENCES:
1. Vernadsky, V.I., Khimicheskoe stroenie biosfery Zemli i ee
okruzheniya (The Chemical Structure of the Earth Biosphere and Its Surrondings), Moscow: Nauka, 1965.
2. Dobrovol’skii, G.V.,
Ekol. Khimiya, 2007, vol. 16,
no. 3, pp. 135–143.
3. Dobrovol’skii, G.V., Voda Tekhnol. Ekol., 2007, no. 1,
pp. 63–68.
4. Perel’man, A.I. and Kasimov, N.S., Geokhimiya landshafta (Geochemistry of Landscape), Moscow: Astreya,
2000.
5. Ivanter, E.V. and Medvedev, N.V., Ekologicheskaya toksikologiya prirodnykh populyatsii (Ecological Toxicology of natural Populations), Moscow: Nauka, 2007.
6.
Ermakov, V.V. and Tyutikov, S.F., Geokhimicheskaya
ekologiya zhivotnykh (Geochemical Ecology of Animals), Moscow: Nauka, 2008.
7. Korzh, V.D., Geokhimiya elementnogo sostava gidrosfery
(Geochemistry of the Element Composition of the
Hydrosphere), Moscow: Nauka, 1991.
8.
Donchenko, V.K., Ivanova, V.V., and Pitul’ko, V.M.,
Ekologo khimicheskie osobennosti pribrezhnykh akvatorii (Ecological and Chemical Characteristics of Lit
toral Areas), St. Petersburg: NITsEB Ross. Akad.
Nauk, 2008, vol. 544.

9. Ostroumov,
S.A., Hydrobiologia, 2005, vol. 542,
pp. 275–286.
10. Ostroumov, S.A.,
Hydrobiologia, 2002, vol. 469,
pp. 203–204.
11. Ostroumov,
S.A., Kolesov, G.M., and
Sapozhnikov, D.Yu., Problemy ekologii i gidrobiologii
(Problems of Ecology and Hydrobiology), Moscow:
MAKS, 2008.
12. Byzova, N.A., Safenkova, I.V., Chirkov, S.N., et al.,
Prikl. Biokhim. Mikrobiol., 2009, no. 2, pp. 225–231.
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General contamination of heavy metals in the environment is a major global concern, which has provoked the emergence of phytoremediation technologies for cleaning aquatic environment. Heavy metals are released into the environment from a wide range of natural and anthropogenic sources. Macrophytes are known as good indicators of heavy metal contamination in aquatic ecosystems and they act as biological filters by accumulating heavy metals from the surrounding environments. Concentrations of heavy metals such as ...

Aquatic plants fulfil a wide range of ecological roles, and make a substantial contribution to the structure, function and service provision of aquatic ecosystems. Given their well-documented importance in aquatic ecosystems, research into aquatic plants continues to blossom. The 14th International Symposium on Aquatic Plants, held in Edinburgh in September 2015, brought together 120 delegates from 28 countries and six continents. This special issue of Hydrobiologia includes a select number of papers on aspects of aquatic plants, covering a wide range of species, systems and issues. In this paper, we present an overview of current trends and future directions in aquatic plant research in the early twenty first century. Our understanding of aquatic plant biology, the range of scientific issues being addressed and the range of techniques available to researchers have all arguably never been greater; however, substantial challenges exist to the conservation and management of both aquatic plants and the ecosystems in which they are found. The range of countries and continents represented by conference delegates and authors of papers in the special issue illustrates the global relevance of aquatic plant research in the early twenty first century but also the many challenges that this burgeoning scientific discipline must address.

The aim of this study was to investigate the short-term (2 weeks) effects of the herbicide metsulfuron methyl alone and in combination with the insecticide cypermethrin in freshwater enclosures (80 l). We used a factorial design with four levels of herbicide (0, 1, 5, 20 μg/l) and two levels of insecticide (0 and 0.05 μg/l). The root growth of the macrophyte species Elodea canadensis and Myriophyllum spicatum decreased following exposure to the lowest concentration of metsulfuron methyl tested. Metsulfuron methyl exposure resulted in a decreased pH in the aquatic enclosure at the lowest concentration tested, which is most likely a further indication of decreased macrophyte primary production. The biomass of periphytic algae growing on the leaves of M. spicatum increased in the enclosures exposed to metsulfuron methyl. The species composition of the periphytic algae differed significantly from the controls in the enclosures exposed to 20 μg/l of the herbicide. The increased biomass of periphytic algae on the leaves of the macrophytes is probably an indirect effect of the herbicide exposure. The exposure to metsulfuron methyl possibly induced a leakage of nutrients from the macrophyte leaves, which promoted an increased algal growth. The exposure to metsulfuron methyl did not alter the biomass or the species composition of the phytoplankton community. The zooplankton communities in the enclosures were dominated by rotifers, which were not affected by the exposure to cypermethrin. However, a cypermethrin exposure of 0.05 μg/l initially decreased the abundance of copepod nauplii. Ten days after exposure, the abundance of nauplii was significantly higher in the insecticide-exposed enclosures compared with the non-exposed enclosures. This might be an indication of a sub-lethal stress response, which either increased the number of offspring produced or induced an increased hatching of copepod resting stages. No combined effects of the herbicide and insecticide exposure, either direct or indirect, were observed in the enclosure study. Significant effects on the macrophytes were observed following exposure to 1 μg metsulfuron methyl per litre in the enclosure study. Furthermore, a single species laboratory assay indicated that the shoot elongation of E. canadensis decreased following exposure to ≥0.1 μg metsulfuron methyl per litre. These concentrations are well within the range of expected environmental concentrations, thus this study shows that aquatic ecosystems, in particular those which are macrophyte-dominated, may be affected by metsulfuron methyl at concentrations that may well occur in water bodies adjacent to agricultural land.

