Differences between main-channel and off-channel food webs in the upper Mississippi River revealed by fatty acid profiles of consumers

Larson, James H.; Bartsch, Michelle R.; Gutreuter, Steve; Knights, Brent C.; Bartsch, Lynn A.; Richardson, William B.; Vallazza, Jonathan M.; Arts, Michael T.

doi:10.5268/iw-5.2.781

Cited by 11 publications

(8 citation statements)

References 28 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…From this biochemical perspective, riverine planktonic diatoms advected into an estuary would be expected to be high food quality for herbivorous invertebrates (De Moura, de Lucena Barbosa, Patrício, Nery & Gonçalves, ; Jassby & Cloern, ), whereas the autochthonous production by Phragmites or Spartina would be expected to be of very low in quality. A similar phenomenon has been observed in the Upper Mississippi, where consumers (bluegill sunfish, zebra mussels, pocketbook mussels) from the main channel (where diatoms predominated) had significantly higher long‐chain PUFA content than the same species occupying backwater habitats, where detrital inputs and cyanobacteria were more prevalent (Larson et al., ). Therefore, the type of primary production (i.e., vascular plants or algae) is actually much more important than whether this production is allochthonous or autochthonous.…”

Section: Marine Allochthony: the Exception That Proves The Rule!supporting

confidence: 69%

“…Conversely, all algae whether phytoplankton or periphyton have little structural carbon, and oftentimes high-essential fatty acid content (Brett & M€ uller-Navarra, 1997;Brett et al, 2009). It is probably biochemically irrelevant whether algal production in lakes is pelagic or benthic because, for consumers (bluegill sunfish, zebra mussels, pocketbook mussels) from the main channel (where diatoms predominated) had significantly higher long-chain PUFA content than the same species occupying backwater habitats, where detrital inputs and cyanobacteria were more prevalent (Larson et al, 2015). Therefore, the type of primary production (i.e., vascular plants or algae) is actually much F I G U R E 2 A principal components analysis of the fatty acid composition of terrestrial detritus (i.e., finely ground Alnus rubra; t-POC), phytoplankton (i.e., Scenedesmus acutus and Cryptomonas ozolinii), and Daphnia fed either pure or mixed diets of phytoplankton and t-POC (Taipale et al, 2015).…”

Section: Impor Tant Prey For Fishmentioning

confidence: 99%

See 1 more Smart Citation

How important are terrestrial organic carbon inputs for secondary production in freshwater ecosystems?

et al. 2017

View full text Add to dashboard Cite

Abstract1. Many freshwater systems receive substantial inputs of terrestrial organic matter.Terrestrially derived dissolved organic carbon (t-DOC) inputs can modify light availability, the spatial distribution of primary production, heat, and oxygen in aquatic systems, as well as inorganic nutrient bioavailability. It is also well-established that some terrestrial inputs (such as invertebrates and fruits) provide highquality food resources for consumers in some systems.2. In small to moderate-sized streams, leaf litter inputs average approximately three times greater than the autochthonous production. Conversely, in oligo/mesotrophic lakes algal production is typically five times greater than the available flux of allochthonous basal resources.3. Terrestrial particulate organic carbon (t-POC) inputs to lakes and rivers are comprised of 80%-90% biochemically recalcitrant lignocellulose, which is highly resistant to enzymatic breakdown by animal consumers. Further, t-POC and heterotrophic bacteria lack essential biochemical compounds that are critical for rapid growth and reproduction in aquatic invertebrates and fishes. Several studies have directly shown that these resources have very low food quality for herbivorous zooplankton and benthic invertebrates. 4.Much of the nitrogen assimilated by stream consumers is probably of algal origin, even in systems where there appears to be a significant terrestrial carbon contribution. Amino acid stable isotope analyses for large river food webs indicate that most upper trophic level essential amino acids are derived from algae. Similarly, profiles of essential fatty acids in consumers show a strong dependence on the algal food resources.5. Primary production to respiration ratios are not a meaningful index to assess consumer allochthony because respiration represents an oxidised carbon flux that cannot be utilised by animal consumers. Rather, the relative importance of allochthonous subsidies for upper trophic level production should be addressed by considering the rates at which terrestrial and autochthonous resources are consumed and the growth efficiency supported by this food.6. Ultimately, the biochemical composition of a particular basal resource, and not just its quantity or origin, determines how readily this material is incorporated into upper trophic level consumers. Because of its highly favourable biochemical composition and greater availability, we conclude that microalgal production supports most animal production in freshwater ecosystems. | WHY DOES ALLOCHTHONY MATTER?A better understanding of where and how allochthony modifies aquatic food web processes will improve our ability to predict how land-use and climate change affect organic carbon export from watersheds to lakes and rivers and how this matter influences upper trophic level production in aquatic systems. If invertebrate and fish consumers in rivers and lakes are strongly subsidised by allochthonous carbon inputs, then watersheds and especially riparian zone management will potentially have as mu...

show abstract

Section: Marine Allochthony: the Exception That Proves The Rule!supporting

confidence: 69%

Section: Impor Tant Prey For Fishmentioning

confidence: 99%

How important are terrestrial organic carbon inputs for secondary production in freshwater ecosystems?

et al. 2017

View full text Add to dashboard Cite

show abstract

“…However, fatty acids may be ineffective at directly determining mussel diets due to the noted ability for mussels to preferentially retain or modify fatty acids into forms which are not present or rare in the seston (Gladyshev et al ., ), including ARA (Newton et al ., ). While Dreissena fatty‐acid profiles have been shown to reflect changes in catchment land‐use (Larson et al ., ) and habitats in large rivers (Larson et al ., ), without further research into the process of fatty‐acid trophic modification by mussels, fatty‐acid profiles may be less applicable for directly determining the specific composition of mussel diets than for other consumers.…”

