Limnological features of coastal-plain wetlands on the Gnangara Mound, Perth, Western Australia

1991 ◽  
Vol 42 (6) ◽  
pp. 761 ◽  
Author(s):  
TJ Wrigley ◽  
SW Rolls ◽  
JA Davis
Keyword(s):  
Chlorophyll A ◽  
Total Phosphorus ◽  
Coastal Plain ◽  
Nutrient Concentrations ◽  
The North ◽  
Large Numbers ◽  
High Nutrient ◽  
Consequent Reduction ◽  
Coastal Plain Wetlands ◽  
Urban Activity

The Gnangara Mound is an area of elevated sandy soil on the Swan Coastal Plain to the north of Perth. It constitutes a major groundwater resource for metropolitan Perth. Sixteen wetlands on the Mound had total phosphorus concentrations of 12-462�g L-1, the high values being attributed to agricultural and urban activity. Sediment concentrations of total phosphorus and total nitrogen were 61-954 and 1212-16739 �g g-1, respectively. Conductivities were 505-10270 �S cm-1, and pH values were 3.3-9.3. Only one wetland was highly coloured (79.9 8440 m-1), with an E4/E6 ratio of 4.6. Chlorophyll a concentrations were 0.01-130.8�g L-1; in wetlands with low gilvin concentrations, Myxophyceae dominated, whereas wetlands with higher gilvin concentrations had large numbers of diatoms and Chlorophyceae. The highly coloured wetland had the lowest chlorophyll a concentration despite high nutrient concentrations, supporting the hypothesis that the consequent reduction in light or other associated factors are important in maintaining low phytoplankton biomass in dystrophic wetlands of the region, particularly those on Bassendean sands.

Relationships among nutrients, algae, and land use in urbanized southern California streams

2006 ◽  
Vol 63 (12) ◽  
pp. 2621-2638 ◽  
Author(s):  
Lilian B Busse ◽  
Juliet C Simpson ◽  
Scott D Cooper
Keyword(s):  
Land Use ◽  
Total Phosphorus ◽  
Algal Biomass ◽  
Southern California ◽  
Stream Water ◽  
Algal Growth ◽  
Nutrient Concentrations ◽  
Total Chlorophyll ◽  
Impervious Surfaces ◽  
High Nutrient

We surveyed algal cover, algal biomass, and physical and chemical factors at 14 sites representing a range of land use types in the Malibu Creek watershed in southern California, USA. We also conducted nutrient diffuser substrate experiments to identify the nutrient limiting algal growth. Algal biomass increased with urbanization, reaching very high levels in the most urbanized streams (up to 322.4 mg chlorophyll a·m-2). Total nitrogen, total phosphorus, and benthic and total chlorophyll concentrations were positively correlated with the proportion of upstream land covered by impervious surfaces. Relationships between land use and algal biomass or nutrient concentrations were evaluated at 100 m, 500 m, and whole subwatershed scales. The closest relationships were found at the 500 m scale, where 56% of the variation in total chlorophyll could be explained by the proportion of land within a 500 m radius upstream covered by impervious surfaces. Floating macroalgae were observed in the summer in pools with high nutrient and light levels, whereas benthic algal biomass was positively related to total phosphorus concentrations and current speed. Other methods of determining nutrient limitation (nutrient diffuser substrate experiment, molar N/P ratios in stream water) produced conflicting results, possibly because algal growth was saturated by high nutrient levels at some of the study sites.

Spatial and temporal distribution of harpacticoid copepods in Mondego estuary

2010 ◽  
Vol 90 (7) ◽  
pp. 1279-1290 ◽  
Author(s):  
A.M.M. Gonçalves ◽  
M. De Troch ◽  
S.C. Marques ◽  
M.A. Pardal ◽  
U.M. Azeiteiro
Keyword(s):  
Suspended Solids ◽  
Salinity Gradient ◽  
Temporal Distribution ◽  
Total Suspended Solids ◽  
Nutrient Concentrations ◽  
The North ◽  
Relative Contribution ◽  
Large Numbers ◽  
Mondego Estuary ◽  
High Level

