Wyniki wyszukiwania

1

Artykuł dostępny w postaci pełnego tekstu - kliknij by otworzyć plik

Spatiotemporal variation of biochemical composition of organic matter and number of bacteria in core sediments of selected beaches of the southern Baltic Sea

100%

Bigus K., Astel A., Stec M., Piskula P.

Baltic Coastal Zone. Journal of Ecology and Protection of the Coastline

|

2017

|

tom 21

Sandy sediments coming from three beaches of the southern Baltic Sea were collected and analyzed. Investigated beaches were divided according to strength of anthropogenic impact and degree of sheltering. The first beach was situated in Ustka on the eastern side of the mouth of the Słupia River, second in Czołpino and the last one in Puck. Core sediment samples were collected seasonally, depending on the influence of the sea water on the examined sediments. At each station, surface sediments (0-5 cm) were collected as well as sediments at the depth of 10-15 cm. The general content of organic matter, proteins, lipids, carbohydrates, organic carbon and total bacterial number were determined. The results of the conducted tests reveal, that anthropopressure, degree of sheltering, the depth where the collected sediments were taken and the direct influence of the sea water on the sediments have impact on the chemical composition of organic matter and bacterial number in beach sediments.

2

Spatio-temporal variability of the phytoplankton biomass in the Levantine basin between 2002 and 2015 using MODIS products

100%

El Hourany R., Fadel A., Gemayel E., Abboud-Abi Saab M., Faour G.

Oceanologia

|

2017

|

tom 59

|

nr 2

The Levantine basin in the Eastern Mediterranean Sea is subject to spatial and seasonal variations in primary production and physical-chemical properties both on a short and long-term basis. In this study, the monthly means of daily MODIS product images were averaged between 2002 and 2015, and used to characterize the phytoplankton blooms in different bioregions of the Levantine basin. The selected products were the sea surface temperature (SST), the chlorophyll-a concentration (Chl-a), the diffuse attenuation coefficient for downwelling irradiance at 490 nm (Kd_490) and the colored dissolved organic matter index (CDOM_ index). Our results showed that phytoplankton blooms were spatially and temporally variable. They occurred in late autumn at the Nile Delta, in early spring and late summer at the eastern coastline, and in spring at the northeastern coastline. The northern coastline and the open water had a common bloom occurring in winter. The Nile Delta was found to be the most productive area of the Levantine basin showing high Chl-a. Kd_490 and Chl-a present a parallel co-variation indicating a dominance of Case 1 waters in the Levantine basin. The CDOM_index shows a phase shift with the Chl-a fluctuation. A strong inverse correlation was observed between both Chl-a and CDOM_index with SST, connoting an indirect relation represented by a depression of CDOM in summer by photobleaching, and a suppression of the chlorophyll-a concentration due to water stratification, together with nutrient stress. An overestimation of the Chl-a values had been signaled by the use of the CDOM_index, suggesting a correction plan in a latter study.

3

Spatio-temporal variability in the Brazil-Malvinas Confluence Zone (BMCZ), based on spectroradiometric MODIS-AQUA chlorophyll-a observations

84%

Telesca L., Pierini J. O., Lovallo M., Santamaria-del-Angel E.

Oceanologia

|

2018

|

tom 60

|

nr 1

The Brazil–Malvinas Confluence Zone (BMCZ) is characterized by high environmental variation, which could be reflected in several optical types of water, from one containing only phytoplankton and sea water to other optically more complex. In this paper, we analyze the spatio-temporal variability of the Chlorophyll-a detected by the ocean color sensor (CHLAsat) in BMCZ in order to understand its environmental variability. We use the MODIS-Aqua CHLAsat monthly composites imagery from 2002 to 2015, and applied two statistical methods: the correlogram-based robust periodogram to identify, over a broad spectrum of temporal, the most significant periodicities, and the pixel gradient distribution to study the spatial-temporal gradients within the BMCZ and variations over the continental shelf and coastal waters. Our results point out to the predominance of the annual cycle over most of the investigated area, although an area from latitude 37°S in direction NE, alongshore of Uruguay to Brazil, evidences interannual periodicities, possibly related to variations in the discharge of the Rio de la Plata associated with the El Niño phenomena. The ocean color spectroradiometric signature in terms of pixel gradient presents a relatively high variability (∼0.0 to 0.65 mg m−3); in particular the high values of the pixel gradient correspond to saline front of the estuarine system of Rio de la Plata, and to the strip of the platform that extends along the isobaths of 80 m (coast of Uruguay), especially in the center and south of the study area.

