Intertidal and subtidal soft-bottom macro- and meiofauna of the Kongsfjord (Spitsbergen)

The intertidal and subtidal soft bottom macro- and meiofauna of a glacier fjord on Spitsbergen was studied after complete ice melt in June 2003. The abundances of the benthic fauna were within the range reported from estuaries and similar intertidal areas of boreal regions. The high proportion of juveniles in the eulittoral zone indicated larval recruitment from subtidal areas. The macrobenthic fauna can be divided into an intertidal and a subtidal community, both being numerically dominated by annelids. Deposit feeders were numerically predominant in intertidal sites, whereas suspension feeders were most abundant in the subtidal area. Among the meiofauna, only the benthic copepods were identified to species, revealing ecological adaptations typical for intertidal species elsewhere.     

Soft-bottom macrobenthic faunal associations and factors affecting species distributions in an Arctic glacial fjord (Kongsfjord,Spitsbergen)

The Kongsfjord (west Spitsbergen) hosts the most active glacier on the island. Therefore the glacial impact on the marine ecosystem is very pronounced and easily recognisable. The study examines the influence of the steep glacier-derived environmental gradients on dominant macrofaunal species distributions and faunal associations in the fjord. The macrobenthic fauna was sampled by van Veen grab at 30 stations situated throughout the fjord (at depths 38–380 m). Two major communities were recognised. An inner basin receives the outflows from three glaciers and is occupied by a Glacial Bay Community dominated by small, surface detritus-feeders, with Chone paucibranchiata and a set of thyasirid and nuculanid bivalves (Thyasira dunbari, Yoldiella solidula, Y. lenticula) as characteristic species. An outer basin of the fjord is characterised by a common set of dominant species, including Heteromastus filiformis, Maldane sarsi, Levinsenia gracilis, Lumbrineris sp. and Leitoscoloplos sp. Three associations may be distinguished within the Outer Basin Community. Association TRANS is of transitional character, with Nuculoma tenuis and Terebellides stroemi. Association CENTR is the most typical for the community. It is dominated by tube-dwelling Prionospio sp., Clymenura polaris, Galathowenia oculata and Spiochaetopterus typicus. Association ENTR contains shelf benthos elements, e.g. Ophiura robusta and Lepeta caeca. An opportunistic eurytopic Chaetozone group is present throughout the fjord and its density and dominance increase with proximity to the glaciers. Dominant species distribution is discussed in relation to environmental factors, of which sediment stability, inorganic particle concentration, sedimentation rate and amount of organic matter in sediments are considered to be most important in structuring the communities.     

Planctomycetes diversity associated with macroalgae

Planctomycetes associated with 12 macroalgae from the north coast of Portugal were isolated, using an improved method. A total of 138 isolates were found to comprise 10 operational taxonomic units (OTUs), with 65% of the strains being closely related to the species Rhodopirellula baltica. The other strains are probably new species or genera related to Rhodopirellula, Blastopirellula and Planctomyces. Some of the OTUs isolated are unique and have never been found before in previous studies. Catalyzed reporter deposition-FISH confirmed the presence of Planctomycetes on macroalgal surfaces. This study provides the first report of the cultured diversity of Planctomycetes on the epiphytic macroalgae community and presents clear evidence of their nutritional and intimate relationship.     

Intra- and interspecific differences in palatability of Arctic macroalgae from Kongsfjorden (Spitsbergen) for two benthic sympatric invertebrates

Information on herbivore-macroalgae interactions is extremely scarce for Arctic habitats. In this study, the potential of 19 macroalgae as food source for herbivores was investigated for the first time in Arctic waters (Kongsfjorden, Spitsbergen) with emphasis on algal defense against grazing. Only two of the 19 tested macroalgae-associated invertebrates consumed macroalgae in measurable amounts, the locally abundant green sea urchin Strongylocentrotus droebachiensis (OF Müller) and the amphipod Gammarellus homari (JC Fabricius). In the inner basin of the fjord, the dense macroalgal stock represents a potential food source. However, in this area, herbivory plays only a minor role. In contrast, in the outer basin of Kongsfjorden S. droebachiensis exerts a strong top-down control on macroalgal assemblages.Laboratory feeding assays in the with the two herbivores showed grazer-specific feeding preferences. The amphipod G. homari exhibits a preference for delicate red algal species like Devaleraea ramentacea, whereas the sea urchin S. droebachiensis significantly preferred more leathery seaweeds like Laminaria and Alaria. The red alga Palmaria palmata is a very attractive food for both herbivores, while the brown alga Desmarestia viridis and the red alga Ptilota gunneri are among the least preferred algae. To distinguish between physical and tissue-specific plant properties, which have a deterring or stimulating effect on the grazing behaviour, both grazers were offered intact algal tissue and artificial food in separate feeding assays. While physical and tissue-specific plant properties-especially in the Laminariales-deterred G. homari, these properties did not deter S. droebachiensis.This study provides insights into herbivore consumption in the benthic food web of Kongsfjorden. As a general potential top-down factor controlling primary production, herbivory needs to be quantified further in Kongsfjorden to develop adequate carbon flow models for this important reference site for the study of climate change on high latitude marine ecosystems.     