Physiological and biochemical effects of cylindrospermopsin (CYN), a cyanobacterial toxin that inhibits protein synthesis and released during a harmful cyanobacterial bloom, has been overlooked in plants. Therefore, at the present research, the toxic effects (physiological and biochemical) of a crude extract containing CYN were assessed in the aquatic fern Azolla filiculoides exposed to three concentrations (0.05, 0.5 and 5 μg CYN mL(-1)). At 5 μg CYN mL(-1), fern growth rate has showed a drastic decrease (0.001 g g(-1) day(-1)) corresponding to a 99.8 % inhibition, but at the concentrations of 0.05 and 0.5 μg CYN mL(-1) the growth rate was similar to the control plants. Growth rate also indicated a IC50 of 2.9 μg CYN mL(-1). Those data point to the presence of other compounds in the crude extract may stimulate the fern growth and/or the fern is tolerant to CYN. Chlorophyll (a and b), carotenoids and protein content as well as the activities of glutathione reductase (GR) and glutath...

General contamination of heavy metals in the environment is a major global concern, which has provoked the emergence of phytoremediation technologies for cleaning aquatic environment. Heavy metals are released into the environment from a wide range of natural and anthropogenic sources. Macrophytes are known as good indicators of heavy metal contamination in aquatic ecosystems and they act as biological filters by accumulating heavy metals from the surrounding environments. Concentrations of heavy metals such as ...

Changes in climate, food abundance and disturbance from humans threaten the ability of species to successfully use stopover sites and migrate between non-breeding and breeding areas. To devise successful conservation strategies for migratory species we need to be able to predict how such changes will affect both individuals and populations. Such predictions should ideally be process-based, focusing on the mechanisms through which changes alter individual physiological state and behavior. In this study we use a process-based model to evaluate how Black Brant (Branta bernicla nigricans) foraging on common eelgrass (Zostera marina) at a stopover site (Humboldt Bay, USA), may be affected by changes in sea level, food abundance and disturbance. The model is individual-based, with empirically based parameters, and incorporates the immigration of birds into the site, tidal changes in availability of eelgrass, seasonal and depth-related changes in eelgrass biomass, foraging behavior and energetics of the birds, and their mass-dependent decisions to emigrate. The model is validated by comparing predictions to observations across a range of system properties including the time birds spent foraging, probability of birds emigrating, mean stopover duration, peak bird numbers, rates of mass gain and distribution of birds within the site: all 11 predictions were within 35% of the observed value, and 8 within 20%. The model predicted that the eelgrass within the site could potentially support up to five times as many birds as currently use the site. Future predictions indicated that the rate of mass gain and mean stopover duration were relatively insensitive to sea level rise over the next 100 years, primarily because eelgrass habitat could redistribute shoreward into intertidal mudflats within the site to compensate for higher sea levels. In contrast, the rate of mass gain and mean stopover duration were sensitive to changes in total eelgrass biomass and the percentage of time for which birds were disturbed. We discuss the consequences of these predictions for Black Brant conservation. A wide range of migratory species responses are expected in response to environmental change. Process-based models are potential tools to predict such responses and understand the mechanisms which underpin them.

Invasive plants alter community structure, threatening ecosystem function and biodiversity, but little information is available on whether invasive species richness responds to environmental conditions in the same way that richness of native plants does. We surveyed submerged and floating-leaved plants in 99 Connecticut (northeast USA) lakes and ponds, collecting quantitative data on abundance and frequency. We used multiple linear and logistic regression to determine which environmental conditions were correlated with species richness of invasive and native plants. Independent variables included lake area, maximum depth, pH, alkalinity, conductivity, phosphorus concentration, productivity, and dominance (the proportional abundance of the most abundant and frequently found species), plus two estimates of human activity. Species richness of both native and invasive richness was correlated with alkalinity and human activity. Native richness also increased with water clarity, lake area...

