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Corcoran AA, Seger M, Niu R, Nirmalakhandan N, Lammers PJ, Holguin FO, Boeing WJ. Evidence for induced allelopathy in an isolate of Coelastrella following co-culture with Chlorella sorokiniana. ALGAL RES 2019. [DOI: 10.1016/j.algal.2019.101535] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
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52
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Kurm V, van der Putten WH, Weidner S, Geisen S, Snoek BL, Bakx T, Hol WHG. Competition and predation as possible causes of bacterial rarity. Environ Microbiol 2019; 21:1356-1368. [PMID: 30803145 PMCID: PMC6850713 DOI: 10.1111/1462-2920.14569] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/22/2018] [Accepted: 02/21/2019] [Indexed: 12/05/2022]
Abstract
We assembled communities of bacteria and exposed them to different nutrient concentrations with or without predation by protists. Taxa that were rare in the field were less abundant at low nutrient concentrations than common taxa, independent of predation. However, some taxa that were rare in the field became highly abundant in the assembled communities, especially under ample nutrient availability. This high abundance points at a possible competitive advantage of some rare bacterial taxa under nutrient-rich conditions. In contrast, the abundance of most rare bacterial taxa decreased at low resource availability. Since low resource availability will be the prevailing situation in most soils, our data suggests that under those conditions poor competitiveness for limiting resources may contribute to bacterial rarity. Interestingly, taxa that were rare in the field and most successful under predator-free conditions in the lab also tended to be more reduced by predation than common taxa. This suggests that predation contributes to rarity of bacterial taxa in the field. We further discuss whether there may be a trade-off between competitiveness and predation resistance. The substantial variability among taxa in their responses to competition and predation suggests that other factors, for example abiotic conditions and dispersal ability, also influence the local abundance of soil bacteria.
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Affiliation(s)
- Viola Kurm
- Department of Terrestrial EcologyNetherlands Institute of Ecology (NIOO‐KNAW)P.O. Box 50, 6700 AB, WageningenThe Netherlands
| | - Wim H. van der Putten
- Department of Terrestrial EcologyNetherlands Institute of Ecology (NIOO‐KNAW)P.O. Box 50, 6700 AB, WageningenThe Netherlands
- Laboratory of NematologyWageningen UniversityP.O. Box 8123, 6700 ES, WageningenThe Netherlands
| | - Simone Weidner
- Institute of Environmental Biology, Ecology and BiodiversityUtrecht UniversityPadualaan 8, 3584 CH, UtrechtThe Netherlands
| | - Stefan Geisen
- Department of Terrestrial EcologyNetherlands Institute of Ecology (NIOO‐KNAW)P.O. Box 50, 6700 AB, WageningenThe Netherlands
| | - Basten L. Snoek
- Department of Terrestrial EcologyNetherlands Institute of Ecology (NIOO‐KNAW)P.O. Box 50, 6700 AB, WageningenThe Netherlands
- Laboratory of NematologyWageningen UniversityP.O. Box 8123, 6700 ES, WageningenThe Netherlands
- Theoretical Biology and BioinformaticsUtrecht UniversityPadualaan 8, 3584 CH, UtrechtThe Netherlands
| | - Tanja Bakx
- Department of Terrestrial EcologyNetherlands Institute of Ecology (NIOO‐KNAW)P.O. Box 50, 6700 AB, WageningenThe Netherlands
| | - Wilhelmina H. Gera Hol
- Department of Terrestrial EcologyNetherlands Institute of Ecology (NIOO‐KNAW)P.O. Box 50, 6700 AB, WageningenThe Netherlands
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53
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Griffin JE, Park G, Dam HG. Relative importance of nitrogen sources, algal alarm cues and grazer exposure to toxin production of the marine dinoflagellate Alexandrium catenella. HARMFUL ALGAE 2019; 84:181-187. [PMID: 31128802 DOI: 10.1016/j.hal.2019.04.006] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/27/2018] [Revised: 03/27/2019] [Accepted: 04/09/2019] [Indexed: 06/09/2023]
Abstract
Dinoflagellate paralytic shellfish toxin (PST) production is mediated by several abiotic and biotic factors. This study compared the relative importance of nitrogen source and concentration, prey alarm cues and grazer presence on toxin production of the marine dinoflagellate Alexandrium catenella (Group I, strain BF-5). In separate assays run under either nutrient-replete (F/2 medium) or nutrient-depleted (filtered seawater) conditions, PST production of A. catenella was measured as a function of varying concentrations of added nitrogen sources (ammonium and urea), alarm cues from lysed conspecific (A. catenella Group I strains) and interspecific (the diatom, Thalassiosira weissflogii, and the green flagellate, Tetraselmis sp.) algae, and the presence of a grazer (the copepod Acartia hudsonica). Results showed that addition of ammonium or urea did not increase PST production. Unexpectedly, interspecific alarm cues increased toxin production but conspecific ones did not. Grazer presence dramatically induced PST production in A. catenella, irrespective of nutrient conditions, and this effect was an order of magnitude greater than any of the other variables tested. These results corroborate previous studies on grazer-induced PST production, and support the hypothesis that grazer-induced toxin production is not an experimental artifact, but rather a prey defense mechanism.
