Essential fatty acids and phosphorus in seston from lakes with contrasting terrestrial dissolved organic carbon content

Gutseit, Kelly; Berglund, Olof; Granéli, Wilhelm

doi:10.1111/j.1365-2427.2006.01668.x

Cited by 36 publications

(48 citation statements)

References 52 publications

(104 reference statements)

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“…The abundance of docosahexaenoic acid (22:6n-3, DHA) in spring samples corresponds with the prevalence of dinoflagellates, as indicated by both the mixing model and microscopic counts. Dinoflagellates are rich in DHA, and a similar connection between the seston DHA concentration and abundance of dinoflagellates have been previously noted (Ahlgren et al 1997, Gutseit et al 2007. Also the proportion of EPA in the seston was the highest in the spring.…”

Section: Discussionmentioning

confidence: 58%

Inferring phytoplankton community composition with a fatty acid mixing model

et al. 2015

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Abstract. The taxon specificity of fatty acid composition in algal classes suggests that fatty acids could be used as chemotaxonomic markers for phytoplankton composition. The applicability of phospholipid-derived fatty acids as chemotaxonomic markers for phytoplankton composition was evaluated by using a Bayesian fatty acid-based mixing model. Fatty acid profiles from monocultures of chlorophytes, cyanobacteria, diatoms, euglenoids, dinoflagellates, raphidophyte, cryptophytes and chrysophytes were used as a reference library to infer phytoplankton community composition in five moderately humic, large boreal lakes in three different seasons (spring, summer and fall). The phytoplankton community composition was also estimated from microscopic counts. Both methods identified diatoms and cryptophytes as the major phytoplankton groups in the study lakes throughout the sampling period, together accounting for 54-63% of the phytoplankton. In addition, both methods revealed that the proportion of chlorophytes and cyanobacteria was lowest in the spring and increased towards the summer and fall, while dinoflagellates peaked in the spring. The proportion of euglenoids and raphidophytes was less than 8% of the phytoplankton biomass throughout the sampling period. The model estimated significantly lower proportions of chrysophytes in the seston than indicated by microscopic analyses. This is probably because the reference library for chrysophytes included too few taxa. Our results show that a fatty acid-based mixing model approach is a promising tool for estimating the phytoplankton community composition, while also providing information on the nutritional quality of the seston for consumers. Both the quantity and the quality of seston as a food source for zooplankton were high in the spring; total phytoplankton biomass was ;56 lg C L À1, and the physiologically important polyunsaturated fatty acids 20:5n-3 and 22:6n-3 comprised ;22% of fatty acids.

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Section: Discussionmentioning

confidence: 58%

Inferring phytoplankton community composition with a fatty acid mixing model

et al. 2015

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“…Earlier studies have hypothesized that the grazing pressure by cladocerans and large rotifers such as Asplanchna on Gonyostomum might be high (Cronberg et al 1988). Moreover, Gutseit et al (2007) showed that G. semen was good-quality food for zooplankton in terms of fatty acid content. However, a limited amount of these fatty acids was transferred to the zooplankton level, suggesting that zooplankton may not successfully feed on G. semen.…”

Section: Discussionmentioning

confidence: 99%

Grazing resistance allows bloom formation and may explain invasion success of Gonyostomum semen

Lebret

Fernandez

Hagman

et al. 2012

Limnology & Oceanography

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The nuisance alga Gonyostomum semen (Raphidophyceae) has expanded in the Nordic countries during the last decades and can dominate lake phytoplankton communities almost completely. A possible explanation to its dominance could be limited grazing by zooplankton. We investigated the potential grazing pressure on G. semen using an experimental approach supported by field data. We determined the grazing rate by cladocerans, calanoid copepods, and Chaoborus larvae to determine which were able to feed on G. semen. Only the large cladoceran Daphnia magna was able to feed successfully on G. semen. The large cell size of G. semen was likely a limiting factor for the filtering apparatus of smaller cladocerans. The copepod Eudiaptomus gracilis did not graze on G. semen, although the mechanism behind this selective feeding is still unknown. In addition to the experimental study, we quantified the zooplankton and phytoplankton communities in 40 lakes to determine the composition and abundance of the zooplankton communities co-occurring with G. semen, suggesting that large cladoceran species were not present in lakes where G. semen occurred. Hence, the growth of G. semen is not significantly controlled by grazing in natural systems, which likely facilitates bloom formation and invasion success of G. semen.

