Impact of Catchment Urbanisation on Lake Macquarie (Australia)

1989 ◽  
Vol 21 (2) ◽  
pp. 205-210 ◽  
Author(s):  
B. L. Simmons ◽  
S. L. Trengove
Keyword(s):  
Nutrient Enrichment ◽  
Benthic Algae ◽  
Water Clarity ◽  
Nutrient Concentrations ◽  
Lake Area ◽  
Seagrass Beds ◽  
Coastal Lake ◽  
Aesthetic Quality ◽  
Wastewater Disposal ◽  
Coastal Lakes

Increasing urbanisation of coastal areas is leading to impacts on coastal lakes which decrease their amenity for recreation and tourism. Runoff and wastewater discharge cause siltation, impact seagrass beds and change the characteristics of open waters, affecting boating, swimming, fishing and the aesthetic quality of the locale. Management of urban development and wastewater disposal is required to minimise sedimentation and nutrient enrichment. This could include development restrictions, runoff controls and a strategy for wastewater treatment and discharge. The catchment of Lake Macquarie, a marine coastal lake, has been progressively urbanised since 1945. Urbanisation, through increased stormwater runoff and point source discharges, has caused a major impact on the lake in terms of sedimentation and nutrient enrichment. Losses of lake area and navigable waters have occurred. Accompanying problems include changes in the distribution of seagrass beds and nuisance growths of benthic algae. Since the 1950's, dry weather nutrient concentrations have increased and mean water clarity has decreased. Severe problems, as observed in other New South Wales coastal lakes, for example benthic algae in Lake Illawarra and Tuggerah Lakes, have not yet developed. Because of the lead time taken to implement policies and controls, trends should be identified and policies developed now so as to avoid nutrient buildup and development of sustained problems.

scholarly journals Mapping of Major Land-Use Changes in the Kolleru Lake Freshwater Ecosystem by Using Landsat Satellite Images in Google Earth Engine

Water ◽  
2020 ◽  
Vol 12 (9) ◽  
pp. 2493 ◽  
Author(s):  
Meena Kumari Kolli ◽  
Christian Opp ◽  
Daniel Karthe ◽  
Michael Groll
Keyword(s):  
Land Use ◽  
Land Cover ◽  
Land Use Changes ◽  
Google Earth ◽  
Nutrient Concentrations ◽  
Freshwater Ecosystem ◽  
Lake Ecosystem ◽  
Lake Basin ◽  
Lake Area ◽  
Google Earth Engine

India’s largest freshwater ecosystem of the Kolleru Lake has experienced severe threats by land-use changes, including the construction of illegal fishponds around the lake area over the past five decades. Despite efforts to protect and restore the lake and its riparian zones, environmental pressures have increased over time. The present study provides a synthesis of human activities through major land-use changes around Kolleru Lake both before and after restoration measures. For this purpose, archives of all Landsat imageries from the last three decades were used to detect land cover changes. Using the Google Earth Engine cloud platform, three different land-use scenarios were classified for the year before restoration (1999), for 2008 immediately after the restoration, and for 2018, i.e., the current situation of the lake one decade afterward. Additionally, the NDVI (Normalized Difference Vegetation Index) and NDWI (Normalized Difference Water Index) indices were used to identify land cover dynamics. The results show that the restoration was successful; consequently, after a decade, the lake was transformed into the previous state of restoration (i.e., 1999 situation). In 1999, 29.7% of the Kolleru Lake ecosystem was occupied by fishponds, and, after a decade of sustainable restoration, 27.7% of the area was fishponds, almost reaching the extent of the 1999 situation. On the one hand, aquaculture is one of the most promising sources of income, but there is also limited awareness of its negative environmental impacts among local residents. On the other hand, political commitment to protect the lake is weak, and integrated approaches considering all stakeholders are lacking. Nevertheless, alterations of land and water use, increasing nutrient concentrations, and sediment inputs from the lake basin have reached a level at which they threaten the biodiversity and functionality of India’s largest wetland ecosystem to the degree that immediate action is necessary to prevent irreversible degradation.

