Diatoms and environmental change in large brackish-water ecosystems

Pauline Snoeijs, Kaarina Weckström

Research output: Chapter in Book/Report/Conference proceedingChapter in bookResearchpeer-review

22 Citations (Scopus)


Introduction Classification of brackish waters Brackish waters comprise a range of exclusive habitats that can be subdivided into three major categories: transition zones between freshwater and marine habitats, transition zones between hyperhaline water and marine habitats, and inland waters without marine water exchange. Salinities of brackish-water habitats vary from relatively stable (e.g. some large saline lakes; see Fritz et al., this volume) to extremely instable in time and space (e.g. estuaries bordering tidal seas; see Trobajo & Sullivan, this volume). In the past, many efforts have been made to classify brackish waters according to salinity and the occurrence of biological species (Kolbe, 1932; Segerstråle, 1959; den Hartog, 1964). The more detailed such classifications are, the less well they appear to fit with all types of brackish waters. Based on salinity, defined as the total concentration of ionic components in g per kg water, generally accepted approximate limits are: limnetic (freshwater) <0.5 practical salinity units (psu) = parts per thousand (ppt), oligohaline 0.5–5 psu, mesohaline 5–18 psu, polyhaline 18–30 psu, euhaline 30–40 psu, hyperhaline 40 psu (known as the “Venice System”: Anonymous, 1959). Large brackish-water ecosystems Earth’s longest salinity gradient comprises the continental microtidal Baltic Sea (Leppäranta & Myrberg, 2009: surface area 377,000 km2, water volume 21,000 km3, mean depth 58 m, maximum depth 459 m) and its transition area to the North Sea.

Original languageEnglish
Title of host publicationThe diatoms
Subtitle of host publicationApplications for the environmental and Earth sciences, Second Edition
EditorsJohn P. Smol, Eugene F. Stoermer
Place of PublicationCambridge, United Kingdom
PublisherCambridge University Press
Number of pages22
ISBN (Electronic)9780511763175
ISBN (Print)9780521509961
Publication statusPublished - 1 Jan 2010

Programme Area

  • Programme Area 5: Nature and Climate


Dive into the research topics of 'Diatoms and environmental change in large brackish-water ecosystems'. Together they form a unique fingerprint.

Cite this