How to use the microscope
We recommend a small usb type microscope with the highest possible resolution with a 5mp camera, or better if available.
You will have collected the sample of plankton and plastic which are now on the filter paper sandwiched between the acrylic plates with 5 x 5mm holes. The filter paper is transferred to a 90mm petri plate, and the assembly is positioned on top of the light box.
Use the 90mm plastic plate to only allow unrestricted light from the centre LED.
Align the filter paper assembly until light shines up through the 5mm hole and the disc is centred on the screen. Wind down the microscope until it pushes down slightly on the top plate. You can now bring the image into sharp focus with the dial on the microscope.
Take a photo and record the results, raise the microscope slightly to allow the petri plate to be moved, such that the light now shines up through the second hole to be viewed, and repeat the process for each of the 5 holes
The diameter of the hole is 5mm this is the same as 5000um (microns). The thickness of a human hair is about 80 um, so this gives you an idea of scale. Most of the micro-plastic fibres will be 20 to about 80um in diameter, so they are really easy to observe.
We would like you to catalogue particles, fibres, zooplankton animals and phytoplankton plants that measure
20um to 200um
200um to 1000um
greater than 1000um.
Most of the plankton will be around the 200um size, however once you become accustomed with the microscope you will be able to estimate the size bands visually using the 5mm holes a gauge.