Lake Chozas (León, NW Spain) until 1997 was a mesotrophic, macrophyte-dominated clear-water lake. The American red swamp crayfish (Procambarus clarkiiGirard) was introduced in 1995–96. In 1998, it increased its numbers coinciding with reductions in plant density from 97% to less than 10% surface cover. The removal of submerged vegetation was accompanied by a fast switch from clear to turbid, Microcystis-dominated conditions in the lake. In situ experiments in Lake Chozas using exclosures and enclosures have proved that the red crayfish are efficient predators of macrophytes. This work gives new evidence of the direct relationship between red-crayfish introduction and the shift from clear to turbid conditions in shallow lakes.

Effective wildlife management is needed for conservation, economic and human well-being objectives. However, traditional
population control methods are frequently ineffective, unpopular with stakeholders, may affect non-target species, and can
be both expensive and impractical to implement. New methods which address these issues and offer effective wildlife
management are required. We used an individual-based model to predict the efficacy of a sacrificial feeding area in
preventing grazing damage by mute swans (Cygnus olor) to adjacent river vegetation of high conservation and economic
value. The accuracy of model predictions was assessed by a comparison with observed field data, whilst prediction
robustness was evaluated using a sensitivity analysis. We used repeated simulations to evaluate how the efficacy of the
sacrificial feeding area was regulated by (i) food quantity, (ii) food quality, and (iii) the functional response of the forager.
Our model gave accurate predictions of aquatic plant biomass, carrying capacity, swan mortality, swan foraging effort, and
river use. Our model predicted that increased sacrificial feeding area food quantity and quality would prevent the depletion
of aquatic plant biomass by swans. When the functional response for vegetation in the sacrificial feeding area was
increased, the food quantity and quality in the sacrificial feeding area required to protect adjacent aquatic plants were
reduced. Our study demonstrates how the insights of behavioural ecology can be used to inform wildlife management. The
principles that underpin our model predictions are likely to be valid across a range of different resource-consumer
interactions, emphasising the generality of our approach to the evaluation of strategies for resolving wildlife management
problems.

We have studied the plasticity of the photosynthetic apparatus in the endangered aquatic macrophyte Althenia orientalis to the gradient of light availability within its meadow canopy. We determined diurnal change in situ irradiance, light quality, in vivo chlorophyll a fluorescence, ex situ oxygen evolution rates, respiration rate and pigment concentration. The levels of photosynthetic photon flux density (PFD) and ultraviolet radiation (UVR) and the red/far-red ratio decreased with depth within the canopies of A. orientalis. Apical leaves had a greater decrease of the maximal quantum yield (F v/F m) in the morning and a faster recovery rate in the afternoon than those in the basal ones. The relative electron transport rate (ETRr) was not saturated at any time of the day, even in the apical leaves that received the highest light. The maximum light-saturated rate of gross photosynthesis (GPmax) took place in apical leaves around noon. The chlorophyll a/b ratio values were higher, and the chlorophyll/carotenoid ratio values lower, in apical leaves than basal ones. The highest concentrations in total carotenoids were reached in the apical leaves around noon. A. orientalis has a high capacity to acclimatize to the changes in the light environment, both in quality and quantity, presenting sun and shade leaves in the same stem through the vertical gradient in the canopy.

Vegetation associated with lacustrine systems in Northern Patagonia was studied for heavy metal and trace element contents, regarding their elemental contribution to these aquatic ecosystems. The research focused on native species and exotic vascular plant Salix spp. potential for absorbing heavy metals and trace elements. The native species studied were riparian Amomyrtus luma, Austrocedrus chilensis, Chusquea culeou, Desfontainia fulgens, Escallonia rubra, Gaultheria mucronata, Lomatia hirsuta, Luma apiculata, Maytenus boaria, Myrceugenia exsucca, Nothofagus antarctica, Nothofagus dombeyi, Schinus patagonicus, and Weinmannia trichosperma, and macrophytes Hydrocotyle chamaemorus, Isöetes chubutiana, Galium sp., Myriophyllum quitense, Nitella sp. (algae), Potamogeton linguatus, Ranunculus sp., and Schoenoplectus californicus. Fresh leaves were analyzed as well as leaves decomposing within the aquatic bodies, collected from lakes Futalaufquen and Rivadavia (Los Alerces National Park), and lakes Moreno and Nahuel Huapi (Nahuel Huapi National Park). The elements studied were heavy metals Ag, As, Cd, Hg, and U, major elements Ca, K, and Fe, and trace elements Ba, Br, Co, Cr, Cs, Hf, Na, Rb, Se, Sr, and Zn. Geochemical tracers La and Sm were also determined to evaluate contamination of the biological tissues by geological particulate (sediment, soil, dust) and to implement concentration corrections.

