scholarly journals Zooplankton in Ancient and Oligotrophic Lake Ohrid (Europe) in Association with Environmental Variables

2017 ◽  
Vol 75 (3) ◽  
pp. 95-103 ◽  
Author(s):  
Orhideja Tasevska ◽  
Maria Špoljar ◽  
Dafina Gušeska ◽  
Goce Kostoski ◽  
Suzana Patcheva ◽  
...  
Keyword(s):  
Environmental Variables ◽  
Phytoplankton Biomass ◽  
Oligotrophic Lake ◽  
Trophic Levels ◽  
Feeding Guilds ◽  
Entire Study Period ◽  
Lake Ohrid ◽  
Entire Study ◽  
South Eastern Europe ◽  
Functional Feeding Guilds

AbstractZooplankton is studied in the ancient, tectonic, oligomictic and oligotrophic Lake Ohrid (Macedonia, South Eastern Europe). The main aim of this study was to assess the seasonal and spatial patterns of the zooplankton functional feeding guilds in relation to the environmental conditions. Metalimnion of the lake was detected as the most productive environment, where biomass of the phytoplankton and abundance of the zooplankton reached their maxima. Pelagial zooplankton of low abundance (25 ± 22 ind. L−1) consisted of 16 species including two endemic copepods, Arctodiaptomus steindachneri (Richard, 1897) and Cyclops ochridanus (Kiefer, 1932). Copepods obtained remarkable share (60%) in the zooplankton assemblage. Microphagous zooplankton was mainly comprised of the most abundant rotifer Kellicottia longispina (Kellicott, 1879) in summer, and copepod nauplii during the spring Eudiaptomus gracilis (Sars, 1862) and C.ochridanus, and autumn C.ochridanus. Due to their requirements for the bacterio-detritus suspension, this microphagous zooplankton occupied aphotic hypolimnion during the entire study period. Raptorials were typically represented by copepodites and adult copepods in the metalimnion, and were significantly and positively affected by temperature (r = 0.417, p = 0.001), dissolved oxygen (r = 0.463, p = 0.0001) and, particularly, phytoplankton biomass (r = 0.708, p < 0.00001). This is the first study in which the link between the lower and higher trophic levels is investigated in Lake Ohrid.

scholarly journals Evaluation of Macroinvertebrate Data Based on Autoecological Information

2016 ◽  
Vol 24 (4) ◽  
pp. 36-44 ◽  
Author(s):  
I. Juhász
Keyword(s):  
Environmental Factors ◽  
Environmental Variables ◽  
Feeding Guilds ◽  
Hydrological Data ◽  
Longitudinal Zonation ◽  
The Status ◽  
Status Assessment ◽  
Macroinvertebrate Fauna ◽  
Functional Feeding Guilds

Abstract Various data (biological, chemical, hydrological and morphological) have been gathered within the frame of the monitoring of the Water Framework Directive from 2007 in Hungary. This data only used a status assessment of certain water bodies in Hungary. The macroinvertebrates indicate many environmental factors well; therefore, they are very useful in detecting changes in the status of an environment. The main aim in this research was to investigate changes in environmental variables and decide how these variables cause big changes in the macroinvertebrate fauna. The macroinvertebrate data was processed using the ASTERICS 4.0.4 program. The program calculated some important metrics (i.e., microhabitat distributions, longitudinal zonation, functional feeding guilds, etc.). These metrics were compared with the chemical and hydrological data. The main conclusion is that if we have enough of a frequency and quality of macroinvertebrate data, we can understand changes in the environment of an ecosystem.

Population biology and diet of the puffer fish Lagocephalus laevigatus (Tetraodontiformes: Tetraodontidae) in Caraguatatuba Bay, south-eastern Brazil

2011 ◽  
Vol 92 (2) ◽  
pp. 407-412 ◽  
Author(s):  
M.R. Denadai ◽  
F.B. Santos ◽  
E. Bessa ◽  
L.P. Bernardes ◽  
A. Turra
Keyword(s):  
Population Biology ◽  
Temporal Distribution ◽  
Late Winter ◽  
Entire Study Period ◽  
Entire Study ◽  
South Eastern ◽  
Eastern Brazil ◽  
Puffer Fish ◽  
Spatio Temporal ◽  
Sexually Mature

