Dystrophic lake

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Dystrophic lake in Bielawa nature reserve in Poland Dystrophic lake in Bielawa nature reserve in Poland.JPG
Dystrophic lake in Bielawa nature reserve in Poland

Dystrophic lakes, also known as humic lakes, are lakes that contain high amounts of humic substances and organic acids. [1] The presence of these substances causes the water to be brown in colour and have a generally low pH of around 4.0-6.0. [2] The presence of humic substances are mainly due to certain plants in the watersheds of the lakes, such as peat mosses and conifers. Due to these acidic conditions, few taxa are able to survive, consisting mostly of aquatic plants, algae, phytoplankton, picoplankton, and bacteria. [3] [4] Dystrophic lakes can be found in many areas of the world, especially in the northern boreal regions. [5] [6]

Contents

Classification of dystrophic lakes

Dystrophia can be categorized as a condition affecting trophic state rather than a trophic state in itself. [7] Lakes typically are categorized according to the increasing productivity as oligotrophic, mesotrophic, eutrophic, and hypereutrophic. [8] Dystrophic lakes used to be classified as oligotrophic due to their low productivity. However, more recent research shows dystrophia can be associated with any of the trophic types. This is due to a wider possible pH range (acidic 4.0 to more neutral 8.0 on occasion) and other fluctuating properties like nutrient availability and chemical composition. Hydrochemical Dystrophy Index is a scale used to evaluate the dystrophy level of lakes. In 2017, Gorniak proposed a new set of rules for evaluating this index, using properties such as the surface water pH, electric conductivity, and concentrations of dissolved inorganic carbon, and dissolved organic carbon. [9]

Chemical properties

Lake Matheson, a dystrophic lake in New Zealand, has water stained so dark by tannins that its reflection of the nearby Southern Alps has made it a tourist attraction Mount Aoraki (Mt. Cook) & Mount Tasman - Lake Matheson (New Zealand).jpg
Lake Matheson, a dystrophic lake in New Zealand, has water stained so dark by tannins that its reflection of the nearby Southern Alps has made it a tourist attraction

Dystrophic lakes have a high level of dissolved organic carbon. This consists of organic carboxylic and phenolic acids, which keep water pH levels relatively stable, possibly by acting as a natural buffer. [10] Therefore, the lake’s naturally acidic pH is largely unaffected by industrial emissions. Dissolved organic carbon also reduces the amount of ultraviolet radiation that enters the lake and can reduce the bioavailability of heavy metals by binding them. [11] There is a significantly lower calcium content in the water and sediment of a dystrophic lake when compared with a non-dystrophic lake. [3] Essential fatty acids, like eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA), are still present in the organisms in humic lakes, but are downgraded in nutritional quality by this acidic environment, resulting low nutritional quality of dystrophic lake's producers, such as phytoplankton. [12] Because of differing trophic status, some dystrophic lakes may differ strongly in their chemical composition from other dystrophic lakes. [7] Studies of the chemical composition of different types of dystrophic lakes have shown differing levels of dissolved inorganic nitrogen, lipase and glucosidase depending on water color.

Life in dystrophic lakes

The catchment area of a dystrophic lake is usually a coniferous forest rich or an area with peat mosses. [13] [14] [3] Despite the presence of ample nutrients, dystrophic lakes can be considered nutrient-poor, because their nutrients are trapped in organic matter, and therefore are unavailable to primary producers. [15] [16] A considerable amount of the organic matter in dystrophic lakes is allochthonous, meaning it is produced externally to the lake. Due to high amounts of organic matter and lack of light, it is bacterioplankton that control the rate of nutrient flux between the aquatic and terrestrial environments. [17] The bacteria are found in high numbers. These bacteria drive the food web of humic lakes by providing energy and supplying usable forms of organic and inorganic carbon to other organisms, primarily to phagotrophic and mixotrophic flagellates. [18] Decomposition of organic matter by bacteria also converts organic nitrogen and phosphorus into their inorganic forms, which are then available for uptake by primary producers including both large and small phytoplankton (algae and cyanobacteria). [4] [3] The biological activity of humic lakes is, however, dominated by bacterial metabolism. The chemistry of humic lakes makes it difficult for higher trophic levels such as planktivorous fish to establish themselves, leaving a simplified food web consisting mostly of plants, plankton, and bacteria. [17] The dominance of the bacteria means that dystrophic lakes generally have a higher respiration rate than primary production rate. [3]

Impacts of dystrophication on a lake ecosystem

The formation of a humic lakes via organic runoff has a dramatic effect on the lake ecosystem. Increases in the lake’s acidity make it difficult for fish and other organisms to proliferate. The quality of the lake for use as drinking water also decreases as the carbon concentration and acidity increase. The fish that do adapt to the increased acidity may also not be fit for human consumption, due to the organic pollutants.