High metal concentrations in water and soil solution result in greater plant uptake and/or leaching of metals. The objective of this research was to ascertain the effects of variations in heavy metal concentrations on phytoremediation processes. Two macrophytes, Typha capensis and Heliconia psittacorum, were engaged in the remediation of arsenic, lead, mercury, and cadmium. The plants were dosed with varying concentrations of heavy metals. The plants were exposed to the investigation by inductive coupled plasma-mass spectroscopy (Agilent 7700 × arrangement ICP-MS produced for complex framework examination). The exposure of the heavy metals under varying concentrations of the heavy metals showed that the level of uptake by the macrophytes was dependent on the level of concentration available in the soil/water. This conclusion implicitly implies that the quantity of heavy to be absorbed by the macrophytes depends largely on the capacity of the macrophyte to absorb a particular kind of heavy metal.

We investigated whether environmental filtering or dispersal-related factors mostly drive helophyte and hydrophyte species richness and community composition in 93 lakes situated in Baikal Siberia. Using partial linear regression and partial redundancy analysis, we studied (1) what are the relative roles of environmental variables, dispersal variables, spatial processes and region identity (i.e., river basins) in explaining variation in the species richness and species composition of helophytes and hydrophytes across 93 Siberian lakes, and (2) what are the differences in the most important explanatory variables driving community variation in helophytes versus hydrophytes? We found that, for both species richness and species composition, environmental variables clearly explained most variation for both plant groups, followed by region identity and dispersal-related variables. Spatial variables were significant only for the species composition of hydrophytes. Nutrient-salinity index, ...

The invasion and inconveniences caused by Water Hyacinth (Eichhornia crassipes) in the Niger Delta was investigated. Many streams and creeks in the region are heavily impacted by this water weed. Studies show that the rapid growth rate and the luxuriant nature of its vegetation have defied all forms of control so far by local co mmunit ies. This study focuses on measuring the percentage area covered by the macrophyte, its biomass and macrophyte load as necessary steps in water hyacinth control in Kolo creek, Bayelsa state. The macrophyte area covered ranged from 24.47% in October to 89.3% in March 2007. The differences in mean macrophyte area covered between wet and dry seasons were statistically significant[t-stat = 11.856&gt; p = 1.36 (0.05) ]. The macrophyte load however ranged between 13.116 of dry weight (DW)/ ha and 5.38t of DW/ha for dry and wet seasons respectively.

Cyanotoxins are a group of compounds produced by cyanobacteria that can have severe physiological effects on other organisms, including humans. The potential allelopathic effects of Microcystis aeruginosa, a toxic cyanobacterium, on the duckweed plant, Lemna gibba L., were examined using three experimental methods: (1) a series of toxicity bioassays, (2) evaluation of toxin production by M. aeruginosa in the direct and indirect presence of L. gibba, and (3) inhibition of oxygen evolution in photosynthesis. The results showed that, first, there were no clear dose-dependent effects of the microcystin-LR standard or the toxic M. aeruginosa culture filtrate on any of the end points measured in the toxicity bioassays (plant and frond number, dry weight, growth rate, chlorophyll content; one-way ANOVA, p > 0.05). In those cases in which an EC50 value could be obtained, chlorophyll a was the most sensitive end point, as it had the lowest EC50 value (14.47 μg/L microcystin-LR) of all the end points. Second, the presence of L. gibba did not result in higher microcystin-LR production in the toxic M. aeruginosa culture. And, last, oxygen evolution was not affected in isolated chloroplasts exposed directly to microcystin-LR. Therefore, microcystins from the toxic cyanobacterium Microcystis aeruginosa do not appear to have an allelopathic effect on the common aquatic macrophyte Lemna gibba. © 2005 Wiley Periodicals, Inc. Environ Toxicol 20: 67–73, 2005.

A field study has been conducted to evaluate the 226Ra bioaccumulation among aquatic plants growing in the stream/river adjoining the uranium mining and ore-processing complex at Jaduguda, India. Two types of plant group have been investigated namely free floating algal species submerged into water and plants rooted in stream & riverbed. The highest 226Ra activity concentration (9850 Bq kg−1) was found in filamentous algae growing in the residual water of tailings pond. The concentration ratios of 226Ra in filamentous algae (activity concentration of 226Ra in plant Bq kg−1 fresh weight/activity concentration of 226Ra in water Bq l−1) widely varied i.e. from 1.1 × 103 to 8.6 × 104. Other aquatic plants were also showing wide variability in the 226Ra activity concentration. The ln-transformed filamentous algae 226Ra activity concentration was significantly correlated with that of ln-transformed water concentration (r = 0.89, p < 0.001). There was no correlation between the activity concentrations of 226Ra in stream/riverbed rooted plants and the substrate. For this group, correlation between 226Ra activity concentration and Mn, Fe, Cu concentration in plants were statistically significant.