{{Short description|Gradual buildup of substances in an organism}} {{use dmy dates |date=August 2021}} '''Bioaccumulation''' is the gradual accumulation of substances, such as pesticides or other chemicals, in an organism.<ref name=":0">{{Cite book|last=Alexander|title=Environmental Geology|year=1999|isbn=978-0-412-74050-3|series=Encyclopedia of Earth Science|pages=43–44|chapter=Bioaccumulation, bioconcentration, biomagnification|doi=10.1007/1-4020-4494-1_31}}</ref> Bioaccumulation occurs when an organism absorbs a substance faster than it can be lost or eliminated by catabolism and excretion. Thus, the longer the biological half-life of a toxic substance, the greater the risk of chronic poisoning, even if environmental levels of the toxin are not very high.<ref>{{Cite journal|jstor=2418066|title=Bioaccumulation of Marine Pollutants [and Discussion]|last1=Bryan|first1=G. W.|last2=Waldichuk|first2=M.|last3=Pentreath|first3=R. J.|last4=Darracott|first4=Ann|journal=Philosophical Transactions of the Royal Society of London. Series B, Biological Sciences|year=1979|volume=286|issue=1015|pages=483–505|bibcode=1979RSPTB.286..504W }}</ref>
Ecotoxicology is the study of these effects.
Bioaccumulation, for example in fish, can be predicted by models.<ref>{{cite journal |doi=10.1021/es2043728|title=Predicting Concentrations of Organic Chemicals in Fish by Using Toxicokinetic Models|year=2012|last1=Stadnicka|first1=Julita|last2=Schirmer|first2=Kristin|last3=Ashauer|first3=Roman|journal=Environmental Science & Technology|volume=46|issue=6|pages=3273–3280|pmid=22324398|pmc=3308199|bibcode=2012EnST...46.3273S}}</ref><ref>{{cite journal |doi=10.1016/j.envsoft.2009.08.009|title=Dynamic multi-compartmental modelling of metal bioaccumulation in fish: Identifiability implications|year=2010|last1=Otero-Muras|first1=I.|last2=Franco-Uría|first2=A.|last3=Alonso|first3=A.A.|last4=Balsa-Canto|first4=E.|journal=Environmental Modelling & Software|volume=25|issue=3|pages=344–353|bibcode=2010EnvMS..25..344O }}</ref> Hypothesis for molecular size cutoff criteria for use as bioaccumulation potential indicators are not supported by data.<ref>{{cite journal |doi=10.1897/IEAM_2009-051.1|title=Molecular Size Cut-Off Criteria for Screening Bioaccumulation Potential: Fact or Fiction?|year=2007|last1=Arnot|first1=Jon A.|last2=Arnot|first2=Michelle|last3=MacKay|first3=Donald|last4=Couillard|first4=Yves|last5=MacDonald|first5=Drew|last6=Bonnell|first6=Mark|last7=Doyle|first7=Pat|journal=Integrated Environmental Assessment and Management|volume=6|issue=2009|pages=210–224|pmid=19919169|doi-access=free}}</ref> Biotransformation can strongly modify bioaccumulation of chemicals in an organism.<ref>{{cite journal |doi=10.1021/es204611h|title=Significance of Xenobiotic Metabolism for Bioaccumulation Kinetics of Organic Chemicals in Gammarus pulex|year=2012|last1=Ashauer|first1=Roman|last2=Hintermeister|first2=Anita|last3=o'Connor|first3=Isabel|last4=Elumelu|first4=Maline|last5=Hollender|first5=Juliane|last6=Escher|first6=Beate I.|journal=Environmental Science & Technology|volume=46|issue=6|pages=3498–3508|pmid=22321051|pmc=3308200|bibcode=2012EnST...46.3498A}}</ref>
Toxicity induced by metals is associated with bioaccumulation and biomagnification.<ref name=":1">{{Citation|last1=Blowes|first1=D. W.|title=9.05 - The Geochemistry of Acid Mine Drainage|date=2003-01-01|url=https://www.sciencedirect.com/science/article/pii/B0080437516091374|work=Treatise on Geochemistry|pages=149–204|editor-last=Holland|editor-first=Heinrich D.|place=Oxford|publisher=Pergamon|language=en|doi=10.1016/b0-08-043751-6/09137-4|isbn=978-0-08-043751-4|access-date=2021-02-17|last2=Ptacek|first2=C. J.|last3=Jambor|first3=J. L.|last4=Weisener|first4=C. G.|editor2-last=Turekian|editor2-first=Karl K.|url-access=subscription}}</ref> Storage or uptake of a metal faster than it is metabolized and excreted leads to the accumulation of that metal.