Macroalgal Bioindicators of Recovery from Eutrophication in a Tidal Lagoon Following Wastewater Diversion and Earthquake Disturbance

AbstractTogether, macroalgal tissue biochemical nitrogen indices (N-indices) and macroalgal abundance can be used as bioindicators of N-enrichment in estuaries. In this study, we examine the extent and rates of response of Ulva bioindicators during rapid N-enrichment perturbations in the eutrophic Avon-Heathcote Estuary (AHE) (Christchurch, New Zealand). With the diversion of the city’s wastewater discharge away from the estuary in March 2010, a ~ 90% reduction in the estuary’s N-concentration was expected. In turn, this was expected to reduce macroalgal biomass and improve the overall trophic condition of the estuary. We surveyed Ulva bioindicators over a five-year period spanning the diversion. There was a rapid (within one year) transition away from eutrophic condition reflected in N-indices (tissue-chlorophyll, -free amino acids, -N and -δ15N) following wastewater diversion, towards values corresponding with ‘cleaner’ water quality. This was accompanied by large reductions in Ulva percent cover, based on seasonal surveys conducted from 2001 to 2014. However, two large earthquakes in February and June 2011 caused a breakdown of the city’s wastewater infrastructure, resulting in overflows of untreated sewage into the estuary between February and November 2011. The re-enrichment of N and changes in N-sources (treated versus untreated sewage) were rapidly reflected in Ulva bioindicators, notably δ15N. Following repair of infrastructure, Ulva bioindicators again reverted towards a less eutrophic state. Overall, bioindicators were sensitive to changes in N-availability and N-source, and useful for identifying the position of algal populations on a eutrophic-to-oligotrophic gradient. These attributes demonstrated their utility as adjuncts to water quality monitoring and algal biomass surveys.

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Evaluation of cattle bedding and grazing BMPs in an agricultural watershed in Alberta

Water Science & Technology ◽

10.2166/wst.2011.637 ◽

2011 ◽

Vol 64 (2) ◽

pp. 326-333 ◽

Cited By ~ 7

Author(s):

Barry M. Olson ◽

Andrea R. Kalischuk ◽

Janna P. Casson ◽

Colleen A. Phelan

Keyword(s):

Water Quality ◽

Management Practices ◽

Environmental Changes ◽

Water Quality Monitoring ◽

Agricultural Watershed ◽

Direct Access ◽

Percent Cover ◽

Dissolved Phosphorus ◽

Beneficial Management Practices ◽

Bedding Site

This paper highlights the environmental impacts of implementing beneficial management practices to address cattle bedding and direct access to the creek in a study watershed in southern Alberta, Canada. Approximately 35 cow–calf pairs grazed 194 ha of grass forage and had direct access to the creek in the spring and summer. During winter, the cattle were fed adjacent to the creek at an old bedding site. The practice changes included off-stream watering, bedding site relocation and fencing for rotational grazing. The cost was $15,225 and 60 h of labour. Four years of data were used in a before-and-after experimental design to evaluate the practice changes. After two years of post-implementation monitoring, riparian assessments showed an increase in plant diversity, but no change in the percent cover of the riparian species Salix exigua and Juncus balitus and a decrease in Carex sp. (P < 0.05). Water quality monitoring showed a decrease in the difference between upstream and downstream concentrations of total phosphorus, total dissolved phosphorus, total nitrogen, organic nitrogen and Escherichia coli (P < 0.10). These results showed that improved environmental changes in riparian and water quality can be measured following the implementation of beneficial management practices for cattle bedding and grazing.

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Ten Years of Operation of Rio De Janeiro'S Ipanema Submarine Outfall

Water Science & Technology ◽

10.2166/wst.1986.0153 ◽

1986 ◽

Vol 18 (11) ◽

pp. 177-187 ◽

Cited By ~ 6

Author(s):

E. R. Britto ◽

E. P. Jordão ◽

J. Semeraro ◽

W. M. Castro

Keyword(s):

