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The Chrysophyceae, usually called chrysophytes, chrysomonads, golden-brown algae or golden algae, are a large group of algae, found mostly in freshwater. [3] Golden algae is also commonly used to refer to a single species, Prymnesium parvum , which causes fish kills .
Diatoms can be obtained from multiple sources. [86] Marine diatoms can be collected by direct water sampling, and benthic forms can be secured by scraping barnacles, oyster and other shells. Diatoms are frequently present as a brown, slippery coating on submerged stones and sticks, and may be seen to "stream" with river current.
Diatoms belong to a large group called the heterokonts, which include both autotrophs such as golden algae and kelp; and heterotrophs such as water moulds. The classification of heterokonts is still unsettled: they may be designated a division , phylum , kingdom , or something intermediate to those.
The deep chlorophyll maximum (DCM), also called the subsurface chlorophyll maximum, [1] [2] is the region below the surface of water with the maximum concentration of chlorophyll. The DCM generally exists at the same depth as the nutricline , the region of the ocean where the greatest change in the nutrient concentration occurs with depth.
Chrysophyta or golden algae is a term used to refer to certain heterokonts. Dinobryon sp. from Shishitsuka Pond, Tsuchiura, Ibaraki Prefecture, Japan. It can be used to refer to: Chrysophyceae (golden algae), Bacillariophyceae (diatoms), and Xanthophyceae (yellow-green algae) together. [1] E.g., Pascher (1914). [2]
Diatoms are routinely used as part of a suite of biomonitoring tools which must be monitored as part of the European Water Framework Directive. [29] Diatoms are used as an indicator of ecosystem health in freshwaters because they are ubiquitous, directly affected by the changes in physico-chemical parameters and show a better relationship with ...
They are most common in marine sediments, but also occur in brackish water, fresh water and terrestrial sedimentary deposits. While every kingdom of life is represented in the microfossil record, the most abundant forms are protist skeletons or cysts from the Chrysophyta , Pyrrhophyta , Sarcodina , acritarchs and chitinozoans , together with ...
Diatoms are enclosed in protective silica (glass) shells called frustules. Each frustule is made from two interlocking parts covered with tiny holes through which the diatom exchanges nutrients and wastes. [156] The frustules of dead diatoms drift to the ocean floor where, over millions of years, they can build up as much as half a mile deep. [160]