Dystrophic lakes and climate change

Lakes are commonly known to be important sinks in the carbon cycle. Dystrophic lakes are typically net heterotrophic due to the large amount of bacterial respiration outweighing phytoplankton photosynthesis, meaning that dystrophic lakes are larger carbon sources than clear lakes, emitting carbon into the atmosphere. [19] The elevated levels of allochthonous carbon in humic lakes are due to vegetation in the lake and catchment area, the runoff from which is the main source of organic material. However, changes in these levels can also be attributed to shifts in precipitation, changing forestry practices, reduced sulphate deposition, and changes in temperature. [20] Contemporary climate change is increasing temperature and precipitation in some parts of the world, thus increasing the supply of humic substances to lakes, making them more dystrophic; this process is referred to as “brownification." [20] [21]

Examples of dystrophic lakes

Examples of dystrophic lakes that have been studied by scientists include Lake Suchar II in Poland, lakes Allgjuttern, Fiolen, and Brunnsjön in Sweden, and Lake Matheson in New Zealand. [3] [9] [22]

Related Research Articles

<span class="mw-page-title-main">Plankton</span> Organisms living in water or air that are drifters on the current or wind

Plankton are the diverse collection of organisms that drift in water but are unable to actively propel themselves against currents. The individual organisms constituting plankton are called plankters. In the ocean, they provide a crucial source of food to many small and large aquatic organisms, such as bivalves, fish, and baleen whales.

<span class="mw-page-title-main">Phytoplankton</span> Autotrophic members of the plankton ecosystem

Phytoplankton are the autotrophic (self-feeding) components of the plankton community and a key part of ocean and freshwater ecosystems. The name comes from the Greek words φυτόν, meaning 'plant', and πλαγκτός, meaning 'wanderer' or 'drifter'.

<span class="mw-page-title-main">Biological pump</span> Carbon capture process in oceans

The biological pump (or ocean carbon biological pump or marine biological carbon pump) is the ocean's biologically driven sequestration of carbon from the atmosphere and land runoff to the ocean interior and seafloor sediments. In other words, it is a biologically mediated process which results in the sequestering of carbon in the deep ocean away from the atmosphere and the land. The biological pump is the biological component of the "marine carbon pump" which contains both a physical and biological component. It is the part of the broader oceanic carbon cycle responsible for the cycling of organic matter formed mainly by phytoplankton during photosynthesis (soft-tissue pump), as well as the cycling of calcium carbonate (CaCO3) formed into shells by certain organisms such as plankton and mollusks (carbonate pump).

<span class="mw-page-title-main">Dissolved organic carbon</span> Organic carbon classification

Dissolved organic carbon (DOC) is the fraction of organic carbon operationally defined as that which can pass through a filter with a pore size typically between 0.22 and 0.7 micrometers. The fraction remaining on the filter is called particulate organic carbon (POC).

Soil acidification is the buildup of hydrogen cations, which reduces the soil pH. Chemically, this happens when a proton donor gets added to the soil. The donor can be an acid, such as nitric acid, sulfuric acid, or carbonic acid. It can also be a compound such as aluminium sulfate, which reacts in the soil to release protons. Acidification also occurs when base cations such as calcium, magnesium, potassium and sodium are leached from the soil.

<span class="mw-page-title-main">Lake ecosystem</span> Type of ecosystem

A lake ecosystem or lacustrine ecosystem includes biotic (living) plants, animals and micro-organisms, as well as abiotic (non-living) physical and chemical interactions. Lake ecosystems are a prime example of lentic ecosystems, which include ponds, lakes and wetlands, and much of this article applies to lentic ecosystems in general. Lentic ecosystems can be compared with lotic ecosystems, which involve flowing terrestrial waters such as rivers and streams. Together, these two ecosystems are examples of freshwater ecosystems.

Heterotrophic picoplankton is the fraction of plankton composed by cells between 0.2 and 2 μm that do not perform photosynthesis. They form an important component of many biogeochemical cycles.

<span class="mw-page-title-main">Microbial loop</span> Trophic pathway in marine microbial ecosystems

The microbial loop describes a trophic pathway where, in aquatic systems, dissolved organic carbon (DOC) is returned to higher trophic levels via its incorporation into bacterial biomass, and then coupled with the classic food chain formed by phytoplankton-zooplankton-nekton. In soil systems, the microbial loop refers to soil carbon. The term microbial loop was coined by Farooq Azam, Tom Fenchel et al. in 1983 to include the role played by bacteria in the carbon and nutrient cycles of the marine environment.

