Abstract
Many marine ecosystems exhibit a characteristic "wasp-waist" structure, where a single species, or at most several species, of small planktivorous fishes entirely dominate their trophic level. These species have complex life histories that result in radical variability that may propagate to both higher and lower trophic levels of the ecosystem. In addition, these populations have two key attributes: (1) they represent the lowest trophic level that is mobile, so they are capable of relocating their area of operation according to their own internal dynamics; (2) they may prey upon the early life stages of their predators, forming an unstable feedback loop in the trophic system that may, for example, precipitate abrupt regime shifts. Experience with the typical "boom-bust" dynamics of this type of population, and with populations that interact trophically with them, suggests a "predator pit" type of dynamics. This features a refuge from predation when abundance is very low, very destructive predation between an abundance level sufficient to attract interest from predators and an abundance level sufficient to satiate available predators, and, as abundance increases beyond this satiation point, decreasing specific predation mortality and population breakout. A simple formalism is developed to describe these dynamics. Examples of its application include (a) a hypothetical mechanism for progressive geographical habitat expansion at high biomass, (b) an explanation for the out-of-phase alternations of abundances of anchovies and sardines in many regional systems that appear to occur without substantial adverse interactions between the two species groups, and (c) an account of an interaction of environmental processes and fishery exploitation that caused a regime shift. The last is the example of the Baltic Sea, where the cod resource collapsed in concert with establishment of dominance of that ecosystem by the cod's 'wasp-waist" prey, herring and sprat.
| Original language | English |
|---|---|
| Pages (from-to) | 271-288 |
| Number of pages | 18 |
| Journal | Progress in Oceanography |
| Volume | 68 |
| Issue number | 2-4 |
| DOIs | |
| State | Published - Feb 1 2006 |
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Keywords
- Ecosystem management
- Environmental conditions
- Population dynamics
- Predator-prey interaction
- Temporal variation
- Trophic relationships
ASJC Scopus subject areas
- Aquatic Science
- Geology
- Oceanography
Cite this
Wasp-waist populations and marine ecosystem dynamics : Navigating the "predator pit" topographies. / Bakun, Andrew.
In: Progress in Oceanography, Vol. 68, No. 2-4, 01.02.2006, p. 271-288.Research output: Contribution to journal › Article
}
TY - JOUR
T1 - Wasp-waist populations and marine ecosystem dynamics
T2 - Navigating the "predator pit" topographies
AU - Bakun, Andrew
PY - 2006/2/1
Y1 - 2006/2/1
N2 - Many marine ecosystems exhibit a characteristic "wasp-waist" structure, where a single species, or at most several species, of small planktivorous fishes entirely dominate their trophic level. These species have complex life histories that result in radical variability that may propagate to both higher and lower trophic levels of the ecosystem. In addition, these populations have two key attributes: (1) they represent the lowest trophic level that is mobile, so they are capable of relocating their area of operation according to their own internal dynamics; (2) they may prey upon the early life stages of their predators, forming an unstable feedback loop in the trophic system that may, for example, precipitate abrupt regime shifts. Experience with the typical "boom-bust" dynamics of this type of population, and with populations that interact trophically with them, suggests a "predator pit" type of dynamics. This features a refuge from predation when abundance is very low, very destructive predation between an abundance level sufficient to attract interest from predators and an abundance level sufficient to satiate available predators, and, as abundance increases beyond this satiation point, decreasing specific predation mortality and population breakout. A simple formalism is developed to describe these dynamics. Examples of its application include (a) a hypothetical mechanism for progressive geographical habitat expansion at high biomass, (b) an explanation for the out-of-phase alternations of abundances of anchovies and sardines in many regional systems that appear to occur without substantial adverse interactions between the two species groups, and (c) an account of an interaction of environmental processes and fishery exploitation that caused a regime shift. The last is the example of the Baltic Sea, where the cod resource collapsed in concert with establishment of dominance of that ecosystem by the cod's 'wasp-waist" prey, herring and sprat.
AB - Many marine ecosystems exhibit a characteristic "wasp-waist" structure, where a single species, or at most several species, of small planktivorous fishes entirely dominate their trophic level. These species have complex life histories that result in radical variability that may propagate to both higher and lower trophic levels of the ecosystem. In addition, these populations have two key attributes: (1) they represent the lowest trophic level that is mobile, so they are capable of relocating their area of operation according to their own internal dynamics; (2) they may prey upon the early life stages of their predators, forming an unstable feedback loop in the trophic system that may, for example, precipitate abrupt regime shifts. Experience with the typical "boom-bust" dynamics of this type of population, and with populations that interact trophically with them, suggests a "predator pit" type of dynamics. This features a refuge from predation when abundance is very low, very destructive predation between an abundance level sufficient to attract interest from predators and an abundance level sufficient to satiate available predators, and, as abundance increases beyond this satiation point, decreasing specific predation mortality and population breakout. A simple formalism is developed to describe these dynamics. Examples of its application include (a) a hypothetical mechanism for progressive geographical habitat expansion at high biomass, (b) an explanation for the out-of-phase alternations of abundances of anchovies and sardines in many regional systems that appear to occur without substantial adverse interactions between the two species groups, and (c) an account of an interaction of environmental processes and fishery exploitation that caused a regime shift. The last is the example of the Baltic Sea, where the cod resource collapsed in concert with establishment of dominance of that ecosystem by the cod's 'wasp-waist" prey, herring and sprat.
KW - Ecosystem management
KW - Environmental conditions
KW - Population dynamics
KW - Predator-prey interaction
KW - Temporal variation
KW - Trophic relationships
UR - http://www.scopus.com/inward/record.url?scp=33645883270&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=33645883270&partnerID=8YFLogxK
U2 - 10.1016/j.pocean.2006.02.004
DO - 10.1016/j.pocean.2006.02.004
M3 - Article
AN - SCOPUS:33645883270
VL - 68
SP - 271
EP - 288
JO - Progress in Oceanography
JF - Progress in Oceanography
SN - 0079-6611
IS - 2-4
ER -