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L. solidungula productivity in this system has been estimated as 6-10 g C
m 2 year 1 (Dunton and Schell 1986 ) compared to an estimate of up to 20 g C
m 2 year 1 in the Canadian High Arctic (Chapman and Lindley 1980 ). In this area,
however, there are no intertidal algae and seaweeds are restricted to small areas on
hard substrata protected from ice scour (Dunton and Schonberg 2000 ).
At another Arctic location, at Hansneset in the middle part of Kongsfjorden in
Svalbard, seaweed communities are better developed and include a greater diversity
of species. The intertidal zone supports Fucus distichus and smaller brown algae
while the shallow subtidal down to 2.5 m is characterized by several annual or
pseudo-perennial seaweeds (Hop et al. 2002 ; Wulff et al. 2011 ). Important species
are the green algae Acrosiphonia spp., Spongomorpha spp., and the brown algae
Chordaria flagelliformis and Chorda filum (Wulff et al. 2011 ). The zone between 5
and 15 m is dominated by kelps including Saccorhiza dermatodea , Alaria
esculenta, Laminaria digitata , and Saccharina latissima , along with a diversity of
smaller red, green, and brown seaweeds (Wiencke et al. 2004 ). Overall, over 70
seaweed species occur here with wet biomass values ranging from 0.02 to
21 kg m 2 (Hop et al. 2002 ). Below this zone of kelps and kelp-like species
Desmarestia aculeata and D. viridis can be very frequent (Beuchel and Gulliksen
2008 ). At greater depths red algae dominate the community, in particular
Coccotylus truncatus and Phycodrys rubens , the latter growing down to as deep
as 60 m (Wiencke, unpublished data). The endemic Arctic Laminaria solidungula
occurs in deep water in the inner (colder) part of Kongsfjorden or as undergrowth
species in the kelp forest. The inner part of the fjord is characterized by high
sedimentation rates (Svendsen et al. 2002 ) and consequently by a much lower
biodiversity. The described zonation pattern is in principle also typical for the
Russian Arctic coast, eastern Greenland, and the Canadian high Arctic (Wulff
et al. 2011 ).
The few studies on succession in polar seaweed communities were recently
summarized by Campana et al. ( 2011 ). Succession starts with rapid colonizers, e.g.,
diatoms and ephemeral seaweeds and goes on with a recruitment of annual and
perennial seaweed species in late winter-spring. Colonization is severely affected
by physical disturbance and seasonal changes in abiotic conditions including UV
stress (see Chap. 20 by Bischof and Steinhoff; Karsten et al. 2011 ) as well as by
biotic factors, such as grazing (Zacher et al. 2007 ).
13.4.2 Elemental and Nutritional Content
Compared to seaweeds in almost all other parts of the world, Antarctic seaweeds
have relatively low Carbon to Nitrogen (C:N) elemental ratios and relatively high
tissue nitrogen levels (Dhargalkar et al. 1987 ; Weykam et al. 1996 ; Dunton 2001 ;
Peters et al. 2005 ). This indicates that they are unlikely to be growth limited by
nitrogen, which is probably a result of the relatively high nitrogen and other nutrient
levels present in Antarctic coastal waters throughout the year (Weykam et al. 1996 ;
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