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Affiliation(s)
- Jessica E Griffin
- University of Connecticut, Department of Marine Sciences, 1080 Shennecossett Road, Groton, CT, 06340, USA.
| | - Gihong Park
- University of Connecticut, Department of Marine Sciences, 1080 Shennecossett Road, Groton, CT, 06340, USA.
| | - Hans G Dam
- University of Connecticut, Department of Marine Sciences, 1080 Shennecossett Road, Groton, CT, 06340, USA.
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54
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Kapsetaki SE, West SA. The costs and benefits of multicellular group formation in algae. Evolution 2019; 73:1296-1308. [PMID: 30883720 DOI: 10.1111/evo.13712] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/2018] [Accepted: 02/20/2019] [Indexed: 11/30/2022]
Abstract
The first step in the evolution of complex multicellular organisms involves single cells forming a cooperative group. Consequently, to understand multicellularity, we need to understand the costs and benefits associated with multicellular group formation. We found that in the facultatively multicellular algae Chlorella sorokiniana: (1) the presence of the flagellate Ochromonas danica or the crustacean Daphnia magna leads to the formation of multicellular groups; (2) the formation of multicellular groups reduces predation by O. danica, but not by the larger predator D. magna; (3) under conditions of relatively low light intensity, where competition for light is greater, multicellular groups grow slower than single cells; (4) in the absence of live predators, the proportion of cells in multicellular groups decreases at a rate that does not vary with light intensity. These results can explain why, in cases such as this algae species, multicellular group formation is facultative, in response to the presence of predators.
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Affiliation(s)
| | - Stuart A West
- Department of Zoology, University of Oxford, Oxford OX1 3PS, United Kingdom
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55
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Harðardóttir S, Wohlrab S, Hjort DM, Krock B, Nielsen TG, John U, Lundholm N. Transcriptomic responses to grazing reveal the metabolic pathway leading to the biosynthesis of domoic acid and highlight different defense strategies in diatoms. BMC Mol Biol 2019; 20:7. [PMID: 30808304 PMCID: PMC6390554 DOI: 10.1186/s12867-019-0124-0] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/05/2018] [Accepted: 02/14/2019] [Indexed: 01/09/2023] Open
Abstract
BACKGROUND A major cause of phytoplankton mortality is predation by zooplankton. Strategies to avoid grazers have probably played a major role in the evolution of phytoplankton and impacted bloom dynamics and trophic energy transport. Certain species of the genus Pseudo-nitzschia produce the neurotoxin, domoic acid (DA), as a response to the presence of copepod grazers, suggesting that DA is a defense compound. The biosynthesis of DA comprises fusion of two precursors, a C10 isoprenoid geranyl pyrophosphate and L-glutamate. Geranyl pyrophosphate (GPP) may derive from the mevalonate isoprenoid (MEV) pathway in the cytosol or from the methyl-erythritol phosphate (MEP) pathway in the plastid. L-glutamate is suggested to derive from the citric acid cycle. Fragilariopsis, a phylogenetically related but nontoxic genus of diatoms, does not appear to possess a similar defense mechanism. We acquired information on genes involved in biosynthesis, precursor pathways and regulatory functions for DA production in the toxigenic Pseudo-nitzschia seriata, as well as genes involved in responses to grazers to resolve common responses for defense strategies in diatoms. RESULTS Several genes are expressed in cells of Pseudo-nitzschia when these are exposed to