Assessing species richness of macrofauna associated with macroalgae in Arctic kelp forests (Hornsund,Svalbard)

Kelp beds support diverse and productive benthic coastal ecosystems and are often perceived as cold water analogs of tropical coral reefs, yet the levels of species richness in polar regions have remained largely unexplored. The present study aims to assess the magnitude of macrozoobenthic species richness associated with the macroalgae in an Arctic kelp forest. The study was conducted in Hornsund, a high latitude Arctic fjord off west Spitsbergen (76–77°N). A total of 403 samples (i.e., individual algae) were collected by scuba divers at three sites located along the fjord axis at varying depths (5–10 m). The most common invertebrate species and the sample species richness (mean 11.5 species per sample) were consistent among the most common algal species (Laminaria digitata, Saccharina latissima, Alaria esculenta, Desmarestia aculeta, Odonthalia dentata, Phycodrys rubens). Fauna associated with overstory kelps was concentrated on the holdfasts. A total of 208 species were identified; Bryozoa, Polychaeta and Hydrozoa yielded the highest numbers of species (70, 52 and 37, respectively). The non-parametric Chao2 estimator of true species richness gave an estimate of 259 species (with 95% confidence intervals from 234 to 308). Despite the high sampling effort, the total species richness was not captured. This may stem from the high level of rarity within the fauna associated with kelps; 38% of the species occurred only in one or two samples. The studied fauna was much less diverse than similar assemblages surveyed at lower latitudes. The high numbers of species and the common occurrence of colonial forms (Bryozoa, Hydrozoa) in the current study show that these taxa cannot be omitted in macrobenthic diversity surveys performed within kelp habitats.     

Fungal community associated with marine macroalgae from Antarctica

Filamentous fungi and yeasts associated with the marine algae Adenocystis utricularis, Desmarestia anceps, and Palmaria decipiens from Antarctica were studied. A total of 75 fungal isolates, represented by 27 filamentous fungi and 48 yeasts, were isolated from the three algal species and identified by morphological, physiological, and sequence analyses of the internal transcribed spacer region and D1/D2 variable domains of the large-subunit rRNA gene. The filamentous fungi and yeasts obtained were identified as belonging to the genera Geomyces, Antarctomyces, Oidiodendron, Penicillium, Phaeosphaeria, Aureobasidium, Cryptococcus, Leucosporidium, Metschnikowia, and Rhodotorula. The prevalent species were the filamentous fungus Geomyces pannorum and the yeast Metschnikowia australis. Two fungal species isolated in our study, Antarctomyces psychrotrophicus and M. australis, are endemic to Antarctica. This work is the first study of fungi associated with Antarctic marine macroalgae, and contributes to the taxonomy and ecology of the marine fungi living in polar environments. These fungal species may have an important role in the ecosystem and in organic matter recycling.     

Agarolytic culturable bacteria associated with three antarctic subtidal macroalgae

Bacterial communities of Antarctic marine macroalgae remain largely underexplored in terms of diversity and biotechnological applications. In this study, three Antarctic subtidal macroalgae (Himantothallus grandifolius, Pantoneura plocamioides and Plocamium cartilagineum), two of them endemic of Antarctica, were investigated as a source for isolation of agar-degrading bacteria. A total of 21 epiphytic isolates showed agarolytic activity at low temperature on agar plates containing agar as the sole carbon source. 16S rRNA identification showed that the agar-degrading bacteria belonged to the genera Cellulophaga, Colwellia, Lacinutrix, Olleya, Paraglaciecola, Pseudoalteromonas and Winogradskyella. The agarase enzyme from a potential new species of the genus Olleya was selected for further purification. The enzyme was purified from the culture supernatant of Olleya sp. HG G5.3 by ammonium sulfate precipitation and ion-exchange chromatography. Molecular weight of the agarase was estimated to be 38 kDa by sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE). The purified enzyme exhibited activity at 4 °C, retaining >?50% of its maximum activity at this temperature. This is the first study reporting the phylogeny of agar-degrading bacteria isolated from Antarctic subtidal macroalgae and the results suggest the huge potential of Antarctic algae-associated bacteria as a source of cold-active hydrolytic enzymes of biotechnological interest.     