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<span class="mw-page-title-main">Human impact on the nitrogen cycle</span>

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<span class="mw-page-title-main">Marine snow</span> Shower of organic detritus in the ocean

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<span class="mw-page-title-main">Bacterioplankton</span> Bacterial component of the plankton that drifts in the water column

Bacterioplankton refers to the bacterial component of the plankton that drifts in the water column. The name comes from the Ancient Greek word πλαγκτός (planktós), meaning "wandering" or "drifting", and bacterium, a Latin term coined in the 19th century by Christian Gottfried Ehrenberg. They are found in both seawater and fresh water.

<span class="mw-page-title-main">Hypoxia (environmental)</span> Low oxygen conditions or levels

Hypoxia refers to low oxygen conditions. Hypoxia is problematic for air-breathing organisms, yet it is essential for many anaerobic organisms. Hypoxia applies to many situations, but usually refers to the atmosphere and natural waters.

<span class="mw-page-title-main">Planktivore</span> Aquatic organism that feeds on planktonic food

A planktivore is an aquatic organism that feeds on planktonic food, including zooplankton and phytoplankton. Planktivorous organisms encompass a range of some of the planet's smallest to largest multicellular animals in both the present day and in the past billion years; basking sharks and copepods are just two examples of giant and microscopic organisms that feed upon plankton.

<span class="mw-page-title-main">Freshwater acidification</span> Acidification of freshwater by rain

Freshwater acidification occurs when acidic inputs enter a body of fresh water through the weathering of rocks, invasion of acidifying gas, or by the reduction of acid anions, like sulfate and nitrate within a lake, pond, or reservoir. Freshwater acidification is primarily caused by sulfur oxides (SOx) and nitrogen oxides (NOx) entering the water from atmospheric depositions and soil leaching. Carbonic acid and dissolved carbon dioxide can also enter freshwaters, in a similar manner associated with runoff, through carbon dioxide-rich soils. Runoff that contains these compounds may incorporate acidifying hydrogen ions and inorganic aluminum, which can be toxic to marine organisms. Acid rain also contributes to freshwater acidification. A well-documented case of freshwater acidification in the Adirondack Lakes, New York, emerged in the 1970s, driven by acid rain from industrial sulfur dioxide (SO₂) and nitrogen oxide (NOₓ) emissions.

The Southern Ocean Carbon and Climate Observations and Modeling (SOCCOM) project is a large scale National Science Foundation funded research project based at Princeton University that started in September 2014. The project aims to increase the understanding of the Southern Ocean and the role it plays in factors such as climate, as well as educate new scientists with oceanic observation.

<span class="mw-page-title-main">Viral shunt</span>

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<span class="mw-page-title-main">Lake metabolism</span> The balance between production and consumption of organic matter in lakes

Lake metabolism represents a lake's balance between carbon fixation and biological carbon oxidation. Whole-lake metabolism includes the carbon fixation and oxidation from all organism within the lake, from bacteria to fishes, and is typically estimated by measuring changes in dissolved oxygen or carbon dioxide throughout the day.

<span class="mw-page-title-main">Marine food web</span> Marine consumer-resource system

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<span class="mw-page-title-main">Particulate inorganic carbon</span>

Particulate inorganic carbon (PIC) can be contrasted with dissolved inorganic carbon (DIC), the other form of inorganic carbon found in the ocean. These distinctions are important in chemical oceanography. Particulate inorganic carbon is sometimes called suspended inorganic carbon. In operational terms, it is defined as the inorganic carbon in particulate form that is too large to pass through the filter used to separate dissolved inorganic carbon.