predator cues. No genes are expressed in Fragilariopsis when treated similarly, indicating that the two taxa have evolved different strategies to avoid predation. Genes involved in signal transduction indicate that Pseudo-nitzschia cells receive signals from copepods that transduce cascading molecular precursors leading to the formation of DA. Five out of seven genes in the MEP pathway for synthesis of GPP are upregulated, but none in the conventional MEV pathway. Five genes with known or suggested functions in later steps of DA formation are upregulated. We conclude that no gene regulation supports that L-glutamate derives from the citric acid cycle, and we suggest the proline metabolism to be a downstream precursor. CONCLUSIONS Pseudo-nitzschia cells, but not Fragilariopsis, receive and respond to copepod cues. The cellular route for the C10 isoprenoid product for biosynthesis of DA arises from the MEP metabolic pathway and we suggest proline metabolism to be a downstream precursor for L-glutamate. We suggest 13 genes with unknown function to be involved in diatom responses to grazers.
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Affiliation(s)
- Sara Harðardóttir
- Natural History Museum of Denmark, University of Copenhagen, Øster Farimagsgade 5, 1353 Copenhagen K, Denmark
| | - Sylke Wohlrab
- Alfred Wegener Institute, Helmholtz Centre for Polar and Marine Research, Am Handelshafen 12, 27570 Bremerhaven, Germany
- Helmholtz Institute for Functional Marine Biodiversity, Ammerländer Heestraße 231, Oldenburg, Germany
| | - Ditte Marie Hjort
- Natural History Museum of Denmark, University of Copenhagen, Øster Farimagsgade 5, 1353 Copenhagen K, Denmark
| | - Bernd Krock
- Alfred Wegener Institute, Helmholtz Centre for Polar and Marine Research, Am Handelshafen 12, 27570 Bremerhaven, Germany
| | - Torkel Gissel Nielsen
- National Institute of Aquatic Resources, Technical University of Denmark, Building 201, Kemitorvet, Lyngby Campus, 2800 Kgs. Lyngby, Denmark
| | - Uwe John
- Alfred Wegener Institute, Helmholtz Centre for Polar and Marine Research, Am Handelshafen 12, 27570 Bremerhaven, Germany
- Helmholtz Institute for Functional Marine Biodiversity, Ammerländer Heestraße 231, Oldenburg, Germany
| | - Nina Lundholm
- Natural History Museum of Denmark, University of Copenhagen, Øster Farimagsgade 5, 1353 Copenhagen K, Denmark
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Cadier M, Andersen KH, Visser AW, Kiørboe T. Competition–defense tradeoff increases the diversity of microbial plankton communities and dampens trophic cascades. OIKOS 2019. [DOI: 10.1111/oik.06101] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
Affiliation(s)
- Mathilde Cadier
- Centre for Ocean Life, DTU Aqua, Technical Univ. of Denmark 2800 Kgs. Lyngby Denmark
| | - Ken H. Andersen
- Centre for Ocean Life, DTU Aqua, Technical Univ. of Denmark 2800 Kgs. Lyngby Denmark
| | - Andre W. Visser
- Centre for Ocean Life, DTU Aqua, Technical Univ. of Denmark 2800 Kgs. Lyngby Denmark
| | - Thomas Kiørboe
- Centre for Ocean Life, DTU Aqua, Technical Univ. of Denmark 2800 Kgs. Lyngby Denmark
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Kiørboe T, Andersen KH. Nutrient affinity, half-saturation constants and the cost of toxin production in dinoflagellates. Ecol Lett 2019; 22:558-560. [PMID: 30677200 DOI: 10.1111/ele.13208] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2018] [Revised: 11/07/2018] [Accepted: 11/16/2018] [Indexed: 01/22/2023]
Abstract
The two parameters of the Michaelis-Menten model, the maximum uptake rate and the half-saturation constant, are not stochastically independent, and the half-saturation constant is not a measure of nutrient affinity, as commonly assumed. Failure to realise their interdependence and mechanistic interpretation may lead to the emergence of false trade-offs.
