The bbe Daphnia Toximeter

The bbe Daphnia Toximeter observes daphnids -  water fleas - under the influence of constantly running sample water. Based on the Extended Dynamic Daphnia Test, bbe developed a new sensitive method to detect hazardous compounds in water from rivers (source-water protection), plants, distribution systems and production drains to preserve human health and to monitor water.

Sample water (0.5 - 2 l/h) continuously runs through the measuring chamber containing the Daphnia. The live images obtained using a CCD-camera are evaluated online with an integrated PC to analyze changes in the behavior of the Daphnia. If this change is statistically significant, an alarm is triggered. The method of image analysis enables a series of measurement methods and plausibility tests to assess the Daphnia behavior using different criteria.

Measuring methods using digital image analysis:

Speed measurements:

• average speed
• speed distribution

Behavior observation:

• swimming height
• fractional dimension measurements
  for turns and circling movements, curviness

Growth observation:

• determination of daphnia size

Toxicity Index:

The concept of the toxicity index is based on the evaluation of certain measurands, such as swim speed or height, and changes in these measurands. Only if more than 2 of the measurands simultaneously show unusual results within a fixed period of time does the Daphnia Toximeter trigger an alarm.

Applications:

• drinking water supply
• dam monitoring
• waterway analysis and assessment
• general environmental monitoring
• intake assessment
• chemical analysis
• limnological work
• research and education

Features:

• 1- or 2-chamber system with up to 10 Daphnia or other organisms
• weekly change of Daphnia and chamber cleaning
• prevention of disturbing air bubbles in the chamber
• Daphnia feeding: integrated algae fermenter (constant supply)
• sample filtration: bbe WaterConditioner with temperature regulation and a high-pressure "back flush" option for sample water with high turbidity
• compact housing: IP54 security protection class - separate compartment for flow-through cell and electrical components 
• simple operating: integrated PC with keyboard, touch pad and graphic monitor, Windows XP software with graphic display of measurement results, live pictures and intuitive user guidance, floppy disc drive and CD-RW for data transfer
• alarm evaluation by the approved Dynsprung software provided by bbe Moldaenke

The database software is used to record and analyze the data.
The most important features are...

• saving of data and parameters at any time
• graphic display of all measurement values
• online display in LAN
• calibration of the instrument
• parameterization of the measurement
• data export to EXCEL and in text files
• print function

Brochure:

• The bbe Daphnia Toximeter

Film:

• bbe Daphnia Toximeter in action

Poster:

• How to protect water distribution online - results with extremely hazardous chemicals (Sarin, Soman, Tabun Cyclosarin).

Specifications:

Measurands: Toxicity detection due to video analysis of Daphnia behaviour with regard to the following:

• average swim speed
• speed distribution
• swim height
• average distance
• fractal dimension of swim paths: curviness, turns
• no. of Daphnia
• distribution in chamber
• size of Daphnia