<ref>{{cite journal |vauthors=Gaion A, Sartori D, Scuderi A, Fattorini D |date=2014 |title=Bioaccumulation and biotransformation of arsenic compounds in Hediste diversicolor (Muller 1776) after exposure to spiked sediments|url=https://link.springer.com/article/10.1007/s11356-014-2538-z|journal=Environmental Science and Pollution Research |volume=21 |issue=9 |pages=5952–5959|doi=10.1007/s11356-014-2538-z|pmid=24458939 |bibcode=2014ESPR...21.5952G |s2cid=12568097 |url-access=subscription }}</ref> The presence of various chemicals and harmful substances in the environment can be analyzed and assessed with a proper knowledge on bioaccumulation helping with chemical control and usage.<ref>{{Cite book |title=Encyclopedia of toxicology|date=2014|editor=Philip Wexler|isbn=978-1-78402-845-9|edition=Third |location=London |oclc=878141491}}</ref>
An organism can take up chemicals by breathing, absorbing through skin or swallowing.<ref name=":1" /> When the concentration of a chemical is higher within the organism compared to its surroundings (air or water), it is referred to as bioconcentration.<ref name=":0" /> Biomagnification is another process related to bioaccumulation as the concentration of the chemical or metal increases as it moves up from one trophic level to another.<ref name=":0" /> Naturally, the process of bioaccumulation is necessary for an organism to grow and develop; however, the accumulation of harmful substances can also occur.<ref name=":1" />
== Examples ==
=== Terrestrial examples === {{main|hyperaccumulators}} Several plants, the so-called hyperaccumulators, concentrate elements (or ions thereof). They can concentrate up to 1000x more than adjacent non-hyperaccumulators. The topic has received attention as a possible means of removing heavy metals from contaminated areas, such as abandoned mines. The possibility of using hyperaccumulators to concentrate valuable metals - phytomining - has also been considered.<ref name=Dang>{{Cite journal |last1=Dang |first1=P. |last2=Li |first2=C. |date=2022-12-01 |title=A mini-review of phytomining |url=https://doi.org/10.1007/s13762-021-03807-z |journal=International Journal of Environmental Science and Technology |language=en |volume=19 |issue=12 |pages=12825–12838 |doi=10.1007/s13762-021-03807-z |bibcode=2022JEST...1912825D |issn=1735-2630 |url-access=subscription}}</ref> One of the most serious consequences of hyperaccumulators are plants that concentrate low levels of selenium to the extent that grazing animals are threatened.<ref>{{cite journal |last1=Terry |first1=N. |last2=Zayed |first2=A. M. |last3=De Souza |first3=M. P. |last4=Tarun |first4=A. S. |title=Selenium in Higher Plants |journal=Annual Review of Plant Physiology and Plant Molecular Biology |date=2000 |volume=51 |pages=401–432 |doi=10.1146/annurev.arplant.51.1.401 |pmid=15012198 }}</ref>
=== Aquatic examples === Coastal fish (such as the smooth toadfish) and seabirds (such as the Atlantic puffin) are often monitored for heavy metal bioaccumulation. Methylmercury enters into freshwater systems through industrial emissions and rain. As its concentration increases up the food web, it can reach dangerous levels for both fish and the humans who rely on fish as a food source.<ref>{{Cite web|date=2017-09-23|title=Mercury: What it does to humans and what humans need to do about it|url=https://www.iisd.org/ela/blog/commentary/mercury-humans-humans-need/|access-date=2020-07-06|website=IISD Experimental Lakes Area}}</ref>
Fish are typically assessed for bioaccumulation when they have been exposed to chemicals that are in their aqueous phases.<ref name=":3">{{Cite book |last=Alan. |first=Hoke, Robert |title=Review of laboratory-based terrestrial bioaccumulation assessment approaches for organic chemicals: current status and future possibilities |oclc=942770368}}</ref> Commonly tested fish species include the common carp, rainbow trout, and bluegill sunfish.<ref name=":3" /> Generally, fish are exposed to bioconcentration and bioaccumulation of organic chemicals in the environment through lipid layer uptake of water-borne chemicals.<ref name=":3" /> In other cases, the fish are exposed through ingestion/digestion of substances or organisms in the aquatic environment which contain the harmful chemicals.<ref name=":3" />