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Affiliation(s)
- Thomas Kiørboe
- Centre for Ocean Life, DTU-Aqua, DTU, DK-2800 Kgs., Lyngby, Denmark
| | - Ken H Andersen
- Centre for Ocean Life, DTU-Aqua, DTU, DK-2800 Kgs., Lyngby, Denmark
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58
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Chakraborty S, Pančić M, Andersen KH, Kiørboe T. The cost of toxin production in phytoplankton: the case of PST producing dinoflagellates. THE ISME JOURNAL 2019; 13:64-75. [PMID: 30108304 PMCID: PMC6298997 DOI: 10.1038/s41396-018-0250-6] [Citation(s) in RCA: 20] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/25/2018] [Revised: 06/29/2018] [Accepted: 07/19/2018] [Indexed: 01/23/2023]
Abstract
Many species of phytoplankton produce toxins that may provide protection from grazing. In that case one would expect toxin production to be costly; else all species would evolve toxicity. However, experiments have consistently failed to show any costs. Here, we show that costs of toxin production are environment dependent but can be high. We develop a fitness optimization model to estimate rate, costs, and benefits of toxin production, using PST (paralytic shellfish toxin) producing dinoflagellates as an example. Costs include energy and material (nitrogen) costs estimated from well-established biochemistry of PSTs, and benefits are estimated from relationship between toxin content and grazing mortality. The model reproduces all known features of PST production: inducibility in the presence of grazer cues, low toxicity of nitrogen-starved cells, but high toxicity of P-limited and light-limited cells. The model predicts negligible reduction in cell division rate in nitrogen replete cells, consistent with observations, but >20% reduction when nitrogen is limiting and abundance of grazers high. Such situation is characteristic of coastal and oceanic waters during summer when blooms of toxic algae typically develop. The investment in defense is warranted, since the net growth rate is always higher in defended than in undefended cells.
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Affiliation(s)
- Subhendu Chakraborty
- Centre for Ocean Life, DTU Aqua, Technical University of Denmark, Kemitorvet, Kgs.2800, Lyngby, Denmark.
| | - Marina Pančić
- Centre for Ocean Life, DTU Aqua, Technical University of Denmark, Kemitorvet, Kgs.2800, Lyngby, Denmark
| | - Ken H Andersen
- Centre for Ocean Life, DTU Aqua, Technical University of Denmark, Kemitorvet, Kgs.2800, Lyngby, Denmark
| | - Thomas Kiørboe
- Centre for Ocean Life, DTU Aqua, Technical University of Denmark, Kemitorvet, Kgs.2800, Lyngby, Denmark
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59
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Hou X, Zhou Q, Wang Z, Kong Q, Sun Y, Zhang L, Zhu X, Huang Y, Yang Z. Magnesium depletion suppresses the anti-grazer colony formation in Scenedesmus obliquus. ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH INTERNATIONAL 2018; 25:34228-34235. [PMID: 30291607 DOI: 10.1007/s11356-018-3191-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/04/2018] [Accepted: 09/10/2018] [Indexed: 06/08/2023]
Abstract
In aquatic ecosystems, many phytoplankton species have evolved various inducible defense mechanisms against the predation. The expression of these defenses is affected by environmental conditions such as nutrient availability. Here, we investigated the anti-grazer colony formation in Scenedesmus obliquus at different magnesium concentrations (0-7.3 mg L-1 Mg2+) in the presence of zooplankton (Daphnia)-derived infochemicals. Results showed that at adequate Mg2+, S. obliquus formed high proportions of multi-celled (e.g., four- and eight-celled) colonies, resulting in significantly increased number of cells per colony in response to Daphnia filtrate. On the other hand, in Mg2+-deficient treatment, the proportion of multi-celled colonies decreased, together with reduced algal growth rate and photosynthetic efficiency. Finally, the treatment without Mg2+ strongly suppressed the formation of large colony (mainly eight-celled colonies), whereas the algal growth rate was comparable to that in Mg2+ sufficient treatment. Despite the inhibition of colony formation, the time reaching the maximum number of cells per colony was not affected by the Mg2+ concentration, which generally took three days in all groups. Our results indicate that Mg2+ deficient/absent environments significantly reduced anti-grazing colony formation but not the algal growth, suggesting strong dependability of this morphological defensive trait to magnesium fluctuation in S. obliquus.
