Download The 4 Nereis Park Conference 7 -10 July 2014, Plymouth Marine

The 4th Nereis Park Conference
7th-10th July 2014, Plymouth Marine Laboratory
Does macrofauna functional diversity affects bacterial and archaeal diveristy: a field
study from the Belgian part of the North Sea.
Maryam Yazdani Foshtomi1,2, Ulrike Braeckman1, Sofie Derycke1, Anne Willems3, Magda
Vincx1 & Jan Vanaverbeke1
1
Ghent University, Department of Biology, Marine Biology Research Group, Krijgslaan
281/S8, 9000 Ghent, Belgium
2
Iranian National Institute for Oceanography, 9, Etemadzadeh Avenue, West Fatemi Street,
Tehran, Iran
3
Laboratory of Microbiology, Department of Biochemistry and Microbiology, Ghent
University, K/L Ledeganckstraat 35, 9000 Gent, Belgium
ABSTRACT
Experimental and field studies showed that macrofaunal functional diversity affects the
benthic N-cycle. This effect is indirect, and related to the habitat-modifying capacities of
macrofaunal organisms. These can alter characteristics of the communities of the key
players in the N-cyle, the ammonia oxidising bacteria and archaea. Evidence for this was
derived from lab experiment, often with strong ecosystem engineers, but temporal and
spatially replicated research in field situations is still lacking.
We sampled 7 stations on the Belgian part of the North Sea, representing sediment types
ranging from muddy to permeable sediments. Stations were sampled in April, June and
September 2011 to reflect different situations with respect to the phytoplankton bloom.
Macrofaunal functional diversity was calculated as the Bioturbation Potential (BPc).
Additional samples were collected for the analysis of the full bacterial and archaeal
communities. Further analyses were devoted to metabolically active ammonia oxidising
bacteria (AOB) and archaea (AOA), involved in the first and rate-limiting step of nitrification:
ammonia-oxidation, We used a DistLM approach to relate functional diversity of macrofauna
to aspects of diversity (richness, Shannon diversity) of the microbial communities.
Our analyses show that BPc was indeed related to the species richness of total bacterial
communities and AOA. Furthermore, BPc affected Shannon diversity of AOB, while Shannon
diversity of AOB was related to macrofaunal density. This shows that, integrated over a
relatively large geographical and temporal scale, functional diversity of macrofauna is indeed
important for structuring the key players in the N-cycle. This suggests that the
experimentally-derived hypothesis that macrofaunal functional diversity indirectly affects
affects N-cycling by shaping the diversity of the microbial communities, is valid in field
situations as well. It furthermore confirms the capacity of BPc to integrate those functional
aspects of macrofaunal communities needed to link macrofauna, microbes and ecosystem
functions.