scholarly journals Carbon Transfer from Cyanobacteria to Pelagic and Benthic Consumers in a Subtropical Lake: Evidence from a 13C Labelling Experiment

Water ◽  
2019 ◽  
Vol 11 (8) ◽  
pp. 1536 ◽  
Author(s):  
Jinlei Yu ◽  
Hu He ◽  
Zhengwen Liu ◽  
Erik Jeppesen ◽  
Feizhou Chen ◽  
...  

Eutrophication of lakes often results in dominance of cyanobacteria, which may potentially lead to serious blooms and toxic water. However, cyanobacterial detritus may act as an important carbon source for aquatic organisms. Using stable isotope carbon (13C) as a tracer, we assessed the carbon transfer from cyanobacteria to pelagic and benthic consumers in a 28-day outdoor mesocosm (~130 L) labelling experiment established in Lake Taihu, China, during a Microcystis aeruginosa bloom. The different organisms were labelled differently after addition of the labelled Microcystis detritus to the water. δ13C of particulate organic matter and of cladoceran zooplankton peaked earlier than for larger invertebrate consumers. Among the pelagic species, Daphnia similis had the highest Δδ13C, while the two snail species Radix swinhoei and Bellamya aeruginosa had lower but similar Δδ13C. The bivalves showed relatively modest changes in δ13C. The δ13C of Anodonta woodiana and Unio douglasiae showed a marginal though not significant increase, while a marked increase occurred for Arconaia lanceolate peaking on day 20, and Corbicula fluminea a slight increase peaking on day 9. Our results suggest that carbon from cyanobacteria can be incorporated by pelagic and some benthic consumers and eventually be transferred to higher trophic levels. Cyanobacterial carbon may, therefore, be considered an important carbon source supporting the entire food web during blooms, even if the cyanobacteria are not consumed directly.

Processes ◽  
2020 ◽  
Vol 8 (10) ◽  
pp. 1306
Author(s):  
Pedro Almeida ◽  
Laurent Dewasme ◽  
Alain Vande Wouwer

The recirculating aquaculture system (RAS) is a land-based water treatment technology, which allows for farming aquatic organisms, such as fish, by reusing the water in the production (often less than 5%). This technology is based on the use of filters, either mechanical or biological, and can, in principle, be used for any species grown in aquaculture. Due to the low recirculation rate, ammonia accumulates in the system and must be converted into nitrate using nitrification reactors. Although less toxic for fish, nitrate can also be further reduced into nitrogen gas by the use of denitrification biofilters which may create several issues, such as incomplete denitrification, resulting in toxic substances, such as nitrite and nitric oxide, or a waste of carbon source in excess. Control of the added quantity of carbon source in the denitrification biofilter is then mandatory to keep nitrate/nitrite concentrations under toxic levels for fish and in accordance with local effluent regulations, and to reduce costs related to wasted organic carbon sources. This study therefore investigates the application of different control methodologies to a denitrification reactor in a RAS. To this end, a numerical simulator is built to predict the RAS behavior and to allow for the comparison of different control approaches, in the presence of changes in the operating conditions, such as fish density and biofilter removal efficiency. First, a classical proportional-integral-derivative (PID) controller was designed, based on an SIMC tuning method depending on the amount of ammonia excreted by fish. Then, linearizing and cascade controllers were considered as possible alternatives.


Chemosphere ◽  
2012 ◽  
Vol 86 (1) ◽  
pp. 36-40 ◽  
Author(s):  
Andréa Novelli ◽  
Bruna Horvath Vieira ◽  
Daniela Cordeiro ◽  
Luciana Teresa Dias Cappelini ◽  
Eny Maria Vieira ◽  
...  

2012 ◽  
Vol 57 (4) ◽  
pp. 1245-1254 ◽  
Author(s):  
Anna de Kluijver ◽  
Jinlei Yu ◽  
Marco Houtekamer ◽  
Jack J. Middelburg ◽  
Zhengwen Liu

1975 ◽  
Vol 189 (1096) ◽  
pp. 305-332 ◽  

A range of chlorinated hydrocarbons derived from C 1 and C 2 hydrocarbons is manufactured industrially. They are used as intermediates for further chemical manufacture and also outside the chemical industry as solvents or carriers. In the latter category losses in use are eventually dispersed to the environment. The distribution of some of these compounds, including chloroform, carbon tetrachloride, trichloroethylene, perchloroethylene and trichloroethane, in the environment (air, water and marine sediments) has been investigated and the results are presented. The concentrations found have been compared with acute toxicity levels to fish and other aquatic organisms, ascertained by laboratory bioassay. The occurrence of the compounds has been determined in a number of marine organisms, especially those at higher trophic levels, and the accumulation of some of them has been investigated in the laboratory. Chemical and microbial degradation processes have been studied in the laboratory to help determine the course of their removal from the aqueous and aerial environment, and the half lives of some of the compounds have been estimated. It is concluded that these compounds are not persistent in the environment, and that there is no significant bioaccumulation in marine food chains.


