Selenium Accumulation in Submerged Aquatic Macrophytes Potamogeton pectinatus L. and Ruppia maritima L. from Water with Elevated Chloride and Sulfate Salinity

2002 ◽  
Vol 51 (1) ◽  
pp. 22-27 ◽  
Author(s):  
Lin Wu ◽  
Xun Guo
Keyword(s):  
Aquatic Macrophytes ◽  
Potamogeton Pectinatus ◽  
Ruppia Maritima ◽  
Selenium Accumulation ◽  
Submerged Aquatic Macrophytes

scholarly journals Use of grass carp (Ctenopharyngodon idella) as a biological control agent for submerged aquatic macrophytes

2014 ◽  
Vol 32 (4) ◽  
pp. 765-773
Author(s):  
A.F. Silva ◽  
C. Cruz ◽  
R.L.C.M. Pitelli ◽  
R.A. Pitelli
Keyword(s):  
Grass Carp ◽  
Aquatic Macrophytes ◽  
Biological Control Agent ◽  
Body Weight Gain ◽  
Predation Rate ◽  
Control Agent ◽  
Ctenopharyngodon Idella ◽  
Ceratophyllum Demersum ◽  
Grass Carp Ctenopharyngodon Idella ◽  
Submerged Aquatic Macrophytes

This study aimed to evaluate feed preference and control efficacy of grass carp (Ctenopharyngodon idella) on the aquatic macrophytes Ceratophyllum demersum, Egeria densa and Egeria najas. An experiment was carried out at mesocosms conditions with 2,000 liters capacity and water residence time of 2.8 days. C. demersum, E. densa e E. najas biomasses were offered individually with sixty g and coupled in similar quantities of 30 g of each species, evaluated during 81 days, envolving 6 treatments. (1 - C. demersum, 2 - E. najas, 3 -E. densa, 4 - C. demersum + E. najas, 5 - C. demersum + E. densa and 6 - E. najas + E. densa). When offered individually, E. najas and C. demersum presented the same predation rate by grass carp, which was higher than E. densa predation rate. When plants were tested in pairs, the order of feed preference was C. demersum > E. najas > E. densa. E. najas and C. demersum percentage control ranged from 73 to 83%. No relation between biomass consumption and grass carp body weight gain was observed, probably due to differences in nutritional quality among macrophyte species according to fish necessities. Therefore, it is concluded that the use of grass carp is one excellent technique to control submersed macrophytes in Brazil.

Emergence of seedlings of aquatic macrophytes from lake sediments

1983 ◽  
Vol 61 (1) ◽  
pp. 148-156 ◽  
Author(s):  
Richard W. Haag
Keyword(s):  
Lake Sediments ◽  
Initial Treatment ◽  
Aquatic Macrophytes ◽  
Potamogeton Pectinatus ◽  
Sediment Texture ◽  
Substantial Variation ◽  
Initial Exposure ◽  
Sediment Samples ◽  
Thermal Effluent ◽  
Myriophyllum Exalbescens

Sediment samples were collected in May 1980 from 11 stations at five sites in Lake Wabamun. Emergence of seedlings was recorded in a greenhouse at 19 °C for 120 days. The sediments were then chilled at 4 °C for 120 days and reexposed to greenhouse conditions for a further 90 days. Total seedling densities varied from 0 to 2335 m−2. Depth and sediment texture each accounted for 20% of the variance in seedling numbers. Discharge of thermal effluent from the Wabamun generating station also caused substantial variation in seedling number; seedling numbers at the shallowest Wabamun Outlet station were over four times those at any other site. Chilling of the sediment samples in the laboratory caused further emergence of seedlings from the four sites with the highest seedling densities in the initial treatment. Total numbers were up to 50% of those for seedlings that emerged during the initial exposure to greenhouse conditions. Potamogeton pectinatus and P. pusillus were most common among the seedlings of six species. Two of the three most common macrophytes in the lake were rare as seedlings, while no seedlings were recorded for the most common angiosperm, Myriophyllum exalbescens. Reproduction by seed makes a secondary contribution to the dynamics of the vegetation of Lake Wabamun.

scholarly journals Sediment Facilitates Microbial Degradation of the Herbicides Endothall Monoamine Salt and Endothall Dipotassium Salt in an Aquatic Environment

2018 ◽  
Vol 15 (10) ◽  
pp. 2255
Author(s):  
Md. Shahidul Islam ◽  
Trevor D. Hunt ◽  
Zhiqian Liu ◽  
Kym L. Butler ◽  
Tony M. Dugdale
Keyword(s):  
Aquatic Environment ◽  
Aquatic Macrophytes ◽  
Direct Evidence ◽  
Microbial Population ◽  
Degradation Pathway ◽  
Lag Phase ◽  
Sediment Sources ◽  
Dipotassium Salt ◽  
Water And Sediment ◽  
Submerged Aquatic Macrophytes

Endothall dipotassium salt and monoamine salt are herbicide formulations used for controlling submerged aquatic macrophytes and algae in aquatic ecosystems. Microbial activity is the primary degradation pathway for endothall. To better understand what influences endothall degradation, we conducted a mesocosm experiment to (1) evaluate the effects of different water and sediment sources on degradation, and (2) determine if degradation was faster in the presence of a microbial community previously exposed to endothall. Endothall residues were determined with LC-MS at intervals to 21 days after endothall application. Two endothall isomers were detected. Isomer-1 was abundant in both endothall formulations, while isomer-2 was only abundant in the monoamine endothall formulation and was more persistent. Degradation did not occur in the absence of sediment. In the presence of sediment, degradation of isomer-1 began after a lag phase of 5–11 days and was almost complete by 14 days. Onset of degradation occurred 2–4 days sooner when the microbial population was previously exposed to endothall. We provide direct evidence that the presence and characteristics of sediment are of key importance in the degradation of endothall in an aquatic environment, and that monoamine endothall has two separate isomers that have different degradation characteristics.

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