Eutrophication study of Lake Daylesford, Victoria

1980 ◽  
Vol 31 (5) ◽  
pp. 573 ◽  
Author(s):  
JL Bales ◽  
GK Curtin ◽  
IC Campbell ◽  
BT Hart
Keyword(s):  
Water Column ◽  
Chlorophyll A ◽  
Total Phosphorus ◽  
Algal Blooms ◽  
Algal Species ◽  
Early Spring ◽  
Algal Community ◽  
Phosphorus Loading ◽  
Phytoplankton Production ◽  
Early Autumn

The occurrence of algal blooms in Lake Daylesford (area 11.6 ha; maximum depth 9 m) each summer in recent years was investigated. Surface water temperature of the lake varied from 7 to 25�C. The lake which is fed by Wombat Creek, a small permanent stream, was cheimomictic with stratification occurring between summer and early autumn. In most years classical 'turnover' would be unlikely; rather, epilimnetic water would be flushed from the lake by inflowing creek waters approximately 12 times per year. Surface waters were always well oxygenated but the hypolimnion was anoxic between December 1976 and March 1977. Transparency was greatest in winter and early spring and least in summer and early autumn, this reduction being caused by autochthonously produced algal matter and allochthonously derived suspended material. Incommon withmany other Australian lakes, Lake Daylesford had ashallow euphoticzone 1-2 m deep that would limit phytoplankton production. In March and June 1977, over 99% of the incident visible light was absorbed in the top 1 m of the water column. The lake was classified as eutrophic on the basis of chlorophyll a levels. productivity, total phosphorus loadings and algal species. Chlorophyll a levels ranged from < 1 �g 1-1 in June 1977 to 79 �g 1-1 in February 1977; the productivity maximum was 210 mg C m-3 day-1 (560 mg O2, m-3 day-1) in March 1977 and the estimated total phosphorus loading was 2.8 g P m-2 year-1. The algal community was dominated by three genera: the blue-green alga Anabaena, the euglenoid Trachelomonas and the diatom Asterionella. Evidence suggests that reduction of the phosphorus loading to the lake will do much to eliminate the annual algal blooms. Provision of sewerage facilities for the township of Daylesford may achieve the required reduction. The lake sediments contain elevated levels of phosphorus, mainly a result of past discharges of waste material from a potato-processing factory; the contribution of this sediment phosphorus to the water column is unknown but should be investigated.

Evidence that increased nitrogen efflux from wave-influenced marine sediment enhances pelagic phytoplankton production on the inner continental shelf of Western Australia

2010 ◽  
Vol 61 (5) ◽  
pp. 625 ◽  
Author(s):  
Jim Greenwood
Keyword(s):  
Continental Shelf ◽  
Surface Waves ◽  
Water Column ◽  
Chlorophyll A ◽  
Wave Height ◽  
Western Australia ◽  
Regional Scale ◽  
Reaction Rates ◽  
Phytoplankton Production ◽  
Biogeochemical Model

Increased biological and chemical reaction rates within permeable continental-shelf sediment can result from the action of passing surface waves, especially when the seabed is rippled. The effect of this on the exchange of nitrogen between the sediment and water column is the focus of the present paper. The continental shelf of Western Australia is used as an example. A time series of chlorophyll a is compared with surface-wave height revealing seasonal and sub-seasonal correlation between the two variables. At the same time, results from a coupled pelagic–benthic biogeochemical model show that temperature-controlled changes in sedimentary nitrogen efflux cannot account for the observed seasonal changes in chlorophyll a in the overlying water column. It is proposed that enhanced pore-water circulation within the sediment, caused by the action of passing surface waves, results in an increase in the efflux of nitrogen from the sediment during winter, supporting higher pelagic phytoplankton production. The parameterisation of sedimentary nitrogen mineralisation as a function of the square of wave height is suggested for the inclusion of this effect in regional-scale continental shelf models.