Toxics ◽  
2021 ◽  
Vol 9 (10) ◽  
pp. 261
Author(s):  
Konstantin Pikula ◽  
Mariya Tretyakova ◽  
Alexander Zakharenko ◽  
Seyed Ali Johari ◽  
Sergey Ugay ◽  
...  

Vehicle emission particles (VEPs) represent a significant part of air pollution in urban areas. However, the toxicity of this category of particles in different aquatic organisms is still unexplored. This work aimed to extend the understanding of the toxicity of the vehicle exhaust particles in two species of marine diatomic microalgae, the planktonic crustacean Artemia salina, and the sea urchin Strongylocentrotus intermedius. These aquatic species were applied for the first time in the risk assessment of VEPs. Our results demonstrated that the samples obtained from diesel-powered vehicles completely prevented egg fertilization of the sea urchin S. intermedius and caused pronounced membrane depolarization in the cells of both tested microalgae species at concentrations between 10 and 100 mg/L. The sample with the highest proportion of submicron particles and the highest content of polycyclic aromatic hydrocarbons (PAHs) had the highest growth rate inhibition in both microalgae species and caused high toxicity to the crustacean. The toxicity level of the other samples varied among the species. We can conclude that metal content and the difference in the concentrations of PAHs by itself did not directly reflect the toxic level of VEPs, but the combination of both a high number of submicron particles and high PAH concentrations had the highest toxic effect on all the tested species.


Water ◽  
2020 ◽  
Vol 12 (8) ◽  
pp. 2265
Author(s):  
Peng Gu ◽  
Qi Li ◽  
Hao Zhang ◽  
Xin Luo ◽  
Weizhen Zhang ◽  
...  

Cyanobacterial blooms caused by eutrophication in Lake Taihu have led to ecological threats to freshwater ecosystems. A pilot scale experiment was implemented to investigate the relationship between cyanobacteria and other aquatic plants and animals in simulated eutrophic ecosystems under different phosphorus (P) regimes. The results of this study showed that cyanobacteria had two characteristics favorable for bloom formation in eutrophic ecosystems. One is the nutrient absorption. The presence of alkaline phosphatase was beneficial for algal cells in nutrition absorption under low P concentration. Cyanobacteria exhibited a stronger ability to absorb and store P compared to Vallisneria natans, which contributed to the fast growth of algal cells between 0.2 and 0.5 mg·L−1 of P (p < 0.05). However, P loads affected only the maximum biomass, but not the growth phases. The growth cycle of cyanobacteria remained unchanged and was not related to P concentration. P cycling indicated that 43.05–69.90% of the total P existed in the form of sediment, and P content of cyanobacteria showed the highest increase among the organisms. The other is the release of microcystin. Toxic microcystin-LR was released into the water, causing indirectly the growth inhibition of Carassius auratus and Bellamya quadrata and the reduction of microbial diversity. These findings are of importance in exploring the mechanism of cyanobacterial bloom formation and the nutrient management of eutrophic lakes.


2017 ◽  
Vol 6 (1) ◽  
pp. 8
Author(s):  
Ana Paula Justiniano Régo ◽  
Ederio Dino Bidoia ◽  
Cassiana Maria Reganhan-Coneglian

The ametryne herbicide is largely used on sugar cane plantation in Brazil. It is persistent in the environment and can be found in bodies of water, impacting the aquatic and terrestrial ecosystems. Generally, in crops are applied mixtures of herbicides in order to obtain a higher success in combating weeds. This study evaluated the toxicity only of ametryne herbicide, without mixture with other herbicides, in order to quantify only the degree of dangerousness. This work evaluated the toxicity of ametryne to one aquatic test organism (Daphnia similis) and two land test organism (Eruca sativa and Lactuca sativa). Immobility of D. similis was evaluated in the presence of ametryne. Influences of ametryne on seed germination and root growth of E. sativa and L. sativa were evaluated. Even at low concentrations (5.00 mg/L), ametryne caused toxic effects on the mobility of D. similis, and 0.25 g/L caused toxic effects on the seeds. Root growth and the percentage of inhibition showed greater sensitivity to ametryne compared with seed germination. Thus, ametryne resulted in toxic effects to the analyzed organisms, which may bring damage to both aquatic and terrestrial ecosystems.


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