The LOIS river monitoring network: strategy and implementation

Ann. Limnol. - Int. J. Lim.

2011

-Although the data on phosphate obtained in surveys are used to assess the distribution of river biota, the approach is flawed when the organisms use P fractions not included in routine analysis. This is especially important where aquatic phototrophs are partially or largely dependent on aqueous organic phosphate. This paper reports a study where the data are sufficient to assess the quantitative importance of organic phosphate in rivers in eastern UK. Filterable hydrolyzable phosphate-P (FHP) is used as a surrogate for organic phosphate, although FHP sometimes includes other P forms. Eighteen sites were sampled weekly for at least one, but mostly three years (2033 samples). The data are compared for mid-and lower-reach sites. FHP formed at least 20% TFP (total filterable phosphate-P) at 14 sites, with the percentage values higher at the more upstream and more northern sites. FHP exceeded 1000 mg.L x1 P in 32 mid-and 53 lower-reach records. The lower the TFP concentration, the higher the % FHP at both types of site. Five sites had over 25% of their records where FHP is likely to be especially important for growth of algae and bryophytes, based on FHP being > 50 mg.L x1 P when TFP j 200 mg.L x1 P. These include the upper site on River Swale, and other literature for this river indicates that FHP becomes increasingly important further upstream and even more so in tributary streams. FHP should be included in monitoring programmes for upland rivers, especially where the catchment includes peat-rich soils.

Section: Monitoring Programmementioning

confidence: 99%

“…This formed part of the Land-Ocean Interaction Study (LOIS), which relates to eastern UK Rivers entering the North Sea (Leeks et al, 1997). It did not include upland streams, but did include data for the middle stretches of rivers draining peaty catchments.…”

Section: Introductionmentioning

confidence: 99%

Organic phosphate in UK rivers and its relevance to algal and bryophyte surveys

Whitton

Ann. Limnol. - Int. J. Lim.

2011

“…Surface grab-sampling methods are commonly employed for stream water sampling, owing to speed and efficiency of sample collection. Good grab-sampling practice necessitates that samples are collected from mid-stream, away from the more quiescent margins of the river (Leeks et al, 1997). However, surface-grab sampling may result in profound underestimation of concentrations of sedimentassociated water-quality determinands, compared with more time-consuming methods of cross-sectionally integrated sampling (e.g.…”

Section: Sampling : Collecting a Representative Samplementioning

confidence: 99%

“…It is, therefore, difficult to design a single standardised storage protocol for natural waters due to the contrasting physico-chemical and biological characteristics of water samples (Lambert et al, 1992;Haygarth et al, 1995;Maher and Woo, 1998;Gardolinski et al, 2001). Indeed, within one major research programme, the Land Ocean Interaction Study (LOIS), the standard protocol used for was for SRP to be determined as soon as possible after sampling and certainly on the day of sampling (Leeks et al, 1997); this is standard procedure within organisations such as the UK Centre for Ecology and Hydrology.…”

Section: Storage Of Samples Prior To P Analysismentioning

confidence: 99%

Review of robust measurement of phosphorus in river water: sampling, storage, fractionation and sensitivity

Jarvie

Withers

Hydrol. Earth Syst. Sci.

2002

Self Cite

181

164

This paper reviews current knowledge on sampling, storage and analysis of phosphorus (P) in river waters. Potential sensitivity of rivers with different physical, chemical and biological characteristics (trophic status, turbidity, flow regime, matrix chemistry) is examined in terms of errors associated with sampling, sample preparation, storage, contamination, interference and analytical errors. Key issues identified include:The need to tailor analytical reagents and concentrations to take into account the characteristics of the sample matrix. The effects of matrix interference on the colorimetric analysis. The influence of variable rates of phospho-molybdenum blue colour formation. The differing responses of river waters to physical and chemical conditions of storage. The higher sensitivities of samples with low P concentrations to storage and analytical errors.Given high variability of river water characteristics in space and time, no single standardised methodology for sampling, storage and analysis of P in rivers can be offered. 'Good Practice' guidelines are suggested, which recommend that protocols for sampling, storage and analysis of river water for P is based on thorough site-specific method testing and assessment of P stability on storage. For wider sampling programmes at the regional/national scale where intensive site-specific method and stability testing are not feasible, 'Precautionary Practice' guidelines are suggested. The study highlights key areas requiring further investigation for improving methodological rigour.

“…The flow weighted mean concentration data were taken from Neal and Robson (2000). Details of the analytical chemistry methodologies used can be found in Leeks et al (1997); l The HMN concentration data were used where the spatial distribution of LOIS data was sparse and where there was a flow gauging station nearby for flow weighted mean concentration and flux estimation. The HMN was instigated in 1974 and is ongoing.…”

Section: Study Area: the Humbermentioning

confidence: 99%

GIS-based methodologies for assessing nitrate, nitrite and ammonium distributions across a major UK basin, the Humber

Davies

Hydrol. Earth Syst. Sci.

2004

Self Cite

The distributions of nitrate, nitrite and ammonium at various monitoring sites across the Humber basin (area 24 000 km 2 ) were examined within a Geographical Information System (GIS) framework. This basin contains diverse characteristics, from areas of high population and industry to rural and arable regions. The Humber River is a major provider of nutrient fluxes to the North Sea from the UK. Within the GIS analysis, the distributions of mean and mean flow weighted concentrations, flux and flux per unit area, were investigated. Empirical relationships between land characteristics and water quality for the whole catchment draining to each water quality monitoring site were established. Thirty-eight catchments were chosen for this analysis, with areas ranging from 46 km 2 to 8225 km 2 . These catchments are distributed across the Humber, encompassing the different conditions across the basin, thus allowing relationships between water quality and catchment characteristics to be used to estimate the nitrogen concentrations and flux throughout the basin river network. The main water quality data source was the Land Ocean Interaction Study (LOIS) dataset. The Environment Agency of England and Wales water quality datasets were used to infill areas of sparse LOIS monitoring network density within the Humber. The work shows the feasibility of estimating nitrate and, to a lesser extent, nitrite and ammonium concentrations and fluxes across the river network based on land characteristics, using a GIS methodology. The estimations work particularly well for the main river channels. However, there are local anomalies which are more difficult to predict. Maps showing concentration variations at 500 m intervals along the Humber basin river networks are presented; these are of particular value for environmental managers and socio-economists.