This study describes the spatio-temporal distribution, population biology, and diet of the puffer fish Lagocephalus laevigatus in Caraguatatuba Bay, south-eastern Brazil. Monthly samples were taken between August 2003 and October 2004 by trawls in two areas, south and north, at depths of 1 to 4 m. The fish were measured and their sex and reproductive stage determined. The abundance of this species was compared between areas and among months, and the items in the diet were identified and quantified. Lagocephalus laevigatus was rare in Caraguatatuba Bay, where only 199 small individuals (4.8 to 15.4 cm) were obtained in the entire study period, suggesting that this species uses the estuary as a nursery. None of the specimens of L. laevigatus captured in Caraguatatuba Bay were sexually mature. Higher densities of L. laevigatus in the bay were recorded in the south area and between October and December 2003, i.e. in the spring, suggesting that spawning may occur from late winter to spring (August through to November). The diet items consumed by L. laevigatus in Caraguatatuba Bay were, as expected from the current literature, crustaceans, mainly amphipods, and fish. However, the most-consumed item was the sea whip Leptogorgia setacea (Cnidaria). This feeding habit may be related to the presence of toxins (tetrodotoxin and saxitoxin) that are frequently found in the skin and viscera of L. laevigatus, which may be sequestered from the sea whip, which possibility still needs to be specifically evaluated.

Physical forcing and the dynamics of the pelagic ecosystem in the eastern tropical Pacific: simulations with ENSO-scale and global-warming climate drivers

2003 ◽  
Vol 60 (9) ◽  
pp. 1161-1175 ◽  
Author(s):  
George M Watters ◽  
Robert J Olson ◽  
Robert C Francis ◽  
Paul C Fiedler ◽  
Jeffrey J Polovina ◽  
...  
Keyword(s):  
Global Warming ◽  
Phytoplankton Biomass ◽  
Southern Oscillation ◽  
Tropical Pacific ◽  
Trophic Levels ◽  
Eastern Tropical Pacific ◽  
Ecosystem Models ◽  
Pelagic Ecosystem ◽  
Physical Forcing ◽  
Physical Effects

We used a model of the pelagic ecosystem in the eastern tropical Pacific Ocean to explore how climate variation at El Niño – Southern Oscillation (ENSO) scales might affect animals at middle and upper trophic levels. We developed two physical-forcing scenarios: (1) physical effects on phytoplankton biomass and (2) simultaneous physical effects on phytoplankton biomass and predator recruitment. We simulated the effects of climate-anomaly pulses, climate cycles, and global warming. Pulses caused oscillations to propagate through the ecosystem; cycles affected the shapes of these oscillations; and warming caused trends. We concluded that biomass trajectories of single populations at middle and upper trophic levels cannot be used to detect bottom-up effects, that direct physical effects on predator recruitment can be the dominant source of interannual variability in pelagic ecosystems, that such direct effects may dampen top-down control by fisheries, and that predictions about the effects of climate change may be misleading if fishing mortality is not considered. Predictions from ecosystem models are sensitive to the relative strengths of indirect and direct physical effects on middle and upper trophic levels.

scholarly journals Mesoscale variations in the assemblage structure and trophodynamics of mesozooplankton communities of the Adriatic basin (Mediterranean Sea)

2021 ◽  
Author(s):  
Emanuela Fanelli ◽  
Samuele Menicucci ◽  
Sara Malavolti ◽  
Andrea De Felice ◽  
Iole Leonori
Keyword(s):  
Food Web ◽  
Food Webs ◽  
Mediterranean Sea ◽  
Environmental Variables ◽  
Complex Structure ◽  
Assemblage Structure ◽  
Trophic Levels ◽  
Ecosystem Functions ◽  
Food Web Structure ◽  
Adriatic Basin

Abstract. Zooplankton are critical to the functioning of ocean food webs because of their utter abundance and vital ecosystem roles. Zooplankton communities are highly diverse and thus perform a variety of ecosystem functions, thus changes in their community or food web structure may provide evidence of ecosystem alteration. Assemblage structure and trophodynamics of mesozooplantkon communities were examined across the Adriatic basin, the northernmost and most productive basin of the Mediterranean Sea. Samples were collected in June–July 2019 along coast-offshore transects covering the whole western Adriatic side, consistently environmental variables were also recorded. Results showed a clear separation between samples from the northern-central Adriatic and the southern ones, with a further segregation, although less clear, of inshore vs. off-shore stations, the latter mostly dominated in the central and southern stations by gelatinous plankton. Such patterns were mainly driven by chlorophyll-a concentration (as a proxy of primary production) for northern-central stations, i.e. closer to the Po river input, and by temperature and salinity, for southern ones, with the DistLM model explaining 46 % of total variance. The analysis of stable isotopes of nitrogen and carbon allowed to identify a complex food web characterized by 3 trophic levels from herbivores to carnivores, passing through the mixed feeding behavior of omnivores, shifting from phytoplankton/detritus ingestion to microzooplankton. Trophic structure also spatially varied according to sub-area, with the northern-central sub-areas differing from each other and from the southern stations. Our results highlighted the importance of environmental variables as drivers of zooplanktonic communities and the complex structure of their food webs. Disentangling and considering such complexity is crucial to generate realistic predictions on the functioning of aquatic ecosystems, especially in high productive and, at the same time, overexploited area such as the Adriatic Sea.

