Distribution of Nutrients in the Gulf of St. Lawrence

The general pattern of nutrient distribution in the Gulf of St. Lawrence results from regeneration processes being superimposed on the physical processes of estuarine circulation within the Gulf. This leads to a general increase in nutrient concentration with depth and with distance into the Gulf from Cabot Strait. Nutrient concentrations in the Laurentian Channel are higher inside the Gulf than at equal or even greater depths in the Atlantic Ocean some distance outside Cabot Strait. Summer nutrient concentrations in the surface layer are generally low. However, during the winter when biological activity is low, quite high concentrations of the nutrients are found in the surface waters of the Gulf. A balance exists between inward and outward fluxes of all three nutrients through Cabot Strait in the winter. However, in the summer the influxes of both nitrate and silicate at Cabot Strait greatly exceed the outgoing fluxes. Losses of biogenic silica to the sediments may account for the silicate imbalance. Excess nitrate may be accounted for if ammonia or nitrogen bound with dissolved organics had been measured. Key words: nutrients, silicate, phosphate, nitrate, distribution, regeneration, transport, Gulf of St. Lawrence, Cabot Strait, Laurentian Channel

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VERTICAL DISTRIBUTION OF NUTRIENTS ON TRANSITIONAL SEASON IN WEDA BAY, NORTH MALUKU

Jurnal Ilmu dan Teknologi Kelautan Tropis ◽

10.28930/jitkt.v7i2.10991 ◽

2016 ◽

Vol 7 (2) ◽

Author(s):

Faisal Hamzah ◽

Abdul Basit ◽

Iis Triyulianti

Keyword(s):

Water Column ◽

North Pacific Ocean ◽

Nutrient Utilization ◽

Nutrient Concentrations ◽

Geochemical Processes ◽

Physical Processes ◽

Nutrient Distribution ◽

Low Salinity ◽

Water Columns ◽

Water Layers

A vertical distribution of nutrient shows an interaction of physical processes, source, and uptake along the water column. These interactions can occur along the water column with different processes in each layer. Water samples from 17 stations were collected for nitrate, phosphate, and silicates concentration analyses during the transitional season in the Weda Bay. During the transitional season, the Weda Bay was characterized by low salinity (33.55-34.10), relatively warm temperature (30.87°C), and the relatively low nutrient concentrations (nitrate=0.03-4.87 µg at/l, phosphate=0.011-0.852 µg at/l, and silicate=0.04-1.21 µg at/l). The present of Western North Pacific Ocean (WNPO) watermass and the influence of Southern Subtropical Lower Water (SSLW) producing high salinity (>35) at the depth of 130-300 m were observed along the Weda Bay. Nutrient geochemical processes in this region were shown by nutrient utilization and regeneration across the water columns. Nutrients utilization was relatively high in the surface layer. Meanwhile, nutrients regeneration and remineralization were more dominant in the thermocline and deeper water layers. Analyses of nutrients showed that nitrate was more dominant than other nutrients with N/P ratio was 3.83-37.99 and N/Si ratio was 0.12-10.98. The effectiveness of silicate (0.25 μg at/l) that was used by phytoplankton found at a depth of 200 m when its concentration decreased at N/P ratio (16:08) close to the Redfield ratio. Due to an uptake, remineralization, and regeneration processes in each layer, a nutrient distribution pattern was formed which the nutrient concentrations decreased in mixed layer and increased in the deeper water.Keywords:nutrien, pattern, Weda Bay, transitional season

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VERTICAL DISTRIBUTION OF NUTRIENTS ON TRANSITIONAL SEASON IN WEDA BAY, NORTH MALUKU

Jurnal Ilmu dan Teknologi Kelautan Tropis ◽

10.29244/jitkt.v7i2.10991 ◽

2016 ◽

Vol 7 (2) ◽

Author(s):

Faisal Hamzah ◽

Abdul Basit ◽

Iis Triyulianti

Keyword(s):