Impacts of golf course construction and operation on headwater streams: bioassessment using benthic algae

2003 ◽  
Vol 81 (8) ◽  
pp. 848-858 ◽  
Author(s):  
Jennifer G Winter ◽  
Peter J Dillon ◽  
Carolyn Paterson ◽  
Ron A Reid ◽  
Keith M Somers
Keyword(s):  
Nutrient Enrichment ◽  
Headwater Streams ◽  
Benthic Algae ◽  
Golf Course ◽  
Golf Courses ◽  
Algal Communities ◽  
Precambrian Shield ◽  
Filamentous Green Algae ◽  
Algal Groups ◽  
Under Construction

The influence of golf course operation and construction on benthic algal communities in headwater streams on the Precambrian Shield was investigated using a reference condition approach. Streams were sampled for water chemistry and epilithic benthic algae on operational golf courses, on courses under construction, and from nearby minimally impacted reference locations. Epilithic diatom community structure was different in reference streams than in operational golf course streams, the latter indicating nutrient enrichment, higher pH, and disturbance. Full counts of diatoms and soft algae revealed that there was a lower proportion of diatoms relative to other algal groups, cyanobacteria in particular, in operational golf course streams compared with samples from reference locations. Dominance by a single taxon was also significantly higher in operational golf course streams. Although differences relative to the reference streams were less marked for the streams on courses under construction, full counts of diatoms and soft algae provided evidence of disturbance and nutrient enrichment. In particular, high proportions of filamentous green algae were recorded. Overall, our results indicate that golf course land management on the Shield is associated with significant differences in the abundance of certain benthic algal taxa in headwater streams.Key words: diatoms, periphyton, biomonitoring, golf courses, canonical correspondence analysis (CCA), Precambrian Shield.

Species richness of both native and invasive aquatic plants influenced by environmental conditions and human activity

Botany ◽  
2009 ◽  
Vol 87 (3) ◽  
pp. 306-314 ◽  
Author(s):  
Robert S. Capers ◽  
Roslyn Selsky ◽  
Gregory J. Bugbee ◽  
Jason C. White
Keyword(s):  
Invasive Species ◽  
Species Richness ◽  
Human Activity ◽  
Environmental Conditions ◽  
Native Plants ◽  
Water Clarity ◽  
Phosphorus Concentration ◽  
Lake Area ◽  
Species Dominance ◽  
High Productivity

Invasive plants alter community structure, threatening ecosystem function and biodiversity, but little information is available on whether invasive species richness responds to environmental conditions in the same way that richness of native plants does. We surveyed submerged and floating-leaved plants in 99 Connecticut (northeast USA) lakes and ponds, collecting quantitative data on abundance and frequency. We used multiple linear and logistic regression to determine which environmental conditions were correlated with species richness of invasive and native plants. Independent variables included lake area, maximum depth, pH, alkalinity, conductivity, phosphorus concentration, productivity, and dominance (the proportional abundance of the most abundant and frequently found species), plus two estimates of human activity. Species richness of both native and invasive richness was correlated with alkalinity and human activity. Native richness also increased with water clarity, lake area, and productivity; invasive species richness also rose with pH. We found no evidence that richness of one group affected richness of the other. We also investigated patterns of dominance and found that native plants were as likely to become dominant as invasive species. Dominance occurred overwhelmingly in shallow lakes with high productivity.

Managed nutrient reduction impacts on nutrient concentrations, water clarity, primary production, and hypoxia in a north temperate estuary

2017 ◽  
Vol 199 ◽  
pp. 25-34 ◽  
Author(s):  
Candace Oviatt ◽  
Leslie Smith ◽  
Jason Krumholz ◽  
Catherine Coupland ◽  
Heather Stoffel ◽  
...  
Keyword(s):  
Primary Production ◽  
Water Clarity ◽  
Nutrient Concentrations ◽  
Nutrient Reduction ◽  
Temperate Estuary

Volatile selenium fluxes from selenium-contaminated sediments in an Australian coastal lake

2016 ◽  
Vol 13 (1) ◽  
pp. 68 ◽  
Author(s):  
Michael J. Ellwood ◽  
Larissa Schneider ◽  
Jaimie Potts ◽  
Graeme E. Batley ◽  
John Floyd ◽  
...  
Keyword(s):  
Significant Loss ◽  
Lake Area ◽  
Early Winter ◽  
Coastal Lake ◽  
Late Autumn ◽  
Power Stations ◽  
Natural Remediation ◽  
Cryogenic Trapping ◽  
Dissolved Selenium ◽  
Remediation Process