4

Spatio-temporal variations in sulfur-oxidizing and sulfate-reducing bacterial activities during upwelling, off South-West coast of India

84%

Kamaleson A. S., Gonsalves M.-J., Kumar S., Jineesh V. K., LokaBharathi P. A.

Oceanologia

|

2019

|

tom 61

|

nr 4

5

Spatio-temporal variation in the prevalence of trematodes in the bivalve Perumytilus purpuratus

84%

Munoz G., Torres P., Valdes J., Rodriguez A.

Acta Parasitologica

|

2013

|

tom 58

|

nr 2

Perumytilus purpuratus is an abundant bivalve located in the intertidal rocky zone of South America that has been considered as a key species of the ecosystem. There are few studies of the host-parasite relationship of this bivalve; thus, this research aims to analyse the spatial and temporal variation in the prevalence of trematodes in P. purpuratus. Bivalves were collected from three localities (El Tabo, Las Cruces and Montemar) of central Chile (33°S, 71°W) during different seasons of 2010. The bivalves were also collected every metre, from the lowest to the highest level of the intertidal rocky zone, to determine the parasite distribution within the localities. Three species of trematodes as sporocyst stages were found: Prosorhynchoides carvajali, Proctoeces sp. and an undetermined fellodistomid species. Of the 37,692 bivalve specimens collected, 2.68% were parasitised. The undetermined fellodistomid species was the most prevalent parasite observed (1.69%). There were little detected differences in the prevalence of some trematode species between seasons. The prevalence of P. carvajali varied between localities, being most prevalent at Montemar. The distribution of trematodes along the rocky zone within the localities was variable, with P. carvajali being more prevalent in the mid-lowest level of the intertidal zone and the undetermined fellodistomid species being more prevalent in the mid-highest level. Both the abundance of definitive hosts and the environmental conditions likely result in different levels of infection by trematodes in P. purpuratus between and within the localities.

6

Spatio-temporal variability of the size-fractionated primary production and chlorophyll in the Levantine Basin (Northeastern Mediterranean)

84%

Yucel N.

Oceanologia

|

2018

|

tom 60

|

nr 3

7

Chromophoric dissolved organic matter (CDOM) variability over the continental shelf of the Northern Bay of Bengal

84%

Das S., Das I., Giri S., Chanda A., Maity S., Lotliker A. A., Kumar T. S., Akhand A., Hazra S.

Oceanologia

|

2017

|

tom 59

|

nr 3

The present paper dealt with the annual dynamics of the absorption coefficient of chromophoric dissolved organic matter at 440 nm {aCDOM(440)} during February 2015 to January 2016 in the continental shelf of northern Bay of Bengal (nBoB) for the first time. Sea surface salinity (SSS), chlorophyll-a (Chl-a), total suspended matter (TSM) were also analyzed. It was hypothesized that CDOM should exhibit significant spatial and temporal variability in this region. aCDOM(440) and spectral slope ranged between 0.1002 m1—0.6631 m1 and 0.0071 nm1— 0.0229 nm1 respectively during the entire study period. Higher values of aCDOM(440) were observed in the near shore stations and gradually decreased towards the offshore. Significant seasonal variability of aCDOM(440) was observed between the monsoon and non-monsoon seasons ( p < 0.05). Thus the framed hypothesis was successfully accepted by means of the present study. The CDOM was mainly found to be of allochthonous character in this region. aCDOM(440) portrayed a significant negative linear relationship with SSS (R2 = 0.80; p < 0.05) implying conservative mixing of marine and terrestrial end members. However, examining the spatial variability of the relationship, it was observed that this relationship was significant only in the nearshore stations. While examining the seasonal variability of this relationship, it was found to be most significant during the monsoon (R2 = 0.81; p < 0.05). Thus it was inferred that whenever the SSS gradient was higher, the relationship between aCDOM(440) and SSS was found to be most significant.

8

Unravelling the spatio-temporal variation of zooplankton community from the river Matla in the Sundarbans Estuarine System, India

84%

Nandy T., Mandal S.

Oceanologia

|

2020

|

tom 62

|

nr 3

9

Spatio-temporal variation of drift and upstream movements of the amphipod Gammarus fossarum in a small unaltered stream

84%

Zganec K., Gottsein S., Hudina S.