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“…It was revealed that Daphnia reproduction rate was higher when fed on metalimnetic Gonyostomum-rich seston as compared to Gonyostomum-poor epilimnetic seston. Further research indicated that cells of this raphidophyte contain significant amounts of v-3 polyunsaturated fatty acids (PUFAs), especially eicosapentaenoic and linolenic acid (Gutseit et al, 2007;Johansson et al, 2016), previously found also in marine raphidophytes (Marshall et al, 2002). PUFAs are one of the main (besides phosphorus) limiting components in daphnids food (Gulati and Demott, 1997) and play an essential role in the growth of D. magna (Becker and Boersma, 2005;Martin-Creuzburg and von Elert, 2009).…”

Section: Discussionmentioning

confidence: 99%

An experimental study on the influence of the bloom-forming alga Gonyostomum semen (Raphidophyceae) on cladoceran species Daphnia magna

Pęczuła

Toporowska

Pawlik‐Skowrońska

et al. 2017

Knowl. Manag. Aquat. Ecosyst.

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-The effect of the unicellular, bloom-forming alga Gonyostomum semen (Raphidiophyceae) on the survival rate and body size of Daphnia magna was tested under experimental laboratory conditions. Using samples from four humic lakes with a long history of Gonyostomum blooms, we exposed D. magna for 72 h to various Gonyostomum treatments which included homogenized biomass (frozen and fresh), live cell populations as well as lake water separated from the concentrated biomass of live cells. Filtered lake water and the chlorophycean alga Stichococcus bacillaris population (homogenized biomass or live cells) we used as controls. Our study revealed that (1) frozen homogenized G. semen biomass in the concentrations typical for blooms was not harmful for Daphnia and appeared to have a nutritive effect because it supported its growth; however, Daphnia mortality occurred after exposure to fresh and highly concentrated cell homogenate containing high amount of mucilage; (2) it is unlikely that living Gonyostomum cells excrete extracellular substances harmful for Daphnia; however, dense live Gonyostomum population that formed mucilaginous aggregates immobilized Daphnia and increased its mortality. The results suggest that various interactions between G. semen and D. magna take place and may play an essential role in natural freshwater ecosystems.Keywords: algal blooms / mucilage / crustaceans / toxicity Résumé -Une étude expérimentale de l'influence de l'algue formant des efflorescences Gonyostomum semen (Raphidophyceae) sur l'espèce de cladocère Daphnia magna. L'effet de l'algue unicellulaire, formant des efflorescences, Gonyostomum semen (Raphidiophyceae) sur le taux de survie et la taille corporelle de Daphnia magna a été testé dans des conditions expérimentales de laboratoire. En utilisant des échantillons de quatre lacs humiques avec un long passé d'efflorescences de Gonyostomum, nous avons exposé D. magna pendant 72 h à différents traitements de Gonyostomum qui incluent : la biomasse homogénéisée (congelée et fraîche), des populations de cellules vivantes ainsi que l'eau du lac séparée de la biomasse concentrée de cellules vivantes. L'eau filtrée du lac et une population d'algues chlorophycées Stichococcus bacillaris (biomasse homogénéisée ou cellules vivantes) ont été utilisées comme témoins. Notre étude a révélé que : (1) la biomasse congelée homogénéisée de G. semen dans les concentrations typiques d'efflorescences n'était pas nocif pour Daphnia et semblait avoir un effet nutritif car elle a soutenu sa croissance, cependant, la mortalité de Daphnia a eu lieu après une exposition à un homogénat frais et hautement concentré de cellules contenant une grande quantité de mucilage ; (2) il est peu probable que les cellules vivantes de Gonyostomum excrètent des substances extracellulaires nocives pour Daphnia, cependant, une population vivante dense de Gonyostomum vivante qui a formé des agrégats mucilagineux a immobilisé Daphnia et a augmenté sa mortalité. Les résultats suggèrent que diverses interactions entre G. se...

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Essential fatty acids and phosphorus in seston from lakes with contrasting terrestrial dissolved organic carbon content

Cited by 36 publications

References 52 publications

Inferring phytoplankton community composition with a fatty acid mixing model

Inferring phytoplankton community composition with a fatty acid mixing model

Grazing resistance allows bloom formation and may explain invasion success of Gonyostomum semen

An experimental study on the influence of the bloom-forming alga Gonyostomum semen (Raphidophyceae) on cladoceran species Daphnia magna

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