Naturally produced toxins can also bioaccumulate. Coral reef fish can be responsible for the poisoning known as ciguatera when they accumulate a toxin called ciguatoxin from the phytoplankton they consume.<ref>{{Cite journal |last1=Estevez |first1=Pablo |last2=Sibat |first2=Manoella |last3=Leão-Martins |first3=José Manuel |last4=Reis Costa |first4=Pedro |last5=Gago-Martínez |first5=Ana |last6=Hess |first6=Philipp |date=2020-04-21 |title=Liquid Chromatography Coupled to High-Resolution Mass Spectrometry for the Confirmation of Caribbean Ciguatoxin-1 as the Main Toxin Responsible for Ciguatera Poisoning Caused by Fish from European Atlantic Coasts |journal=Toxins |language=en |volume=12 |issue=4 |page=267 |doi=10.3390/toxins12040267 |doi-access=free |pmid=32326183 |pmc=7232264 |issn=2072-6651}}</ref> In some eutrophic aquatic systems, biodilution can occur. This is a decrease in a contaminant with an increase in trophic level, due to higher concentrations of algae and bacteria diluting the concentration of the pollutant.<ref>{{Cite journal |last1=Deines |first1=Peter |last2=Bodelier |first2=Paul L. E. |last3=Eller |first3=Gundula |date=May 2007 |title=Methane-derived carbon flows through methane-oxidizing bacteria to higher trophic levels in aquatic systems |url=https://sfamjournals.onlinelibrary.wiley.com/doi/10.1111/j.1462-2920.2006.01235.x |journal=Environmental Microbiology |language=en |volume=9 |issue=5 |pages=1126–1134 |doi=10.1111/j.1462-2920.2006.01235.x |pmid=17472629 |bibcode=2007EnvMi...9.1126D |issn=1462-2912|url-access=subscription }}</ref><ref>{{Cite journal |last1=Lin |first1=Han-Yang |last2=Costello |first2=Mark John |date=2023-09-07 |title=Body size and trophic level increase with latitude, and decrease in the deep-sea and Antarctica, for marine fish species |journal=PeerJ |language=en |volume=11 |article-number=e15880 |doi=10.7717/peerj.15880 |doi-access=free |issn=2167-8359 |pmc=10493087 |pmid=37701825}}</ref>
Wetland acidification can raise the chemical or metal concentrations, which leads to an increased bioavailability in marine plants and freshwater biota.<ref name=":2">{{Cite journal|last1=Albers|first1=Peter H.|last2=Camardese|first2=Michael B.|date=1993|title=Effects of acidification on metal accumulation by aquatic plants and invertebrates. 1. Constructed wetlands|url=https://setac.onlinelibrary.wiley.com/doi/abs/10.1002/etc.5620120602|journal=Environmental Toxicology and Chemistry|language=en|volume=12|issue=6|pages=959–967|doi=10.1002/etc.5620120602|bibcode=1993EnvTC..12..959A |url-access=subscription}}</ref> Plants situated there which includes both rooted and submerged plants can be influenced by the bioavailability of metals.<ref name=":2" />
== Studies of turtles as model species == {{Anchor|Turtles}} Bioaccumulation in turtles occurs when synthetic organic contaminants (i.e., PFAS), heavy metals, or high levels of trace elements enter a singular organism, potentially affecting their health. Although there are ongoing studies of bioaccumulation in turtles, factors like pollution, climate change, and shifting landscape can affect the amounts of these toxins in the ecosystem.<ref>{{Cite journal |last1=Franke |first1=Christian |last2=Studinger |first2=Gabriele |last3=Berger |first3=Georgia |last4=Böhling |first4=Stella |last5=Bruckmann |first5=Ursula |last6=Cohors-Fresenborg |first6=Dieter |last7=Jöhncke |first7=Ulrich |date=October 1994 |title=The assessment of bioaccumulation |url=https://linkinghub.elsevier.com/retrieve/pii/004565359490281X |journal=Chemosphere |language=en |volume=29 |issue=7 |pages=1501–1514 |doi=10.1016/0045-6535(94)90281-X|bibcode=1994Chmsp..29.1501F |url-access=subscription }}</ref>