Lichens on lignum in the coastal regions of western Spitsbergen (Svalbard)

Eighteen species of eleven lichen genera were found on driftwood and worked timber deposited on the beaches in the Hornsund and Billefjorden regions (the west coast of Spitsbergen, Svalbard archipelago). Majority of them indicate low substrate specificity in the high arctic regions. Only three species (Caloplaca spitsbergensis, Lecanora mughicola, L. orae-frigidae) are typical for lignum. Most of the taxa are widespread in Svalbard. Species like: Caloplaca holocarpa, C. spitsbergensis, Protothelenella sphinctrinoidella, Rinodina archaea were sporadically reported till now. Lecanora mughicola was not reported from Svalbard up to the present and this is the first record of the species for the region.     

Seasonal dynamics of mesozooplankton in the Arctic Kongsfjord (Svalbard) during year-round observations from August 1998 to July 1999

We conducted a year-round mesozooplankton study in the Arctic Kongsfjord from August 1998 until July 1999 to investigate seasonal abundance and vertical as well as stage distributions of the prevalent taxa. It is the first investigation in Kongsfjord that covers the Arctic winter season and provides reasonable estimates also of small-sized copepod species. Abundant smaller copepods comprised Oithona similis, Pseudocalanus minutus, Microcalanus spp., Triconia borealis and Acartia longiremis. Among the larger copepods, Calanus finmarchicus, C. glacialis, C. hyperboreus and Metridia longa dominated. The thecosome pteropod Limacina helicina was also an important component. Abundance maxima occurred in November (988,669 ind. m^?2) with one to two orders of magnitude higher numbers as compared to all other months (39,832–200,067 ind. m^?2). The summers of 1998 and 1999 were characterized by intrusions of Atlantic water, but the community was not entirely dominated by advected boreal species. During winter, the majority of the mesozooplankton occurred below 100 m. Advection is the most likely reason for the accumulation of zooplankton at depth in winter, but local production may also contribute to high overwintering numbers. Much lower abundances of most species in spring suggest high winter mortality and emphasize the importance of sufficient reproductive success during the previous summer to ensure enough winter survivors as seed stock for the coming reproductive season. This study was conducted prior to the recent warming trend in the Arctic. Therefore, it provides valuable baseline data and allows comparing present and future states of the zooplankton community in Kongsfjord.     

Enriching marine macroalgae with eicosatetraenoic (arachidonic) and eicosapentaenoic acids by chilling

Summary Twelve macroalgae belonging to the Chlorophyta, Phaeophyta and Rhodophyta were collected from the Arabian Gulf. Field samples and samples that were first incubated at 5° C and 24° C in the light for 1 week were analysed for lipids and fatty acids. The lipid contents varied according to the macroalga and, within the Chlorophyta and Phaeophyta, some representatives accumulated more lipids at 5° C and others at 24° C. All samples of algae had similar lipid composition with only quantitative differences. The temperature did not have a common effect on the lipid composition of representative algae, although changes in the relative concentration of specific classes were recorded. The Phaeophyta and Rhodophyta were as a rule richer than the Chlorophyta in eicosatetranoic (20:4) and eicosapentaenoic (20:5) but poorer in linolenic (18:3) acids. In most of the algae, incubation at 5° C was associated with lowering the proportion of palmitic acid (16:0) in the total lipids, and, but only in the Phaeophyta and Rhodophyta, increasing the concentration of 20:4 and 20:5. These polyunsaturated fatty acids occurred in high levels in monogalactosyldiacylglycerols (MGDG) and digalactosyldiacylglycerols (DGDG) of the Phaeophyta and Rhodophyta but not the Chlorophyta, the MGDG and DGDG of which were rich in 18:3 and hexadecatrienoic acid (16:3). Offprint requests to: R. H. Al-Hasan     

Effect of simulated macroalgae on the fish assemblage associated with a temperate reef system

