scholarly journals Zooplankton communities in the Drake Passage through environmental boundaries: a snapshot of 2010, early spring

PeerJ ◽  
2019 ◽  
Vol 7 ◽  
pp. e7994
Author(s):  
Andrey A. Vedenin ◽  
Eteri I. Musaeva ◽  
Daria N. Zasko ◽  
Alexander L. Vereshchaka

Background Spatial distribution of zooplankton communities influenced by various environmental factors is always important for understanding pelagic ecosystems. The area of the Drake Passage (Southern Ocean) is of particular interest owing to the high spatial and temporal variability of hydrological parameters affecting marine fauna. This study provides a survey of zooplankton composition and spatial distribution along a transect in the Drake Passage sampled during the 31th Cruise of RV “Akademik Sergey Vavilov” in November, 2010. The main aim was to trace the main regularities in spatial zooplankton structure and its relationships with the environmental parameters. Methodology A total of 43 vertical hauls from the surface to 1,000 m depth were made at 13 stations using the Juday plankton net. 60 taxa were recorded, abundance and biomass of each were assessed. Environmental parameters including temperature, salinity, depth, horizontal distance between stations and surface chlorophyll concentration were tested as environmental factors possibly explaining plankton distribution. Results Higher zooplankton abundance and biomass with lower diversity were observed near the Polar Front. Cluster analysis revealed five different groups of zooplankton samples, four of which were arranged mostly by depth. Along the transect within the 1,000 m depth range, the qualitative taxonomical composition differed significantly with depth and to some extent differed also among horizontal hydrological regimes, while the quantitative structure of the communities (abundance of taxa) was mainly determined by depth. Plankton assemblages within the upper 300-m layer depended on hydrological fronts. Abundance of dominant taxa as well as total zooplankton abundance showed a clear correlation with depth, salinity and surface chlorophyll concentration. Some taxa also showed correlations with temperature and latitude. Between the stations the similarity in zooplankton structure was clearly dependent on the distance among them which indicates an importance of latitudinal gradient. Surface chlorophyll concentration was not correlated with zooplankton biomass, which can be explained by the uncompleted seasonal migrations of zooplankton from deeper waters in early spring.

Biologia ◽  
2014 ◽  
Vol 69 (4) ◽  
Author(s):  
Małgorzata Kłonowska-Olejnik ◽  
Tomasz Skalski

AbstractA study of the species composition of mayfly communities in connection with environmental parameters was made in headwater streams of the Pieniny Mts. The rhithral zone is inhabited maximally by 19 mayfly species. In most of the streams studied the mayfly communities were found to be similar, however the vertical zonation which reflected human impact was visible (NMDS analysis). The main factors responsible for mayfly communities at all the sites studied were stream regulation and organic pollution, followed by type of bottom substrate (pebble and gravel), riparian vegetation (shrubs), pH and water temperature. At undisturbed sites the most important factors were pH, substrate type, distance from the source, current velocity and riparian vegetation (CCA analysis). Analysis of mayfly communities and environmental characteristics in different seasons showed that occurrence of mayfly species varied substantially depending on the season. Only in early spring and autumn do mayfly communities occur which are dependent on many environmental factors, the most significant of which are substrate type, phosphate, distance from source and altitude (CCA analysis).


Diversity ◽  
2021 ◽  
Vol 13 (7) ◽  
pp. 286
Author(s):  
Marcin Kalarus ◽  
Anna Panasiuk

Appendicularians are one of the most common animals found within zooplankton assemblages. They play a very important role as filter feeders but are, unfortunately, inconsistently reported in the Antarctic literature. The present paper attempts to describe the zonal diversity of appendicularians and the main environmental factors influencing their communities in the Drake Passage. Samples were collected during Antarctic summer in 2009–2010. A total of eight species of larvaceans were identified. Fritillaria borealis was the species found in the highest numbers in almost the entire studied area, and was observed at all sampling stations. The distributions of other taxa were limited to specific hydrological zones and hydrological conditions. F. fraudax and Oikopleura gaussica were typical of the areas between the Polar Front and the Subantarctic Front zones, and their distributions were significantly correlated with temperature and salinity, likely making them good indicator species. The F. fusiformis distribution was strictly related to South American waters. In summary, temperature was the strongest environmental factor influencing the larvacean community structure in the Drake Passage, and we also found that testing environmental factors on larvaceans as a whole group did not give entirely reliable results.