The influence of physical stability on spring, summer and autumn phytoplankton blooms in the Celtic Sea

1976 ◽  
Vol 56 (4) ◽  
pp. 845-873 ◽  
Author(s):  
R. D. Pingree ◽  
P. M. Holligan ◽  
G. T. Mardell ◽  
R. N. Head
Keyword(s):  
Water Column ◽  
Chlorophyll A ◽  
Physical Stability ◽  
Temporal Variations ◽  
Inorganic Nutrients ◽  
Tidal Mixing ◽  
Phytoplankton Production ◽  
North West ◽  
Water Column Stability ◽  
Celtic Sea

The Celtic Sea extends from the south of Ireland and the St Georges Channel across the continental shelf, with the Bristol and English Channels as its eastern limits (Fig. 1) (Cooper, 1967). Although various investigations of the physical oceanography (Matthews, 1914; Cooper, 1967) and zooplankton (Russell, 1934, a, b, 1936; Corbin, 1947; and more recently Southward, 1962; Bary, 1963) of this area have been carried out, there is little or no information on seasonal changes in levels of chlorophyll ‘a’ and inorganic nutrients, and on the importance of tidal mixing in determining these distributions. Since the speeds of the tidal streams range from weak (∼ 0.5 knot) in the northern part of the Celtic Sea to strong (∼ 3 knots) around the Scilly Isles and Ushant (Fig. 2), the vertical stability of the water column as well as the duration of the seasonal thermocline (Pingree, 1975) are likely to be important factors in determining spatial and temporal variations of phytoplankton production. In this paper the influence of water-column stability on phytoplankton distributions (in spring, summer and autumn) in the Celtic Sea is described, using data for temperature, salinity, chlorophyll ‘a’ and inorganic nutrients obtained during seven cruises in 1975. An account of the red tide conditions that occurred in late July to the north-west of Ushant has already been published (Pingree, Pugh, HoUigan & Forster, 1975).

Nearshore–offshore comparison of chlorophyll a and phytoplankton production in the dreissenid-colonized eastern basin of Lake Erie

2006 ◽  
Vol 63 (5) ◽  
pp. 1115-1129 ◽  
Author(s):  
David C Depew ◽  
Stephanie J Guildford ◽  
Ralph E.H Smith
Keyword(s):  
Primary Production ◽  
Chlorophyll A ◽  
Total Phosphorus ◽  
Lake Erie ◽  
Light Attenuation ◽  
Phytoplankton Production ◽  
Light Climate ◽  
Production Rates ◽  
Chl A ◽  
Underwater Light Climate

Planktonic primary production, chlorophyll a (chl a), underwater light climate, and total phosphorus were measured at 18 stations during 2001 and 2002 in eastern Lake Erie to characterize spatial and seasonal patterns in this system colonized by dreissenid mussels (Dreissena spp.). Areal production rates and chl a displayed a seasonal pattern typical of the Laurentian Great Lakes, with highest production in the early and late summer. Daily and seasonal (May–October) primary production was significantly lower nearshore than offshore. Although light attenuation was similar between nearshore and offshore, the nearshore light climate was generally more favorable for phytoplankton because of shallower mixing depths. However, chl a was significantly lower nearshore, which accounted for most of the depression in production rates. Nearshore chl a was lower than predicted from relationships with total phosphorus in comparable dreissenid-free systems. Offshore, subepilimnetic communities contributed up to 67% of daily production but only up to 19% of seasonal production. The depression of chl a and primary production in the nearshore was a reversal from historic patterns in eastern Lake Erie and from the pattern traditionally expected in large lakes. Decreased external nutrient loading and dreissenid colonization may both have contributed to this new spatial pattern, but dreissenids appear to be key agents.

Impact of zebra mussel (Dreissena polymorpha) on phosphorus cycling and chlorophyll in lakes

1995 ◽  
Vol 52 (12) ◽  
pp. 2553-2573 ◽  
Author(s):  
Eric Mellina ◽  
Joseph B. Rasmussen ◽  
Edward L. Mills
Keyword(s):  
Water Column ◽  
Chlorophyll A ◽  
Zebra Mussel ◽  
Dreissena Polymorpha ◽  
Size Structure ◽  
Algal Cell ◽  
Algal Community ◽  
Community Size ◽  
Western Basin ◽  
Excretion Rates

