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Wyszukujesz frazę "environment" wg kryterium: Temat


Tytuł:
Phytoplankton and environmental variables as a water quality indicator for the beaches at Matrouh, South-Eastern Mediterranean Sea, Egypt: an assessment
Autorzy:
Gharib, S.M.
El-Sherif, Z.M.
Abdel-Halim, A.M.
Radwan, A.A.
Powiązania:
https://bibliotekanauki.pl/articles/48802.pdf
Data publikacji:
2011
Wydawca:
Polska Akademia Nauk. Instytut Oceanologii PAN
Tematy:
abiotic environment
beach
biotic environment
community structure
diversity index
Egypt
environment variability
hydrochemical change
hydrographic change
marine environment
Matrouh beach
Mediterranean Sea
nutrient concentration
phytoplankton
water quality
Opis:
This study was carried out to determine the water quality of the beaches at Matrouh, south-eastern Mediterranean Sea, Egypt, by studying environmental variables as well as phytoplankton abundance and community structure. Surface water samples were monitored from a series of beach sites over a period of five seasons during 2009–2010. A total of 203 phytoplankton species were identified from seven algal divisions. Seasonal differences in the quantitative and qualitative composition of the phytoplankton communities in the different sites were marked. Nutrient concentrations and phytoplankton abundances were found to be poorer than those of many other areas along Egyptian coast. The Shannon-Wiener Diversity Index classified Matrouh water as being between clean and moderately polluted, whereas the WQI demonstrated that it was between good and excellent. It can be concluded that the index based onWQI is currently more suitable than the phytoplankton species index for assessing the quality of the water of the Matrouh beaches.
Źródło:
Oceanologia; 2011, 53, 3
0078-3234
Pojawia się w:
Oceanologia
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
The effect of humic substances isolated from a variety of marine and lacustrine environments on different microorganisms
Autorzy:
Kupryszewski, G.
Pempkowiak, J.
Kedzia, A.
Powiązania:
https://bibliotekanauki.pl/articles/48478.pdf
Data publikacji:
2001
Wydawca:
Polska Akademia Nauk. Instytut Oceanologii PAN
Tematy:
marine environment
humic substance
sea water
lacustrine environment
microorganism
antimicrobial activity
bottom sediment
lake water
Opis:
The antimicrobial activity of twelve preparations of humic substances isolated from sea water, marine bottom sediments and lake water was examined. Humic substances from marine bottom sediment samples were fractionated into humic and/or fulvic acids. The susceptibility of 11 strains of anaerobic, 8str ains of aerobic bacteria and 2 strains of yeast-like fungi to preparations of humic substances, humic and/or fulvic acids was determined employing the plate dilution technique in Brucella agar (anaerobic bacteria), Mueller-Hinton agar (aerobic bacteria) and Sabouraud agar (yeast-like fungi). Concentrations from 150 to 600 μg ml−1 of the preparations examined inhibited the growth of numerous microorganisms (Table). The results obtained seem to indicate that humic substances are involved in the self-purification of sea and lake waters.
Źródło:
Oceanologia; 2001, 43, 2
0078-3234
Pojawia się w:
Oceanologia
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
A concept for biological valuation in the marine environment
Autorzy:
Derous, S.
Agardy, T.
Hillewaert, H.
Hostens, K.
Jamieson, G.
Lieberknecht, L.
Mees, J.
Moulaert, I.
Olenin, S.
Paelinckx, D.
Rabaut, M.
Rachor, E.
Roff, J.
Stienen, E.W.M.
Van Der Wal, J.T.
Van Lancker, V.
Verfaillie, E.
Vincx, M.
Weslawski, J.M.
Degraer, S.
Powiązania:
https://bibliotekanauki.pl/articles/47513.pdf
Data publikacji:
2007
Wydawca:
Polska Akademia Nauk. Instytut Oceanologii PAN
Tematy:
ecology
marine environment
biodiversity
biological valuation
Opis:
In order to develop management strategies for sustainable use and conservation in the marine environment, reliable and meaningful, but integrated ecological information is needed. Biological valuation maps that compile and summarize all available biological and ecological information for a study area, and that allocate an overall biological value to subzones, can be used as baseline maps for future spatial planning at sea. This paper provides a concept for marine biological valuation which is based on a literature review of existing valuation criteria and the consensus reached by a discussion group of experts.
Źródło:
Oceanologia; 2007, 49, 1
0078-3234
Pojawia się w:
Oceanologia
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
The Baltic Sea - an example of how to protect marine coastal ecosystems
Autorzy:
Nehring, D.