The most common elements studied in turtles are mercury, cadmium, lead, and selenium.<ref>{{cite journal |last1=Storelli |first1=M. M |last2=Marcotrigiano |first2=G. O |title=Heavy metal residues in tissues of marine turtles |url=https://www.sciencedirect.com/science/article/abs/pii/S0025326X02002308 |website=Marine Pollution Bulletin |pages=397–400 |doi=10.1016/S0025-326X(02)00230-8 |date=1 April 2003 |volume=46|url-access=subscription }}</ref><ref>{{cite journal |last1=Abdallah |first1=Maha Ahmed Mohamed |title=Bioaccumulation and biomagnifications of toxic metals in tissues of loggerhead turtles (Caretta caretta) from the Mediterranean Sea coast, Egypt |journal=Scientific Reports |date=17 May 2023 |volume=13 |issue=1 |page=7995 |doi=10.1038/s41598-023-33972-9 |url=https://www.nature.com/articles/s41598-023-33972-9 |language=en |issn=2045-2322|pmc=10192338 |pmid=37198257 }}</ref> Heavy metals are released into rivers, streams, lakes, oceans, and other aquatic environments, and the plants that live in these environments will absorb the metals. Since the levels of trace elements are high in aquatic ecosystems, turtles will naturally consume various trace elements throughout various aquatic environments by eating plants and sediments.<ref name=":02">{{Cite journal |last1=Dias de Farias |first1=Daniel Solon |last2=Rossi |first2=Silmara |last3=da Costa Bomfim |first3=Aline |last4=Lima Fragoso |first4=Ana Bernadete |last5=Santos-Neto |first5=Elitieri Batista |last6=José de Lima Silva |first6=Flávio |last7=Lailson-Brito |first7=José |last8=Navoni |first8=Julio Alejandro |last9=Gavilan |first9=Simone Almeida |last10=Souza do Amaral |first10=Viviane |date=2022-07-01 |title=Bioaccumulation of total mercury, copper, cadmium, silver, and selenium in green turtles (Chelonia mydas) stranded along the Potiguar Basin, northeastern Brazil |url=https://www.sciencedirect.com/science/article/pii/S0045653522008244 |journal=Chemosphere |language=en |volume=299 |article-number=134331 |doi=10.1016/j.chemosphere.2022.134331 |pmid=35339524 |bibcode=2022Chmsp.29934331D |s2cid=247638704 |issn=0045-6535|url-access=subscription }}</ref> Once these substances enter the bloodstream and muscle tissue, they will increase in concentration and will become toxic to the turtles, perhaps causing metabolic, endocrine system, and reproductive failure.<ref name=":12">{{Cite journal |last1=Frossard |first1=Alexandra |last2=Coppo |first2=Gabriel Carvalho |last3=Lourenço |first3=Amanda Toledo |last4=Heringer |first4=Otávio Arruda |last5=Chippari-Gomes |first5=Adriana Regina |date=2021-05-01 |title=Metal bioaccumulation and its genotoxic effects on eggs and hatchlings of giant Amazon river turtle (Podocnemis expansa) |journal=Ecotoxicology |language=en |volume=30 |issue=4 |pages=643–657 |doi=10.1007/s10646-021-02384-8 |pmid=33754232 |bibcode=2021Ecotx..30..643F |s2cid=232315423 |issn=1573-3017}}</ref>
Some marine turtles are used as experimental subjects to analyze bioaccumulation because of their shoreline habitats, which facilitate the collection of blood samples and other data.<ref name=":02" /> The turtle species are very diverse and contribute greatly to biodiversity, so many researchers find it valuable to collect data from various species. Freshwater turtles are another model species for investigating bioaccumulation.<ref>{{Cite journal |last1=Beale |first1=David J. |last2=Hillyer |first2=Katie |last3=Nilsson |first3=Sandra |last4=Limpus |first4=Duncan |last5=Bose |first5=Utpal |last6=Broadbent |first6=James A. |last7=Vardy |first7=Suzanne |date=2022-02-01 |title=Bioaccumulation and metabolic response of PFAS mixtures in wild-caught freshwater turtles (Emydura macquarii macquarii) using omics-based ecosurveillance techniques |journal=Science of the Total Environment |language=en |volume=806 |issue=Pt 3 |article-number=151264 |doi=10.1016/j.scitotenv.2021.151264 |pmid=34715216 |bibcode=2022ScTEn.80651264B |issn=0048-9697|doi-access=free }}</ref> Due to their relatively limited home-range freshwater turtles can be associated with a particular catchment and its chemical contaminant profile.