We determined the effects of zebra mussel (Dreissena polymorpha) on water column phosphorus (P) and chlorophyll a levels and algal community size structure as well as rates of P excretion in laboratory experiments. Zebra mussel at a threshold density of 0.25/L were able to decouple the nutrient–chlorophyll relationship, to induce erratic patterns in P and chlorophyll a trends, and to decrease mean algal cell sizes. Using shell length we explained 75 and 71% of the variability in P excretion rates in trials held at 17 and 22 °C. Using mass balance modeling, we examined the effects of zebra mussel growth and mortality on mean annual steady-state P levels as functions of hydraulic flushing and P loadings for the western basin of Lake Erie, for Lake St. Clair, and for Oneida Lake. Zebra mussel affected water column P levels only when the annual P accumulated into mussel biomass represented >20% of the lake's annual P loading. The mussel populations in all three lakes did not substantially affect water column P levels but decoupling of the nutrient–chlorophyll relationship was observed in lakes Erie and St. Clair. No evidence was found for increased decoupling of this relationship with increasing zebra mussel density in European lakes.

Comparison of an Ecological Model of Lake Ontario and Phosphorus Loading Models

1977 ◽  
Vol 34 (2) ◽  
pp. 286-290 ◽  
Author(s):  
Donald Scavia ◽  
Steven C. Chapra
Keyword(s):  
Chlorophyll A ◽  
Total Phosphorus ◽  
Ecological Model ◽  
Lake Ontario ◽  
Phosphorus Loading ◽  
Empirical Relationships ◽  
Annual Average ◽  
Phosphorus Loads

Predicted responses of Lake Ontario to phosphorus loads from two empirical relationships and an ecological model were compared. Predictions of annual average concentrations of total phosphorus and chlorophyll a by the ecological model were consistent with those predicted by the simpler models. We concluded that the use of a particular type of model is governed by the nature of the problems being addressed rather than an inherent superiority of either approach.

Patterns in Algal Recruitment from Sediment to Water in a Dimictic, Eutrophic Lake

1994 ◽  
Vol 51 (12) ◽  
pp. 2825-2833 ◽  
Author(s):  
Lars-Anders Hansson ◽  
Lars G. Rudstam ◽  
Timothy B. Johnson ◽  
Patricia Soranno ◽  
Yvonne Allen
Keyword(s):  
Water Column ◽  
Algal Blooms ◽  
Standing Stock ◽  
Algal Species ◽  
Euphotic Zone ◽  
Eutrophic Lake ◽  
Sediment Surface ◽  
Lake Mendota ◽  
Ceratium Hirundinella ◽  
Key Factor

In the large, dimictic, and highly productive Lake Mendota (Wisconsin, USA), the recruitment rates from sediment to water were determined for some characteristic and dominating algal species during a 1-yr cycle. Quantifying recruitment in relation to abundance in the water on a whole-lake basis revealed that recruitment usually accounted for less than 1% of the total standing stock of each species per day, indicating that recruitment may not be an important population variable in Lake Mendota, but may instead function as an inoculum for future growth in the water column. The recruitment of Cryptomonas erosa and Ceratium hirundinella showed a dephasing among sites, suggesting that algae on the sediment surface rise into the water column in response to some depth-related cue. With the exception of one recruitment period for Aphanizomenon, no recruitment was recorded below the thermocline during the stratification period, indicating that a variable associated with stratified conditions affected algal movements from the hypolimnion to the euphotic zone. We argue that the understanding of recruitment patterns from sediment to water is a key factor in managing algal blooms in highly productive lakes.

scholarly journals Isotope stratification of meromictic Lake Trekhtzvetnoe at the White Sea coast (Russia)

2018 ◽  
Vol 54 ◽  
pp. 23
Author(s):  
Yurij K. Vasil’chuk ◽  
Natalia L. Frolova ◽  
Nikolay S. Kasimov ◽  
Frank Winde ◽  
Nadine A. Budantseva ◽  
...  
Keyword(s):  
Dissolved Oxygen ◽  
Water Column ◽  
White Sea ◽  
Major Ions ◽  
Isotope Composition ◽  
Bottom Layer ◽  
Quality Parameters ◽  
Early Spring ◽  
Water Composition ◽  
Early Autumn

