~.2 BIOgeochemical Processes and Interactions
121
Spio martinensis and Nepthys hombergi appeared frequently. The Mytilus-Lanicecommunity was more diverse in topography and habitat heterogeneity. The infauna
here was dominated by oligochaetes, Aphelochaeta marioni, Heteromastus filiformis and Capitella capitata. Typical epifaunal organisms, as they were described
from more stable mussel beds in the North Frisian Wadden Sea (Dittmann 1990),
were missing. Table 5.2.3 summarizes the most important characteristics of the
two major benthic communities distinguished on the Swinnplate (Bergfeld 1996).
Comparing the mussel bed (SP I) and sandflat reference site (SP6) showed distinct benthic assemblages differing in the species composition, abundance and
biomass (Krtincke, unpubl. data). In multivariate analyses, the sandflat site (SP6)
was always separated from the mussel bed site (SPI) for both the abundances as
well as the biomass of the macrobenthos. In the mussel bed, small, fast-growing,
opportunistic polychaetes (r-strategist) dominated the benthic community whereas
deeper-dwelling polychaetes occurred in the sandflat.
Along the transect with increasing distance from the centre of the mussel bed,
species numbers, abundances and biomass decreased in the direction of the sandtlat. Compared to site SP3 (Lanice-site), quantitative parameters for macrofauna
(species numbers, abundances and biomass) were lower at the old mussel bed
(sites SP I +2). Abundances of macrofauna organisms were also lower at these sites
in comparison to site SP5 with the new settlement of blue mussels. However, the
initial trend along the transect was not as pronounced in all study years and was
also subject to seasonal variations.
Table 5.2.3. Characteristics of the macrofauna surveyed on the Swinnplate in 1994/95 by
Bergfeld ( 1996)
parameter
sandflat
concentration of organic low
matter
hiogenic influence
hioturhation
sediment surface and -
homogeneous, structure-poor
structure
sediment turnover
macrofauna
community
characteristic species
high
poor in hiomass, species and
Individuals
Arenico/({
Seolop/os armiger,
Spio marlinensis,
HwiroiJia u/vae,
Eleone tonga,
Nepthrs homgergii,
Pygospio e/egal1s
mussel bed
high
hioscdimentation
heterogeneous, structure-rich
low-medium
rich in hiomass. species and
individuals
Mytilus-Lanice
Oligochaeta,
Aphelochaela marioni,
Capitella capitata
feeding-type
surface deposit-feeder. carnivore suhsurface deposit-feeder. ompolychaetes. grazers
nivore polychaetes, filter feeder
121
Spio martinensis and Nepthys hombergi appeared frequently. The Mytilus-Lanicecommunity was more diverse in topography and habitat heterogeneity. The infauna
here was dominated by oligochaetes, Aphelochaeta marioni, Heteromastus filiformis and Capitella capitata. Typical epifaunal organisms, as they were described
from more stable mussel beds in the North Frisian Wadden Sea (Dittmann 1990),
were missing. Table 5.2.3 summarizes the most important characteristics of the
two major benthic communities distinguished on the Swinnplate (Bergfeld 1996).
Comparing the mussel bed (SP I) and sandflat reference site (SP6) showed distinct benthic assemblages differing in the species composition, abundance and
biomass (Krtincke, unpubl. data). In multivariate analyses, the sandflat site (SP6)
was always separated from the mussel bed site (SPI) for both the abundances as
well as the biomass of the macrobenthos. In the mussel bed, small, fast-growing,
opportunistic polychaetes (r-strategist) dominated the benthic community whereas
deeper-dwelling polychaetes occurred in the sandflat.
Along the transect with increasing distance from the centre of the mussel bed,
species numbers, abundances and biomass decreased in the direction of the sandtlat. Compared to site SP3 (Lanice-site), quantitative parameters for macrofauna
(species numbers, abundances and biomass) were lower at the old mussel bed
(sites SP I +2). Abundances of macrofauna organisms were also lower at these sites
in comparison to site SP5 with the new settlement of blue mussels. However, the
initial trend along the transect was not as pronounced in all study years and was
also subject to seasonal variations.
Table 5.2.3. Characteristics of the macrofauna surveyed on the Swinnplate in 1994/95 by
Bergfeld ( 1996)
parameter
sandflat
concentration of organic low
matter
hiogenic influence
hioturhation
sediment surface and -
homogeneous, structure-poor
structure
sediment turnover
macrofauna
community
characteristic species
high
poor in hiomass, species and
Individuals
Arenico/({
Seolop/os armiger,
Spio marlinensis,
HwiroiJia u/vae,
Eleone tonga,
Nepthrs homgergii,
Pygospio e/egal1s
mussel bed
high
hioscdimentation
heterogeneous, structure-rich
low-medium
rich in hiomass. species and
individuals
Mytilus-Lanice
Oligochaeta,
Aphelochaela marioni,
Capitella capitata
feeding-type
surface deposit-feeder. carnivore suhsurface deposit-feeder. ompolychaetes. grazers
nivore polychaetes, filter feeder