=== Developmental effects of turtles === Toxic concentrations in turtle eggs may damage the developmental process of the turtle. For example, in the Australian freshwater short-neck turtle (''Emydura macquarii macquarii''), environmental PFAS concentrations were bioaccumulated by the mother and then offloaded into their eggs that impacted developmental metabolic processes and fat stores.<ref>{{Cite journal |last1=Beale |first1=David J. |last2=Nilsson |first2=Sandra |last3=Bose |first3=Utpal |last4=Bourne |first4=Nicholas |last5=Stockwell |first5=Sally |last6=Broadbent |first6=James A. |last7=Gonzalez-Astudillo |first7=Viviana |last8=Braun |first8=Christoph |last9=Baddiley |first9=Brenda |last10=Limpus |first10=Duncan |last11=Walsh |first11=Tom |last12=Vardy |first12=Suzanne |date=2022-04-15 |title=Bioaccumulation and impact of maternal PFAS offloading on egg biochemistry from wild-caught freshwater turtles (Emydura macquarii macquarii) |journal=Science of the Total Environment |language=en |volume=817 |article-number=153019 |doi=10.1016/j.scitotenv.2022.153019 |pmid=35026273 |bibcode=2022ScTEn.81753019B |issn=0048-9697|doi-access=free }}</ref> Furthermore, there is evidence PFAS impacted the gut microbiome in exposed turtles.<ref>{{Cite journal |last1=Beale |first1=David J. |last2=Bissett |first2=Andrew |last3=Nilsson |first3=Sandra |last4=Bose |first4=Utpal |last5=Nelis |first5=Joost Laurus Dinant |last6=Nahar |first6=Akhikun |last7=Smith |first7=Matthew |last8=Gonzalez-Astudillo |first8=Viviana |last9=Braun |first9=Christoph |last10=Baddiley |first10=Brenda |last11=Vardy |first11=Suzanne |date=2022-09-10 |title=Perturbation of the gut microbiome in wild-caught freshwater turtles (Emydura macquarii macquarii) exposed to elevated PFAS levels |journal=Science of the Total Environment |language=en |volume=838 |issue=Pt 3 |article-number=156324 |doi=10.1016/j.scitotenv.2022.156324 |pmid=35654195 |bibcode=2022ScTEn.83856324B |s2cid=249213966 |issn=0048-9697|doi-access=free }}</ref>
In terms of toxic levels of heavy metals, it was observed to decrease egg-hatching rates in the Amazon River turtle, ''Podocnemis expansa''.<ref name=":12"/> In this particular turtle egg, the heavy metals reduce the fat in the eggs and change how water is filtered throughout the embryo; this can affect the survival rate of the turtle egg.<ref name=":12" />
== See also == * Biomagnification (magnification of toxins with increasing trophic level) * Chelation therapy * Drug accumulation ratio * Environmental impact of pesticides * International POPs Elimination Network * Persistent organic pollutants * Phytoremediation (removal of pollutants by bioaccumulation in plants)
==References== {{reflist}}
==External links== * [https://web.archive.org/web/20051102093918/http://www.marietta.edu/~biol/102/2bioma95.html Bioaccumulation & Biomagnification] * [https://www.ecotoxmodels.org/hot-topics/bioaccumulation-biotransformation/ Bioaccumulation & Biotransformation]
{{modelling ecosystems}} {{Toxicology}} {{Authority control}}
Category:Biodegradable waste management Category:Biodegradation Category:Ecotoxicology Category:Food chains Category:Pollution Category:Species