Additional Data Evaluation of the Daphnia Toximeter and its Benefits Arco Wagenvoort & Corina...
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Additional Data Evaluation of the Daphnia Toximeter and its Benefits Arco Wagenvoort & Corina Carpentier AquaLife Workshop, Kiel, Germany 31 st May 2010
Additional Data Evaluation of the Daphnia Toximeter and its Benefits Arco Wagenvoort & Corina Carpentier AquaLife Workshop, Kiel, Germany 31 st May 2010
Additional Data Evaluation of the Daphnia Toximeter and its
Benefits Arco Wagenvoort & Corina Carpentier AquaLife Workshop,
Kiel, Germany 31 st May 2010
Slide 2
Introduction History of alarm detectors Evaluation in addition
to Hinkley and Gradient detectors insight into types of changes
Examples of advanced data evaluation and assessment of alarm
situations
Slide 3
History: The Daphnia Test Alarm: activity below lower alarm
threshold Upper alarm threshold unusable: drift, insensitive
Slide 4
Drift: growth leads to an increase of average swim speed
Slide 5
Improvements Daphnia Test ALARM: activity below lower alarm
threshold Upper alarm threshold unusable: drift, insensitive 1994 -
introduction of Hinkley detector ALARM: response to sudden changes
1999 - introduction of two gradient detectors relatively slow rise
or fall in parameter values
Slide 6
Hinkley detector and gradient detectors
Slide 7
Data evaluation based on changes compared to previous
data-points De Hoogh-Carpentier et al. (2006) and Wagenvoort et al.
(2006): standardisation and quality assurance protocols
introduction of size-based alarm thresholds and a mortality
parameter to explain the action mode of chemicals (in use since
2004) ADVANCED DATA EVALUATION
Slide 8
Size-based data evaluation Standardisation: use of animals of
the same age (24 - 48 h) Growth after (simultaneous) moulting
Larger animals show a greater swim speed range
Slide 9
Noise of signal increases with size
Slide 10
Normal values derived for Keizersveer Monitoring Station
Slide 11
Normal growth pattern of Daphnia Size of Daphnia Number of
Daphnia
Slide 12
Growth: indicator for Daphnia well-being Alarm situation at
Eijsden Monitoring Station
Slide 13
Size-based data-evaluation: summary Comparison to absolute
values for swim speed Early detection of technical malfunction
(e.g. clogging of feeding tubes) Indication of Daphnia well-being
in general Explanation of action mode of chemicals that cause
alarms: hyperactivity paralysis
Slide 14
Example 2004/2005 : increased swim speed and mortality caused
by 3-cyclohexyl-1,1- dimethylurea De Hoogh-Carpentier et al.
(2006)
Slide 15
Example 2004/2005 : increased swim speed and mortality caused
by 3-cyclohexyl-1,1- dimethylurea
Slide 16
Example 2007: increased swim speed and mortality caused by
chlorpyrifos and diazinon Wagenvoort et al. (2010)
Slide 17
Determination of the end of an alarm The decrease in the Toxic
Index does NOT mean that the alarm situation is over!
Slide 18
Example 2007: spill of chlorpyrifos and cypermethrin in River
Meuse by Chimac- Agriphar near Liege Mortality of replaced
Daphnia
Slide 19
Advanced data evaluation: recent results from the River
Meuse
Slide 20
Advanced data evaluation for the River Meuse Period: Eijsden:
2007 Beegden: 2009 Keijzersveer: 2007-2009
Slide 21
Advanced data evaluation - summary Results of the Daphnia
Toximeter are reliable and reproducible Quality assurance protocols
reduce number of false positive alarms Use of size-based alarm
limits and individual parameter assessments provide: earlier
response indication of action mode of chemicals Evaluation method
shows more alarms, but almost always the causes can be found
Slide 22
Thank you for your attention Acknowledgement: Colleagues at
Eijsden, Beegden and Keizersveer Monitoring Stations in NL Arco
Wagenvoort & Corina Carpentier AquaLife Workshop, Kiel, Germany
31 st May 2010
