Size-Based Structure and Production in the Pelagia of Lakes Ontario and Michigan

1994 ◽  
Vol 51 (11) ◽  
pp. 2603-2611 ◽  
Author(s):  
W. Gary Sprules ◽  
Andy P. Goyke
Keyword(s):  
Particle Size ◽  
Analytical Solutions ◽  
Secondary Production ◽  
Aquatic Ecosystems ◽  
Lake Ontario ◽  
Quadratic Trend ◽  
Periodic Oscillations ◽  
Predator Prey ◽  
Pelagic Food Webs ◽  
Biomass Spectra

Analytical solutions to allometric models of predator–prey interactions in aquatic ecosystems indicate that normalized biomass spectra should consist of a smooth quadratic trend around which periodic oscillations occur. We confirm these assertions by showing that parabolas provide good models of normalized biomass as a function of body mass within homogeneous trophic groupings of organisms (phytoplankton, zooplankton, or fish) in the pelagic food webs of Lakes Ontario and Michigan. In addition, we show that the normalized biomass spectrum for the whole pelagic community in these lakes can be modelled by a series of parabolas of constant curvature that are aligned along a smooth quadratic base, as predicted by theory. Total secondary production in Lake Ontario is predicted from these models to be 234 kcal∙m−2∙yr−1 (1 kcal = 4.19 kJ), which compares favourably with sampling estimates of about 154 kcal∙m−2∙yr−1 for the whole community except rotifers and some hypolimnetic organisms, but both are higher than particle-size conversion efficiency estimates of 75–125 kcal∙m−2∙yr−1.

Particle-Size-Conversion Efficiency and Contaminant Concentrations in Lake Ontario Biota

1983 ◽  
Vol 40 (3) ◽  
pp. 328-336 ◽  
Author(s):  
Uwe Borgmann ◽  
D. M. Whittle
Keyword(s):  
Particle Size ◽  
Body Size ◽  
Conversion Efficiency ◽  
Food Chain ◽  
Lake Ontario ◽  
Dry Weight ◽  
Growth Efficiency ◽  
Fish Production ◽  
The Relationship ◽  
Zooplankton Production

The particle-size-conversion efficiency (log food consumption/production divided by log predator prey size ratio) is shown to be directly related to the relationship between the concentration of persistent contaminants accumulated primarily through the food chain and body size for organisms in pelagic ecosystems. The difference between particle-size-conversion efficiency for biomass and that for the contaminant gives the slope of the relationship between log contaminant concentration and log body size. This provides a useful theoretical framework for analyzing contaminant concentrations in aquatic biota without the need for specifying trophic level but still incorporating the idea of food chain accumulation. Concentrations of PCB, DDT, and mercury were examined in aquatic organisms from Lake Ontario, ranging in size from zooplankton to large salmonids (a 108 -fold range in dry weight). The slope of the double log plot of concentration versus weight varied from 0.20 to 0.22 for PCB and DDT and was approximately equal to 0.13 for mercury. This indicates that mercury is accumulated less efficiently through the food chain than PCB or DDT. After correcting for incomplete uptake and retention of the contaminant, an estimate of particle-size-conversion efficiency for biomass of about 0.26 was obtained, which agrees reasonably well with previous estimates obtained from growth efficiency experiments and analysis of particle-size spectra. These calculations indicate that potential fish production in Lake Ontario is ~ 120-fold lower than zooplankton production (for fish averaging 108-fold larger in body size as compared to zooplankton).Key words: particle-size-conversion efficiency, PCB, DDT, mercury, zooplankton production, fish production

scholarly journals Secondary production as a tool for better understanding of aquatic ecosystems

2012 ◽  
Vol 69 (7) ◽  
pp. 1230-1253 ◽  
Author(s):  
M. Dolbeth ◽  
M. Cusson ◽  
R. Sousa ◽  
M.A. Pardal
Keyword(s):  
Secondary Production ◽  
Aquatic Ecosystems ◽  
Trophic Ecology ◽  
Aquatic Ecology ◽  
Empirical Models ◽  
Ecosystem Dynamics ◽  
Ecological Change ◽  
Production Studies ◽  
Dynamics And Function ◽  
And Function

