scholarly journals Response of Marine Plankton Communities in Ponds to the Presence of Vertical Structures

2021 ◽  
Author(s):  
Maria Emília Cunha ◽  
Hugo Quental Ferreira ◽  
Ana Barradas ◽  
Pedro Pousão-Ferreira

The effects of bottom vertical structures like AquaMats® in enhancing plankton productivity was evaluated. One experimental earthen pond of 500 m2 was provided with AquaMats® increasing the surface substrate area 12 times and water quality, phytoplankton and zooplankton populations developed during almost 100 days was compared with a pond without AquaMats®. Their presence favored the development of Dinoflagellates (Miozoa, Dinophyceae), mostly Gymnodiniales, which may be of some concern since some species of this group have been associated with toxic algal blooms while in the ponds without AquaMats® Diatoms (Bacillariophyta) predominate. In both ponds plankton production was very much sculptured by external nutrients added to the systems. The balance between different nutrients is extremely important to regulate the phytoplankton populations with Diatoms blooming at silicate concentrations higher than 2 μM and below this level and at low nitrate and high ammonium being more appropriate for Dinoflagellates. The linkage between phytoplankton and zooplankton population in ponds is strong with zooplankton exerting control over the phytoplankton population and vice-versa. The use of vertical substrates enhances plankton productivity by increasing the substrate area for periphyton fixation. The main zooplankton taxonomic groups associated with the presence of AquaMats® were Calanoid and Harpacticoid copepodites and nauplii, veligers of gastropods and trochophore of polychaets, larval stages of organisms that except for calanoid copepods are benthic and correspond to the meroplanktonic phase in the life cycle of those organisms.

Author(s):  
Gede Iwan Setiabudi ◽  
Dietriech G. Bengen ◽  
Hefni Effendi ◽  
Ocky Karna Radjasa

<p>The aimed of this study was to determine  the plankton communities and its relationship with the chemical and physical condition in seagrass ecosystem at Pegametan Bay. The composition and abundance of plankton were observed in the sea water underneath the surface and were identified based on the guideline of Illustration of the Marine Plankton of Japan. The water quality was measured in situ using <em>WQC </em>HI 9829. The water sample was measured using closed reflux spectrometry for COD, TOC analyzer for DOC and APHA 2102 (4500) method for Nt and Pt. There are 27 species of plankton identified, which can be classified into three groups. Diatom group consists of 18 species with a 74.56% abundance. The non-litoral group consists of 6 species with a 23.35% abundance. Moreover, dinoflagellate group consist of 3 species with a 2.09% abundance. An abundance of plankton greater than 10<sup>4 </sup>cell.L<sup>-1</sup> was found in diatome group (<em>Nitzschia </em>sp.<em>, Thalassiosira</em> sp.,<em> Chaetoceros</em> sp., <em>Flagillaria</em> sp., <em>Thalassiothrix</em> sp., and <em>Melosira</em> sp.) and non-litoral group (<em>Oscillatoria</em> sp. and <em>Spirogyra</em> sp.). The abundance of those species indicated the algae bloom phenomenon. <em>Dinophysis</em> sp. was also identified, which was harmful algal blooms.</p><p><strong>How to Cite</strong></p><p>Setiabudi, G. I., Bengen, D. G., Effendi, H., &amp; Radjasa, O. K. (2016). The Community Structure of Phytoplankton in Seagrass Ecosystem and its Relationship with Environmental Characterstics. <em>Biosaintifika: Journal of Biology &amp; Biology Education</em>, 8(3), 257-269.</p>


Author(s):  
P. G. Whitehead ◽  
J. Crossman ◽  
B. B. Balana ◽  
M. N. Futter ◽  
S. Comber ◽  
...  

The catchment of the River Thames, the principal river system in southern England, provides the main water supply for London but is highly vulnerable to changes in climate, land use and population. The river is eutrophic with significant algal blooms with phosphorus assumed to be the primary chemical indicator of ecosystem health. In the Thames Basin, phosphorus is available from point sources such as wastewater treatment plants and from diffuse sources such as agriculture. In order to predict vulnerability to future change, the integrated catchments model for phosphorus (INCA-P) has been applied to the river basin and used to assess the cost-effectiveness of a range of mitigation and adaptation strategies. It is shown that scenarios of future climate and land-use change will exacerbate the water quality problems, but a range of mitigation measures can improve the situation. A cost-effectiveness study has been undertaken to compare the economic benefits of each mitigation measure and to assess the phosphorus reductions achieved. The most effective strategy is to reduce fertilizer use by 20% together with the treatment of effluent to a high standard. Such measures will reduce the instream phosphorus concentrations to close to the EU Water Framework Directive target for the Thames.