Section: Discussionmentioning

confidence: 99%

Combined stable‐isotope and fatty‐acid analyses demonstrate that large wood increases the autochthonous trophic base of a macroinvertebrate assemblage

et al. 2016

View full text Add to dashboard Cite

1. Large wood (LW), defined as pieces of wood greater than 10 cm in diameter and 1 m long, is well known to alter river hydromorphology and the availability of potential food resources for consumers. However, there has been a lack of studies investigating whether these can cause shifts in the trophic base, which may explain alterations to the total abundance and taxonomic structure of the macroinvertebrate assemblage. 2. We aimed to determine how the presence of LW altered the trophic base of the macroinvertebrate consumer assemblage in a lowland river, and to provide a methodological comparison of two assimilation-based food web methods: stable-isotope analysis (SIA) and fattyacid biomarker profiles (FA). To do so, we quantified the contribution of trophic resources to the diets of macroinvertebrates colonising the surface of LW, present in this study as single logs, and surrounding bed sediments with those from bed sediments of a nearby control site with minimal amounts of LW. 3. SIA showed that the macroinvertebrate food web, even for non-filter feeding taxa, was mostly sustained by seston exported from a lake 1 km upstream, highlighting a high degree of lake-river coupling. The presence of wood altered the trophic base from being predominantly seston-supported to one with increased support from epixylic autochthonous production (i.e. periphyton and bryophytes on wood). Terrestrial matter (i.e. leaves and grass) and organic sediments were a relatively unimportant fraction of the trophic base (<10%) in all locations. 4. FA did not directly track the influence of seston, but instead differentiated between overall allochthonous (terrestrial) and autochthonous (aquatic) components of the trophic base. In particular, FA analysis demonstrated the higher nutritional value of autochthonous primary producers, and provided supporting evidence that most consumers, even seston-feeders, were primarily supported by autochthonous resources and not by allochthonous matter. FA indicated shifts in some taxaspecific diets not detected by stable isotopes alone. 5. Our study demonstrated that the combined use of stable isotopes and fatty acids provides new insights into determining the trophic base of a complex food web with trophic resources of both terrestrial/aquatic and lacustrine/riverine origins. In addition, directly comparing results from both stable-isotope and fatty-acid analyses provided additional information on selective feeding by sestonfeeding taxa on autochthonous and allochthonous fractions of the seston. 6. The presence of LW in the river channel decreased lake-river coupling by providing alternative basal resources, primarily through increasing high-quality autochthonous production on wood and by providing a superior substratum for net-spinning caddisflies to feed on a fraction of the seston Correspondence: Matthew J. Cashman, richer in essential fatty acids. River management strategies that incorporate instream LW therefore have the potential to alter energy flows and enhance ecosystem productivity by increasin...

show abstract

“…As a result, consumer FA content has often been used as a biomarker of food sources (Iverson ) and as an indicator of habitat quality (Larson et al. ). Fatty acids are an important aspect of food quality for consumers because most metazoans cannot synthesize de novo many of the long‐chained polyunsaturated FAs (PUFAs) necessary for development and immune system function (Ahlgren et al.…”

Section: Introductionmentioning

confidence: 99%

Measuring spatial variation in secondary production and food quality using a common consumer approach in Lake Erie

Larson

Richardson

Evans

et al. 2016

Ecological Applications

Self Cite

View full text Add to dashboard Cite

Lake Erie is a large lake straddling the border of the USA and Canada that has become increasingly eutrophic in recent years. Eutrophication is particularly focused in the shallow western basin. The western basin of Lake Erie is hydrodynamically similar to a large estuary, with riverine inputs from the Detroit and Maumee Rivers mixing together and creating gradients in chemical and physical conditions. This study was driven by two questions: (1) How does secondary production and food quality for consumers vary across this large mixing zone? and (2) Are there correlations between cyanobacterial abundance and secondary production or food quality for consumers? Measuring spatial and temporal variation in secondary production and food quality is difficult for a variety of logistical reasons, so here a common consumer approach was used. In a common consumer approach, individuals of a single species are raised under similar conditions until placed in the field across environmental gradients of interest. After some period of exposure, the response of that common consumer is measured to provide an index of spatial variation in conditions. Here, a freshwater mussel (Lampsilis siliquoidea) was deployed at 32 locations that spanned habitat types and a gradient in cyanobacterial abundance in the western basin of Lake Erie to measure spatial variation in growth (an index of secondary production) and fatty acid (FA) content (an index of food quality). We found secondary production was highest within the Maumee river mouth and lowest in the open waters of the lake. Mussel tissues in the Maumee river mouth also included more eicosapentaenoic and docosapentaenoic fatty acids (EPA and DPA, respectively), but fewer bacterial FAs, suggesting more algae at the base of the food web in the Maumee river mouth compared to open lake sites. The satellite-derived estimate of cyanobacterial abundance was not correlated to secondary production, but was positively related to EPA and DPA content in the mussels, suggesting more of these important FAs in locations with more cyanobacteria. These results suggest that growth of secondary consumers and the availability of important fatty acids in the western basin are centered on the Maumee river mouth.

show abstract

Differences between main-channel and off-channel food webs in the upper Mississippi River revealed by fatty acid profiles of consumers

Cited by 11 publications

References 28 publications

How important are terrestrial organic carbon inputs for secondary production in freshwater ecosystems?

How important are terrestrial organic carbon inputs for secondary production in freshwater ecosystems?

Combined stable‐isotope and fatty‐acid analyses demonstrate that large wood increases the autochthonous trophic base of a macroinvertebrate assemblage

Measuring spatial variation in secondary production and food quality using a common consumer approach in Lake Erie

Contact Info

Product

Resources

About