Borrowed from German Gelbstoff (literally “yellow substance”) (coined by K. Kalle in a 1966 article: see the quotation), from German gelb (“amber, yellow”) (ultimately from Proto-Indo-European *ǵʰelh₃wós (“yellow”), from *ǵʰelh₃- (“to shine”) + *-wós (“suffix forming adjectives from verb stems”)) + German Stoff (“matter, stuff, substance”) (from Proto-Germanic *stuppōną (“to close; to fill, stop up”), possibly ultimately from Proto-Indo-European *(s)tew- (“to hit; to push”)).
- (hydrology, oceanography) The optically measurable component of dissolved organic matter in water, which primarily occurs naturally from tannin released from decaying detritus. As the amount of organic matter increases, it causes the water to appear green, yellow-green, and then brown. [from 1966]
- 1979, Stephen [H.] Spotte, Seawater Aquariums: The Captive Environment, New York, N.Y.: Wiley-Interscience, →ISBN, page 103:
- Like soil humus and humic materials indigenous to freshwaters, seawater gelbstoff absorbs light strongly into the ultraviolet region of the spectrum: Sieburth and Jensen (1968) noted a peak at 263 nm.
- 1984, M. Ehrhardt, “Marine Gelbstoff”, in Otto Hutzinger, editor, The Natural Environment and the Biogeochemical Cycles (The Handbook of Environmental Chemistry; 1, part 1C), Berlin: Springer-Verlag, →ISBN; reprinted as Berlin; Heidelberg: Springer-Verlag, 2013, DOI:10.1007/978-3-540-38829-6, →ISBN, pages 63 and 67:
- [page 63] Kalle concluded that dissolved yellow substances contribute substantially to any deviation from the blue colour of pure water into the longer wavelengths region of the visible spectrum. […] Chemically the material defied unequivocal characterization, a situation which has remained essentially unchanged. Thus, for want of a systematic designation Kalle called the material "Gelbstoff", the German word for "yellow material". […] Marine Gelbstoff is a material formed in the sea with certain spectral characteristics. It is not derived from terrestrial sources and appears to be composed of fulvic and humic components both of which are structrally different from their terrestrial counterparts. […] [page 67] These are more indications of an autochthonous origin of marine Gelbstoff supported by the interesting observation that Gelbstoff from a bog water precipitated within a week at room temperature when an equal amount of seawater was added to its solution.
- 1996, Steven W. Effler; Mary Gail Perkins, “Optics”, in Steven W. Effler, editor, Limnological and Engineering Analysis of a Polluted Urban Lake: Prelude to Environmental Management of Onondaga Lake, New York (Springer Series on Environmental Management), New York, N.Y.: Springer-Verlag New York, →ISBN; reprinted as New York, N.Y.: Springer-Verlag, 2012, DOI:10.1007/978-1-4612-2318-4, →ISBN, ISSN 0172-6161, section 7.1 (Introduction), page 535:
- Light is absorbed in water by four components: water itself, dissolved yellow substances (gelbstoff), phytoplankton, and tripton (inanimate particulate material).