A review of important concepts in the trophic organization of pelagic ecosystems

Landry, Michael R.

doi:10.1007/bf02207821

Cited by 65 publications

(35 citation statements)

References 37 publications

(30 reference statements)

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“…Historical events often cause switching to other directions (whi& is also a normal process in the pelagic environment: see e.g. Landry, 1977) or a step ba& to earlier stages. An improved theory of community organization, which is necessary for the derivation of models predicting natural and man-influenced behaviour of ecosystems, should consider the existence of both in the marine environment, i.e., multiple stable points and succession-like sequences leading to them.…”

Section: Theoretical Aspects and Conclusionmentioning

confidence: 99%

Development of a subtidal epifaunal community at the island of Helgoland

Anger

1978

Helgolander Wiss. Meeresunters

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Epifaunal community development on plexiglas panels submerged in Helgoland Harbour (North Sea) was observed over one year. The course of colonization is described, and some data are presented on autecology, reproduction, and growth rate of particular species. About three months al~er initial settlement, conditions of coexistence in a mixed barnacle-ascidian community began to change increasingly due to heavy competition for space. The colonial species Botryllus schlosseri proved to be potentially dominant. Shortly before it attained monopolization by replacing barnacles (mainly ElrMnius modestus), a major physical disturbance eliminated the fast growing ascidian. The roles of physical factors, of biological interactions, and of historical events in community development are discussed in context with succession theory and other concepts evolved more recently. It is concluded that succession-like processes can occur in subtidal fouling communities, but there the existence of a globally stable climax is unlikely. Generally the concept of multistable points seems to be better applicable to marine ecosystems than that of succession in the classical sense. There is considerable need for further natural history observations and experiments as an empirical basis for current theory and modelling.

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Section: Theoretical Aspects and Conclusionmentioning

confidence: 99%

Development of a subtidal epifaunal community at the island of Helgoland

Anger

1978

Helgolander Wiss. Meeresunters

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“…Such changes, when coupled with advective processes, may result in asynchronous distributions of larvae and their principle prey (Nelson et al 1977, Lasker 1978, Bailey 1981. Persistent turbulence may also influence zooplankton species composition and food chain length (Greve & Parsons 1977, Landry 1977) and turbulent events (e.g. storms) may dilute aggregations of microzooplankton (Lasker 1978, Lough 1984, Tilseth & Ellertsen 1984.…”

Section: Introductionmentioning

confidence: 99%

Effect of prey abundance and size on the growth and survival of larval fish: an experimental study employing large volume enclosures

Frank¹,

Leggett²

1986

Mar. Ecol. Prog. Ser.

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We examined the effect of natural variations in the concentration and size composition of plankton in coastal waters on the growth and survival of recently hatched larval capelin Mallotus villosus. Known numbers of larvae were stocked into 4 m3 j n sjtu enclosures, containing plankton communities whose size composihon and total particle concentration mirrored those occurnng naturally dunng times when the nearshore waters were alternately dominated by deep upwelled waters, and by warmer surface waters. Daily growth of larvae was unrelated to total plankton concentrahon, but strongly correlated with the concentrahon of plankton in the 40 to 51 pm (esd) size range. Daily mortality was negatively correlated with concentrations of plankton <81 pm (esd). This correlation was strongest with prey in the 32 to 40 pm and 40 to 51 pm (esd) size classes. The in situ concentration of plankton in the optimum size range for growth and survival was temporally dynamic and strongly influenced by wind-driven water mass exchange. The relevance of these findings to previous studies of the effect of prey concentration on growth and survival in larval fishes is discussed.

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“…Our initial interpretation was that the increasing TTE with N to the left of the transition point was attributable to the increased consumption of P l by Z, and the associated shortening of the average length of the food chain (e.g. Ryther 1969, Landry 1977. However, as we shall demonstrate below, the actual explanation lies in the effects of saturating resource utilization.…”

Section: Phase-shift Responses and Trophic Efficiencymentioning

confidence: 95%

“…Previous studies have suggested that major changes in trophic efficiencies may arise with eutrophication via several mechanisms, including alterations in species composition (and attendant nutritional value) of phytoplankton and zooplankton (e.g. Landry 1977, Scavia et al 1988). In addition, there are numerous reports of eutrophication-induced degradation of habitat conditions in lakes (e.g.…”

Section: Concluding Commentsmentioning

confidence: 99%

“…Although it has been suggested that environmentally controlled changes in plankton community structure may alter trophic efficiencies (e.g. Landry 1977, Edmondson 1991, broad quantitative explanations for these postulated relationships between TTE and nutrient enrichment are generally lacking. This uncertainty is disturbing in the light of 2 parallel worldwide trends of increases in both exploitation rates of fish populations (Pauly et al 1998) and nutrient enrichment in marine and freshwater ecosystems (e.g.…”

Section: Introductionmentioning

confidence: 99%

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Nutrient enrichment, habitat variability and trophic transfer efficiency in simple models of pelagic ecosystems

Kemp¹,

Brooks²,

Hood³

2001

Mar. Ecol. Prog. Ser.

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We developed 4 simple numerical models of plankton dynamics to explore how nutrient enrichment and habitat variability might influence the efficiency by which phytoplankton (P) production is transferred to growth of zooplankton (Z) consumers in coastal ecosystems. The 4 models range in complexity from 2 (P and Z) to 5 state variables (including detritus, nutrients, and 2 algal size-groups). The models employ generic equation formulations, which are generally well supported by empirical studies and are widely used in coastal ecosystem modeling. Simulation experiments revealed that trophic transfer efficiency (TTE = zooplankton growth per unit phytoplankton production) tends to be enhanced with increased variability of resources, particularly at low nutrient levels. Numerical and analytical studies also showed that, regardless of resource variability, these model formulations produce a trend of initial enhancement of trophic efficiency with increasing nutrient levels, followed by a marked reduction in efficiency beginning at moderately eutrophic conditions. This precipitous drop in trophic efficiency is attributable to a saturation of the ability of zooplankton to utilize the increased primary production associated with nutrient enrichment. Under these conditions, an increasing fraction of the primary production is shunted to microbial food chains and associated respiratory losses. The steepness of this reduction in trophic efficiency with nutrient enrichment is related to the strength of predation (or disease) control at upper trophic levels. Model formulations simulating more intense top-down control (i.e. increasing mortality rates with increasing Z abundance) resulted in sharper declines in TTE with increasing nutrients. We speculate that these model results may help to explain how observed reductions in relative fish yield (per unit primary production) in many shallow nutrient-enriched estuaries and lakes are related to interacting effects of cultural eutrophication and intense fisheries exploitation. Furthermore, we surmise that these relationships are robust characteristics of most existing aquatic ecosystem models.

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A review of important concepts in the trophic organization of pelagic ecosystems

Cited by 65 publications

References 37 publications

Development of a subtidal epifaunal community at the island of Helgoland

Development of a subtidal epifaunal community at the island of Helgoland

Effect of prey abundance and size on the growth and survival of larval fish: an experimental study employing large volume enclosures

Nutrient enrichment, habitat variability and trophic transfer efficiency in simple models of pelagic ecosystems

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