1
Return

Balanced top-down and bottom-up control in coastal planktonic food webs

delete2026-08-13
delete0
delete
OA
AI
T
TI Thomas Imbert † *
L
LR Lena Rönn †
K
KW Kai Wirtz †
DOI:10.3389/fmars.2026.1858560delete
deleteOriginal
deleteOriginal request for help
deleteShare
deleteSave
Abstract

Abstract

En 中文
Aquatic food webs are controlled by physical and chemical factors (bottom-up) and by predation (top-down) processes. However; the relative importance of these controls is unclear; which impedes the understanding of ecosystem changes due to climatic or anthropogenic forcing. For example; while high nutrient levels are generally considered to shape coastal ecosystems; sustained or even increasing stocks of primary producers in coastal areas with decreasing nutrient input suggests a weak bottom-up control. To unravel the relevance of bottom-up and top-down regulation; we analyze 15 years of environmental conditions and seven trophic groups in the Wadden Sea; Southern North Sea. We use size- and trait- based feeding theory to aggregate species into trophic groups. Based on a novel explorative; theoretical framework linking causal and statistical relations; we correlate fluctuations of biomass on weekly-monthly and annual time scales. We found signs of bottom-up influences on the community structure and growth of phytoplankton during spring blooms. In late spring and summer; phytoplankton blooms seemed to be terminated by grazing with concurrent elevated concentration of zooplankton. In turn; zooplankton and dinoflagellates appeared to be controlled by their prey and by higher trophic levels. These findings provide an ensemble of possible trophic relationships; and suggest a similar importance of top-down processes compared to bottom-up; both at annual and sub-seasonal scales; which indicate an important link between the ecology of higher trophic levels and the plankton food-web and; ultimately; biogeochemical cycling.
Keywords:
phytoplankton
food web
time series analysis
zooplankton
coastal ecosystem
bottom-up control and top-down control

Journal

Frontiers in Marine Science cover
Frontiers in Marine Science
IF:
3
Papers:
2.2K
Citations:
4.0W

Organization

I
Institute of Coastal Systems
Scholars:
8
Papers: 5
Citations: 0
L
lower saxony water management
Scholars:
2
Papers: 1
Citations: 0
Cited Papers

Cited Papers

Citing Papers

Citing Papers