Seasonal and spatial variations in the composition and relative contribution of the harpacticoid species in the Mondego estuary (western Portugal) were studied based on a monthly sampling along a salinity gradient. These benthic harpacticoids were collected in the water column by means of a 63-µm plankton net. The influence of hydrological parameters (temperature, salinity, oxygen dissolved concentration, pH, turbidity, chlorophyll-a, total suspended solids and nutrient concentrations) was analysed by means of a redundancy data analysis. In addition, this is the first study to provide a checklist of benthic harpacticoids from this estuary. In total, 13 species plus six species not yet identified but known to belong to the genus Canuella, Microsetella, Ectinosoma, Mesochra, Harpacticus and Parapseudoleptomesochra were identified. Copepodites and adults of Euterpina acutifrons and Paronychocamptus nanus were most abundant in this harpacticoid community. While P. nanus dominated in winter and spring at upstream stations, E. acutifrons dominated more downstream. Although this species occurred along the whole salinity gradient, its highest abundances were found in the north arm of the estuary, except in autumn. This distribution may be due to the adaptability of E. acutifrons to different environments and the intermediate position between marine and estuarine conditions assigned to this species. Paraleptastacus cfr. spinicauda showed a relative occurrence of 5–10% in all stations, except at the mouth of the estuary (M). Tachidius discipes was found in low densities in Mondego estuary in spite of the large numbers of copepodites of this species in the southern arm, characterized by a high level of total suspended solids. The northern arm of the estuary was characterized by a higher numerical occurrence of harpacticoid organisms throughout the study years, with the higher densities towards the freshwater part (upstream areas). Canuella sp., Ectinosoma sp. (copepodite), Ectinosoma melaniceps, Leptocaris brevicornis, Phyllognathopus viguieri, Microsetella norvegica (copepodite) and Macrosetella gracilis (copepodite) were considered rare species. Nonetheless harpacticoid species were represented by a higher number of adults in the northern arm, and juveniles in the southern arm.

The nutrient regime of Bass Strait

1986 ◽  
Vol 37 (4) ◽  
pp. 451 ◽  
Author(s):  
CF Gibbs ◽  
M Tomczak Jr ◽  
AR Longmore
Keyword(s):  
Chlorophyll A ◽  
Total Phosphorus ◽  
Inorganic Phosphate ◽  
Nutrient Supply ◽  
Nutrient Concentrations ◽  
Nutrient Input ◽  
Nutrient Regime ◽  
Phosphate Silicate ◽  
East And West ◽  
Eastern Edge

Charts of temperature, salinity, nitrate plus nitrite, inorganic phosphate, silicate, ammonia, total phosphorus, and chlorophyll a are presented for Bass Strait for all seasons, based on seven cruises from August 1979 to November 1981. Temperature and salinity observations are consistent with eastward flow in winter and weak or westward flow in summer. Nutrient concentrations in Bass Strait are low (< 1 �M) throughout the year but rise to somewhat higher levels at the western edge, and to considerably higher levels (up to 7 �M) at the eastern edge, during winter. Chlorophyll a concentrations are also low (generally <0.5 �g I-1) but show highest concentrations over the shelf just inside both edges, again in winter. It is suggested that nutrient input to Bass Strait occurs from the deeper waters in the east and west, and that the nutrients are used as soon as they enter Bass Strait, leaving a very limited nutrient supply for the interior of Bass Strait.

Nutrient and gilvin levels in waters of coastal-plain wetlands in an agricultural area of Western Australia

1988 ◽  
Vol 39 (5) ◽  
pp. 685 ◽  
Author(s):  
TJ Wrigley ◽  
JM Chambers ◽  
AJ McComb
Keyword(s):  
Coastal Plain ◽  
Phytoplankton Biomass ◽  
Particulate Material ◽  
Agricultural Activity ◽  
Estuarine System ◽  
Light Penetration ◽  
Phytoplankton Blooms ◽  
Consequent Reduction ◽  
Coastal Plain Wetlands ◽  
High Concentrations

The Peel-Harvey catchment lies on a sandy coastal plain, largely cleared for agriculture, and drains into a eutrophic estuarine system. Sixty-eight wetlands in the catchment had total phosphorus concentrations of 0.4-7.8 mg I-1, the high values being atrributed to agricultural activity. Conductivity was 150-8770 �S cm-1, pH 4.1-9.3. Waters contained high concentrations of gilvin, up to 262 g440 m-1 with a mean ratio of 6.2. Particulate material contributed little to light absorption at lower wavelengths (400-450 nm) but governed absorbance at 600-700 nm. Wetlands with the largest concen- trations of gilvin were located in the grey Bassendean sands, leachates from which had gilvin levels up to 748 g440 m-1. NO phytoplankton blooms were observed, and it is suggested that high gilvin levels and the consequent reduction in light penetration are important in maintaining low phytoplankton biomass in these lakes.

APLIKASI CITRA LANDSAT 8 OLI UNTUK IDENTIFIKASI STATUS TROFIK WADUK GAJAH MUNGKUR WONOGIRI, JAWA TENGAH

2017 ◽  
Vol 19 (2) ◽  
pp. 113
Author(s):  
Kusuma Wardani Laksitaningrum ◽  
Wirastuti Widyatmanti
Keyword(s):  
Chlorophyll A ◽  
Total Phosphorus ◽  
Trophic State ◽  
Water Clarity ◽  
Coefficient Of Determination ◽  
Physical Factors ◽  
Landsat 8 ◽  
Trophic State Index ◽  
Landsat 8 Oli ◽  
State Index