2014 ◽  
Vol 1 (2) ◽  
pp. 147 ◽  
Author(s):  
Suprastini Suprastini ◽  
Erwin Riyanto Ardli ◽  
Agus Nuryanto

Fish is one of the aquatic commodities with significant economic value, and Segara Anakan areas is a habitat for valuable fishes for local fisherman. Segara Anakan is a eutrophic waters and serves as nursery and spawning ground and also provide an optimal environment for several species fish larvae to grow, either sedentary or migratory species. Therefore it is suggested that diverse species inhabit Segara Anakan and different part of those areas has different species because different species commonly exhibit different habitat preferences. The objectives of this research were to determine the diversity and spatial distribution of fish species in Segara Anakan Cilacap. This research was a survey with the Cluster Random Sampling was implemented as sampling technique. Species diversity was analyzed descriptively, as well as the spatial distribution. The relationships between environmental parameters and spatial distribution were analyzed using Principal Component Analysis. Environmental factors such as temperature, pH, salinity, and water DO were measured. The result showed that Stolephorus indicus was the most dominant species in Segara Anakan. The spatial distribution of fishes in every sampling station was found fluctuated. The environmental factors and fish were found highly correlated.


2019 ◽  
Vol 25 (1) ◽  
pp. 1
Author(s):  
Asep Ma'mun ◽  
Asep Priatna ◽  
Khairul Amri ◽  
Erfind Nurdin

Kepadatan dan penyebaran sumber daya ikan di perairan banyak dipengaruhi oleh variasi kondisi oseanografinya. Untuk mengkaji interaksi antara kondisi oseanografi dengan sebaran spasial ikan pelagis di Laut Jawa, telah dilakukan penelitian hydro acoustic dengan menggunakan KR. Bawal Putih III pada 17 Oktober-11 November 2017. Akuisisi data akustik menggunakan multi beam Simrad ME (70-120 kHz) dengan posisi transduser dipasang pada lunas kapal. Parameter lingkungan (oksigen, pH, salinitas, klorofil, suhu) diukur menggunakan CTD SBE 19 plus V2 dan parameter oseanogafi fisik (arah dan kecepatan arus) menggunakan ARM current meter, keduanya diturunkan secara vertikal sesuai kedalaman pada 48 stasiun. Analisa korelasi antara parameter oseanografi dengan kelimpahan ikan dan distribusi spasial menggunakan analisis statistik PCA (Principal Component Analysis). Hasil penelitian menunjukkan densitas ikan pelagis dipengaruhi secara berturut-turut oleh salinitas, oksigen, klorofil, pH dan suhu. Urutan ini didasarkan pada jarak dan kedekatan terhadap garis yang dibentuk faktor lingkungan terhadap titik pusat korelasi. Komponen lingkungan yang memiliki interaksi langsung dengan kelimpahan ikan pelagis adalah salinitas dan oksigen. Kedua faktor ini merupakan faktor utama dalam kegiatan osmoregulasi dan pembentukan energi untuk tubuh ikan, sementara keempat faktor lingkungan lainnya (klorofil pH, suhu dan kecepatan arus) berkorelasi secara parsial terhadap keberadaan ikan pelagis.The density and distribution of fish resources in the waters are much influenced by variations in oceanographic conditions. To examine interaction between oceanographic condition with spatial distribution of pelagic fish in Java Sea, hydroacoustic research was done using KR. Bawal Putih III on October 17 to November 11, 2017. Acoustic data acquisition used Simrad ME multi beam (70-120 kHz) with the position of the transducer installed on the keel. Environmental parameters (oxygen, pH, salinity, chlorophyll, temperature) were measured using the SBE 19 plus V2 CTD and physical oceanographic parameter (current direction and speed) using the ARM current meter, both are lowered vertically according to depth at 48 station. Correlation analysis between oceanographic parameter with fish abundance and spatial distribution using PCA (Principal Component Analysis) statistical analysis. Results show that density of pelagic fish was influenced respectively by salinity, oxygen, chlorophyll, pH and temperature. This sequence based on distance and proximity to the line formed by environmental factors towards the center of correlation. The environmental components that have a direct interaction with the abundance of pelagic fish are salinity and oxygen. These two factors are the main factors in osmoregulation and energy formation for fish bodies, while the other four environmental factors (chlorophyll pH, temperature and current velocity) correlate partially to the presence of pelagic fish. 


2021 ◽  
Vol 13 (2) ◽  
pp. 325
Author(s):  
Leon Biscornet ◽  
Christophe Révillion ◽  
Sylvaine Jégo ◽  
Erwan Lagadec ◽  
Yann Gomard ◽  
...  

Leptospirosis, an environmental infectious disease of bacterial origin, is the infectious disease with the highest associated mortality in Seychelles. In small island territories, the occurrence of the disease is spatially heterogeneous and a better understanding of the environmental factors that contribute to the presence of the bacteria would help implement targeted control. The present study aimed at identifying the main environmental parameters correlated with animal reservoirs distribution and Leptospira infection in order to delineate habitats with highest prevalence. We used a previously published dataset produced from a large collection of rodents trapped during the dry and wet seasons in most habitats of Mahé, the main island of Seychelles. A land use/land cover analysis was realized in order to describe the various environments using SPOT-5 images by remote sensing (object-based image analysis). At each sampling site, landscape indices were calculated and combined with other geographical parameters together with rainfall records to be used in a multivariate statistical analysis. Several environmental factors were found to be associated with the carriage of leptospires in Rattus rattus and Rattus norvegicus, namely low elevations, fragmented landscapes, the proximity of urbanized areas, an increased distance from forests and, above all, increased precipitation in the three months preceding trapping. The analysis indicated that Leptospira renal carriage could be predicted using the species identification and a description of landscape fragmentation and rainfall, with infection prevalence being positively correlated with these two environmental variables. This model may help decision makers in implementing policies affecting urban landscapes and/or in balancing conservation efforts when designing pest control strategies that should also aim at reducing human contact with Leptospira-laden rats while limiting their impact on the autochthonous fauna.


