Trophic interactions in Zostera marina beds along the Swedish coast
(2008) In Marine Ecology - Progress Series 369. p.63-76- Abstract
- We compared eelgrass Zostera marina communities in 3 regions in Sweden believed to be affected by eutrophication and overfishing, to determine whether bottom-up or top-down processes control the biomass of epiphytic macroalgae and grazers. Nitrogen and carbon isotope signatures were analyzed to explore the food webs and to identify the grazing species feeding on filamentous algae and/or eelgrass. Mixing model (IsoSource version 1.3.1) analysis of the isotope signatures indicated that the amphipods Gammarus locusta and Microdeutopus gryllotalpa fed primarily on filamentous algae and that only 2 small gastropod species consumed eelgrass. Moreover, the grass shrimp Palaemon elegans and F adspersus were ca. 1 trophic level above amphipods and... (More)
- We compared eelgrass Zostera marina communities in 3 regions in Sweden believed to be affected by eutrophication and overfishing, to determine whether bottom-up or top-down processes control the biomass of epiphytic macroalgae and grazers. Nitrogen and carbon isotope signatures were analyzed to explore the food webs and to identify the grazing species feeding on filamentous algae and/or eelgrass. Mixing model (IsoSource version 1.3.1) analysis of the isotope signatures indicated that the amphipods Gammarus locusta and Microdeutopus gryllotalpa fed primarily on filamentous algae and that only 2 small gastropod species consumed eelgrass. Moreover, the grass shrimp Palaemon elegans and F adspersus were ca. 1 trophic level above amphipods and algae, but according to the mixing model played different trophic roles in the different areas. The highest biomass of filamentous algae was found in the west coast beds housing grazers with the lowest biomass and mean size (predominantly G. locusta and M. gryllotalpa, 0.5 to 3 mm). In contrast, the Baltic Sea beds had low algal biomass, but the grazers (mostly G. locusta and Idotea baltica) had higher biomass and were significantly larger (mean size ca. 10 mm). An overall negative correlation was found between grazer biomass and biomass of filamentous algae. The significantly smaller grazers and absence of isopod grazers on the west coast may be due to substantial consumption by small predatory fish. This supports the suggestions that, in Swedish eelgrass beds, grazers are top-down controlled, and overexploitation. of large predators and eutrophication play an important role in the recent increases in algal biomass. (Less)
Please use this url to cite or link to this publication:
https://lup.lub.lu.se/record/1283029
- author
- Jephson, Therese LU ; Nyström, Per LU ; Moksnes, Per-Olav and Baden, Susanne P.
- organization
- publishing date
- 2008
- type
- Contribution to journal
- publication status
- published
- subject
- keywords
- interactions, Trophic, Mixing model, Stable isotopes, Zostera, Seagrass, Eelgrass
- in
- Marine Ecology - Progress Series
- volume
- 369
- pages
- 63 - 76
- publisher
- Inter-Research
- external identifiers
-
- wos:000260873400006
- scopus:56149114744
- ISSN
- 1616-1599
- DOI
- 10.3354/meps07646
- language
- English
- LU publication?
- yes
- id
- 61d328a6-f344-4038-9e1d-35efb5d8c003 (old id 1283029)
- date added to LUP
- 2016-04-01 12:56:21
- date last changed
- 2022-03-21 07:43:47
@article{61d328a6-f344-4038-9e1d-35efb5d8c003,
abstract = {{We compared eelgrass Zostera marina communities in 3 regions in Sweden believed to be affected by eutrophication and overfishing, to determine whether bottom-up or top-down processes control the biomass of epiphytic macroalgae and grazers. Nitrogen and carbon isotope signatures were analyzed to explore the food webs and to identify the grazing species feeding on filamentous algae and/or eelgrass. Mixing model (IsoSource version 1.3.1) analysis of the isotope signatures indicated that the amphipods Gammarus locusta and Microdeutopus gryllotalpa fed primarily on filamentous algae and that only 2 small gastropod species consumed eelgrass. Moreover, the grass shrimp Palaemon elegans and F adspersus were ca. 1 trophic level above amphipods and algae, but according to the mixing model played different trophic roles in the different areas. The highest biomass of filamentous algae was found in the west coast beds housing grazers with the lowest biomass and mean size (predominantly G. locusta and M. gryllotalpa, 0.5 to 3 mm). In contrast, the Baltic Sea beds had low algal biomass, but the grazers (mostly G. locusta and Idotea baltica) had higher biomass and were significantly larger (mean size ca. 10 mm). An overall negative correlation was found between grazer biomass and biomass of filamentous algae. The significantly smaller grazers and absence of isopod grazers on the west coast may be due to substantial consumption by small predatory fish. This supports the suggestions that, in Swedish eelgrass beds, grazers are top-down controlled, and overexploitation. of large predators and eutrophication play an important role in the recent increases in algal biomass.}},
author = {{Jephson, Therese and Nyström, Per and Moksnes, Per-Olav and Baden, Susanne P.}},
issn = {{1616-1599}},
keywords = {{interactions; Trophic; Mixing model; Stable isotopes; Zostera; Seagrass; Eelgrass}},
language = {{eng}},
pages = {{63--76}},
publisher = {{Inter-Research}},
series = {{Marine Ecology - Progress Series}},
title = {{Trophic interactions in Zostera marina beds along the Swedish coast}},
url = {{http://dx.doi.org/10.3354/meps07646}},
doi = {{10.3354/meps07646}},
volume = {{369}},
year = {{2008}},
}