Postglacial isostatic uplift of the coastal zone resulted in the formation of isolated lakes along the shores of White Sea developed into permanently stratified (meromictic) lakes. On the basis of monitoring the vertical distribution of selected water quality parameters including temperature, salinity, concentration of major ions, microbial activity, dissolved oxygen and hydrogen sulfide, seasonal changes in the structure of the stratified water column are explored and governing factors identified. Lake Trekhtzvetnoe has a strong vertical stratification with seasonal mixing being confined to the upper part of the water column (mixolimnion). Сhemical water composition in the mixolimnion reflects the influence of precipitation with the underlying chemocline being defined by sharp gradients of salinity, dissolved oxygen and hydrogen sulphide levels. We found strong stable isotope stratification of water column in winter-early spring seasons of 2013, 2015 and 2016 and in the early autumn of 2015. The lowest isotope values were obtained near the surface in the mixolimnion. There was a gradual increase of isotope values towards the chemocline reaching the maximum in the bottom layer (monimolimnion). It was found that water in the mixolimnion was isotopically depleted in winter as a result of ice formation and isotopically enriched in the early autumn due to evaporation. Obvious desalination of mixolimnion and upper chemocline from 2012 to 2016 was possibly caused by the increase of precipitation and freshwater inflow in lake supply. Monimolimnion is a stable layer of high salinity, and it has enriched isotope composition that corresponds with meromictic structure of water column.

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>

The Use of Sodium Carbonate Peroxyhydrate to Treat Off-Flavor in Commercial Catfish Ponds

1992 ◽  
Vol 25 (2) ◽  
pp. 315-321 ◽  
Author(s):  
J. F. Martin
Keyword(s):  
Water Column ◽  
Sodium Carbonate ◽  
Algal Species ◽  
The Other ◽  
Average Depth ◽  
Oscillatoria Chalybea ◽  
Catfish Ponds ◽  
Pond Ecology ◽  
Sodium Carbonate Peroxyhydrate

Sodium carbonate peroxyhydrate (SCP) was applied to seven commercial catfish ponds in Mississippi to study the effects of treatment on fish flavor and pond ecology. The seven ponds were treated on alternate days in the morning with two doses of SCP at 55 kg hectare−1 (average depth 1-1.6 m). In three of the ponds, a potent 2-methylisoborneol (MIB) producing planktonic Oscillatoria chalybea-like species that was initially present was absent from the water column after treatment. In addition, the fish from two of these ponds were judged on-flavor 7 to 10 days after treatment. The off-flavor chemicals in three other ponds were diminished when measured seven days after treatment and fish were harvested from two of these ponds 10-14 days after treatment. The fish from the other two ponds were harvested 21 days after treatment. In the sixth pond, the predominant algal species was a 2-methylisoborneol producing O. chalybea-like species at 380 cells ml−1 and the treatment was ineffective. The treatment was most successful when off-flavor was less than two months duration and where application of the chemical was accomplished uniformly over the entire pond surface.

scholarly journals Effect of red algal bloom on growth and production of carps

Our Nature ◽  
2018 ◽  
Vol 16 (1) ◽  
pp. 48-54
Author(s):  
Ram Bhajan Mandal ◽  
Sunila Rai ◽  
Madhav Kumar Shrestha ◽  
Dilip Kumar Jha ◽  
Narayan Prasad Pandit
Keyword(s):  
Water Quality ◽  
Body Weight ◽  
Chlorophyll A ◽  
Total Nitrogen ◽  
Total Phosphorus ◽  
Algal Bloom ◽  
Total Dissolved Solids ◽  
Dissolved Solids ◽  
Aquaculture Farm ◽  
Red Algal

An experiment was carried to assess the effect of red algal bloom on growth and production of carp, water quality and profit from carp for 120 days at Aquaculture Farm of Agriculture and Forestry University, Chitwan. The experiment included two treatments: carp polyculture in non-red pond and carp polyculture in red pond with algal bloom each with three replicates. Carp fingerlings were stocked at 1 fish/m2 and fed with pellet containing 24% CP at 3% body weight. Net yield of rohu was found significantly higher (p<0.05) in non-red ponds (0.38±0.01 t ha-1) than red ponds (0.24±0.05 t ha-1). Survival of rohu (84.9±1.4%), bighead (95.2±2.0%) and mrigal (88.1±14.4%) were also significantly higher (p<0.05) in non-red ponds than red ponds. Red algal bloom affected DO, nitrate and chlorophyll-a, nitrite, total nitrogen, total phosphorus, total dissolved solids and conductivity. However, overall carp production and profit from carp remained unaffected.

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