Pond Boss Forums INTRO Questions & Observations Fish Bioenergetics - the basic rule of energy use

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Applications of Bioenergetics Models to Fish Ecology and Management: Where Do We Go from Here?
MICHAEL J. HANSEN, DANIEL BOISCLAIR, STEPHEN B. BRANDT , STEVEN W. HEWETT, JAMES F. KITCHELL, MARTYN C. LUCAS, and JOHN J. NEY


Bioenergetics models have been applied to a variety of research and management questions relating to fish stocks, populations, food webs, and ecosystems. Applications include estimates of the intensity and dynamics of predator–prey interactions, nutrient cycling within aquatic food webs of varying trophic structure, and food requirements of single animals, whole populations, and communities of fishes. As tools in food web and ecosystem applications, bioenergetics models have been used to compare forage consumption by salmonid predators across the Laurentian Great Lakes for single populations and whole communities, and to estimate the growth potential of pelagic predators in Chesapeake Bay and Lake Ontario.


Development and Test of a Whole-Lifetime Foraging and Bioenergetics Growth Model for Drift-Feeding Brown Trout
John W. Hayes, John D. Stark, and Karen A. Shearer



We developed and tested a combined foraging and bioenergetics model for predicting growth over the lifetime of drift-feeding brown trout. The foraging component estimates gross energy intake within a fish- and prey size-dependent semicircular foraging area that is perpendicular to the flow, with options for fish feeding across velocity differentials. The bioenergetics component predicts how energy is allocated growth, reproduction, foraging costs, and basal metabolism. The model can reveal the degree to which growth is limited by the density and size structure of invertebrate drift within the physiological constraints set by water temperature.



Bioenergetics Modeling in the 21st Century:

Reviewing New Insights and Revisiting Old Constraints

STEVEN R. CHIPPS*

U.S. Geological Survey, South Dakota Cooperative Fish and Wildlife Research Unit, Department of Wildlife
and Fisheries Sciences, South Dakota State University, Brookings, South Dakota 57007, USA

DAVID H. WAHL

Illinois Natural History Survey, Division of Ecology and Conservation Science, Kaskaskia Biological Station,

Rural Route 1, Box 157, Sullivan, Illinois 61951, USA



Bioenergetics models provide a sound theoretical

approach for estimating energy allocation in animals by

partitioning consumed energy into three basic components:

(1) metabolism, (2) wastes, and (3) growth

(Winberg 1956). Because the models are based on

mass-balance equations, they are often used to estimate

growth or consumption given information on other

variables. Bioenergetics models are particularly attractive

for estimating food consumption by free-ranging

fishes because of the time and effort required for more

traditional approaches (Kitchell et al. 1977). Today

these models are widely used as a tool in fisheries

management and research; the availability of userfriendly

software has led to the popularity of

bioenergetics models (Figure 1; Hanson et al. 1997).

Nonetheless, the proliferation of bioenergetics modeling

has not been without controversy (Ney 1993).



Model Development

Like other mathematical models, bioenergetics

models are simplifications of reality. How well they

describe the real world depends on appropriate

parameterization of the model and the accuracy of

input data used to drive them (Bartell et al. 1986).

Consider, for example, the variables used to estimate

fish respiration. Respiration rate is usually measured

across a range of fish sizes and water temperatures and

then expressed as a function of these two variables. In

most cases, such formulations provide reasonable

estimates of respiration rate. But what if other factors,

such as dissolved oxygen concentration, also affect

respiration rate? Applying the model under variable

oxygen concentrations, we might find that respiration

rate is poorly defined because our parameter estimate is

based on incomplete data.





Model Evaluation

Because bioenergetics models are based on a sound

theoretical footing (e.g., thermodynamics), they provide

a useful template for evaluating energy flow.

Indeed, there is no evidence that conceptual models for

mass-balance energy budgets are wrong (Ney 1993).

When model output poorly represents observed data,

one of several things may be true: (1) the model is

incorrectly parameterized, (2) the input data used to

drive the model are inaccurate, (3) the independent data

being compared with the model results are wrong, or

(4) some combination of the above.