Wyniki wyszukiwania - BazTech

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Formation and species composition of stormcast beach wrack in the Gulf of Riga, Baltic Sea

Suursaar Ű., Torn K., Martin G., Herkül K., Kullas T.

Oceanologia

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2014

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No. 56 (4)

673--695

EN

The aim of the study was to investigate hydrodynamic effects on the formation of beach wrack at three locations in the northern Baltic Sea and to quantify the differences between the composition of species found in the beach wrack and in the neighbouring sea. Hydrodynamic measurements and modelling indicated that the beach wrack was mostly of local origin and that it was formed during high sea level and wave events. Comparison of the methods of beach wrack sampling and seabed sampling (diver, underwater video) demonstrated that beach wrack sampling can be considered an alternative tool for describing the species composition of macrovegetation in near-coastal sea areas. Although the hydrodynamic variability is greater in autumn and more biological material is cast ashore, the similarity between the two sampling methods was higher in spring and summer.

2

Density dependent growth of the red algae Furcellaria lumbricalis and Coccotylus truncatus in the West Estonian Archipelago Sea, northern Baltic Sea

Kotta J., Paalme T., Kersen P., Martin G., Herkül K., Möller T.

Oceanologia

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2008

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No. 50 (4)

577-585

EN

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. lumbricalis. Economic analyses aiming to establish sustainable harvesting limits for F. lumbricalis in the study area should take account of the density dependent growth of these red algae.

3

Effects of physical disturbance, isolation and key macrozoobenthic species on community development, recolonisation and sedimentation processes

Herkül K., Kotta J., Kotta I., Orav-Kotta H.

Oceanologia

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2006

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No. 48 (S)

267-282

EN

The relative effect of physical disturbance, isolation and key macrozoobenthic species on community development and sedimentation processes were studied in an in situ factorial field mesocosm experiment in the northern Baltic Sea. Differences in abundance and biomass structure of recolonising invertebrates were due to exposure and isolation. The initial invertebrate communities had a negligible effect on the final communities. However, the organic matter content of the sediment in isolated cages increased with the initial number of invertebrate species. The main conclusion of the study: physically driven fluxes override the effects of biological interactions in shallow water systems of the northern Baltic Sea.