Changes in the δ13C of pelagic food webs: the influence of lake area and trophic status on the isotopic signature of whitefish (Coregonus lavaretus)

2004 ◽  
Vol 61 (8) ◽  
pp. 1485-1492 ◽  
Author(s):  
Marie-Elodie Perga ◽  
Daniel Gerdeaux
Keyword(s):  
Food Web ◽  
Food Webs ◽  
Trophic Status ◽  
Dissolved Inorganic Carbon ◽  
Alpine Lakes ◽  
Coregonus Lavaretus ◽  
Lake Area ◽  
Pelagic Food Web ◽  
Pelagic Food Webs ◽  
Lake Size

We investigated the relationships between the pattern of variation of δ13C in pelagic food webs and various morphologic and trophic characteristics of peri-alpine lakes. We used the δ13C of whitefish (Coregonus lavaretus), a long-lived zooplanktivorous fish, to assess the isotope ratio of dissolved inorganic carbon (DIC) at the origin of the pelagic food web. The δ13C of DIC depends on its origin, which may be the atmosphere or the mineralization of organic matter. A synchronic study of 22 peri-alpine lakes shows that the surface area of the lake accounts for much of the variability of the δ13C in pelagic food webs (r2 = 0.76). The δ13C increases with lake size, which suggests that the origin of the DIC integrated into the pelagic food web depends on lake size. To differentiate the influence of trophic status from morphological effects, a diachronic study was performed on the δ13C of fish scales collected over the 20-year re-oligotrophication of Lake Geneva. The δ13C of whitefish increased with phosphorus concentration (r2 = 0.71). This pattern is related to the growing demand for atmospheric DIC as primary production increases.

Effect of Somatic Growth and Reproduction on Biomass Transfer up Pelagic Food Webs as Calculated from Particle-Size-Conversion Efficiency

1983 ◽  
Vol 40 (11) ◽  
pp. 2010-2018 ◽  
Author(s):  
Uwe Borgmann
Keyword(s):  
Particle Size ◽  
Food Web ◽  
Food Webs ◽  
Conversion Efficiency ◽  
Somatic Growth ◽  
Mysis Relicta ◽  
Biomass Transfer ◽  
Pelagic Food Webs ◽  
Simple Equations ◽  
Growth And Reproduction

Biomass or energy transfer up pelagic food webs to larger sized organisms is a function of (1) direct trophic level transfer through predation, (2) somatic growth, a process that augments biomass transfer through predation, and (3) reproduction, which impedes biomass transfer by moving biomass down the food web to smaller sizes. By assuming that particle-size-conversion efficiency (log (food consumed/biomass produced)/log (predator–prey size ratio)) is relatively constant, I derive simple equations to calculate the effect of somatic growth and reproduction on biomass transfer up the food web. This defines the conditions under which somatic growth and reproduction can be ignored and biomass flow can be calculated from predation alone, using a previously developed model. When these conditions are not met, the effect of somatic growth and reproduction can be calculated from data on cohort growth and mortality rates. It is not necessary to identify the food of any species. This eliminates one of the problems often encountered when modeling food webs. I have applied these equations to production of Mysis relicta. If the estimates of Mysis abundance and growth rates are correct, then size-corrected production is about 25% greater for this species when somatic growth is accounted for in the calculations. This is because mortality of young Mysis appears to be low and most production occurs during somatic growth and not during reproduction.

Interactions with the Benthos Alter Pelagic Food Web Structure in Coastal Waters

1991 ◽  
Vol 48 (11) ◽  
pp. 2276-2284 ◽  
Author(s):  
Barbara K. Sullivan ◽  
Peter H. Doering ◽  
Candace A. Oviatt ◽  
Aimee A. Keller ◽  
Jeffrey B. Frithsen
Keyword(s):  
Food Web ◽  
Water Column ◽  
Coastal Waters ◽  
Benthic Communities ◽  
Food Web Structure ◽  
Web Structure ◽  
Pelagic Food Web ◽  
High Nutrient ◽  
Pelagic Food Webs ◽  
Benthic Pelagic Coupling

Results from studies in experimental enclosures containing both water column and benthic communities show that the benthos has an important effect on the structure and productivity of pelagic food webs whether the system is nutrient enriched or nutrient limited. Research over a 10-yr period in 13-m3 mesocosms showed that changes in the pelagic food web were correlated with different sediment communities and with the presence or absence of a benthos. The abundance of copepods was inversely correlated with numbers of macrofauna. At both low and high nutrient levels, systems without benthos had greatly enhanced numbers of carnivorous holozooplankton including ctenophores, medusans, chaetognaths, and fish. Our observations indicate that the presence of the benthos shortens the pelagic food web.and inhibits the response of pelagic fauna to nutrient enrichment in well-mixed coastal waters. The strength of benthic–pelagic coupling, which is controlled by the amount of turbulence in the water column, may be more important to food web structure than the rate of nutrient supply and could determine which subsystem responds to eutrophication.