Increased habitat complexity is supposed to promote increased diversity, abundance and biomass. This study tested the effect of the macroalgal cover on temperate reef fishes by mimicking macroalgae on artificial reefs in NW Sicily (Mediterranean Sea). Macroalgal cover affected reef fishes in different ways and independently of intrinsic temporal trends. The fish assemblages of manipulated and control artificial reef units differed in the relative abundances of the associated species, but little in species composition. In line with studies in seagrass habitats, fishes were most abundant in reefs covered by artificial macroalgae. Three species (Boops boops, Serranus scriba and Symphodus ocellatus) exhibited consistently greater abundance on vegetated reef units than on control reef units. The total number of species and the abundance of three particular species (S. scriba, S. ocellatus and Thalassoma pavo) displayed temporal trends which were independent on short and large temporal scales. Only fish total biomass and one species (Spicara flexuosa) displayed strong effects of interaction among the experimental factors. Mechanisms to explain these findings are discussed from observational evidence on habitat use and interactions among multiple species. This study highlights that manipulative experiments involving repeated sampling of fish in artificial habitats appear to be a valid approach to study fish-habitat relationships in fluctuating environments. It is also concluded that macroalgae mimics may serve as a tool for restoring lost marine vegetated habitats when current human-induced conditions prevent the recovery of pristine macroalgal stands.     

Distribution of Polychaeta Communities in the West Spitsbergen Area in Winter (December 2015)

Using the materials collected in 2015, modern data have been obtained on the polychaete species composition and quantitative distribution in the West Spitsbergen area in winter. Polychaete species complexes corresponding to different habitat conditions have been identified in the outer and inner parts of the bays. The distribution of the Polychaeta communities proved to be dependent on the bottom sediment composition, depth, and specific hydrological regime.     

Rocky bottom fauna in arctic Kongsfjord (Svalbard) studied by means of suction sampling and photography

The bottom fauna (16–30 m depth) of Kongsfjord (Svalbard) was investigated by direct observation, a SCUBA-diver operated suction sampler (quantitative) and underwater photography (semi-quantitative). The fauna on horizontal surfaces showed low similarity to that on vertical faces and overhangs, and had larger species heterogeneity between sampling sites. This was due to sedimentation and ice-rafted pebbles and stones creating “soft-bottom habitats” on the rocky bottom. Suction sampling resulted in collection of 73 taxa, including some species usually regarded as “soft-bottom” inhabitants. Fewer species were observed on the photographs, demonstrating the selectivity of this technique, but underwater photography may be a useful “non-destructive” method for obtaining information about conspicuous epifaunal taxa. Accepted: 18 July 2000     

Tardigrada of the Revdalen (Spitsbergen) with the descriptions of two new species: Bryodelphax parvuspolaris (Heterotardigrada) and Isohypsibius coulsoni (Eutardigrada)

Despite a century long history of research, tardigrade fauna of the Svalbard Archipelago remains poorly known. In order to deepen our knowledge of tardigrade biodiversity in the Arctic, we collected forty-one moss and lichen samples from the Revdalen and on the south-east slopes of the Rotjesfjellet (Spitsbergen, Svalbard Archipelago) in June 2010. In these samples, twenty-five tardigrade species were found, including two new for science: Bryodelphax parvuspolaris sp. nov. and Isohypsibius coulsoni sp. nov. B. parvuspolaris sp. nov. belongs to the weglarskae group but differs from all other species of the group by a unique configuration of ventral plates. I. coulsoni sp. nov. differs from the most similar species I. ceciliae Pilato and Binda, 1987 mainly by the absence of ventral sculpture. Two additional species, Milnesium asiaticum Tumanov, 2006 and Diphascon (Adropion) prorsirostre Thulin, 1928, are recorded from the Svalbard Archipelago for the first time.     

Meiofauna associated with vermetid reefs: the role of macroalgae in increasing habitat size and complexity

Coral Reefs - We present the first dataset of meiofauna associated with vermetid reefs (biogenic constructions of Mediterranean intertidal habitat) in two areas along the northern coast of Sicily,...     

Diversity and bioprospecting of fungal communities associated with endemic and cold-adapted macroalgae in Antarctica

We surveyed the distribution and diversity of fungi associated with eight macroalgae from Antarctica and their capability to produce bioactive compounds. The collections yielded 148 fungal isolates, which were identified using molecular methods as belonging to 21 genera and 50 taxa. The most frequent taxa were Geomyces species (sp.), Penicillium sp. and Metschnikowia australis. Seven fungal isolates associated with the endemic Antarctic macroalgae Monostroma hariotii (Chlorophyte) displayed high internal transcribed spacer sequences similarities with the psychrophilic pathogenic fungus Geomyces destructans. Thirty-three fungal singletons (66%) were identified, representing rare components of the fungal communities. The fungal communities displayed high diversity, richness and dominance indices; however, rarefaction curves indicated that not all of the fungal diversity present was recovered. Penicillium sp. UFMGCB 6034 and Penicillium sp. UFMGCB 6120, recovered from the endemic species Palmaria decipiens (Rhodophyte) and M. hariotii, respectively, yielded extracts with high and selective antifungal and/or trypanocidal activities, in which a preliminary spectral analysis using proton nuclear magnetic resonance spectroscopy indicated the presence of highly functionalised aromatic compounds. These results suggest that the endemic and cold-adapted macroalgae of Antarctica shelter a rich, diversity and complex fungal communities consisting of a few dominant indigenous or mesophilic cold-adapted species, and a large number of rare and/or endemic taxa, which may provide an interesting model of algal–fungal interactions under extreme conditions as well as a potential source of bioactive compounds.     

