Lakes monitoring

Table 3 Results from trend analyses of 20 Alpine lakes monitored between 1980-2004. For each site are indicated the range of the number of data points (depending on the parameter), the calculated trends (Sen s method), the p-value from the Mann-Kendall test and for each parameter the median trend and the number of sites with significant positive or negative or no trend are shown... 

NJDEP Water monitoring and standards, 2007. Ambient Lake Monitoring Network, Panel 1 Lake Report, Vol. 1 of 2. 

Poretti, V. and Franken, I., 2008. New lersey ambient lake monitoring, 6th National Monitoring Conference, Atlantic City, New Jersey. 

Coordination of satellite imagery and gronnd trath measnrement collection was carried ont. Algorithms from the University of Miimesota lake monitoring program were nsed to... 

Traditionally, lake monitoring has focused on physico-chemical parameters (nutrients, oxygen profiles, etc.) and on phytoplankton biomass as indicated by chlorophyll a, on which several classification schemes exist (e.g. OECD, 1982 Cailson, 1977). Only recently, following the new requirement introduced by the WFD to assess lake ecological status (see Cardoso et al., 2006 for a review) have most European countries included several other biological quality elements in their routine monitoring programmes, such as phytoplankton, macrophytes and phytobenthos, benthic invertebrates and fish. 

Phytoplankton is widely used as an important water quality indicator because of its high species differentiation and sensitivity to environmental factors. Murphy et al. (2002) list the following main advantages of using phytoplankton in lake monitoring ... 

Phytoplankton abundance and occurrence of blooms are the parameters for which a not necessarily taxonomic determination is required. The abundance can be measured as the total count of cells and/or colonies in a unit volume of water or recalculated further into biovolume or biomass. The WFD allows use of chlorophyll a as a surrogate for phytoplankton biomass, thus it is considered a biological parameter. In fact, chlorophyll a is the most frequently measured phytoplankton metric in lakes. Not all countries have included the bloom occurrence in routine monitoring as in some areas (e.g. countries belonging to the Alpine GIG) they occur too rarely and inegu-larly (if at all). Other non-taxonomy-based metrics, like size composition and primary productivity, are successively less considered in lake monitoring schemes. 

Kallio, K., Koponen, S. and Pulbainen, J. (2003) Feasibility of airborne imaging spectrometry for lake monitoring - a case study of spatial chlorophyll a distribution in two meso-eutrophic lakes. International Journal of Remote Sensing, 24, pp. 3771-3790. 

Wiederholm, T. (1980) Use of benthos in lake monitoring. Journal of the Water Pollution Control Federation, 51, pp. 537-547. 

The NIR spectra can be used for reconstruction of water chemistry, or other environmental parameters, from lake sediments. This approach requires establishment of transfer functions by calibration of MR spectra from surface sediment samples against measured parameters of the water, such as pH, total phosphorus (TP) or total organic carbon (TOC). These transfer functions can then be applied down-core for inference of past water quality. A similar application is in contemporary lake monitoring programs. Surface sediment samples could be taken, for example, each 5th year for MR measurements and subsequent inference of sevCTal wate chemistry parametCTS, or other environmental parameters, for which transfer functions are available. In this approach effects of diagenetic processes on MRS, which may be a problem in down-core studies, are circumvented. 

These trends do not indicate that a pH change across all areas of Europe has been effected, as the rivers and lakes monitored are those likely to have been affected the most. 

R.J. Norstrom, T.P. Clark and D.V. Weseloh, Great Lakes monitoring using Herring Gulls, Ch. 8 iji "Hazardous Contaminants in Ontario Human and Environmental Effects," Institute for Environmental Studies, U. of Toronto, Toronto, Ontario (1985). 

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