<p align="center"><strong>ABSTRAK</strong></p><p class="abstrak">Waduk Gajah Mungkur (WGM) adalah bendungan buatan yang memiliki luas genangan maksimum 8800 ha, terletak di Desa Pokoh Kidul, Kecamatan Wonogiri, Kabupaten Wonogiri. Kondisi perairan WGM dipengaruhi oleh faktor klimatologis, fisik, dan aktivitas manusia yang dapat menyumbang nutrisi sehingga mempengaruhi status trofiknya. Tujuan dari penelitian ini adalah mengkaji kemampuan citra Landsat 8 OLI untuk memperoleh parameter-parameter yang digunakan untuk menilai status trofik, menentukan dan memetakan status trofik yang diperoleh dari citra Landsat 8 OLI, dan mengevaluasi hasil pemetaan dan manfaat citra penginderaan jauh untuk identifikasi status trofik WGM. Identifikasi status trofik dilakukan berdasarkan metode <em>Trophic State Index</em> (TSI) Carlson (1997) menggunakan tiga parameter yaitu kejernihan air, total fosfor, dan klorofil-a. Model yang diperoleh berdasar pada rumus empiris dari hasil uji regresi antara pengukuran di lapangan dan nilai piksel di citra Landsat 8 OLI. Model dipilih berdasarkan nilai koefisien determinasi (R<sup>2</sup>) tertinggi. Hasil penelitian merepresentasikan bahwa nilai R<sup>2</sup> kejernihan air sebesar 0,813, total fosfor sebesar 0,268, dan klorofil-a sebesar 0,584. Apabila nilai R<sup>2 </sup>mendekati 1, maka semakin baik model regresi dapat menjelaskan suatu parameter status trofik. Berdasarkan hasil kalkulasi diperoleh distribusi yang terdiri dari kelas eutrofik ringan, eutrofik sedang, dan eutrofik berat yaitu pada rentang nilai indeks 50,051 – 80,180. Distribusi terbesar adalah eutrofik sedang. Hal tersebut menunjukkan tingkat kesuburan perairan yang tinggi dan dapat membahayakan makhluk hidup lain.</p><p><strong>Kata kunci: </strong>Waduk Gajah Mungkur, citra Landsat 8 OLI, regresi, TSI, status trofik</p><p class="judulABS"><strong>ABSTRACT</strong></p><p class="Abstrakeng">Gajah Mungkur Reservoir is an artificial dam that has a maximum inundated areas of 8800 ha, located in Pokoh Kidul Village, Wonogiri Regency. The reservoir’s water conditions are affected by climatological and physical factors, as well as human activities that can contribute to nutrients that affect its trophic state. This study aimed to assess the Landsat 8 OLI capabilities to obtain parameters that are used to determine its trophic state, identifying and mapping the trophic state based on parameters derived from Landsat 8 OLI, and evaluating the results of the mapping and the benefits of remote sensing imagery for identification of its trophic state. Identification of trophic state is based on Trophic State Index (TSI) Carlson (1997), which uses three parameters there are water clarity, total phosphorus, and chlorophyll-a. The model is based on an empirical formula of regression between measurements in the field and the pixel values in Landsat 8 OLI. Model is selected on the highest value towards coefficient of determination (R<sup>2</sup>). The results represented that R<sup>2</sup> of water clarity is 0.813, total phosphorus is 0.268, and chlorophyll-a is 0.584. If R<sup>2</sup> close to 1, regression model will describe the parameters of the trophic state better. Based on the calculation the distribution consists of mild eutrophic, moderate eutrophic, and heavy eutrophic that has index values from 50.051 to 80.18. The most distribution is moderate eutrophication, and it showed the high level of trophic state and may harm other living beings.</p><p><strong><em>Keywords: </em></strong><em>Gajah Mungkur Reservoir, </em><em>L</em><em>andsat 8 OLI satellite imagery, regression, TSI, trophic state</em></p>

Nutrient Input and Trophic Status of the “Neue Donau”, a High-Water Control System along the River Danube in Vienna, Austria

1990 ◽  
Vol 22 (5) ◽  
pp. 137-144 ◽  
Author(s):  
M. T. Dokulil ◽  
G. A. Janauer
Keyword(s):  
Water Quality ◽  
Control System ◽  
Trophic Status ◽  
High Water ◽  
Nutrient Concentrations ◽  
Nutrient Input ◽  
Water Control ◽  
Trophic Conditions ◽  
River Danube ◽  
High Nutrient

The system “Neue Donau” functions as a control system for high waters of the river Danube and is an important recreational area for many people. Water quality and trophic status of the water body is thereforeof prime importance. The high nutrient concentrations of the river Danube (P-tot 238±41µg/l, N-tot 2.53±0.78 mg/l) reach the system via groundwater seepage. Present conditions in the basin of Neue Donau are,as a result of this nutrient in-flux,eutrophic to hypertrophic. Average values during the summer period have declined from 366 µg/l total phosphorus to 78 µg/l, and from 86 µg/l chlorophyll-a tol7µg/l between the years 1985 and 1988. However, a dam which is planned in the river at Vienna will permanently raise the water level of the river thus increasing the the groundwater flow in the direction to the Neue Donau and therefore the nutrient input which will enhance trophic conditions in the impoundment. Since macrophytes play an important role in one part of the system macrophyte management together with measures along the river are some of the suggested strategies to keep the system Neue Donau at acceptable trophic conditions and good water quality.

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