Related Experiment Video
Updated: Aug 8, 2026
12:24
Laboratory Estimation of Net Trophic Transfer Efficiencies of PCB Congeners to Lake Trout (Salvelinus namaycush) from Its Prey
Published on: August 29, 2014
Maximal yields from multispecies fisheries systems: rules for systems with multiple trophic levels
Hiroyuki Matsuda1, Peter A Abrams
1Faculty of Environment and Information Sciences, Yokohama National University, 79-7, Tokiwadai, Hodogaya-ku, Yokohama, Kanagawa 240-8501 Japan. matsuda@ynu.ac.jp
Summary
Maximizing economic yield from food webs often leads to species extinctions, with optimal strategies typically harvesting only one trophic level. Biodiversity conservation constraints can increase harvested species but may reduce total yield.
Area of Science:
- Ecology
- Marine Biology
- Fisheries Science
Background:
- Centralized fisheries management and food-web knowledge prompt efforts to maximize economic yield from entire ecosystems.
- Current analyses of yield-maximizing strategies are limited, especially beyond simple predator-prey interactions.
Purpose of the Study:
- To investigate yield-maximizing exploitation strategies in complex food webs using simple models.
- To understand the impact of indirect effects and species eradication on ecosystem stability and yield.
Main Methods:
- Utilized simple food-web models, including three- and six-species systems across multiple trophic levels.
- Simulated yield- or profit-maximizing exploitation strategies under various conditions.
Main Results:
- Optimal strategies often involve harvesting few species, typically from a single trophic level, leading to significant species loss.
- Extinctions result from indirect harvesting effects and intentional eradication of non-target species.
- Direct density dependence in consumers and biodiversity conservation constraints alter harvest policies.
Conclusions:
- Yield-maximizing fisheries can lead to substantial biodiversity loss, with top predators rarely included in optimal strategies.
- Biodiversity conservation constraints can increase harvested species but may decrease overall yield.
- Understanding food-web dynamics is crucial for sustainable fisheries management.
Related Concept Videos
01:35Trophic Levels
All organisms in an ecosystem occupy a trophic level in the food chain. The lowest level consists of primary producers, which synthesize their food from either solar or chemical energy. Each subsequent level obtains energy from the levels below. Detritivores can occupy any of the levels above primary producers.
00:46Trophic Efficiency
Trophic level transfer efficiency (TLTE) is a measure of the total energy transfer from one trophic level to the next. Due to extensive energy loss as metabolic heat, an average of only 10% of the original energy obtained is passed on to the next level. This pattern of energy loss severely limits the possible number of trophic levels in a food chain.
00:48Optimal Foraging
How animals obtain and eat their food is called foraging behavior. Foraging can include searching for plants and hunting for prey and depends on the species and environment.
01:24Freshwater Microbial Ecology
Freshwater systems such as streams, rivers, and lakes exhibit distinct physical and biological characteristics that influence their microbial communities. These environments are broadly categorized into lotic systems—those with flowing waters like streams and most rivers—and lentic systems, which include still or slow-moving waters such as lakes, ponds, and marshes.In lentic systems, phytoplankton drive primary production, generating autochthonous organic carbon. In contrast, lotic systems...
01:15Determination of Multiple Dosing Parameters: Steady-State, Minimum and Maximum Concentrations
Gentamicin, an aminoglycoside antibiotic, is commonly administered via intermittent intravenous infusion to treat severe infections. An intermittent one-hour infusion of gentamicin, administered at eight-hour intervals, allows for precise control of plasma drug concentrations, minimizing toxicity while ensuring therapeutic efficacy. Pharmacokinetic principles govern the dynamics of plasma concentrations and can be mathematically described using specific equations.The plasma drug concentration...
01:27Growth Models with Integration: Problem Solving
In population modeling, integration provides a systematic way to determine accumulated quantities from known rates of change. One such application arises in ecology, where the total weight of a fish population in a body of water is referred to as its biomass. When the rate of growth of this biomass is known as a function of time, calculus can be used to determine the total biomass at a future date.Growth Rate and Biomass FunctionLet the growth rate of the fish population be represented by a...