Purpose of the site. What are phytoplankton?

The mysterious and invisible world of the Black Sea microscopic algae is presented on the website through photos and short descriptions. The microalgae living in the Black Sea are presented in Classes, Orders, Families, Genuses and Species and can serve both for the purpose of research and to enrich the knowledge and ideas about the hidden beauty and biodiversity of living organisms in our sea.

Phytoplankton (from the ancient Greek φυτόν (phyton) - plant, and πλαγκτός (planktos) - wandering) is a diverse group of autotrophic, myxotrophic, heterotrophic, prokaryotic or eukaryotic microalgae from different taxons. Living suspended near the water surface (in the Black Sea most of them mainly in the layer 0 - 25 m, but they are also found in the whole depth of the euphotic zone), where the intensity of the light is sufficient for their vital functions. It is autotrophic component of the planktonic community and its qualitative and quantitative composition provide valuable information on trophic status, biodiversity and primary productivity of marine ecosystems.

Phytoplankton cells are very small (usually 3-50 micrometers) and invisible to the human eye (without the use of a special device (microscope). The resolution of the human eye is 100 μm, as the thickness of a hair.) but in the accumulation of larger quantities of them - water basins, most often near the shore, are colored in a variety of colors - red, brown, green, yellow, white and more. (this phenomenon is called bloom of water); the staining is obtained due to the presence in the bodies of microscopic algae of the so-called photosynthetic pigments (chlorophyll, carotenoids, phycobilins, etc.).

The species richness of phytoplankton worldwide includes about 4,000 - 5,000 species (Sournia et al. 1991; Tett and Barton, 1995). The species richness of the phytoplankton species growing in the Black Sea area has more than doubled in the last decade compared to the 1980s. - from 700 species in 1978 (Black Sea, 1978), to 1621 confirmed and 48 unconfirmed species in the Black Sea Phytoplankton checklist (BSPC Editorial Board, 2013).  

The collected information on the taxonomic composition of phytoplankton in the Black Sea is based on long-term monitoring of the Black Sea ecosystem carried out by specialists - phytoplanktonologists from the Institute of Fish Resources (IFR), AA - Sofia, Bulgaria. https://www.ifrvarna.com/index.php/bg/

Authors of the original photos on this website are Prof. Dr. Daniela Klisarova (CV) and Dr. Dimitar Gerdzhikov (CV). Other photos used are marked with the number in the species description where the author or source of the photo is indicated.

Sournia, A., M.-J. Chrétiennot-Dinet, M. Ricard, 1991. Marine plankton: how many species in the world oceans? Journal of Plankton Research, 13, 1093–9.

Tett, P., E.D. Barton, 1995. Why are there about 5000 species of phytoplankton in the sea? Journal of Plankton Research, 17, 1693–704.

Black Sea, 1978. Collection Publishing House "Georgi Bakalov" - Varna, p. 635.

BSPC Editorial Board, 2013. Black Sea Phytoplankton Checklist from http://phyto.bss.ibss.org.ua.


img from : https://bg.wikipedia.org/wiki/Фитопланктон#/media/Файл:Phytoplankton1.jpg