scholarly journals Vertical and horizontal distribution of the microcystin producer Planktothrix rubescens (Cyanobacteria) in a small perialpine reservoir

2017 ◽  
Vol 8 (2) ◽  
Author(s):  
Adriano Boscaini ◽  
Flavia Brescancin ◽  
Leonardo Cerasino ◽  
Chiara Fedrigotti ◽  
Elisa Anna Fano ◽  
...  
Keyword(s):  
Optimal Growth ◽  
Eastern Alps ◽  
Horizontal Distribution ◽  
Seasonal Development ◽  
Planktothrix Rubescens ◽  
Light Intensities ◽  
Extended Surface ◽  
Vertical And Horizontal Distribution ◽  
Mixed Layers ◽  
Autumn And Winter

Among cyanobacteria, Planktothrix rubescens (De Candolle ex Gomont) Anagnostidis & Komárek is a species that is well adapted to develop in moderately nutrient rich and deep lakes. In this typology of waterbodies, the competitive abilities of this species rely in its capacity to stand and growth in the dimly illuminated metalimnetic layer during the warmer months. I this work, we have studied the seasonal development and distribution of this species in Lake Ledro, a meso-oligotrophic reservoir located in the Eastern Alps. During the last decade, this species has given rise to numerous and extended surface bloom episodes, causing the reddening of vaste areas of the lake. In summer, the light intensities in the zone of the greater development of this cyanobacterium (in the metalimnion, between the euphotic depth and the layer of maximum development of the species) were bewteen 2 and 20 µmol m-2 s-1, i.e. values that were well within the light intensities required to sustain the optimal growth of filaments. The formation of the autumn and winter blooms was triggered by the cooling of surface waters and increase of the mixed layer, which, eroding the metalimnion, entrained the filaments of Planktothrix in the surface mixed layers. The formation of the surface blooms was associated with the presence of high amounts of microcistins, which in a few occasions reached concentrations between 10 and 22 µg L-1, posing potential problems for the exploitation of water resources.

Behavior and Distribution of Nonylphenol Ethoxylates and their Metabolites in Sediments of Nansi Lake, China

2011 ◽  
Vol 356-360 ◽  
pp. 1733-1738
Author(s):  
Fang He ◽  
Aya Obara ◽  
Shi Long Wang ◽  
Li Guo Wang
Keyword(s):  
Water Flow ◽  
Flow Direction ◽  
Sediment Cores ◽  
Sewage Treatment ◽  
Vertical Direction ◽  
Total Content ◽  
Horizontal Distribution ◽  
Nansi Lake ◽  
Increasing Trend ◽  
Vertical And Horizontal Distribution

The vertical and horizontal distribution of NPEOn and their metabolites of NP and NPEnC in the Upper Nansi Lake, North China were investigated using LC-MS and LC-MS/MS methods, sampling at three sites (St.1, St.2 and St.3) along the water flow direction. The total content of NPEOn (n=1–15) bound onto the sediment of this lake changed in the range of 60.7–631.5 μg/kg-dry with the horizontal flow direction and the vertical direction of the sediment cores with sediment thickness up to 35 cm. Compared to the presence levels of all detected NPEOn species, the content of NP was much higher, falling in 26.5–1,998.4 μg/kg-dry. A general increasing trend of the NP content along the water flow direction of this lake was revealed. NPEnC showed a roughly increasing trend from the upstream to the downstream, with the total concentrations being obviously lower than NPEOn and NP and falling in 2.13–23.1 μg/kg-dry. The short chain NPEOn dominant in NPEO mixtures in these sedimentary cores indicated that this lake received some effluents from STPs, and the sewage treatment ratio is relatively low in this area. Furthermore, the computed magnitudes of NPEO 1-2/NPEO1-15, NP/NPEO 1-15 and NPEC 1-10/NPEO 1-15 suggested that the non-oxidative hydrolytic transformation seemed to be a major process occurring within the sediment phase of Nansi Lake, while the oxidative hydrolytic transformation pathway was probably less involved.