References

  1. ↑ Górniak, A.; Jekatierynczuk-Rudczyk, E.; Dobrzyń, P. (1999). "Hydrochemistry of Three Dystrophic Lakes in Northeastern Poland". Acta Hydrochimica et Hydrobiologica. 27 (1): 12–18. doi:10.1002/(SICI)1521-401X(199901)27:1<12::AID-AHEH12>3.0.CO;2-X. ISSN   1521-401X.
  2. ↑ Kullberg, A (1993-01-01). "The ecological significance of dissolved organic carbon in acidified waters". Ambio (Journal of the Human Environment, Research and Management). 22 (5): 331–337.
  3. 1 2 3 4 5 6 Drzymulska, D., Fiłoc, M., Kupryjanowicz, M., Szeroczyńska, K., & Zieliński, P. 2015. Postglacial shifts in lake trophic status based on a multiproxy study of a humic lake. Holocene, 25(3), 495-507.
  4. 1 2 Jasser, I. 1997. The dynamics and importance of picoplankton in shallow, dystrophic lake in comparison with surface waters of two deep lakes with contrasting trophic status. Hydrobiologia, 342/343(1), 87-93.
  5. ↑ Sobek, Sebastian; Tranvik, Lars J.; Prairie, Yves T.; Kortelainen, Pirkko; Cole, Jonathan J. (May 2007). "Patterns and regulation of dissolved organic carbon: An analysis of 7,500 widely distributed lakes". Limnology and Oceanography. 52 (3): 1208–1219. doi:10.4319/lo.2007.52.3.1208. ISSN   0024-3590.
  6. ↑ Kostrzewska-Szlakowska, I. 2017. Microbial Biomass and Enzymatic Activity of the Surface Microlayer and Subsurface Water in Two Dystrophic Lakes. Polish Journal of Microbiology, 66(1), 75-84.
  7. 1 2 Kostrzewska-Szlakowska, I, Jasser, I. 2011. Black box: what do we know about humic lakes? Polish Journal of Ecology, 59(4), 647-664.
  8. ↑ Carlson, Robert E. (March 1977). "A trophic state index for lakes1". Limnology and Oceanography. 22 (2): 361–369. doi:10.4319/lo.1977.22.2.0361. ISSN   0024-3590.
  9. 1 2 Górniak, A. 2016. A new version of the Hydrochemical Dystrophy Index to evaluate dystrophy in lakes. Ecological Indicators, 78(1), 566-573.
  10. ↑ Kullberg, Anders; Bishop, Kevin H.; Hargeby, Anders; Jansson, Mats; Petersen, Robert C. (1993). "The Ecological Significance of Dissolved Organic Carbon in Acidified Waters". Ambio. 22 (5): 331–337. ISSN   0044-7447. JSTOR   4314098.
  11. ↑ Korosi, J. B. and Smol, J. P. 2012. Contrasts between dystrophic and clearwater lakes in the long-term effects of acidification on cladoceran assemblages. Freshwater Biology, 57(1), 2449–2464.
  12. ↑ Taipale, S.J, Vuorio, K, Strandberg, U, et al. 2016. Lake eutrophication and brownification downgrade availability and transfer of essential fatty acids for human consumption. Environment International, 96(1), 156-166.
  13. ↑ Gray, Emma; Cappelli, Giovanni; Gammell, Martin P.; Roden, Cilian M.; Lally, Heather T. (August 2022). "A review of dystrophic lake and pool habitat in Europe: An Irish perspective". Journal for Nature Conservation. 68: 126189. doi:10.1016/j.jnc.2022.126189.
  14. ↑ Górniak, Andrzej (July 2017). "A new version of the Hydrochemical Dystrophy Index to evaluate dystrophy in lakes". Ecological Indicators. 78: 566–573. doi:10.1016/j.ecolind.2017.03.030.
  15. ↑ Meili, Markus (1992-02-01). "Sources, concentrations and characteristics of organic matter in softwater lakes and streams of the Swedish forest region". Hydrobiologia. 229 (1): 23–41. doi:10.1007/BF00006988. ISSN   1573-5117.
  16. ↑ Drakare, S, Blomqvist, P, Bergstro, A, et al. 2003. Relationships between picophytoplankton and environmental variables in lakes along a gradient of water colour and nutrient content. Freshwater Biology, 48(1), 729-740.
  17. 1 2 Newton, R.J. et al. 2006. Microbial community dynamics in a humic lake: differential persistence of common freshwater phylotypes. Environmental Microbiology, 8(6), 956-970.
  18. ↑ Salonen, K, and Jokinen, S. 1988. Flagellate grazing on bacteria in a small dystrophic lake. Hydrobiologia, 161(1), 203-209.
  19. ↑ Likens, Gene E. (2009). Encyclopedia of inland waters (1st ed.). London Boston: Academic Press. ISBN   978-0-12-370626-3.
  20. 1 2 Klante, Clemens; Larson, Magnus; Persson, Kenneth M. (August 2021). "Brownification in Lake Bolmen, Sweden, and its relationship to natural and human-induced changes". Journal of Hydrology: Regional Studies. 36: 100863. doi:10.1016/j.ejrh.2021.100863.
  21. ↑ Larsen, S., Andersen, T., and Hessen, D. O. 2010. Global Change Biology, 17(2), 1186-1192.
  22. ↑ Flint, E. A. (1979). "Comments on the phytoplankton and chemistry of three monomictic lakes in Westland National Park, New Zealand". New Zealand Journal of Botany. 17 (2): 127–134. Bibcode:1979NZJB...17..127F. doi:10.1080/0028825X.1979.10426885.
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