Environmental context Methylation of sedimentary selenium to volatile dimethylselenide is a natural remediation process for contaminated aquatic systems. We present flux estimates for the loss of dimethylselenide from sediments of an anthropogenically affected lake and observe a 6-fold difference between late autumn–early winter and summer. The loss of dimethylselenide represents a significant sediment loss vector, of the same order as the diffusive loss flux for inorganic selenium across the sediment–water interface. Abstract Overflows from ash dams associated with the operation of coal-fired power stations in Lake Macquarie, NSW, Australia, have been a historical source of selenium to the lake. Although dissolved selenium concentrations have been marginally elevated, sediments are the major sink. Methylation of sedimentary selenium to volatile dimethylselenide (DMSe) is known to be a natural remediation process. Sediments from north of Wyee Bay and the Vales Point Power Station were the subject of field sampling and monitoring to determine the extent to which selenium is being lost to the atmosphere as DMSe. Flux estimates were obtained by trapping volatile selenium species using benthic domes, followed by analysis in the field using a fully automated cryogenic trapping system with atomic fluorescence detection. The detection limit of the system was 0.1ngL–1 for DMSe and 1ngL–1 for dimethyl diselenide (DMDSe). Measurements in both summer and late autumn–early winter showed a distinct seasonal difference, with a higher summer DMSe flux of 53±25ng Se m–2h–1 (±s.d.) compared with 8±5ng Se m–2h–1 in late autumn–early winter. No DMDSe was detected. These fluxes are similar to those measured in Europe and North America, and represent an annual loss of 1.3kg of selenium per year from the nearby lake area. Lake-wide this would represent a significant loss to the atmosphere.

Waterbirds and nutrient enrichment in Mar Menor Lagoon, a shallow coastal lake in southeast Spain

2008 ◽  
Vol 13 (1) ◽  
pp. 37-49 ◽  
Author(s):  
Francisco Robledano Aymerich ◽  
Iluminada Pagán Abellán ◽  
José Francisco Calvo Sendín
Keyword(s):  
Nutrient Enrichment ◽  
Coastal Lake ◽  
Mar Menor ◽  
Mar Menor Lagoon ◽  
Southeast Spain

scholarly journals Hubungan Nutrien Pada Sedimen dan Penutupan Lamun Di Perairan Jepara

2019 ◽  
Vol 22 (1) ◽  
pp. 42
Author(s):  
Sarah Nabilla ◽  
Retno Hartati ◽  
Ria Azizah Tri Nuraini
Keyword(s):  
Nutrient Content ◽  
Limiting Factors ◽  
Nutrient Concentrations ◽  
Seagrass Beds ◽  
Strong Positive Relationship ◽  
Seagrass Cover ◽  
Phosphate Analysis ◽  
The Difference ◽  
The Relationship ◽  
Rule Out

The availability of nutrients in seagrass beds can act as growth limiting factors. Absorption of nutrients in the water column is carried out by the leaves while the absorption of nutrients from the sediment is carried out by the roots but does not rule out the transport of nutrients by the roots will also arrive at the leaves of the seagrass. If the nutrient requirement is not met properly, then the growth will be disrupted. Like the difference in distribution and density of seagrass itself. Nutrient concentrations in waters vary. Nitrate and phosphate levels in the waters are strongly influenced by sources of organic material from outside/land (allochthonous) or from the water itself (autocthonous). This research was conducted with the aim of nothing: to determine the relationship between nutrient content (nitrate and phosphate) in sediment to seagrass cover in Teluk Awur and Pantai Blebak, JeparaData collection of seagrass and sediment was carried out on March 2018 in the waters of Teluk Awur and Blebak Beach, Kabupaten Jepara. Type identification, density, and coverage are carried out at the research location. Nitrate and phosphate analysis in sediments is carried out in Laboratorium Pengujian dan Peralatan. Based on the results of research that has been carried out, it can be concluded that there is a very strong positive relationship between nutrients and seagrass closure in the two research locations, each of which is 0.955 (91.1%) in Teluk Awur waters and 0.962 (92.6%) in Blebak Beach.Ketersediaan nutrien di perairan padang lamun dapat berperan sebagai faktor pembatas pertumbuhan. Penyerapan nutrien pada lamun pada kolom air dilakukan oleh daun sedangkan penyerapan nutrien dari sedimen dilakukan oleh akar namun tidak menutup kemungkinan pengangkutan nutrien oleh akar juga akan sampai pada bagian daun. Jika kebutuhan nutrien tidak terpenuhi dengan baik, maka pertumbuhannya mengalami gangguan. Seperti perbedaan sebaran dan kepadatan lamun itu sendiri. Konsentrasi nutrien di perairan bervariasi. Kadar nitrat dan fosfat di perairan sangat dipengaruhi oleh sumber bahan organik yang berasal dari luar/ daratan (allochthonous) maupun dari dalam perairan itu sendiri (autocthonous). Penelitian ini dilakukan dengan tujuan: untuk mengetahui hubungan antara kandungan nutrien (nitrat dan fosfat) pada sedimen terhadap tutupan lamun di Teluk Awur dan Pantai Blebak, Jepara. Identifikasi jenis, kepadatan dan penutupan dilakukan pada lokasi penelitian. Analisa nitrat dan fosfat dalam sedimen dilakukan di Laboratorium Pengujian dan Peralatan. Berdasarkan hasil penelitian yang telah dilakukan dapat di ambil kesimpulan bahwa terdapat hubungan sangat kuat positif antara nutrien dengan penutupan lamun pada dua lokasi penelitian, nilainya masing-masing sebesar 0,955 (91,1%) di Perairan Teluk Awur dan 0,962 (92,6%) di Pantai Blebak.

