Abstract: A ballast water monitoring device and a method for detecting live phytoplankton are disclosed. The device comprises a chamber for receiving a sample, at least one light source to emit light towards the sample, a light detector to receive light from the sample and generate a light signal, and a controller. The controller is configured to control the at least one light source to emit a single pulse of light, calculate the variable fluorescence [Fv] of the sample in response to the pulse of light, at time intervals less than the duration of the pulse of light, compare the calculated variable fluorescence to a predetermined reference limit, and perform an action if the calculated variable fluorescence is greater than the predetermined reference limit.

Abstract: Cell counting device A cell counting device and a method of using a cell counting device are disclosed. The cell counting device comprises a chamber for receiving a sample, at least one light source to emit light towards a section of the chamber. The section of the chamber comprises a sub-sample of the sample. The cell counting device also comprises a light detector to receive a light emitted from the section of the chamber and to generate an electronic signal associated with the received light, and a controller. The controller is configured to estimate the number of photoactive cells in the sample by calculating the distribution of variable fluorescence [Fv] values of a predetermined number of sub-samples about the mean Fv value.

Abstract: A ballast water monitoring device and a method for detecting live phytoplankton are disclosed. The device comprises a chamber for receiving a sample, at least one light source to emit light towards the sample, a light detector to receive light from the sample and generate a light signal, and a controller. The controller is configured to control the at least one light source to emit a single pulse of light, calculate the variable fluorescence [Fv] of the sample in response to the pulse of light, at time intervals less than the duration of the pulse of light, compare the calculated variable fluorescence to a predetermined reference limit, and perform an action if the calculated variable fluorescence is greater than the predetermined reference limit.