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Affiliation(s)
- Xinying Hou
- Jiangsu Key Laboratory for Biodiversity and Biotechnology, School of Biological Sciences, Nanjing Normal University, 1 Wenyuan Road, Nanjing, 210023, China
| | - Qiming Zhou
- Jiangsu Key Laboratory for Biodiversity and Biotechnology, School of Biological Sciences, Nanjing Normal University, 1 Wenyuan Road, Nanjing, 210023, China
| | - Zeshuang Wang
- Jiangsu Key Laboratory for Biodiversity and Biotechnology, School of Biological Sciences, Nanjing Normal University, 1 Wenyuan Road, Nanjing, 210023, China
| | - Qingdan Kong
- Jiangsu Key Laboratory for Biodiversity and Biotechnology, School of Biological Sciences, Nanjing Normal University, 1 Wenyuan Road, Nanjing, 210023, China
| | - Yunfei Sun
- Jiangsu Key Laboratory for Biodiversity and Biotechnology, School of Biological Sciences, Nanjing Normal University, 1 Wenyuan Road, Nanjing, 210023, China
| | - Lu Zhang
- Jiangsu Key Laboratory for Biodiversity and Biotechnology, School of Biological Sciences, Nanjing Normal University, 1 Wenyuan Road, Nanjing, 210023, China
| | - Xuexia Zhu
- Department of Marine Biology, College of Oceanography, Hohai University, 1 Xikang Road, Nanjing, 210098, China.
| | - Yuan Huang
- Jiangsu Key Laboratory for Biodiversity and Biotechnology, School of Biological Sciences, Nanjing Normal University, 1 Wenyuan Road, Nanjing, 210023, China.
| | - Zhou Yang
- Jiangsu Key Laboratory for Biodiversity and Biotechnology, School of Biological Sciences, Nanjing Normal University, 1 Wenyuan Road, Nanjing, 210023, China
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Våge S, Bratbak G, Egge J, Heldal M, Larsen A, Norland S, Lund Paulsen M, Pree B, Sandaa RA, Skjoldal EF, Tsagaraki TM, Øvreås L, Thingstad TF. Simple models combining competition, defence and resource availability have broad implications in pelagic microbial food webs. Ecol Lett 2018; 21:1440-1452. [PMID: 30014593 DOI: 10.1111/ele.13122] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2018] [Revised: 04/11/2018] [Accepted: 06/13/2018] [Indexed: 01/07/2023]
Abstract
In food webs, interactions between competition and defence control the partitioning of limiting resources. As a result, simple models of these interactions contain links between biogeochemistry, diversity, food web structure and ecosystem function. Working at hierarchical levels, these mechanisms also produce self-similarity and therefore suggest how complexity can be generated from repeated application of simple underlying principles. Reviewing theoretical and experimental literature relevant to the marine photic zone, we argue that there is a wide spectrum of phenomena, including single cell activity of prokaryotes, microbial biodiversity at different levels of resolution, ecosystem functioning, regional biogeochemical features and evolution at different timescales; that all can be understood as variations over a common principle, summarised in what has been termed the 'Killing-the-Winner' (KtW) motif. Considering food webs as assemblages of such motifs may thus allow for a more integrated approach to aquatic microbial ecology.
