0000000000637924
AUTHOR
Aaron W. E. Galloway
showing 8 related works from this author
A Fatty Acid Based Bayesian Approach for Inferring Diet in Aquatic Consumers
2015
We modified the stable isotope mixing model MixSIR to infer primary producer contributions to consumer diets based on their fatty acid composition. To parameterize the algorithm, we generated a 'consumer-resource library' of FA signatures of Daphnia fed different algal diets, using 34 feeding trials representing diverse phytoplankton lineages. This library corresponds to the resource or producer file in classic Bayesian mixing models such as MixSIR or SIAR. Because this library is based on the FA profiles of zooplankton consuming known diets, and not the FA profiles of algae directly, trophic modification of consumer lipids is directly accounted for. To test the model, we simulated hypothet…
Diet-specific biomarkers show that high-quality phytoplankton fuels herbivorous zooplankton in large boreal lakes
2014
SUMMARY 1. The zooplankton is a key link in the transfer of energy from primary producers up through aquatic food webs. Previous efforts to quantify the importance of basal resources to aquatic consumers have used stable isotopes (SI) and simple ternary models, including only ‘bulk’ phytoplankton, bacteria or terrestrial particulate organic matter (t-POM). 2. We used a novel Bayesian mixing model based on fatty acids (FA) to quantify the dietary assimilation of seven basal resources, including five phytoplankton groups, pelagic bacteria and t-POM, to Cladocera in large boreal lakes in Finland. To account for trophic enrichment of FA from the diet to consumers, we parameterised the model wit…
How important are terrestrial organic carbon inputs for secondary production in freshwater ecosystems?
2017
Article
Eutrophication and browning influence Daphnia nutritional ecology
2019
Climate change and land-use practices can enhance lake eutrophication and browning, which influence phytoplankton composition by decreasing the availability of food high in nutritional quality (algae) and increasing the abundance of low-quality food (terrestrial detritus, bacteria) for herbivorous zooplankton. Nutritionally valuable algae for zooplankton are rich in essential biomolecules such as amino acids, polyunsaturated fatty acids (PUFAs), sterols, and phosphorus. We performed laboratory experiments and showed a stronger positive relationship between zooplankton (Daphnia) cumulative offspring number and availability of high-quality algae (Cryptophytes: Rhodomonas/Cryptomonas; and Chry…
Terrestrial carbohydrates support freshwater zooplankton during phytoplankton deficiency
2016
Article
Inferring phytoplankton community composition with a fatty acid mixing model
2015
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 compo…
Fatty acid composition as biomarkers of freshwater microalgae: analysis of 37 strains of microalgae in 22 genera and in seven classes
2013
The fatty acid (FA) composition of algae is an important determinant of their food quality for consumers, and FAs can also be used as biomarkers for biochemical and energetic pathways in food webs. FA analyses of 7 freshwater algal classes and 37 strains showed clear similarity within classes and strong differences amongst classes. Class was a dominant factor (66.4%) explaining variation in FA signatures of microalgae. The 7 algal classes comprised 4 separate groups according to their FA profiles: (1) Chlorophyceae and Trebouxiophyceae, (2) Bacillariophyceae, (3) Cryptophyceae, Chrysophyceae, and Raphidophyceae, and (4) Euglenophyceae. Each group had a characteristic FA composition, althoug…
Eutrophication and browning influence Daphnia nutritional ecology
2019
Climate change and land-use practices can enhance lake eutrophication and browning, which influence phytoplankton composition by decreasing the availability of food high in nutritional quality (algae) and increasing the abundance of low-quality food (terrestrial detritus, bacteria) for herbivorous zooplankton. Nutritionally valuable algae for zooplankton are rich in essential biomolecules such as amino acids, polyunsaturated fatty acids (PUFAs), sterols, and phosphorus. We performed laboratory experiments and showed a stronger positive relationship between zooplankton (Daphnia) cumulative offspring number and availability of high-quality algae (Cryptophytes: Rhodomonas/Cryptomonas; and Chry…