Water Quality ◽

Prestressed Concrete ◽

Video Recording ◽

Monitoring Program ◽

Water Quality Monitoring ◽

Sewer Network ◽

Flow Through ◽

One Year ◽

The City ◽

Water Uses

Monitoring and surveys of the Ipanema Submarine Outfall of the city of Rio de Janeiro have been practiced during the 10 years of the outfall operation. The outfall is a 2.4m diameter prestressed concrete pipeline, 4.3 km long, extending 3.3 km seaward to a depth of 27m. It discharges presently 6 m3/s average raw sewage flow, through a 450m long diffuser. A planned survey program was established in order to verify pipe conditions through periodical deep sea inspection, monitored by radio and video recording; this paper discusses the preventive and corrective maintenance of the outfall, especially the failures that occurred in 5 accidents. It discusses also the water quality monitoring program established one year before the outfall began its operation in 1975. A program had been prepared which established beneficial water uses, water quality standards required for protection of the uses,and a monitoring system which provides the input data for verifying compliance with the standards. Pre-discharge studies were conducted for one year prior to operation, to provide background data on the various parameters, and over 70 000 analyses were made during the 10 years of the outfall operation. This paper evaluates the results of grease, coliforms, and hydrobiological indicators, as the most representative parameters of water quality in the sea. It shows that a marked improvement has occurred in the water quality. It also shows that the beaches receive a great amount of pollution through the canals of Visconde de Albuquerque Avenue and Jardim de Alá (Rodrigo de Freitas Lagoon), due to sewage overflows from the sewer network and the storm-water networks. The importance of giving special attention to the sewer network in systems involving submarine outfalls is stressed.

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Investigative monitoring in the context of detecting anthropogenic impact on an epipotamal river

Water Science & Technology ◽

10.2166/wst.2008.134 ◽

2008 ◽

Vol 57 (7) ◽

pp. 1023-1030 ◽

Cited By ~ 2

Author(s):

S. Winkler ◽

M. Zessner ◽

E. Saracevic ◽

K. Ruzicka ◽

N. Fleischmann ◽

...

Keyword(s):

Water Quality ◽

System Analysis ◽

Water Quality Monitoring ◽

Monitoring Station ◽

Online Data ◽

Emission Data ◽

Additional Information ◽

River Stretch ◽

Data Assessment ◽

One Year

In the context of an investigative monitoring programme a monitoring system comprising of a water quality monitoring station and a camera station has been installed and operated for more than one year. The monitoring target was to investigate changes of water quality which can be related to a repeated occurrence of foam, observed at a river stretch downstream the monitoring station. The extent and frequency of foam buildup was recorded by means of the camera station. The analysis of the online data clearly showed that some of the measured parameters can be used as indicators for specific discharges, which from additional targeted investigations could be identified as contributors to the foaming problems. The continuous ammonium measurement could be used to detect nitrification problems of WWTPs discharging upstream of the monitoring station. By combining different data sources (emission data, operative and investigative monitoring data) additional information can be gained, which can be used for a comprehensive data assessment as well as a detailed system analysis.

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Assessing the occurrence of cyanotoxins in two urban reservoirs through a community science monitoring program

10.32469/10355/88087 ◽

2021 ◽

Author(s):

◽

Emily C. Kinzinger

Keyword(s):

Water Quality ◽

High School Students ◽

Monitoring Program ◽

Water Quality Monitoring ◽

Quality Parameters ◽

Cyanobacterial Blooms ◽

Environmental Drivers ◽

School Students ◽

One Year ◽

Community Science

Cyanobacterial blooms are an ongoing threat to aquatic systems worldwide. These potentially toxic blooms have typically been observed in summer to early fall, but there are increasing reports of blooms in colder seasons. From the few studies available, weknow that blooms can produce toxins in the winter. The objective of this research was to assess the year-round presence, concentration, and environmental drivers of the cyanotoxins microcystin and cylindrospermopsin in two reservoirs located in Columbia, Missouri, USA. To fulfill this objective, I coordinated and managed the Reservoir Observer Student Scientists (ROSS) program. This community science initiative combined educating high school students about limnology and cyanobacterial blooms with training students hands-on to collect weekly water quality samples. Data for this project was collected over two years in Bethel Lake and one year in Stephens Lake. We found detectable concentrations of the cyanotoxins year-round. There was no relationship between microcystin nor cylindrospermopsin and chlorophyll-a in either reservoir. Presence and concentration of microcystin and cylindrospermopsin were related to physical water quality parameters in Bethel Lake. This study provides evidence for the necessity of year-round water quality monitoring.

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