There is a growing need for diversification of seaweed aquaculture practices in Europe. In the Baltic Sea, very few seaweed species are utilised commercially, and only the kelp Saccharina latissima is presently cultivated, although a common red alga - Furcellaria lumbricalis - has the longest harvesting history in the region. Nevertheless, in recent years, there has been an increasing interest in cultivating F. lumbricalis in Estonian coastal waters. Several pilot studies have been initiated to develop techniques for the vegetative propagation of sporophytes and gametophytes. Based on a literature survey, ongoing investigations and expert opinion, a comprehensive overview of the ecophysiological requirements and chemical composition of different forms of F. lumbricalis is given in this review, together with its potential for biotechnological applications. Recommendations for cultivating the species in open water are given. Overall, biotechnological applications of F. lumbricalis rely on high-value biochemicals like furcellaran, R-phycoerythrin, lutein (carotenoids) and phenolic content (antioxidants). Further bioprospecting is needed to estimate the possible content of oxylipins in the alga.

The West Estonian Archipelago Sea hosts a loose-lying red macroalgal community dominated by Furcellaria lumbricalis and Coccotylus truncatus. The community is truly unique in European seas. In factorial field experiments we evaluated separate and interactive effects of algal density and the proportions of F. lumbricalis and C. truncatus on their growth rates in a set of monospecific and mixed communities. Our experiment demonstrated that the growth of red algae was density dependent and that increased algal densities resulted in a fall of daily growth rates. An elevated growth of the red algae was observed at their lower proportions in the community. A potential mechanism behind the observed patterns is the light availability for photosynthesis, i.e. light utilization is more efficient in mixed communities.

The West Estonian Archipelago Sea hosts a loose-lying red macroalgal community dominated by Furcellaria lumbricalis and Coccotylus truncatus. The community is truly unique in European seas. In factorial field experiments we evaluated separate and interactive effects of algal density and the proportions of F. lumbricalis and C. truncatus on their growth rates in a set of monospecific and mixed communities. Our experiment demonstrated that the growth of red algae was density dependent and that increased algal densities resulted in a fall of daily growth rates. An elevated growth of the red algae was observed at their lower proportions in the community. A potential mechanism behind the observed patterns is the light availability for photosynthesis, i.e. light utilization is more efficient in mixed communities.

The north-eastern Baltic Sea is known to have relatively low species richness due to unfavourable salinity for many species. Here I report new records of two phytobenthic species for the Estonian marine flora: the yellow-green alga Vaucheria cf. dichotoma (L.) Martius and the epiphytic brown alga Punctaria tenuissima (C. Agardh) Greville. Besides, the former is the first observation of a species of the class Xanthophyceae in the Estonian coastal waters and is the first macrophytobenthic record of the class in the entire Gulf of Riga. The brown alga P. tenuissima was found for the first time in the entire Gulf of Finland. Morphological characteristics are shown for both species and possible reasons behind the new records are discussed.

The north-eastern Baltic Sea is known to have relatively low species richness due to unfavourable salinity for many species.Here I report new records of two phytobenthic species for the Estonian marine flora: the yellow-green alga Vaucheria cf.dichotoma (L.) Martius and the epiphytic brown alga Punctaria tenuissima (C.Agardh) Greville.Besides, the former is the first observation of a species of the class Xanthophyceae in the Estonian coastal waters and is the first macrophytobenthic record of the class in the entire Gulf of Riga.The brown alga P. tenuissima was found for the first time in the entire Gulf of Finland.Morphological characteristics are shown for both species and possible reasons behind the new records are discussed.

Biological water quality indices are increasingly used for coastal water quality assessment. It is not clear, how are anthropogenic disturbances and climate variability captured in the dynamics of different indices. In this study, we evaluate simultaneous contributions of both eutrophication- and climate-related factors to the variability of a benthic invertebrate index ZKI. The index is adopted to classify the coastal brackish waters in the NE Baltic Sea. We found quite similar contributions of climate and eutrophication, which together described on average about 65% of the variability of the ZKI in the study area. These interactions are likely affected by local geomorphology, with the index values being less related to eutrophication on coarse bottoms and more to climate patterns on steep slopes. The relative contribution of eutrophication to index variability did not change across the pressure gradient according to the Baltic Sea Pressure Index. The results indicate that index assessments may easily become misinterpreted if the knowledge about the other sources of variability is missing and advise to account for climatic and hydrographic factors.

Fucus vesiculosus L. is an important habitat-forming macroalga both in the saline and high diverse North Sea and the diluted and low diversity Baltic Sea. Despite its importance, comparisons of the spatial patterns of its epiphytes have rarely been reported. In this study we examined the species composition and density of macro-epiphytes and mobile fauna on the canopy-forming macroalga F. vesiculosus inhabiting different regimes of wave exposure in the North and Baltic Seas. The North and Baltic Seas had distinct epiphyte and mobile faunal communities. Wave exposure and segments of host fronds significantly contributed to the variability in species composition and dominance structure of epiphytes on F. vesiculosus in the North Sea and Baltic Sea. The study indicated that there is no clear spatial scale where environmental variables best predicted epiphytic and mobile faunal communities, and the formation of epiphytic and faunal communities is an interplay of factors operating through micro-to regional scales.

