Diatoms as aquatic bioindicators

Thanks to their sensitivity to organic and inorganic contaminants and their quick response to chemical changes in the water, diatoms are excellent witnesses to the ecological state of aquatic, flowing ecosystems. Diatomes colonise all types of substances submerged in aquatic systems (rocks, gravel, sands, silt, macrophytes, animals, etc.) therefore, the study of one or another communities provides different information on the contamination levels in water


Epilithic communities are considered the most representative of circulating water quality. This is the reason why diatome epilithics are being widely used as bioindicaters for river pollution, detecting pressures due to eutrophication, acidification and salinity changes.

Treatment of diatom samples

Both diatom sampling as well as subsequent analysis and identification in the laboratory, is performed according to the protocols and regulations in force.


All samples collected are conserved in permanent preparations which are stored in a ficoteca available to clients for possible future reviews and consultations.


Furthermore, together with the results of the determinations and preparations, a collection of photographs of the taxa can be presented.


Given the difficulty of identification, the analysis of samples requires the participation of experts in the taxonomic determination of Diatones. Cimera has specialists in this field, and with extensive experience in the identification of this group of algae.

Analysis of results

Combining the values abundance of taxa identified with its sensitivity to pollution and its indicator value, different Diatom indexes of water quality are obtained.


For the analysis of data obtained, Cimera has self-developed computer software called INDAT, which enables quick and efficient management of the results. Thanks to this, remote incorporation and consultation of identification results, indexes or metres installed is possible in real time.