scholarly journals Prevalence of the nematodes Eustrongylides exisus Jägerskiöld, 1909, – larvae (Nematoda: Dioctophymatidae) infection in the Rutilis rutilis, linnaeus 1758 and the seasonal dynamics of the infection in the waters of the Dnipro-Buh estuari in southern Ukrai

2020 ◽  
Vol 22 (97) ◽  
pp. 31-38
Author(s):  
S. L. Honcharov
Keyword(s):  
Entire Study Period ◽  
Sample Collection ◽  
Upward Trend ◽  
Entire Study ◽  
Total Prevalence ◽  
The Mean ◽  
Predatory Fishes ◽  
Two Peaks ◽  
The Village ◽  
Collection Sites

In this study, we determined the prevalence and seasonal dynamic of the infection of the Rutilis rutilis, Lіnnaeus 1758 with the nematode Eustrongylides excisus. The fish was caught in the waters of the Dnipro-Buh estuary in seven sample collection sites between 2016 and 2019. They all underwent ichthyopathological examination. Parasites, found during examination, undergone microscopy to determine their taxonomy. Overall 595 specimens were obtained. The mean prevalence of infection over entire study period (2016–2019) was 17.4 %. Ichthyopathological examination of the roach caught in the waters of the Dnipro-Buh estuary revealed the infection with larvae E. excises nematode. The parasitic larvae were found in the muscles of the ventral abdominal wall of the roach. There was more than two-fold difference in the prevalence of infection between sample collection sites – from 12 % in site 5 near Sofiivka to 28 % in site 3 near the village Oleksandrivka over the study period in 2016–2019. The total prevalence of infection in roaches in the Dnipro-Buh estuary was 17.4 %. Seasonal changes were not statistically significant and ranged from 12.8 % in summer to 20.1 % in spring. Annual changes suggested a possible upward trend, but more observations are needed to confirm it. Аnnual changes were not statistically significant. The prevalence of infection changed throughout the year: there were two peaks in spring (20.1 %) and autumn (18.3 %). In summer (12.8 %) and winter (15.1 %) the prevalence of infection was lower. Morphologically, the E. excisus larvae found in roaches were different compared to those found in predatory fishes: they had more pale color and were smaller in length. E. excisus is a prevalent infection of roach in Dnipro-Buh estuary. Considering seemingly increasing prevalence of E.excisus infection, further studies are required to understand a pathophysiology of E.excisus infection  in mammals and humans, since data remain limited.

Analysis of extreme rains through climate indicators in the context of climate change in southern Benin

2021 ◽  
Vol 2 (1b) ◽  
pp. C20A01-1-C20A01-33
Author(s):  
Ferdinand Sourou HOUNVOU ◽  
◽  
K. F. Guedje ◽  
Hilaire Kougbeagbede ◽  
Adebiyi Joseph Adechinan ◽  
...  
Keyword(s):  
Climate Change ◽  
Global Warming ◽  
West Africa ◽  
Economic System ◽  
Entire Study Period ◽  
Entire Study ◽  
Climate Indicators ◽  
Large Growth ◽  
Southern Benin ◽  
Heavy Rains

The recurrence of flooding in recent years in West Africa is dramatically affecting the socio-economic system of most countries in the region. This work is devoted to the analysis of the heavy rains of its last years in the context of global warming in subequatorial Benin through eight rainfall indicators. For this purpose, the daily rains collected at seventeen stations in the south of Benin between 1960 and 2018, the maximum and minimum daily temperatures of the two synoptic stations in the study area between 1970 and 2018 are used. Analysis of the results shows a non-uniform trend in rainfall indicators over the entire study period. The monthly trend is in accordance with the bimodal rain regime of southern Benin for each of the climatic indicators studied. After the break in the downward trend in rainfall in the 1980s or 1990s at the various stations, the last three decades have been marked above all by ten-year averages of the various indicators that are higher than those obtained over the entire study period. Despite the low proportion of extreme rains, their frequency has increased since the resumption of rainfall in the 1980s or 1990s, especially compared to the 1970s and 1980s. The highest heights are observed for the most part in the towns close to the sea Atlantic Ocean. Global warming in southern Benin is characterized above all by high decadal temperature variation rates in the 1990s. This significant global warming in this pivotal decade is accompanied by relatively large growth in all indicators in southern Benin.

scholarly journals Biological contamination of soils in urbanized ecosystems by Toxocara sp. eggs.

