Monitoring strategies sampling

Chlorophyll.pdf presents the concentration (mg/m ) of chlorophyll a and phaeopigment a from monitoring cruises of the lOW from 1997 to 2005. In some cases, also data from research projects are included if they fit to the monitoring strategy. Samples were taken from different depths (2.5 or 5 m distance) and the data averaged by linear integration over the upper 20 m of the water column, at shallower stations down to the bottom (in 1999-2003) or over the upper 10 m (in 2004-2005). 

It is only after information goals and appropriate indicators have been defined accurately and precisely that sample location and frequency can be decided. Continuous monitoring of some water quality parameters is now commonplace in many parts of the world. However, the cost of these systems and limits to the parameters that can be measured with them means that spot or grab samples for testing probably always will form part of environmental quality monitoring strategies (Hazleton, 1998), and this remains true for bioassays. 

In summary, when designing any environmental monitoring strategy, including one with bioassays, considerable advice is available on optimal location and timing of samples. It is no longer necessary simply to rely on tradition or guesswork. 

The setup of the monitoring strategy includes decisions on sample matrix, sampling locations, frequencies and methods. This selection depends on the purpose of monitoring and usually represents a compromise between a sufficient coverage of samples in time and space and limiting the monitoring costs. 

The sampling strategy should be adapted to the situation that is to be monitored and should be consistent with the objectives and purpose of the specific monitoring. The sampling locations, frequencies and techniques will depend on the tasks, the types of release, the radionuclide compositions concerned and the exposures that are to be expected as a consequence of the releases. 

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