A major challenge for ecologists is understanding ecosystem dynamics and function under environmental and anthropogenic stresses. An approach for addressing this challenge is the analysis of the different components contributing to secondary production (i.e., consumer incorporation of organic matter or energy per time unit) and how this production is influenced by external factors. Production studies have been recognized as a powerful tool in aquatic ecology, with applications in energy–biomass flow studies, trophic ecology, management of biological resources, as well as assessment of environmental stress. In this paper, we summarize ideas and techniques related to the estimation of secondary production and discuss how this approach may be used to evaluate ecological change in aquatic ecosystems. We include a critical review of classical methods and empirical models to estimate secondary production and provide several applications of production studies to current stresses affecting aquatic ecosystems, such as climate change, pollution, and the introduction of non-indigenous invasive species. Our goal is to illustrate the advantages of using secondary production as a more integrative tool for the assessment of the ecosystem function, in particular when subjected to strong anthropogenic and climatic stress.

Periodic Oscillations in an Ideal-Free Predator-Prey Distribution

Oikos ◽  
1990 ◽  
Vol 59 (1) ◽  
pp. 85 ◽  
Author(s):  
Susanne Schwinning ◽  
Michael L. Rosenzweig
Keyword(s):  
Periodic Oscillations ◽  
Predator Prey ◽  
Prey Distribution ◽  
Ideal Free

scholarly journals Characterizing the Phase Transitions between Stable Equilibrium and Periodic Oscillations in Predator-prey Population Dynamics: A Theoretical Appraisal from an Extended Nicholson & Bailey Model

2020 ◽  
pp. 32-45
Author(s):  
Jean Béguinot
Keyword(s):  
Phase Transitions ◽  
Continuous Phase ◽  
Real Field ◽  
Periodic Oscillations ◽  
Predator Prey ◽  
Host Interactions ◽  
Interacting Species ◽  
Equilibrium Level ◽  
Interactive Dynamics ◽  
Multi Phase

Multi-phase patterns with more or less sharp phase transitions, first highlighted in thermodynamics, have progressively revealed having wider relevance, being encountered in various other contexts, for example fluid mechanics, and can even occur in the interactive dynamics in biological populations involving two or more species that share opposite interests, such as predator-prey or parasite-host pairs of species. In the latter, the pattern of abundances of both interacting species usually reaches an equilibrium level which can be either stable or cyclic (with large periodic oscillations in the latter case). Both alternative modes are separated by well-define boundaries and, accordingly, can relevantly be described in terms of phases and phase transitions. While this has recently been approached from very general perspectives, a more focused analysis is still lacking, regarding the nature of the phase transitions between stable and oscillatory equilibria and – still more importantly – how the nature of these phase transitions may possibly depend (or not) on the biological and contextual factors driving the parasite-host interactive dynamics. These issues are addressed hereafter, on a theoretical basis, yet intimately related to the real field context, by taking advantage of a newly derived extension of the classical Nicholson & Bailey model of parasite-host interactions. Highlighted in particular are the possibility of either first-order, second-order or continuous phase-transitions, depending on (i) the respective own dynamics of both host and parasite, (ii) the density of feeding resource for the host, (iii) the level of migration exchange in a meta-population context.

scholarly journals Biomass and production of Cladocera in Furnas Reservoir, Minas Gerais, Brazil

2010 ◽  
Vol 70 (3 suppl) ◽  
pp. 879-887 ◽  
Author(s):  
RM Santos ◽  
NF. Negreiros ◽  
LC. Silva ◽  
O. Rocha ◽  
MJ. Santos-Wisniewski
Keyword(s):  
Secondary Production ◽  
Aquatic Ecosystems ◽  
Total Production ◽  
In Situ Data ◽  
Production Values ◽  
Physical And Chemical Variables ◽  
Order Of Magnitude ◽  
The Mean ◽  
Physical And Chemical