Pathogens ◽  
2021 ◽  
Vol 10 (5) ◽  
pp. 590
Author(s):  
Maria Kantere ◽  
Labrini V. Athanasiou ◽  
Alexios Giannakopoulos ◽  
Vassilis Skampardonis ◽  
Marina Sofia ◽  
...  

Canine parvovirus type 2 (CPV-2) primarily infects dogs, which are the main host reservoir, causing severe gastrointestinal disease associated with immunosuppression. The present study was conducted in Thessaly, Greece and aimed to identify risk and environmental factors associated with CPV-2 infection in diarrheic dogs. Fecal samples were collected from 116 dogs presenting diarrhea and were tested by polymerase chain reaction (PCR) for the presence of CPV-2 DNA. Supplementary data regarding clinical symptoms, individual features, management factors and medical history were also gathered for each animal during clinical evaluation. Sixty-eight diarrheic dogs were found to be positive for the virus DNA in their feces. Statistical analysis revealed that CPV-2 DNA was less likely to be detected in senior dogs, while working dogs, namely hounds and shepherds, had higher odds to be positive for the virus. Livestock density and land uses, specifically the categories of discontinuous urban fabric and of human population density, were identified as significant environmental parameters associated with CPV-2 infection by using Geographical Information System (GIS) together with the Ecological Niche Model (ENM). This is the first description of the environmental variables associated with the presence of CPV-2 DNA in dogs’ feces in Greece.


2010 ◽  
Vol 76 (21) ◽  
pp. 7076-7084 ◽  
Author(s):  
C. N. Johnson ◽  
A. R. Flowers ◽  
N. F. Noriea ◽  
A. M. Zimmerman ◽  
J. C. Bowers ◽  
...  

ABSTRACT Although autochthonous vibrio densities are known to be influenced by water temperature and salinity, little is understood about other environmental factors associated with their abundance and distribution. Densities of culturable Vibrio vulnificus containing vvh (V. vulnificus hemolysin gene) and V. parahaemolyticus containing tlh (thermolabile hemolysin gene, ubiquitous in V. parahaemolyticus), tdh (thermostable direct hemolysin gene, V. parahaemolyticus pathogenicity factor), and trh (tdh-related hemolysin gene, V. parahaemolyticus pathogenicity factor) were measured in coastal waters of Mississippi and Alabama. Over a 19-month sampling period, vibrio densities in water, oysters, and sediment varied significantly with sea surface temperature (SST). On average, tdh-to-tlh ratios were significantly higher than trh-to-tlh ratios in water and oysters but not in sediment. Although tlh densities were lower than vvh densities in water and in oysters, the opposite was true in sediment. Regression analysis indicated that SST had a significant association with vvh and tlh densities in water and oysters, while salinity was significantly related to vibrio densities in the water column. Chlorophyll a levels in the water were correlated significantly with vvh in sediment and oysters and with pathogenic V. parahaemolyticus (tdh and trh) in the water column. Furthermore, turbidity was a significant predictor of V. parahaemolyticus density in all sample types (water, oyster, and sediment), and its role in predicting the risk of V. parahaemolyticus illness may be more important than previously realized. This study identified (i) culturable vibrios in winter sediment samples, (ii) niche-based differences in the abundance of vibrios, and (iii) predictive signatures resulting from correlations between environmental parameters and vibrio densities.


2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Yong Kwan Lim ◽  
Oh Joo Kweon ◽  
Hye Ryoun Kim ◽  
Tae-Hyoung Kim ◽  
Mi-Kyung Lee

AbstractCorona virus disease 2019 (COVID-19) has been declared a global pandemic and is a major public health concern worldwide. In this study, we aimed to determine the role of environmental factors, such as climate and air pollutants, in the transmission of COVID-19 in the Republic of Korea. We collected epidemiological and environmental data from two regions of the Republic of Korea, namely Seoul metropolitan region (SMR) and Daegu-Gyeongbuk region (DGR) from February 2020 to July 2020. The data was then analyzed to identify correlations between each environmental factor with confirmed daily COVID-19 cases. Among the various environmental parameters, the duration of sunshine and ozone level were found to positively correlate with COVID-19 cases in both regions. However, the association of temperature variables with COVID-19 transmission revealed contradictory results when comparing the data from SMR and DGR. Moreover, statistical bias may have arisen due to an extensive epidemiological investigation and altered socio-behaviors that occurred in response to a COVID-19 outbreak. Nevertheless, our results suggest that various environmental factors may play a role in COVID-19 transmission.


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