We quantified the relative importance of scale-specific variability of macroalgal and benthic invertebrate communities in the Vaindloo area, the central Gulf of Finland. Macrophyte communities had a clear variability minimum at 8 km spatial scale. In contrast to macrophytes, the scale-specific variability of benthic invertebrate communities was small with no clear variability peak or minimum. The spatial distribution patterns of macrophytes and benthic invertebrates did not vary with regard to the species composition and dominance structure of communities. Among environmental variables the coverage of boulders and depth contributed most to the variability of the species composition and biomass dominance structure of macrophytes as well as of the species composition of benthic invertebrates. In addition to these environmental factors, the variability in the abundance and biomass dominance structure of benthic invertebrates was described by coastal slope, exposure, and cover of sediment size fractions other than boulders. The study suggests that the scale-specific variability of marine communities is complex and differs notably among different ecosystem elements. The variability of macrophytes and benthic invertebrate communities was also described by the abiotic environment operating at multiple spatial scales.

The effects of local nutrient loading, harvesting, regional temperature patterns and weather induced light conditions were assessed on the interannual dynamics of the commercially important loose-lying red algal community of Furcellaria lumbricalis and Coccotylus truncatus. Higher algal biomasses were due to higher temperatures and number of calm days (i.e. clear water phases) during the active growing season in spring and summer. In addition, higher biomasses were associated with a higher number of stormy days in November-February, which is linked to a reduced ice cover and longer growing season. Commercial harvesting and nutrient load did not appear to drive the interannual dynamics of these red algae. Thus, the dynamics of the loose-lying red algal community is constrained by regional rather than local environmental factors. (c) 2011 Elsevier B.V. All rights reserved.

Biomass distribution patterns of attached and drifting forms of Furcellaria lumbricalis in the whole Estonian coastal sea including the Gulf of Riga, the West Estonian Archipelago Sea, the Gulf of Finland, and the Baltic Proper are described.The study showed that the combination of multiple environmental variables explained the distribution of attached and drifting forms of F. lumbricalis and different environmental variables were important for different forms of the red alga.The attached F. lumbricalis inhabited deep hard-bottom areas that were exposed to waves.The drifting F. lumbricalis was confined to deep but more sheltered habitats characterized by the presence of a weak topographic depression, soft bottoms, and a high sediment load.

In an in situ experiment we evaluated the growth of the red algae Furcellaria lumbricalis and Coccotylus truncatus in the Archipelago Sea. The results showed that the growth rates of both species were similar but, that growth decreased with increasing algal coverage. The effects were more pronounced for C. truncatus than for F. lmnbricalis. Econornic analyses airning to establish sustainable harvesting limits for F. lumbricalis in the study area should take account of the density dependent growth of these red algae.

A unique, commercially exploited loose-lying red algal community in the Baltic Sea is situated in Kassari Bay, the Väinameri area (NE Baltic Sea).These macroalgae have been harvested since the 1960s, and continuous monitoring of biological characteristics of the community has been carried out to enable sustainable exploitation of this marine living resource.In this study the losses of the red algal community through beach casts were calculated from the estimates of the amounts of marine wrack on the NE shores of Saaremaa Island from April to November 2002.The community loss through beach casts was estimated at ~ 5000 tonnes wet weight per year.These annual losses via wrack deposition represent ~ 3% of the community standing stock in summer.Commercial exploitation in the form of bottom trawling of the loose algal community made up only 20% of the losses due to beach casts.

The main isolation procedures (extraction, alkali modification, and precipitation) of hybrid carrageenan blend from seaweeds of the Kassari algal stratum (the Baltic Sea, Estonia) were quantitatively investigated. In the case of all extracting agents (water, KOH and NaOH solutions) used, a sharp rise occurred in the extracting rate during the first 2 h. Pure water was the most efficient extracting medium for carrageenans from the biomass of Furcellaria lumbricalis- Coccotylus truncatus with regard to yield but certainly not gelling properties (gel strength) of polysaccharides extracted. Long-time alkali extraction causes great losses due to degradation of carrageenans; however, alkali treatment is an obligatory step for the isolation of high-quality gelling galactans from the Kassari algal stratum, resulting in a more than 3-fold increase in gel strength. In the case of a typical algal blend from this stratum (69% F. lumbricalis and 10% C. truncatus), the most effective medium for the isolation of carrageenan mixture is 0.05 M KOH solution and the preferred duration of extraction is 3-4 h.