Vertical Distribution ◽

Water Column ◽

North Pacific Ocean ◽

Nutrient Utilization ◽

Nutrient Concentrations ◽

Physical Processes ◽

Nutrient Distribution ◽

Low Salinity ◽

Water Columns ◽

Water Layers

A vertical distribution of nutrient shows an interaction of physical processes, source, and uptake along the water column. These interactions can occur along the water column with different processes in each layer. Water samples from 17 stations were collected for nitrate, phosphate, and silicates concentration analyses during the transitional season in the Weda Bay. During the transitional season, the Weda Bay was characterized by low salinity (33.55-34.10), relatively warm temperature (30.87°C), and the relatively low nutrient concentrations (nitrate=0.03-4.87 µg at/l, phosphate=0.011-0.852 µg at/l, and silicate=0.04-1.21 µg at/l). The present of Western North Pacific Ocean (WNPO) watermass and the influence of Southern Subtropical Lower Water (SSLW) producing high salinity (>35) at the depth of 130-300 m were observed along the Weda Bay. Nutrient geochemical processes in this region were shown by nutrient utilization and regeneration across the water columns. Nutrients utilization was relatively high in the surface layer. Meanwhile, nutrients regeneration and remineralization were more dominant in the thermocline and deeper water layers. Analyses of nutrients showed that nitrate was more dominant than other nutrients with N/P ratio was 3.83-37.99 and N/Si ratio was 0.12-10.98. The effectiveness of silicate (0.25 μg at/l) that was used by phytoplankton found at a depth of 200 m when its concentration decreased at N/P ratio (16:08) close to the Redfield ratio. Due to an uptake, remineralization, and regeneration processes in each layer, a nutrient distribution pattern was formed which the nutrient concentrations decreased in mixed layer and increased in the deeper water.Keywords:nutrien, pattern, Weda Bay, transitional season

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Bank filtration: a suitable process for the removal of iodinated X-ray contrast media?

Water Science & Technology ◽

10.2166/wst.2004.0336 ◽

2004 ◽

Vol 50 (5) ◽

pp. 261-268 ◽

Cited By ~ 33

Author(s):

S. Schittko ◽

A. Putschew ◽

M. Jekel

Keyword(s):

Drinking Water ◽

Contrast Media ◽

Surface Waters ◽

Sampling Period ◽

Transformation Products ◽

Bank Filtration ◽

Anoxic Conditions ◽

X Ray ◽

High Concentrations ◽

Media Concentration

After bank filtration, effluent influenced surface waters are often used as raw drinking water. It is known that high concentrations of iodinated X-ray contrast media are detectable in such surface waters and thus, more knowledge about the behaviour of the contrast media during bank filtration is necessary and the subject of investigations in this study. The adsorbable organic iodine (AOI), four widely used iodinated X-ray contrast media and four possible transformation products were quantified in an influenced lake, five groundwater wells and a drinking water well. Under anoxic conditions the AOI as well as the concentration of the contrast media are decreased by bank filtration, whereby the AOI is decreased by 64% and the contrast media concentration can be reduced up to 95%, depending on the compound. In the raw drinking water the following average concentrations were determined: Iopromid <20 ng/L, Diatrizote 166 ng/L, Iopamidol 166 ng/L and Iohexol 34 ng/L. Instationary conditions during the sampling period indicate that, at least under anoxic conditions, a large part of the contrast media and transformation products, which are still iodinated, may be associated to colloids and/or humic material.

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Nutrient distribution in the Bosphorus and surrounding areas

Water Science & Technology ◽

10.2166/wst.2002.0145 ◽

2002 ◽

Vol 46 (8) ◽

pp. 59-66 ◽

Cited By ~ 4

Author(s):

E. Okuş ◽

A. Aslan-Yilmaz ◽

A. Yüksek ◽

S. Taş ◽

V. Tüfekçi

Keyword(s):

Chlorophyll A ◽

Black Sea ◽

Nutrient Dynamics ◽

Lower Layer ◽

Water Quality Monitoring ◽

Nutrient Concentrations ◽

The Black Sea ◽

Sea Of Marmara ◽

Nutrient Distribution ◽

Northwestern Shelf

As part of a five years monitoring project “Water Quality Monitoring of the Strait of Istanbul”, February-December 1999 nutrient dynamics of the Black Sea-the Sea of Marmara transect are studied to evaluate the effect of discharges given by deep disposals. Through a one-year study, upper layer nutrient concentrations were generally under the effect of northwestern-shelf Black Sea originated waters. This effect was strictly observed in July, when the upper layer flow was the thickest. On the other hand, partly in November but especially in December the northwestern-shelf Black Sea originated water flow was a minimum resulting in similar concentrations in both layers. Nutrient fluctuations also affected the chlorophyll a and POC concentrations as parameters of productivity. The nutrient concentrations decreased with the effect of spring bloom and highest chlorophyll a values were detected in November at Strait stations that did not match to the Sea of Marmara values. This fact represents the time-scale difference between the Black Sea and the Sea of Marmara. On the contrary, high nutrient concentrations in the lower layer (especially inorganic phosphate), and therefore low N:P ratios reflect the effect of deep discharge. Vertical mixing caused by meteorological conditions of the shallow station (M3) under the effect of surface discharges resulted in homogenous distribution of nutrients. Nutrient concentrations of the stations affected by deep discharge showed that the two-layer stratification of the system did not permit the discharge mix to the upper layer.