Pelagic Food Web Structure in Acidic Adirondack Mountain, New York, Lakes of Varying Humic Content

1993 ◽  
Vol 50 (12) ◽  
pp. 2688-2691 ◽  
Author(s):  
Karl E. Havens
Keyword(s):  
New York ◽  
Food Web ◽  
Species Number ◽  
Lake Area ◽  
Food Web Structure ◽  
Web Structure ◽  
Pelagic Food Web ◽  
Adirondack Mountain ◽  
Acid Waters ◽  
Total P

Pelagic food web models were constructed for 28 acidic (pH < 5.0) Adirondack Mountain lakes, and multiple regression analyses were done to quantify relationships between abiotic variables (DOC, monomeric Al, total P, and H+ concentrations and lake area) and three food web attributes (number of species, number of links, and links per species) Regression models contained log DOC and H+ as significant predictors of food web structure. The models explained over 35% of the variation in species, links and links per species; most of the variation was explained by log DOC. Species, links and links per species increased as DOC increased from <2 to roughly 4 mg∙L−1. At higher DOC levels, the food web attributes reached plateaus at 35 species, 120 links, and 4 links per species. The results support the view that in acidic lakes, DOC ameliorates the toxic effects of Al, so that above a saturating DOC level of approximately 4 mg∙L−1, Al-sensitive biota can exist in acid waters. Hence, food webs of high DOC acid lakes are larger and more complex than their low DOC counterparts.

scholarly journals A novel approach to quantifying trophic interaction strengths and impact of invasive species in food webs

2021 ◽  
Author(s):  
Edoardo Calizza ◽  
Loreto Rossi ◽  
Giulio Careddu ◽  
Simona Sporta Caputi ◽  
Maria Letizia Costantini
Keyword(s):  
Invasive Species ◽  
Food Web ◽  
Food Webs ◽  
Fish Species ◽  
Trophic Interaction ◽  
Coregonus Lavaretus ◽  
Commercial Fish ◽  
Novel Approach ◽  
Allochthonous Species ◽  
The Impact

AbstractMeasuring ecological and economic impacts of invasive species is necessary for managing invaded food webs. Based on abundance, biomass and diet data of autochthonous and allochthonous fish species, we proposed a novel approach to quantifying trophic interaction strengths in terms of number of individuals and biomass that each species subtract to the others in the food web. This allowed to estimate the economic loss associated to the impact of an invasive species on commercial fish stocks, as well as the resilience of invaded food webs to further perturbations. As case study, we measured the impact of the invasive bass Micropterus salmoides in two lake communities differing in food web complexity and species richness, as well as the biotic resistance of autochthonous and allochthonous fish species against the invader. Resistance to the invader was higher, while its ecological and economic impact was lower, in the more complex and species-rich food web. The percid Perca fluviatilis and the whitefish Coregonus lavaretus were the two species that most limited the invader, representing meaningful targets for conservation biological control strategies. In both food webs, the limiting effect of allochthonous species against M. salmoides was higher than the effect of autochthonous ones. Simulations predicted that the eradication of the invader would increase food web resilience, while that an increase in fish diversity would preserve resilience also at high abundances of M. salmoides. Our results support the conservation of biodiverse food webs as a way to mitigate the impact of bass invasion in lake ecosystems. Notably, the proposed approach could be applied to any habitat and animal species whenever biomass and diet data can be obtained.

Effects of Ocean Acidification on Pelagic Organisms and Ecosystems

2011 ◽  
Author(s):  
Ulf Riebesell ◽  
Philippe D. Tortell
Keyword(s):  
Ocean Acidification ◽  
Food Web ◽  
Food Webs ◽  
Spatial Scales ◽  
Scale Up ◽  
Carbonate System ◽  
Marine Food Web ◽  
Pelagic Food Webs ◽  
Carbon Pump ◽  
Marine Food