Powiązania:
https://bibliotekanauki.pl/articles/48329.pdf
Data publikacji:
2001
Wydawca:
Polska Akademia Nauk. Instytut Oceanologii PAN
Tematy:
marine environment
crude oil
inorganic nutrient
environment
trace metal
ecosystem protection
contamination
chlorinated hydrocarbon
HELCOM Baltic Monitoring Programme
Baltic Sea
eutrophication
Opis:
The Baltic Sea covers an area of 415 000 km2. A typical brackish sea, it is very sensitive to anthropogenic activities. Inorganic nutrients, trace metals, chlorinated hydrocarbons and crude oil products are contaminants studied in the Baltic Monitoring Programme of HELCOM. The data collected by the riparian countries forms the basis for the periodic assessments of the state of the marine environment of the Baltic Sea Area produced by HELCOM every five years. Since 1992 marine nature conservation has been part of the HELCOM convention. According to the third status report issued in 1996, it was the first time that HELCOM could strike a positive balance with regard to the decreasing environmental load. This is also reflected in lower concentrations of harmful substances in fish, marine mammals and seabirds in the Baltic Sea Area. The reasons for this progress are the protective actions initiated by HELCOM and the economic collapse in some of the former East Bloc countries, the latter resulting in an abrupt fall in industrial and agricultural production. Although the restoration of the Baltic ecosystem has only just begun, the protective measures introduced to achieve this aim can serve as an example of how to solve similar problems in other semi-enclosed basins and shelf seas.
Źródło:
Oceanologia; 2001, 43, 1
0078-3234
Pojawia się w:
Oceanologia
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Environmental changes in the central Baltic Sea during the past 1000 years: inferences from sedimentary records, hydrography and climate
Autorzy:
Leipe, T.
Dippner, J.W.
Hille, S.
Voss, M.
Christiansen, C.
Bartholdy, J.
Powiązania:
https://bibliotekanauki.pl/articles/47746.pdf
Data publikacji:
2008
Wydawca:
Polska Akademia Nauk. Instytut Oceanologii PAN
Tematy:
bottom water anoxia
sediment
hydrography
environment condition
little ice age
Baltic Sea
modern warm period
saline water
environment change
climate
Gotland Basin
Opis:
Short sediment cores from the eastern Gotland Basin were investigated using a multi-proxy approach in order to reconstruct the environmental conditions of the area during the past 1000 years. Sediment data and facies were discussed in relation to hydrographic features (salinity, oxygen) and climate change. During the medieval warm period (MWP), from about 900 to 1250 AD, the hydrographic and environmental conditions were similar to those of the present time (modern warm period, since about 1850): a temporally stable halocline, caused by regular saline water inflows from the North Sea, prevents vertical mixing and leads to bottom water anoxia and the deposition of laminated, organic-rich sapropels. During the period from about 1250 to 1850, referred to as the cold phase (including the Little Ice Age), the environmental conditions of the central Baltic Sea were distinctly different: the lower salinity, resulting from reduced North Sea water inflows, allowed vertical convection of the water column and long-term stable ventilation of the sea bed (oxic stage). Both the productivity of the planktonic ecosystem as well as the preservation of organic matter in the sediments improved during the warm periods. The anthropogenic impact can be identified within the recent laminated sequence by a temporal reconstruction of pollutant deposition. Our findings imply a climate-change driven shift in the environmental conditions and the ecosystem of the Baltic from the north to the south and back to the north.
Źródło:
Oceanologia; 2008, 50, 1; 23-41
0078-3234
Pojawia się w:
Oceanologia
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Effect of mangrove forest structures on wave attenuation in coastal Vietnam
Autorzy:
Bao, T.Q.
Powiązania:
https://bibliotekanauki.pl/articles/48094.pdf
Data publikacji:
2011
Wydawca:
Polska Akademia Nauk. Instytut Oceanologii PAN
Tematy:
brackish water
coastal region
forest structure
mangrove forest
marine environment
river mouth
saline water
storm
terrestrial environment
Vietnam
water quality
wave
wave attenuation
Opis:
This paper analyses wave attenuation in coastal mangrove forests in Vietnam. Data from 32 mangrove plots of six species located in 2 coastal regions are used for this study. In each plot, mangrove forest structures and wave height at different cross-shore distances are measured. Wave height closely relates to cross- shore distances. 92 exponential regression equations are highly significant with R2 >0.95 and P val. <0.001. Wave height reduction depends on initial wave height, cross-shore distances, and mangrove forest structures. This relationship is used to define minimum mangrove band width for coastal protection from waves in Vietnam.
