Diatom method
Achnanthes laevis (Oest.) Cymbella mesiana Cholnoky Diatoms are unicellar algae with golden-brown photosynthetic pigments. Their cell wall is silicified to form a frustule, comprising two valves, one overlapping the other like the lid of a box. Diatoms are the dominant marine primary producers and play a particularly important role in the carbon, silica and nutrient budgets of the modern ocean. Diatoms distribution Diatoms are autotrophic and form the basis of food chains in many aquatic ecosystems. Different species occupy benthic and planktonic niches in ponds, lakes, rivers, salt marshes, lagoons, seas and oceanic waters, while some thrive in the soil, in ice, or attached to trees and rocks. peat diatomite sapropeles sand clay