2003 ◽  
Vol 46 (8) ◽  
pp. 964-971 ◽  
Author(s):  
F. Bianchi ◽  
F. Acri ◽  
F.Bernardi Aubry ◽  
A. Berton ◽  
A. Boldrin ◽  
...  

2011 ◽  
Vol 8 (4) ◽  
pp. 870-876 ◽  
Author(s):  
Baghdad Science Journal

The study aimes to investigate the effects of leaves & fruits ethanolic extract of Duranta repens L. on biological performance for all stages of life cycle of the mosquito Culex pipiens piepiens L., For this purpose the mosquitoes were reared in the laboratory till the fourth generation .Different concentrations of leaves (800,1000,1200,1400ppm) and fruits (800,1000,1200ppm) were tested on (eggs,larval stages,pupal stages and the adult stages). The results revealed that the extracts gave highest mortality rate for the eggs at(100%) compared with control,fruits extract shown highest mortality rate of the four larval instars (100%)at 1200ppm compared with leave extract at(80,50,33.33,20%).Also the extract caused a high mortality rate for pupal stage compared with fruits extract at(76.66,53.33%)respectively.Also ethanolic extract caused a 83.33,76.66% for male &femail. Developmental deformation was observed.. In conclusion, the findings of the present study indicate that the leaves &fruits extracts of Duranta repens L., , can be widely and effectively used in the control of mosquito.


The River has got religious importance in India. The Bhima River is beginning from Bhimashankar hill and it flows through some parts of Maharashtra and Karnataka state. The assessment of water quality for the development of the places near the bank of River is important. These is controlled by various manmade activities. The quality of river water resources is facing problems because of the continuous agricultural runoff, development and urbanization. Due to mixing of nutrients causes algal blooms, which results eutrophication. The modeling of water quality can be deliberated as useful tool for assessing river water. Bhima River is demarcated as a major and important water body located in Pandharpur, dist. Solapur, Maharashtra. As Pandharpur is having historical background and known as one of the famous Holly places in Maharashtra, this place is facing huge population fluctuation due to migrated pilgrims and rapid growth of urbanization. These two things detrimentally affect River water quality. The main objective of current study was to develop a hydrodynamic model combined with river water quality model for the Bhima River to measure and recognize the processes harmful for the River. For Bhima River a hydrodynamic model was constructed using the HEC-RAS 4.1 software combined with a river water quality model to estimate the amount, distribution and sources of algae, nitrate and temperature. The river model has standardized with the help of previous water levels near the Pandharpur region. It has standardized and calibrated for the assessed parameters by competing them with the present data. The result showed a relationship between DO and temperature range. DO level in Pandharpur and Gopalpur were observed to be fluctuating with respective temperature and during Vari season. However, wastewater discharge from Nalha in sample station 3 i.e. Goplapur shows slit changes in DO and due to this there is necessity to learn other parameters also.


1978 ◽  
Vol 29 (1) ◽  
pp. 1 ◽  
Author(s):  
M Ahsanullah ◽  
GH Arnott

Acute toxicity tests were carried out on the larvae of P. quadridentatus and 96-h LC50 values of 0.17, 0.49, and 1.23 mg/l were determined for copper, cadmium, and zinc respectively. Potency ratios of the three metals were as follows: Cu/Cd 3.1, Cu/Zn 7.2, and Cd/Zn 2.4. Larvae were found to be nine times more sensitive to zinc and at least 29 times more sensitive to cadmium than were adults. The larval 96-h LC50 values multiplied by an application factor of 0.01 (as recommended in Victorian water quality criteria) results in derived 'safe' concentrations, which in the case of copper and zinc are below the stated 'minimal risk concentrations' of 10 and 20 �g/I respectively. In view of the known greater sensitivity of larvae of many taxa to heavy metal toxicity, the validity of using the same application factor for both adult and larval stages is questioned.


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