Secondary production of zooplankton, the main energy pathway in many aquatic ecosystems, is crucial to an Understanding of functioning of these systems function. In this study, we analyzed the magnitude and seasonal variations of the population density, biomass and secondary production of Cladocera in the Furnas Reservoir (Brazil). Samples were carried out monthly at 6 points in the reservoir, from August 2006 to July 2007. Main physical and chemical variables in the water column were measured in situ. Data on density, biomass and development times were obtained and used to calculate the secondary production of eight Cladocera species. The total production of Cladocera varied from 0.02 to 28.6 mgDWm-3.day-1, among the sampling sites. The highest values were recorded in spring and summer months (September to January), and were correlated to the increase in the biomass of the phytoplankton. The mean production:biomass ratio was 0.32. The level of production in Furnas Reservoir fell within the range of those reported in the literature and was of the same order of magnitude of the production values recorded for oligotrophic reservoirs. Cladocera production differed spatially inside the Sapucaí compartment and also in the temporal scale, seasonally.

scholarly journals Analytical Solutions of a Modified Predator-Prey Model through a New Ecological Interaction

2019 ◽  
Vol 2019 ◽  
pp. 1-7 ◽  
Author(s):  
Noufe H. Aljahdaly ◽  
Manar A. Alqudah
Keyword(s):  
Analytical Solutions ◽  
Animal Population ◽  
Hyperbolic Functions ◽  
Sexual Interaction ◽  
Mating Period ◽  
Predator Prey ◽  
Ecological Interaction ◽  
Predator Prey Model ◽  
Prey Model ◽  
Males And Females

The predator-prey model is a common tool that researchers develop continuously to predict the dynamics of the animal population within a certain phenomenon. Due to the sexual interaction of the predator in the mating period, the males and females feed together on one or more preys. This scenario describes the ecological interaction between two predators and one prey. In this study, the nonlinear diffusive predator-prey model is presented where this type of interaction is accounted for. The influence of this interaction on the population of predators and preys is predicted through analytical solutions of the dynamical system. The solutions are obtained by using two reliable and simple methods and are presented in terms of hyperbolic functions. In addition, the biological relevance of the solutions is discussed.

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.

Coexistence of Periodic Oscillations Induced by Predator Cannibalism in a Delayed Diffusive Predator–Prey Model

2019 ◽  
Vol 29 (07) ◽  
pp. 1950089
Author(s):  
Daifeng Duan ◽  
Ben Niu ◽  
Junjie Wei
Keyword(s):  
Hopf Bifurcation ◽  
Center Manifold ◽  
Hopf Bifurcations ◽  
Center Manifold Reduction ◽  
Periodic Oscillations ◽  
Predator Prey ◽  
Predator Prey Model ◽  
Prey System ◽  
Predator Cannibalism ◽  
Manifold Reduction

This paper is concerned with the effect of predator cannibalism in a delayed diffusive predator–prey system. We aim for the case where the corresponding linear system has two pairs of purely imaginary eigenvalues at a critical point, leading to Hopf–Hopf bifurcation. An approach of center manifold reduction is applied to derive the normal form for such nonresonant Hopf–Hopf bifurcations. We find that the system exhibits very rich dynamics, including the coexistence of periodic and quasi-periodic oscillations. Numerically, we show that Hopf–Hopf bifurcation is induced if the strength of the predator cannibalism term belongs to an appropriate interval.

Biomass Spectra of Aquatic Ecosystems in Relation to Fisheries Yield

1992 ◽  
Vol 49 (8) ◽  
pp. 1528-1538 ◽  
Author(s):  
P. R. Boudreau ◽  
L. M. Dickie
Keyword(s):  
Body Size ◽  
Aquatic Ecosystems ◽  
Detailed Data ◽  
Biomass Density ◽  
Short Term ◽  
The World ◽  
Long Term Changes ◽  
Biomass Spectra

The biomass density of aquatic ecosystems can be expressed as an allometric function of organism body size. The log–log plot of this relation, termed the biomass spectrum, is used to compare aquatic ecosystems in various parts of the world. We develop a standardized presentation for several example environments where detailed data on biomass density by body size in the trophic positions, phytoplankton, zooplankton, benthos, and fish, make it possible to establish overall or primary spectral slopes. The basic methodology is adapted for application to other ecosystems where less detailed data are available. Spectra from all the different environments exhibit a uniform low slope, but with different intercepts that appear to reflect ecosystem differences in nutrient circulation and availability. Detail on the secondary structuring at various positions in the trophic system appears to provide information useful for distinguishing between long-term changes in productivity and short-term perturbations in biomass or abundance.

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