Źródło:
Oceanologia; 2011, 53, 3
0078-3234
Pojawia się w:
Oceanologia
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Making coastal research useful — cases from practice
Autorzy:
von Storch, H.
Emeis, K.
Meinke, I.
Kannen, A.
Matthias, V.
Ratter, B.M.W.
Stanev, E.
Weisse, R.
Wirtz, K.
Powiązania:
https://bibliotekanauki.pl/articles/48154.pdf
Data publikacji:
2015
Wydawca:
Polska Akademia Nauk. Instytut Oceanologii PAN
Tematy:
maritime spatial planning
monitoring
hazard
risk
utility
eutrophication
environment degradation
Źródło:
Oceanologia; 2015, 57, 1
0078-3234
Pojawia się w:
Oceanologia
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Comparison of two models in the estimation of nitrogen uptake rates using data from 15-N incubation experiments
Autorzy:
Tungaraza, C.
Brion, N.
Baeyens, W.
Powiązania:
https://bibliotekanauki.pl/articles/48263.pdf
Data publikacji:
2005
Wydawca:
Polska Akademia Nauk. Instytut Oceanologii PAN
Tematy:
marine environment
nitrogen isotope
Elskens' model
phytoplankton
nitrogenous nutrient
comparison
Opis:
This paper compares two uptake rate models, Dugdale & Goering’s (D&G) model and Elskens’ model. The aim is to provide an insight into how estimates of uptake processes, i.e. regeneration and loss rates from both dissolved and particulate nitrogen pools, influence the total uptake rates when the two models are compared. The uptake rates of three nitrogenous nutrients (nitrate, ammonium and urea) from 15-N incubation experimental data were compared. The comparison indicated that the D&G model underestimated nitrate uptake rates by about 34%, implying a significant regeneration and loss rates of the nutrient. Elskens’ model further showed that the loss rates from the dissolved phase were about 40% and 25% for the ammonium and urea pools, respectively, indicating that the D&G model underestimated the experimental uptake rates of the nutrients. On average, nitrification made up about 30% of the total ammonium uptake flux, whereas the sinks from particulate nitrogen and dissolved nitrogen were estimated at 36% and 56%, respectively. The D&G model sometimes overestimated the f-ratio values to about 60% and higher as a result of ammonium and urea uptake rates underestimation. This paper also shows that detritus adsorption, bacterial uptake and cell lysis are equally important processes.
Źródło:
Oceanologia; 2005, 47, 3
0078-3234
Pojawia się w:
Oceanologia
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Ecosystem maturation follows the warming of the Arctic fjords
Autorzy:
Weslawski, J.M.
Buchholz, F.
Gluchowska, M.
Weydmann, A.
Powiązania:
https://bibliotekanauki.pl/articles/48879.pdf
Data publikacji:
2017
Wydawca:
Polska Akademia Nauk. Instytut Oceanologii PAN
Tematy:
climate change
biodiversity
ecosystem
maturation
Arctic fjord
Hornsund
Kongsfjorden
physical environment
Opis:
Two fjords in West Spitsbergen (Hornsund 77°N and Kongsfjorden 79°N) differ with regard to their exposure towards increasingly warm Atlantic water inflow. Hornsund remains in many respects cooler than Kongsfjorden (on average 2°C SST in summer) and is less influenced by warmer and more saline Atlantic waters. Reported changes in the physical environment (temperature rise, freshwater inflow, salinity drop, turbidity, fast-ice reduction, coastal change) are discussed in the context of biological observations in the pelagic and benthic realms with special reference to krill (Euphausiacea). We conclude that well-documented changes in the physical environment have had little effect on the fjord biota and that both organisms and their ecological functions in the fjords are well adapted to the scale of ongoing change. The observed changes fit the definition of ecosystem maturation, with greater diversity, a more complex food web and dispersed energy flow at the warmer site.
Źródło:
Oceanologia; 2017, 59, 4
0078-3234
Pojawia się w:
Oceanologia
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Coastal processes of Central Tamil Nadu, India: clues from grain size studies
Autorzy:
Angusamy, N.
Rajamanickam, G.V.