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Nutrients, Chlorophyll, and Internal Tides in the St. Lawrence Estuary

Journal of the Fisheries Research Board of Canada ◽

10.1139/f76-326 ◽

1976 ◽

Vol 33 (12) ◽

pp. 2747-2757 ◽

Cited By ~ 44

Author(s):

Jean-Claude Therriault ◽

Guy Lacroix

Keyword(s):

Surface Waters ◽

Internal Tides ◽

Upstream Region ◽

Mixing Process ◽

Low Oxygen ◽

Lawrence Estuary ◽

Deep Waters ◽

High Nutrient ◽

Phosphate Nitrate ◽

St Lawrence Estuary

Tide-dependent variations of temperature, salinity, dissolved oxygen, phosphate, nitrate, and chlorophyll a support the existence of internal tides (longitudinal and transversal) in the St. Lawrence estuary. Vertical oscillations of the poorly oxygenated and nutrient-rich intermediate and deep waters of the estuary have been documented at the head of the Laurentian Channel, the region in which the internal tides are thought to be generated. Penetration of intermediate waters (high-nutrient and low-oxygen concentrations) beyond the Laurentian Channel associated with the internal tides and linked with an intense mixing process in the upstream region permits the nutrient enrichment of the surface waters and their eventual advection in the seaward direction.

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The influence of hydrological pathways on the transport of the herbicide, isoproturon, through an underdrained clay soil

Water Science & Technology ◽

10.2166/wst.1999.0532 ◽

1999 ◽

Vol 39 (12) ◽

pp. 77-84 ◽

Cited By ~ 2

Author(s):

C. M. Heppell ◽

T. P. Burt ◽

R. J. Williams ◽

A. H. Haria

Keyword(s):

Surface Waters ◽

Clay Soil ◽

Quality Standard ◽

Early Spring ◽

Hydrological Response ◽

Macropore Flow ◽

Ephemeral Stream ◽

Low Intensity ◽

Flow Through ◽

High Concentrations

This paper reports the findings of a 12 month field monitoring programme at Wytham (Oxfordshire, UK), which examined the leaching of the phenylurea herbicide, isoproturon, from an agricultural clay hillslope to the adjacent ephemeral stream. Isoproturon was shown to reach the drains (at 50 cm depth) through a combination of vertical and lateral macropore flow through wormholes and inter-pedal cracks. Seasonal changes in hydrological response were also observed at the site, with lateral flow through inter-pedal cracks providing an important route by which herbicide was transported during autumn and early spring when the clay soils were wetting up. Concentrations of isoproturon in drainflow frequently exceeded the Environment Agency's (EA) non-statutory Environmental Quality Standard (EQS) of 20 μg/l for isoproturon in surface waters. Even under low intensity rainfall (< 1 mm/hr) the saturated region at the base of the hillslope was shown to conduct macropore flow containing significantly high concentrations of herbicide to the drain. The results of this study suggest that those regions close to surface waters which are areas of converging hydrological flow may be key contributors to the problem of isoproturon contamination of surface waters.

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Dissolved iron (II) in the Baltic Sea surface water and implications for cyanobacterial bloom development

Biogeosciences Discussions ◽

10.5194/bgd-6-3803-2009 ◽

2009 ◽

Vol 6 (2) ◽

pp. 3803-3850 ◽

Cited By ~ 4

Author(s):

E. Breitbarth ◽

J. Gelting ◽

J. Walve ◽

L. J. Hoffmann ◽

D. R. Turner ◽

...

Keyword(s):

Baltic Sea ◽

Surface Waters ◽

Cyanobacterial Bloom ◽

Euphotic Zone ◽

Strong Wind ◽

Ferrous Ions ◽

The Baltic Sea ◽

High Concentrations ◽

Wind Events ◽

The Baltic

Abstract. Iron chemistry measurements were conducted during summer 2007 at two distinct locations in the Baltic Sea (Gotland Deep and Landsort Deep) to evaluate the role of iron for cyanobacterial bloom development in these estuarine waters. Depth profiles of Fe(II) were measured by chemiluminescent flow injection analysis (CL-FIA) and reveal several origins of Fe(II) to the water column. Photoreduction of Fe(III)-complexes and deposition by rain are main sources of Fe(II) (up to 0.9 nmol L−1) in light penetrated surface waters. Indication for organic Fe(II) complexation resulting in prolonged residence times in oxygenated water was observed. Surface dwelling heterocystous cyanobacteria where mainly responsible for Fe(II) consumption in comparison to other phytoplankton. The significant Fe(II) concentrations in surface waters apparently play a major role in cyanobacterial bloom development in the Baltic Sea and are a major contributor to the Fe requirements of diazotrophs. Second, Fe(II) concentrations up to 1.44 nmol L−1 were observed at water depths below the euphotic zone, but above the oxic anoxic interface. Finally, all Fe(III) is reduced to Fe(II) in anoxic deep water. However, only a fraction thereof is present as ferrous ions (up to 28 nmol L−1) and was detected by the CL-FIA method applied. Despite their high concentrations, it is unlikely that ferrous ions originating from sub-oxic waters could be a temporary source of bioavailable iron to the euphotic zone since mixed layer depths after strong wind events are not deep enough in summer time.