scholarly journals Temperature ranges for survival and growth of juvenile Saccharina sculpera (Laminariales, Phaeophyta) and applications for field cultivation

ALGAE ◽  
2021 ◽  
Vol 36 (4) ◽  
pp. 231-240
Author(s):  
Soo Hong Kim ◽  
Young Dae Kim ◽  
Mi Sook Hwang ◽  
Eun Kyoung Hwang ◽  
Hyun Il Yoo
Keyword(s):  
Seawater Temperature ◽  
Sustainable Use ◽  
Value Added ◽  
Optimal Growth ◽  
Human Consumption ◽  
Cultivation Period ◽  
Light Intensities ◽  
Sustainable Cultivation ◽  
Survival And Growth ◽  
Upper Level

Saccharina sculpera is highly valued for human consumption and value-added products. However, natural resources of this kelp have decreased sharply and it is in danger of extinction. Resources recovery through cultivation is being trialed to enable the sustainable use of this species. In this study, the temperature range for survival and optimal growth of juvenile S. sculpera was identified and applied to field cultivation. This study investigated the survival and growth of juvenile S. sculpera under six temperatures (i.e., 5, 10, 15, 16, 18, and 20°C) and two light intensities (i.e., 20 and 40 μmol photons m-2 s-1) in an indoor culture experiment. In these experiments, the blade length decreased at 16°C under the both light intensities. The thalli died at 20°C and 20 μmol photons m-2 s-1, and at 18‒20°C and 40 μmol photons m-2 s-1. During the field cultivation, early growth of S. sculpera was highest at the 5 m depth and growth decreased as the water depth increased. When the initial rearing depth was maintained without adjustment throughout the cultivation period (from December to October), all the cultivated S. sculpera plants died during August and September. However, S. sculpera plants lowered from 5 to 15 m and grew to 90.8 ± 13.1 cm in July. The seawater temperature at 15 m depth was similar to the upper level of thermal tolerance demonstrated by juvenile S. sculpera in the indoor culture experiments (16°C or lower). The plants were subsequently lowered to 25 m depth in August, which eventually led to their maturation in October. The present study confirmed that improved growth rates and a delay in biomass loss can be achieved by adjusting the depth at which the seaweeds are grown during the cultivation period. These results will contribute to the establishment of sustainable cultivation systems for S. sculpera.

scholarly journals Wątrobowce (Hepaticae) Beskidu Żywiecko-Orawskiego (Karpaty Zachodnie) [Liverworts (Hepaticae) of the Beskid Żywiecko-Orawski Range (Polish Western Carpathians)]

2014 ◽  
Vol 79 ◽  
pp. 1-144 ◽  
Author(s):  
Henryk Klama
Keyword(s):  
Endangered Species ◽  
Habitat Preferences ◽  
Horizontal Distribution ◽  
Western Carpathians ◽  
Vulnerable Species ◽  
Floristic Analysis ◽  
Vertical And Horizontal Distribution

The study area comprises two mountain groups – Wielka Racza and Pilsko – situated in western part of the Beskid Żywiecko-Orawski Range in Polish Western Carpathians. The flora of this area includes 111 species of liverworts and 2 species of hornworts. 81 species of liverworts and 2 species of hornworts were found in the area of the Wielka Racza group, 108 species of liverworts and 2 species of hornworts – in the area of the Pilsko group. The species new for the Polish part of the Beskid Żywiecki Range were found (27), as well as for the whole Range including the Slovakian part (22) and for the Western Beskids (2). Moreover, 20 species rare in the Western Beskids as well as 11 species rare in the whole area of the Western Carpathians were recorded. 6 species regarded as threatened in the Polish flora occur in the study area. Four of them belong to the category of endangered species (E):<em> Fossombronia wondraczekii, Frullania tamarisci, Porella baueri</em> and <em>P. platyphylla</em>, the remaining two belong to the category of vulnerable species (V): <em>Geocalyx graveolens</em> and <em>Metzgeria conjugata</em>. A particular attention should be payed to the species threatened on European scale: <em>Lophozia ascendens</em> (R category), <em>Porella baueri</em> (T) and <em>Scapania parvifolia</em> (T). The floristic analysis of habitats covered by liverworts as well as habitat groups of liverworts and habitat preferences of particular species arę presented in the paper. The phytogeographic characteristics of the flora is also given, including vertical and horizontal distribution of liverworts in the study area.

