Trophic responses to nutrient enrichment in a temperate seagrass food chain

York, Paul H., Kelaher, Brendan P., Booth, David J. and Bishop, Melanie J. 2012, Trophic responses to nutrient enrichment in a temperate seagrass food chain, Marine ecology progress series, vol. 449, pp. 291-296, doi: 10.3354/meps09541.

Attached Files
Name Description MIMEType Size Downloads

Title Trophic responses to nutrient enrichment in a temperate seagrass food chain
Author(s) York, Paul H.
Kelaher, Brendan P.
Booth, David J.
Bishop, Melanie J.
Journal name Marine ecology progress series
Volume number 449
Start page 291
End page 296
Total pages 6
Publisher Inter-Research
Place of publication Oldendorf, Germany
Publication date 2012-03-08
ISSN 0171-8630
Keyword(s) epiphytes
functional response
ratio dependence
resource dependence
trophic dynamics
Summary Simple ecological models that predict trophic responses to bottom-up forcing are valuable tools for ecosystem managers. Traditionally, theoretical ecologists have used resource-dependent functional responses to explain the modification of food chains exposed to bottom-up perturbations. These models predict alternating positive, negative and zero responses at each trophic level. More recently, ratio-dependent functional response models that predict proportional increases at each level have challenged this paradigm. The present study tested the predictions of the 2 hypotheses empirically by comparing the relative biomasses of 4 trophic levels of an estuarine seagrass food chain in relatively undisturbed, low-nutrient catchments and ‘developed’ catchments subjected to a prolonged period of nutrient enrichment. We found that nutrient-enriched sites had significantly greater biomass of both epiphytic algae and grazing invertebrates; however, the bottom-up forcing of nutrients was attenuated at higher trophic levels (occupied by juvenile and piscivorous fish), with no significant effect of catchment development. This disconnect in the upward cascade of energy may be due to a number of possible reasons including high levels of diversity and omnivory, trophic subsidy within the system or the strength or nature of perturbations. Although the predictions of both hypotheses failed to hold across all trophic groups, ratio dependence was prevalent at the lower levels of the food chain, which has implications for catchment management.
Language eng
DOI 10.3354/meps09541
Field of Research 050102 Ecosystem Function
060205 Marine and Estuarine Ecology (incl Marine Ichthyology)
060202 Community Ecology (excl Invasive Species Ecology)
Socio Economic Objective 960802 Coastal and Estuarine Flora, Fauna and Biodiversity
HERDC Research category C1.1 Refereed article in a scholarly journal
Copyright notice ©2012, Inter-Research
Persistent URL

Connect to link resolver
Unless expressly stated otherwise, the copyright for items in DRO is owned by the author, with all rights reserved.

Version Filter Type
Citation counts: TR Web of Science Citation Count  Cited 5 times in TR Web of Science
Scopus Citation Count Cited 5 times in Scopus
Google Scholar Search Google Scholar
Access Statistics: 102 Abstract Views, 2 File Downloads  -  Detailed Statistics
Created: Mon, 03 Sep 2012, 14:11:14 EST

Every reasonable effort has been made to ensure that permission has been obtained for items included in DRO. If you believe that your rights have been infringed by this repository, please contact