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Exposure of the Main Italian River Basin to Pharmaceuticals

Journal of Toxicology ◽

10.1155/2011/989270 ◽

2011 ◽

Vol 2011 ◽

pp. 1-11 ◽

Cited By ~ 14

Author(s):

Federico Ferrari ◽

Agata Gallipoli ◽

Matteo Balderacchi ◽

Maria M. Ulaszewska ◽

Ettore Capri ◽

...

Keyword(s):

Surface Waters ◽

Point Sources ◽

Preliminary Survey ◽

Italian Economy ◽

Sediment Samples ◽

Pharmaceutical Contamination ◽

Low Levels ◽

High Concentrations ◽

River Po ◽

Sources Of Contamination

This study give a preliminary survey of pharmaceutical contamination and accumulation in surface waters and sediments along the river Po basin (74,000 km2, the largest in Italy), a strategic region for the Italian economy: it collects sewage from a vast industrialized area of Italy (Autorità di Baciono del fiume Po, 2006, 2009). 10 pharmaceuticals (atenolol, propanolol, metoprolol, nimesulide, furosemide, carbamazepine, ranitidine, metronidazole, paracetamol, and atorvastatin) from several therapeutic classes were searched in 54 sampling points along the river Po from the source to the delta, and at the mouth of its major effluents. In water samples were found pharmaceuticals in the range of 0.38–0.001 μg/L, except for furosemide (max conc. 0.605 μg/L), paracetamol (max conc. 3.59 μg/L), metoprolol (never detected) and for atenolol (not analysed). In sediment samples, only paracetamol was not detected, while the others were generally found in the range of 0.4–0.02 μg/kgwwwith high concentrations for atenolol (max conc. 284μg/kgww) and furosemide (max conc. 98.4μg/kgww). The findings confirm also STPs as point sources of contamination. Despite of the much evidence for the adverse effects of pharmaceuticals in the aquatic environment, the observed low levels cannot be considered to pose a serious risk to human health; further studies are necessary for a comprehensive risk assessment.

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Nutrient enrichment effect on macroinvertebrates in a lowland stream of Argentina

Iheringia Série Zoologia ◽

10.1590/1678-476620151052228234 ◽

2015 ◽

Vol 105 (2) ◽

pp. 228-234 ◽

Cited By ~ 2

Author(s):

Agustina Cortelezzi ◽

Carolina Ocón ◽

María V. López van Oosterom ◽

Rosana Cepeda ◽

Alberto Rodrigues Capítulo

Keyword(s):

Climate Change ◽

Global Climate Change ◽

Global Climate ◽

Nitrogen Concentration ◽

Nutrient Concentrations ◽

Phosphorus Concentration ◽

Lowland Stream ◽

Pampean Streams ◽

High Concentrations ◽

Intensive Land Use

ABSTRACT One of the most important effects derived from the intensive land use is the increase of nutrient concentration in the aquatic systems due to superficial drainage. Besides, the increment of precipitations in South America connected to the global climate change could intensify these anthropic impacts due to the changes in the runoff pattern and a greater discharge of water in the streams and rivers. The pampean streams are singular environments with high natural nutrient concentrations which could be increased even more if the predictions of global climate change for the area are met. In this context, the effect of experimental nutrient addition on macroinvertebrates in a lowland stream is studied. Samplings were carried out from March 2007 to February 2009 in two reaches (fertilized and unfertilized), upstream and downstream from the input of nutrients. The addition of nutrients caused an increase in the phosphorus concentration in the fertilized reach which was not observed for nitrogen concentration. From all macroinvertebrates studied only two taxa had significant differences in their abundance after fertilization: Corbicula fluminea and Ostracoda. Our results reveal that the disturbance caused by the increase of nutrients on the benthic community depends on basal nutrients concentration. The weak response of macroinvertebrates to fertilization in the pampean streams could be due to their tolerance to high concentrations of nutrients in relation to their evolutionary history in streams naturally enriched with nutrients. Further research concerning the thresholds of nutrients affecting macroinvertebrates and about the adaptive advantages of taxa in naturally eutrophic environments is still needed. This information will allow for a better understanding of the processes of nutrient cycling and for the construction of restoration measures in natural eutrophic ecosystems.

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