Variability of protistan and bacterial communities in two Arctic fjords (Spitsbergen)

Krossfjorden and Kongsfjorden are Arctic fjords on the western side of Spitsbergen. These fjords share a common mouth to the open sea, and both are influenced by the input of sediment-rich glacial meltwater leading to decreased surface salinity, increased turbidity and decreased light penetration during summer. Earlier classical taxonomic studies had described the pelagic protistan composition of the Kongsfjorden during summer, revealing the dominance of flagellates of often unresolved taxonomic origin. Only little information existed on microbial eukaryote composition of the Krossfjorden as well as the bacterial composition of both fjords. The aim of the present study was to analyze and compare surface summertime protistan and bacterial communities in both fjords, using molecular approaches (16S and 18S rRNA DGGE, sequencing). Samples were collected three times a week from the central Kongsfjorden over a 1-month period. Additionally, 10 marine and 2 freshwater sites were sampled within a 1-week period in both Kongsfjorden and Krossfjorden. The central Kongsfjorden revealed a relatively stable protistan community over time with dinoflagellates, chlorophytes and small heterotrophs dominating. In contrast, the bacterial community varied over time and appeared to be correlated with the inflow of glacial meltwater. The Kongsfjorden and Krossfjorden were found to harbor distinctive bacterial and eukaryotic communities. We speculate that differences in glacial meltwater composition and fjord bathymetry affect the surface water properties and therefore the observed spatial variability in the community fingerprints.     

Macrofauna biodiversity of mussel bed assemblages in Thermaikos Gulf (northern Aegean Sea)

Biomonitoring of mussel bed assemblages can provide valuable information about the impact of pollution on hard substrate assemblages. This study of Mytilus galloprovincialis mussel beds in Thermaikos Gulf (northern Aegean Sea) deals with the spatial and temporal structure of the associated fauna. Samples were collected and abiotic factors were measured in two successive years. Common biocoenotic methods were employed to analyze the data. The samples could be separated into three groups, with summer and winter samples being clearly different. A total of 100 species were found: polychaetes and crustaceans were the most dominant taxa. The assemblage shows high diversity with respect to species abundance. Biotic interactions within the assemblage appear to influence its composition, although the total evenness remains unaffected in space and time. The M. galloprovincialis assemblages can be found in clean as well as in polluted waters and, therefore, are of great interest in biomonitoring studies.Communicated by H.-D. Franke     

The genus Leptophytum (Melobesioideae, Corallinales, Rhodophyta) in NW Spitsbergen

Three species of the genus Leptophytum , viz. the generitype L. laeve, L. foecundum and the new Arctic endemic L. jenneborgii nov. sp. are described from localities in NW Spitsbergen. A fourth species, related to L. laeve , may also be present and its status requires further comparative studies with Lithothamnion tenue described from western Greenland. Leptophytum jenneborgii is restricted to sublittoral sites around Vasahalvøya, between 8 and 30 m depth growing on hard substrates (usually on Lithothamnion glaciate ) and forming encrusting to foliose thalli up to 10 cm in diameter. New lamellae develop in an unattached-superimposed pattern, overgrowing the parent thallus, so that individuals can reach at least 1.5 cm in thickness. Thallus organization is dorsiventral, with a noncoaxial hypothallium (producing rare patches of coaxial cells) and an ascending perithallium with short subepithallial and flattened epithallial cells. Multiporate conceptacles have convex or flattened roof and develop specialized (thinner-wider) pore cells lining the canals. This character combination supports a position in the genus Leptophytum , as recently emended by Athanasiadis & Adey (2006), and simultaneously distinguishes L. jenneborgii from its Arctic and North Atlantic congeners. Like Leptophytum arcticum nov. comb., that is only known from Uddebay on the east coast of Novaja Zemlya, L. jenneborgii shows a restricted distribution on the presumed north periphery of maximum ice cover during the latest glaciation. It is suggested that these two species represent the first evidence of algal glacial survivals in this part of the Arctic.