Polish Journal of Ecology

|

2013

|

tom 61

|

nr 4

Stream invertebrates use ‘drift’ or downstream transport in the water column to disperse, but they also actively move upstream against current. These movements have important role in re-colonization of empty stream reaches and in regulation of population size. For more than half a century, research of stream drift was stimulated by the problem of ‘drift paradox’, i.e. the question how upstream reaches of streams remain inhabited despite constant and often ample losses of individuals by drift. In this study we examined drift and upstream movements of the amphipod Gammarus fossarum through monthly sampling over one-year period at two sites in the upper and middle course of a small unaltered stream in the northwest Croatia. Differences in tendency to drift and to move upstream and effects of environmental factors (temperature, flow, population density and detritus dry weight) on the movement dynamics on both temporal and spatial scale were examined for three size categories (adults, subadults and juveniles). While seasonal variations of drift and upstream movements were similar at two examined sites, at the middle course we recorded higher density, and higher drift and upstream movement rates. In both drift and upstream movements, adults were the most represented size category. In subadults and juveniles, both type of movements depended on population density. Adult upstream movements peaked in November and May/June, with massive upstream movements in May in the middle course. Seasonality of diurnal and nocturnal drift was very similar at both sites, while seasonality of diurnal and nocturnal upstream movements differed between the sites. Out of four examined independent environmental factors, density and temperature had the most important positive effect on spatiotemporal variations of diurnal drift, while nocturnal drift was more strongly affected by density and flow. Temperature was the most significant driver of diurnal upstream movements, while nocturnal upstream movements were most significantly positively affected by density. Massive upstream movements were driven by overcrowding and enabled adults to colonize microhabitats where food is more abundant and competition is less severe.

10

Spatio-temporal variation of microphytoplankton in the upwelling system of the South-Eastern Arabian Sea during the summer monsoon of 2009

84%

Thomas L. C., Padmakumar K. B., Smitha B. R., Asha Devi C. R., Nandan S. B., Sanjeevan V. N.

Oceanologia

|

2013

|

tom 55

|

nr 1

11

Spatio-temporal variability of mesozooplankton from the Gulf of Gdansk [Baltic Sea] in 1999-2000

84%

Mudrak S., Zmijewska M. I.

Oceanological and Hydrobiological Studies

|

2007

|

tom 36

|

nr 2

12

Annual spatio-temporal variation of the euphotic depth in the SW-Finnish archipelago, Baltic Sea

67%

Luhtala H., Tolvanen H., Kalliola R.

Oceanologia

|

2013

|

tom 55

|

nr 2

13

Solar radiation at the surface in the Baltic Proper

67%

Keevallik S., Loitjarv K.

Oceanologia

|

2010

|

tom 52

|

nr 4

Radiation data recorded at 12 sites around the central part of the Baltic Sea during 1996–2000 drawn from the BALTEX (Baltic Sea Experiment) meteorological data archives are used to study the spatio-temporal variability of daily global radiation totals. The annual average daily global radiation total varies from about 10MJ m−2 at Visby (on Gotland) and Kołobrzeg (on the coast of Poland) to less than 9 MJ m−2 at Z¯ıl¯ani (inland Latvia), ˇ Silut˙e (Lithuania) and Jokioinen (Finland). The monthly average daily global radiation total over the whole region extends from 0.93 in December to 19.0 in June. The variability in global radiation is analysed on the basis of the fraction of the daily total at the top of the atmosphere. The spatial and temporal variability is the least in August – this shows that the variation in the cloud cover and atmospheric properties at this time of year is the smallest. The spatial correlation is the strongest between the two Finnish stations – Vantaa and Jokioinen. It is also high between Stockholm and Norrk¨oping, on the east coast of Sweden. The correlation coefficients are the largest over the whole area in April. Radiation data from coastal stations are compared with an earlier parameterization based on ship observations (Rozwadowska & Isemer 1998, Isemer & Rozwadowska 1999). It is concluded that in climatological research, actinometric data from Visby can be used to characterize the radiation field over the northern part of the Baltic Proper and those from Kołobrzeg to characterize the adiation field over the southern part of this sea.

14

Monitoring the effect of upwelling on the chlorophyll a distribution in the Gulf of Finland (Baltic Sea) using remote sensing and in situ data

67%

Uiboupin R., Laanemets J., Sipelgas L., Raag L., Lips I., Buhhalko N.

