Samples for the diatom research

Hi everyone,

We’ve just returned from the field work, seems that we’ve done a great job there! Diatoms are very special microorganisms that can live almost everywhere! That’s why we collect so many different materials from the coast. First of all, we were collected sea water, to look for phytoplankton species. The phytoplankton is a group of organisms living in the surface water. They can’t swim, but some morphological features help them to keep afloat in the oceans. This group consists mainly of centric diatoms (to find out more, see learning module 1). On the other hand, we have also benthic communities. Diatoms can grow on rocks (we call them epilithic organisms), sand grains (epipsammic), other marine plants (epiphytic) and even on animals (epizootic) like whales or sea cucumbers. Amazing, isn’t it?! On these substrates occur mostly pennate diatoms with the raphe (slit-like structure which help them attached to the various surface).

Take a look on the picture to see what we have. If we want to investigate diatom benthic flora, we have to scrape rocks on the tidal pools or marine plants, cause they occur there very abundantly. The most important thing in field work is to write down the co-ordinates of sampling site from GPS device. Later on, it will be necessary in publications or if you want to go back to this specific site. We also use the multiparameter meter for each sampling sites to find out in what environmental conditions diatoms are living in. This simple device measures for example salinity and temperature of sea water, pH or dissolved oxygen. After collecting, ethanol or Lugol's solution are used to preserve and slow down bacterial activity in the samples. The next step is carried out in the laboratory…

take care young explorers,
best…
Przemek