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Affiliation(s)
- Selina Våge
- Marine Microbiology Research Group, Department of Biological Sciences, University of Bergen, PO box 7803, 5020, Bergen, Norway
| | - Gunnar Bratbak
- Marine Microbiology Research Group, Department of Biological Sciences, University of Bergen, PO box 7803, 5020, Bergen, Norway
| | - Jorun Egge
- Marine Microbiology Research Group, Department of Biological Sciences, University of Bergen, PO box 7803, 5020, Bergen, Norway
| | - Mikal Heldal
- Marine Microbiology Research Group, Department of Biological Sciences, University of Bergen, PO box 7803, 5020, Bergen, Norway
| | - Aud Larsen
- UNI Research Environment, Nygårdsgaten, 112, 5008, Bergen, Norway
| | - Svein Norland
- Marine Microbiology Research Group, Department of Biological Sciences, University of Bergen, PO box 7803, 5020, Bergen, Norway
| | - Maria Lund Paulsen
- Marine Microbiology Research Group, Department of Biological Sciences, University of Bergen, PO box 7803, 5020, Bergen, Norway
| | - Bernadette Pree
- Marine Microbiology Research Group, Department of Biological Sciences, University of Bergen, PO box 7803, 5020, Bergen, Norway
| | - Ruth-Anne Sandaa
- Marine Microbiology Research Group, Department of Biological Sciences, University of Bergen, PO box 7803, 5020, Bergen, Norway
| | - Evy Foss Skjoldal
- Marine Microbiology Research Group, Department of Biological Sciences, University of Bergen, PO box 7803, 5020, Bergen, Norway
| | - Tatiana M Tsagaraki
- Marine Microbiology Research Group, Department of Biological Sciences, University of Bergen, PO box 7803, 5020, Bergen, Norway
| | - Lise Øvreås
- Marine Microbiology Research Group, Department of Biological Sciences, University of Bergen, PO box 7803, 5020, Bergen, Norway
| | - T Frede Thingstad
- Marine Microbiology Research Group, Department of Biological Sciences, University of Bergen, PO box 7803, 5020, Bergen, Norway
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61
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Charry MP, Keesing V, Costello M, Tremblay LA. Assessment of the ecotoxicity of urban estuarine sediment using benthic and pelagic copepod bioassays. PeerJ 2018; 6:e4936. [PMID: 29868297 PMCID: PMC5984583 DOI: 10.7717/peerj.4936] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/07/2018] [Accepted: 05/21/2018] [Indexed: 12/25/2022] Open
Abstract
Urban estuarine sediments are sinks to a range of contaminants of anthropogenic origin, and a key challenge is to characterize the risk of these compounds to receiving environments. In this study, the toxicity of urban estuarine sediments was tested using acute and chronic bioassays in the benthic harpacticoid Quinquelaophonte sp., and in the planktonic calanoid Gladioferens pectinatus, two New Zealand copepod species. The sediment samples from the estuary tributary sites significantly impacted reproduction in Quinquelaophonte sp. However, results from one of the estuary sites were not significantly different to those from the tributaries sites, suggesting that chemicals other than trace metals, polycyclic aromatic hydrocarbons and ammonia may be the causative stressors. Sediment elutriate samples had significant effects on reproductive endpoints in G. pectinatus, and on the induction of DNA damage in cells, as shown by the comet assay. The results indicate that sediment contamination at the Ahuriri Estuary has the potential to impact biological processes of benthic and pelagic organisms. The approach used provides a standardized methodology to assess the toxicity of estuarine sediments.
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Affiliation(s)
- Maria P Charry
- School of Biological Sciences, University of Auckland, Auckland, New Zealand.,Cawthron Institute, Nelson, New Zealand
| | | | - Mark Costello
- Institute of Marine Science, University of Auckland, Auckland, New Zealand
| | - Louis A Tremblay
- School of Biological Sciences, University of Auckland, Auckland, New Zealand.,Cawthron Institute, Nelson, New Zealand
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