Oceanologia

|

2012

|

tom 54

|

nr 3

The spatio-temporal variability of chlorophyl a (Chl a) caused by a sequence of upwelling events in the Gulf of Finland in July–August 2006 was studied using remote sensing data and field measurements. Spatial distributions of sea surface temperature (SST) and Chl a concentration were examined using MODIS and MERIS data respectively. The MERIS data were processed with an algorithm developed by the Free University of Berlin (FUB) for case 2 waters. Evaluation of MERIS Chl a versus in situ Chl a showed good correlation (r2 = 0.67), but the concentration was underestimated. The linear regression for a 2 h window was applied to calibrate MERIS Chl a. The spatio-temporal variability exhibited the clear influence of upwelling events and related filaments on Chl a distribution in the western and central Gulf. The lowest Chl a concentrations were recorded in the upwelled water, especially at the upwelling centres, and the highest concentrations (13 mg m−3) were observed about two weeks after the upwelling peak along the northern coast. The areas along the northern coast of upwelled water (4879 km2) on the SST map, and increased Chl a (5526 km2) two weeks later, were roughly coincident. The effect of upwelling events was weak in the eastern part of the Gulf, where Chl a concentration was relatively consistent throughout this period.

15

Rolnicze okresy termiczne na Lubelszczyźnie w latach 1981-2010

67%

Acta Agrophysica

|

2017

|

tom 24

|

nr 3

W artykule przedstawiono wyniki badań zmienności czasowo-przestrzennej rolniczych okresów termicznych na Lubelszczyźnie w aspekcie obserwowanego wzrostu temperatury powietrza. W tym celu wykorzystano dane dotyczące średniej miesięcznej temperatury powietrza za okres 1981-2010 pochodzące z dziewięciu stacji meteorologicznych położonych na obszarze województwa lubelskiego (Bezek, Czesławice, Lublin-Felin, Puławy, Terespol, Tomaszów Lubelski, Uhrusk) i jego obrzeżach (Sandomierz i Siedlce). Na podstawie przeprowadzonych badań dla sześciu stacji stwierdzono istotny statystycznie wzrost średniej rocznej temperatury powietrza, którego następstwem była zmiana terminów początku i końca oraz długości analizowanych okresów termicznych. Obliczone w pracy długości okresów: gospodarczego, wegetacyjnego, intensywnej wegetacji oraz dojrzewania okazały się dłuższe w porównaniu do wyznaczonych przez innych autorów okresów termicznych dla wcześniejszych wieloleci. Skróceniu natomiast uległ okres pozawegetacyjny (zimowego spoczynku roślin) i termicznej zimy. Wiosną daty rozpoczęcia okresów termicznych były wcześniejsze, a daty zakończenia jesienią - późniejsze. W konsekwencji okres pozawegetacyjny oraz termiczna zima rozpoczynały się później i kończyły wcześniej.

Ograniczanie wyników

Spatiotemporal variation of biochemical composition of organic matter and number of bacteria in core sediments of selected beaches of the southern Baltic Sea

Spatio-temporal variability of the phytoplankton biomass in the Levantine basin between 2002 and 2015 using MODIS products

Spatio-temporal variability in the Brazil-Malvinas Confluence Zone (BMCZ), based on spectroradiometric MODIS-AQUA chlorophyll-a observations

Spatio-temporal variations in sulfur-oxidizing and sulfate-reducing bacterial activities during upwelling, off South-West coast of India

Spatio-temporal variation in the prevalence of trematodes in the bivalve Perumytilus purpuratus

Spatio-temporal variability of the size-fractionated primary production and chlorophyll in the Levantine Basin (Northeastern Mediterranean)

Chromophoric dissolved organic matter (CDOM) variability over the continental shelf of the Northern Bay of Bengal

Unravelling the spatio-temporal variation of zooplankton community from the river Matla in the Sundarbans Estuarine System, India

Spatio-temporal variation of drift and upstream movements of the amphipod Gammarus fossarum in a small unaltered stream

Spatio-temporal variation of microphytoplankton in the upwelling system of the South-Eastern Arabian Sea during the summer monsoon of 2009

Spatio-temporal variability of mesozooplankton from the Gulf of Gdansk [Baltic Sea] in 1999-2000

Annual spatio-temporal variation of the euphotic depth in the SW-Finnish archipelago, Baltic Sea

Solar radiation at the surface in the Baltic Proper

Monitoring the effect of upwelling on the chlorophyll a distribution in the Gulf of Finland (Baltic Sea) using remote sensing and in situ data

Rolnicze okresy termiczne na Lubelszczyźnie w latach 1981-2010