Powiązania:
https://bibliotekanauki.pl/articles/48429.pdf
Data publikacji:
2007
Wydawca:
Polska Akademia Nauk. Instytut Oceanologii PAN
Tematy:
depositional environment
Tamil Nadu
beach
grain size
India
sediment
coastal process
Opis:
The sediments of the beaches along the central coast of Tamil Nadu from Pondicherry to Vedaranyam were studied for their textural variation. 108 sediment samples collected from the low-, mid-, and high-tidal zones, as well as the berms and dunes of different beach morpho-units were analysed. The study area was divided into three sectors (northern, central and southern) on the basis of prevailing energy conditions and oceanographic parameters. The poorly sorted, negatively skewed, coarser sediments of the northern sector are indicative of denudational processes taking place there. Medium-to-fine, moderately-to-well sorted, positivesymmetrically skewed sediments dominate the central sector, probably as a result of the influence of palaeo-sediments deposited by rivers from inland as well as by waves and currents from offshore. Fine, poorly sorted, positive-symmetrically skewed sediments dominate the southern sector, highlighting depositional processes. Linear Discriminant Function Analysis (LDF) of the samples indicates a shallow marine environment origin for all the three sectors. These results show that reworked sediments, submerged during the Holocene marine transgression, are being deposited on present-day beaches by waves, currents and rivers in the study area.
Źródło:
Oceanologia; 2007, 49, 1
0078-3234
Pojawia się w:
Oceanologia
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Historical occurrences of marine microalgal blooms in Indian Peninsula: Probable causes and implications
Autorzy:
Oyeku, O.G.
Mandal, S.K.
Powiązania:
https://bibliotekanauki.pl/articles/2079002.pdf
Data publikacji:
2021
Wydawca:
Polska Akademia Nauk. Instytut Oceanologii PAN
Tematy:
marine environment
algal bloom
microalga
sea surface
water temperature
Indian Peninsula
Opis:
The Indian marine environment supports employment for over 200 million people, including revenue of nearly $7 billion per annum. However, ecological goods and services of the shallow coast and the marine environment of the Indian peninsula are being affected by recurrent blooms of microalgae. One hundred and six published literature, starting from the first report in 1908 to 2017, were reviewed to investigate the historical occurrences of marine microalgal blooms (MMBs) around the Indian peninsula. 154 MMBs comprising 24 genera and 7 classes were reported during the study period. Noctiluca (dinophyceae) and Trichodesmium (cyanophyceae) bloom contributed 34.4% and 31.8% of total blooms. PCA revealed that high sea surface temperature (SST) and salinity were significant driving forces for Trichodesmium blooms formation, while high nutrients (NO3-N, PO4-P, and SiO4-Si) and low salinity triggered prymnesiophyceae, raphidophyceae, bacillariophyceae and most of the dinophyceae blooms. Noctiluca blooms were linked with both eutrophication and the abundance of prey organisms. HABs were generally dinophyceae dominated and were associated with mass mortality of aquatic fauna, human intoxication, paralytic, and ciguatera shellfish poisoning and even death. Increasing SST and anthropogenic influences around the Indian peninsula could increase the occurrences of MMBs (including HABs) and the number of causative taxa. Proper safety measures such as routine monitoring of phycotoxin levels in the environment and local seafood are required to be put in place in other to protect the health of the public.
Źródło:
Oceanologia; 2021, 63, 1; 51-70
0078-3234
Pojawia się w:
Oceanologia
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Identifying the main sources of silicate in coastal waters of the Southern Gulf of Valencia (Western Mediterranean Sea)
Autorzy:
Sospedra, J.
Niencheski, L.F.H.
Falco, S.
Andrade, C.F.F.
Attisano, K.K.
Rodilla, M.
Powiązania:
https://bibliotekanauki.pl/articles/48753.pdf
Data publikacji:
2018
Wydawca:
Polska Akademia Nauk. Instytut Oceanologii PAN
Tematy:
silicon
coastal water
Valencia Gulf
Mediterranean Sea
salinity
discharge
nutrient
marine environment
Opis:
Silicon is a major nutrient for siliceous primary producers, which can become a potential limiting nutrient in oligotrophic areas. Most of the silicon inputs to the marine environment come from continental discharges, from both superficial and ground waters. This study analyses the main sources of silicon and their dynamics along the southernmost 43 km of shoreline in the Gulf of Valencia (Western Mediterranean Sea). The salinity and silicate concentration in the different compartments (springs, freshwater wells, beach groundwater, surf zone and coastal waters) in this coastal area were determined. In addition, chlorophyll a and phytoplankton community were analyzed in the surf zone and coastal waters. Silicate concentrations in freshwater wells ranged between 130 and 150 μM, whereas concentrations of this nutrient declined to 49 μM in freshwater–seawater mixture transects. At the same time, there was a positive gradient in silicate for both freshwater and coastal waters southward. An amount of 18.7 t of dissolved silicate was estimated in the nearest first kilometre nearest to the coastline, 6 t of this silicate belonged to the background sea level. On the other hand, the sum of the main rivers in the area supplies 1.6 t of dissolved silicate per day. This implies that a large amount of the remaining 11.1 t must derive from submarine groundwater discharges, which would thus represent 59% of the coastal dissolved silicate budget. Overall, it is suggested that a subterranean transport pathway must contribute considerably to silicate concentrations throughout this zone, which is characterized as permeable.