2020 ◽  
Vol 169 ◽  
pp. 04002
Author(s):  
Olga Maslennikova ◽  
Viktoriya Erofeeva
Keyword(s):  
Average Rate ◽  
50Th Anniversary ◽  
Entire Study Period ◽  
Entire Study ◽  
Fecal Samples ◽  
Biological Contamination ◽  
Dog Walking ◽  
Special Area ◽  
Contamination Of Soils ◽  
Study Sites

As a result of the study of three sites (two city parks and a special area for walking dogs) on the contamination of Toxocara sp. eggs it was found that 28.0±2.3% of the studied fecal samples from the territories of the Kirov Park were infected with Тохосаrа eggs, 21.0±3.6% of fecal samples from the territory of the Park of the 50th anniversary of the Komsomol and 7.0±0.4% of fecal samples were infected with Тохосаrа eggs selected at a specially equipped dog walking area in the Metrograd residential complex in Kirov. The average rate of dogs which were infected by Toxocara (EI) was 18.7±6.2%. The average rate of contamination of soil by eggs Тохосаrа in the study sites amounted to 34.6%. Contamination of soil samples with eggs of Toxocara sp. in parks was 45.6% and 45.8%, respectively, and in the dog walking area it was 12%. The largest number of dogs, including stray ones, were registered in the parks: 74.8±7.1 and 62.8±7.0 individuals, respectively. There were no stray individuals in the dog walking area, and there were 21.6±1.0 individuals over the entire study period.

scholarly journals Locating Seismo-Conductivity Anomaly before the 2017 MW 6.5 Jiuzhaigou Earthquake in China Using Far Magnetic Stations

2020 ◽  
Vol 12 (11) ◽  
pp. 1777
Author(s):  
Zhiqiang Mao ◽  
Chieh-Hung Chen ◽  
Suqin Zhang ◽  
Aisa Yisimayili ◽  
Huaizhong Yu ◽  
...  
Keyword(s):  
Transfer Function ◽  
Moving Window ◽  
Entire Study Period ◽  
Conductivity Anomaly ◽  
Promising Candidate ◽  
Jiuzhaigou Earthquake ◽  
Entire Study ◽  
Background Distribution ◽  
Geomagnetic Data ◽  
Magnetic Transfer

Changes in the underlying conductivity around hypocenters are generally considered one of the promising mechanisms of seismo-electromagnetic anomaly generation. Parkinson vectors are indicators of high-conductivity materials and were utilized to remotely monitor conductivity changes during the MW 6.5 Jiuzhaigou earthquake (103.82°E, 33.20°N) on 8 August 2017. Three-component geomagnetic data recorded in 2017 at nine magnetic stations with epicenter distances of 63–770 km were utilized to compute the azimuths of the Parkinson vectors based on the magnetic transfer function. The monitoring and background distributions at each station were constructed by using the azimuths within a 15-day moving window and over the entire study period, respectively. The background distribution was subtracted from the monitoring distribution to mitigate the effects of underlying inhomogeneous electric conductivity structures. The differences obtained at nine stations were superimposed and the intersection of a seismo-conductivity anomaly was located about 70 km away from the epicenter about 17 days before the earthquake. The anomaly disappeared about 7 days before and remained insignificant after the earthquake. Analytical results suggested that the underlying conductivity close to the hypocenter changed before the Jiuzhaigou earthquake. These changes can be detected simultaneously by using multiple magnetometers located far from the epicenter. The disappearance of the seismo-conductivity anomaly after the earthquake sheds light on a promising candidate of the pre-earthquake anomalous phenomena.