scholarly journals Nutrient enrichment induced by tropical cyclone Seroja in the southeastern tropical Indian Ocean

2021 ◽  
Vol 925 (1) ◽  
pp. 012021
Author(s):  
D W Purnaningtyas ◽  
F Khadami ◽  
Avrionesti
Keyword(s):  
Tropical Cyclone ◽  
Indian Ocean ◽  
Surface Temperature ◽  
Sea Surface Temperature ◽  
Nutrient Enrichment ◽  
Tropical Indian Ocean ◽  
Sea Surface ◽  
Nutrient Concentrations ◽  
Biochemical Alterations ◽  
Southeastern Tropical Indian Ocean

Abstract Tropical cyclone (TC) passage triggers a complex response from the adjacent ocean, including vertical mixing, leading to biochemical alterations and affecting the surrounding ecosystem’s dynamics. In previous studies, increased nutrient concentrations and primary production were observed along the cyclone track after the storm. TC Seroja was awakened near the equator in the southeastern tropical Indian Ocean, making it interesting to investigate how the ambient ecosystem responds. Hence, we analyzed the sea surface temperature and nutrient changes during the Seroja event using multi-satellite remote sensing and numerical model data in the south of Indonesia and East Timor along the Seroja track between April 2 and 10, 2021. Immediately after the TC Seroja passed, the sea surface temperature cooled to 3 °C around the TC lane. At the same time, the spatial distribution patterns showed the upsurge of some nutrients in response to the passage of TC Seroja; the surface nitrate swells up to 1.5 mmol/m3, while phosphate increased up to 0.2 mmol/m3, and the dissolved silicate concentration enhanced up to 1.0 mmol/m3. The responses recover within 2-7 days. These results indicate that tropical cyclones contribute to nutrient enrichment in oligotrophic areas outside of their usual annual upwelling time, thereby further supporting ecosystem sustainability.

Influence of benthic diatoms on the nutrient release from sediments of shallow lakes recovering from eutrophication

1995 ◽  
Vol 32 (4) ◽  
pp. 89-97 ◽  
Author(s):  
F. Van Luijn ◽  
D. T. Van der Molen ◽  
W. J. Luttmer ◽  
P. C. M. Boers
Keyword(s):  
Laboratory Experiments ◽  
Light Availability ◽  
Water System ◽  
Nutrient Release ◽  
Benthic Algae ◽  
Benthic Diatoms ◽  
Direct Result ◽  
Nutrient Concentrations ◽  
Overlying Water ◽  
Stimulation Of

Measures taken to combat eutrophication resulted in a decrease in phytoplankton chlorophyll and an increase in transparency in the lakes studied. Because of the low nutrient concentrations in the overlying water, the increased light availability and the relatively nutrient rich sediments, a benthic algae community developed. In this study the interactions between the benthic algae and the nutrient release from the sediments is examined. In laboratory experiments it is demonstrated that benthic diatoms are able to grow on nutrients released from the sediments. The direct result is a decrease of the nutrient flux from the sediments by uptake by benthic diatoms. An indirect effect is an increased loss of nitrogen from the sediment water system to the atmosphere by stimulation of the coupled nitrification-denitrification. This is caused by an increased O2 penetration depth due to the photosynthesis of benthic diatoms. Based upon these laboratory results and additional calculations, it is concluded that the benthic diatoms in the field are able to reduce the nutrient release from the sediments and thus the availability for the phytoplankton. The benthic diatoms therefore may accelerate the process of recovery from eutrophication.

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