Źródło:
Oceanologia; 2018, 60, 1
0078-3234
Pojawia się w:
Oceanologia
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
The dependence between bacterial production and environmental conditions in the Gulf of Gdańsk
Autorzy:
Ameryk, A.
Podgorska, B.
Witek, Z.
Powiązania:
https://bibliotekanauki.pl/articles/48815.pdf
Data publikacji:
2005
Wydawca:
Polska Akademia Nauk. Instytut Oceanologii PAN
Tematy:
primary production
Baltic Sea
Gdansk Gulf
environment condition
bacterial production
heterotrophic bacteria
Opis:
Bacterial production, primary production and a number of other environmental factors were measured during six cruises in the Gulf of Gdańsk conducted in various seasons from 1995 to 2001. Bacterial production (BP) in the epipelagic layer ranged from 1.5% (April) to 80% (July) of the gross primary production (PP). Significant differences were observed between the BP/PP ratios in estuarine and open-water areas. The highest values were recorded in the coastal area and near the mouth of the river Vistula. It suggests that allochthonous organic matter has a great influence on BP. The correlations between particular parameters and regression analyses indicated that BP in the Gulf of Gdańsk depended on temperature, organic nitrogen concentration, PP, chlorophyll a concentration, organic phosphorus concentration, salinity and biochemical oxygen demand. Of all the independent variables, the temperature had the greatest impact on BP (R2 = 0.62). There was an inverse parabolic relationship between bacterial production and temperature. It appears that above a temperature of 12◦C bacterial production depended on substrates to a higher degree than on temperature. The negative correlation between BP and concentrations of mineral nitrogen and phosphorus in the annual cycle were probably due to an indirect dependence. A multiple regression equation, which included temperature and organic phosphorus concentrations, explained 78% of the variation in BP. Increasing BP resulted in an increasing biomass of bacterivorous nanoflagellates and of bacterivorous ciliates, which is indicative of bottom-up control in this segment of the trophic chain.
Źródło:
Oceanologia; 2005, 47, 1
0078-3234
Pojawia się w:
Oceanologia
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Parameterisation of a population model for Acartia spp. in the Southern Baltic Sea. Part 2. Egg production
Autorzy:
Dzierzbicka-Glowacka, L.
Lemieszek, A.
Zmijewska, M.I.
Powiązania:
https://bibliotekanauki.pl/articles/48730.pdf
Data publikacji:
2009
Wydawca:
Polska Akademia Nauk. Instytut Oceanologii PAN
Tematy:
environment condition
Baltic Sea
Gdansk Deep
Acartia
population model
copepod
egg production
Opis:
The paper describes the modelling ofeg g production in Acartia spp. under changing environmental conditions in the southern Baltic Sea (Gdańsk Deep). The hypothesis (Sekiguchi et al. 1980) that the food-saturated rate of egg matter production is equivalent to specific growth rate ofco pepods is applied. The average number ofeggs produced per day by one Acartia female is obtained as a function ofg rowth rate, i.e. by multiplying exp gN3 − 1 from the growth rate of the nauplius stage equation by Wfemale/Wegg. The copepod model, reduced to a zerodimensional population model calibrated for Acartia spp. under the environmental conditions typical ofthe southern Baltic Sea, was used to determine the effects of temperature and food concentration on the growth rate ofeac h oft he model stages (see Part 1 – Dzierzbicka-Głowacka et al. 2009 – this issue). In this part, egg production as a function of the above parameters is evaluated. The rate of reproduction during the seasons in the upper layer ofthe Gdańsk Deep is also determined.
Źródło:
Oceanologia; 2009, 51, 2; 185-201
0078-3234
Pojawia się w:
Oceanologia
Dostawca treści:
Biblioteka Nauki
Artykuł

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