Evaluation of dosing and safety outcomes of low-dose prophylactic warfarin in children after cardiothoracic surgery

2020 ◽  
Vol 77 (13) ◽  
pp. 1018-1025
Author(s):  
Maura Harkin ◽  
Brittany Powers Shaddix ◽  
Stephen B Neely ◽  
Leigh A Peek ◽  
Katy Stephens ◽  
...  
Keyword(s):  
Low Dose ◽  
Warfarin Dose ◽  
International Normalized Ratio ◽  
Primary Objective ◽  
Cardiothoracic Surgery ◽  
Entire Study Period ◽  
Entire Study ◽  
Frequent Monitoring ◽  
Safety Outcomes ◽  
Warfarin Dosing

Abstract Purpose Prophylactic warfarin with an International Normalized Ratio (INR) goal of 1.5 to 2.0 is one antithrombotic therapy utilized in children after cardiothoracic surgery (CTS); published sources suggest a dose of 0.1 mg/kg per day to achieve this goal. However, few studies have evaluated dosing in this population. The purpose of this study was to evaluate dosing and safety outcomes in children receiving warfarin after CTS. Methods A descriptive, retrospective review was conducted to evaluate warfarin dosing and INR outcomes in patients 18 years of age or younger who underwent CTS and received prophylactic warfarin with an INR goal of 1.5 to 2.0 from January 2014 through December 2018. The primary objective was to determine the median initial warfarin dose. Secondary objectives included identifying the percentage of documented INR values that were outside the therapeutic range, the percentage of patients with therapeutic INRs at discharge, and the 30-day readmission rate. Results Twenty-six patients were included in the review. The median initial warfarin dosage was 0.07 mg/kg/d (interquartile range [IQR], 0.05-0.10 mg/kg/d). Of the total of 177 INR values collected during the entire study period, 67 (37.9%) were therapeutic, 64 (36.2%) were subtherapeutic, and 46 (26.0%) were supratherapeutic. Eighteen patients (69.2%) had at least 1 supratherapeutic INR at any point during the study period, most frequently on days 2 through 4 of therapy. At discharge, 11 patients (42.3%) had therapeutic INRs. Four patients (15.4%) were readmitted within 30 days, with bleeding documented in 2 patients during their readmission. Conclusion The majority of patients received an initial warfarin dose less than that specified in published recommendations but still had a supratherapeutic INR at least once during the study period. When initiating warfarin after CTS, a dosage of &lt;0.1 mg/kg per day and frequent monitoring may be needed to achieve an INR goal of 1.5 to 2.0.

scholarly journals Dynamics of Cyanobacteria and Related Environmental Drivers in Freshwater Bodies Affected by Mitten Crab Culturing: A Study of Lake Guchenghu, China

Water ◽  
2019 ◽  
Vol 11 (12) ◽  
pp. 2468
Author(s):  
Hongmin Li ◽  
Huihui Chen ◽  
Xiaohong Gu ◽  
Zhigang Mao ◽  
Qingfei Zeng ◽  
...  
Keyword(s):  
Environmental Variables ◽  
Phytoplankton Biomass ◽  
Dominant Species ◽  
N:P Ratio ◽  
Water Bodies ◽  
Environmental Drivers ◽  
Mitten Crab ◽  
Total Phytoplankton ◽  
Freshwater Bodies ◽  
Harmful Species

Mitten crab aquaculture is prevalent in China, however, knowledge about the threat of cyanobacteria in mitten crab aquaculture-impacted water bodies is limited. Here, seasonal variations of cyanobacteria and their relationships with environmental factors were investigated for Lake Guchenghu area. Results suggested the changes of cyanobacteria community in crab ponds distinguished from the adjacent lake. In the lake, cyanobacterial biomass (3.86 mg/L, 34.6% of the total phytoplankton) was the highest in autumn with the dominance of Oscillatoria, Aphanocapsa and Pesudanabaena. By contrast, in crab ponds, cyanobacteria (46.80 mg/L, 97.2% of the total phytoplankton biomass) were the most abundant in summer when Pesudanabaena and Raphidiopsis were the dominant species. Of particular note was that obviously higher abundance of filamentous and potentially harmful species (e.g., Raphidiopsis raciborskii and Dolichospermum circinale) were observed in ponds compared to the lake. Specifically, water depth (WD), permanganate index (CODMn), total phosphorus (TP), N:P ratio, and NO 2 −-N were the key environmental variables affected cyanobacteria composition. For crab ponds, N:P ratio, water temperature (WT) and TP were the potential environmental drivers of cyanobacteria development. This study highlighted the fact that mitten crab culture had non-negligible influences on the cyanobacteria community and additional attention should be paid to the cyanobacteria dynamics in mitten crab culture-impacted water bodies, especially for those potentially harmful species.

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