Over the past decade there has been rapidly growing interest in the potential effects of ocean acidification and perturbations of the carbonate system on marine organisms. While early studies focused on a handful of phytoplankton and calcifying invertebrates, an increasing number of investigators have begun to examine the sensitivity to ocean acidification of various planktonic and benthic organisms across the marine food web. Several excellent review articles have recently summarized the rapidly expanding literature on this topic (Fabry et al. 2008; Doney et al. 2009 ; Joint et al. 2011). The focus of this chapter is on the potential ecosystem-level effects of ocean acidification. Starting with a brief review of the basic physical, chemical, and biological processes which structure pelagic marine ecosystems, the chapter explores how organismal responses to perturbations of the carbonate system could scale up in both time and space to affect ecosystem functions and biogeochemical processes. As with many chapters in this volume, and indeed much of the ocean acidification literature at present, our review raises more questions than it answers. It is hoped that these questions will prove useful for articulating and addressing key areas of future research. Complexity in marine pelagic food webs results from the interactions of multiple trophic levels across a range of temporal and spatial scales. The traditional view of marine food webs (Steele 1974) involved a relatively short trophic system in which large phytoplankton (e.g. net plankton such as diatoms) were grazed by a variety of mesozooplankton (e.g. copepods), which were in turn consumed by second-level predators, including many economically important fish and invertebrate species. This ‘classic’ marine food web is typical of high-productivity regions such as coastal upwelling regimes (Lassiter et al. 2006). A characteristic feature of these systems is a strong decoupling between primary production and grazing, which results from the different metabolic rates of consumers and producers and, in many cases, ontogenetic and seasonal delays in the emergence of feeding predators. The uncoupling between phytoplankton and their consumers leads to significant export of organic material out of the euphotic zone, the so-called biological carbon pump (discussed further below).

Stable carbon isotopes as pelagic food web tracers in adjacent shelf and slope regions off British Columbia, Canada

1999 ◽  
Vol 56 (12) ◽  
pp. 2477-2486 ◽  
Author(s):  
R Ian Perry ◽  
Peter A Thompson ◽  
David L Mackas ◽  
Paul J Harrison ◽  
Douglas R Yelland
Keyword(s):  
British Columbia ◽  
Food Web ◽  
Food Webs ◽  
Stable Carbon Isotopes ◽  
Water Mass ◽  
Larval Fish ◽  
Deep Ocean ◽  
Food Web Interactions ◽  
Deep Ocean Water ◽  
Pelagic Food Webs

Surveys were conducted in spring 1992 to examine the use of 13C/12C ratios to differentiate pelagic food webs and to trace food web interactions between adjacent continental shelf and slope/deep ocean environments off southwestern British Columbia, Canada. Salinity was used to define shelf or slope/deep ocean water masses and their productivity conditions because eddies and meanders at the shelf break were observed to draw water off the shelf. The 13C/12C ratio of plankton was related to the mean upper layer (0-50 m) salinity. 13C abundance was enriched (relative to 12C) in the shelf water mass compared with the slope water mass. This enrichment persisted up the food web from particulate organic matter through three size-classes of zooplankton to larval fish. The cross-shelf spatial scale separating these food webs, as determined from spatial semivariograms of 13C/12C and the upper layer mean salinity, was 40-45 km, similar to the Rossby radius for eddies at this location (50 km). Larval fish may provide a means to monitor exchanges of plankton between geographically adjacent food webs if time scales for incorporation of new isotope signatures from diets into tissues are determined.

Using ratios of stable nitrogen and carbon isotopes to characterize the biomagnification of DDE, mirex, and PCB in a Lake Ontario pelagic food web

1995 ◽  
Vol 52 (12) ◽  
pp. 2660-2674 ◽  
Author(s):  
Richard M. Kiriluk ◽  
Mark R. Servos ◽  
D. Michael Whittle ◽  
Gilbert Cabana ◽  
Joseph B. Rasmussen
Keyword(s):  
Stable Isotopes ◽  
Food Web ◽  
Trophic Status ◽  
Lake Trout ◽  
Trophic Position ◽  
Lake Ontario ◽  
Osmerus Mordax ◽  
Rainbow Smelt ◽  
Slimy Sculpin ◽  
Pelagic Food Web

Stable isotopes of nitrogen (δ15N) and carbon (δ13C) were used to describe the trophic status and interactions of biota characteristic of a Lake Ontario pelagic food web. Stable isotopes of nitrogen were further used to characterize the relationship between an organism's trophic position and the biomagnification of specific hydrophobic contaminants through this food web. The δ15N defines the relative trophic status as (i) the top predator, lake trout (Saivelinus namaycush); (ii) prey species, alewife (Alosa pseudoharengus), rainbow smelt (Osmerus mordax), and slimy sculpin (Cottus cognatus); (iii) macroinvertebrates, mysids (Mysis relicta), and amphipods (Diporeia hoyi); (iv) net zooplankton, dominated by cyclopoids (Diacyclops thomasi) and cladocerans (Bosmina longirostris); and (v) net phytoplankton, dominated by diatoms (Melosira spp.). The separation of the four fish species, lake trout and associated prey items (alewife, rainbow smelt, and slimy sculpin), on the basis of their mean δ13C signatures complements what is known about the preferred diet of these fishes. The enrichment of 15N through this food web indicates that there is a strong correlation between the biomagnification of persistent lipophilic contaminants (p,p′-DDE, mirex, and PCB) and the relative trophic status of an organism as described by stable isotopes of nitrogen.

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