scholarly journals Occurrence and ecological notes on Rocinela signata (Isopoda, Flabellifera) off Brazil

1977 ◽  
Vol 26 (2) ◽  
pp. 293-301 ◽  
Author(s):  
Plínio Soares Moreira
Keyword(s):  
Host Specificity ◽  
Horizontal Distribution ◽  
Maximum Depth ◽  
Fish Parasite ◽  
Southern Brazil ◽  
Santa Catarina ◽  
Free Living ◽  
Southern Limit ◽  
Vertical And Horizontal Distribution

This paper discuss the vertical and horizontal distribution of the marine isopod Rocinela signata Schiödte & Meinert, 1879, along Brazil. Published records and new data gathered in recent years were used. The species, widely distributed along Brazil, has its most southern limit of occurrence considerably extended to off State of Santa Catarina (27º08'S, 48º11'W) . It is typically a shelf species. So far it was recorded off Brazil at a maximum depth of 73 m, while particularly in southern Brazil at 53 m. The species has been collected free living on the bottom or as a fish parasite, and a few times has been reported attacking and sucking swimmers. Available data suggest any host specificity. R. signata seems a facultative and not an obligate fish parasite.

Cadmium Migration and Distribution Process

2012 ◽  
Vol 518-523 ◽  
pp. 1873-1876
Author(s):  
Xue Ying Song ◽  
Xiao Jun Hu ◽  
Cai Xia Jin ◽  
Ji Song Yang ◽  
Hong Liang Chen ◽  
...  
Keyword(s):  
Vertical Migration ◽  
Horizontal Distribution ◽  
Two Phase ◽  
Public Property ◽  
Major Disaster ◽  
Distribution Process ◽  
Variation Rate ◽  
Vertical And Horizontal Distribution ◽  
Different Depths ◽  
And Migration

The significant pollution accidents which not only threaten public health and public property safety, but also bring major disaster, have become the world concerning environmental problems. The migration process and feature of CdCl2 in the vertical and horizontal profiles of soil were studied by the stimulating experiment to present the theory for the treatment of significant pollution accident. The column leaching device was taken to simulate the vertical and horizontal migration of CdCl2 in the soil profile under two-phase rainfall during 16 days. The portable manual control negative pressure pump was taken to extract soil solution sample and the CdCl2 concentration was determined by the atomic absorption spectrophotometer. Results showed that during the whole experiment, the obvious horizontal and vertical migration features of CdCl2 appeared. The CdCl2 covered the whole horizontal profile in 0.5 h and the whole vertical profile in 146 hours. The relative variation rate of CdCl2 in the different depth of bulk showed that the rapid passing time differed in the different depths. The simulating device used in this paper could well investigate the vertical and horizontal distribution and migration of contaminant. Under the condition of greater rainfall, the CdCl2 gave priority to the horizontal runoff in the surface soil, followed by the vertical migration.

scholarly journals Vertical and horizontal distribution of coccolithophores in the Caribbean Sea

2002 ◽  
Vol 22 (3) ◽  
pp. 150-161 ◽  
Author(s):  
Winter A. ◽  
Rost B. ◽  
Hilbrecht H. ◽  
Elbr&#x000E4;chter M.
Keyword(s):  
Caribbean Sea ◽  
Horizontal Distribution ◽  
Vertical And Horizontal Distribution ◽  
The Caribbean
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