The experiment just started! Day 0, we started sampling the water for the analysis of the nutrients and after that, at 8.00 am with the sampling of the sea surface microlayer… I thought we would have made a simple sampling with a syringe or something similar but… we used a glass plate and a scrubber! How does it work? We have to dip the glass plate in the water up to a line ( 30 cm below the surface) and remove it slowly, so that a film of organic material sticks to the plate. Then we have to wait for a moment to let the biggest drops fall down and try to collect as many drops of water attached to the glass plate as possible and transfer it to a bottle! It is not so easy as it could seem, because we had to collect almost 300 ml and we did 70 dips of the glass plate for each mesocosm! The first sampling was very exhausting… But it was just the beginning! Then we collected the bulk water from each mesocosm, almost 5 liters, enough for all the analysis… and what about the microplastics? In the afternoon, we started the real treatment: Luisa added the same amount of polystyrene microplastic particles in 3 of the 6 mesocosms!! Almost 1 300 000 pieces of 30 µm for each one! We’ll see their effects in the mesocosms in the next days.
For the nutrients, P04 and NH4 values aren’t very high, but they’re enough for a real situation and we decided we won’t add nutrients and see the natural development of the phytoplankton bloom…Let’s get the experiment started!