Coverage was assessed as a percentage of the sea bottom covered by vegetation or a certain species within the extent of the sampling site.

Along the transects, the total coverage of the macrovegetation community, coverage of individual species and character of substrate were registered visually by the diver or recorded with an underwater video camera. Observations were carried out to the deepest limit of vegetation on the transect. In the Kõiguste and buy GSK458 Sõmeri areas, 8–10 observations were made along the transects (the deepest vegetation at 10 m depth). In the Orajõe area the number of observations per transect was 7–9 (the deepest vegetation at 8.3 m depth). Paired with the sampling of seabed phytobenthic community in May, July and September, beach wrack samples were also collected in April, June, August and October (Table 1). Wrack samples were collected from three transects parallel to the shoreline in each area. The distance between the transects was about 60 m. The selleck chemicals lengths of the transects were 5 m and five samples were collected from each transect. The samples were collected using a 20 cm × 20 cm metal frame at

a distance of 1 m from one another. Each individual frame sample served as a sampling unit in further statistical analyses. This design (3 transects and 5 samples per transect) resulted in 15 samples per area in each month. Distances from the water edge [m], thickness [cm] and coverage [%] of the wrack layer inside the sampling frame were measured.

The freshest beach wrack closest to the Beta adrenergic receptor kinase sea was always chosen for sampling. As a rule, older, more or less decomposed wrack strips were located higher on the shore. In April, only three samples were collectable from fresh beach cast material. As the rest of the samples included old material cast ashore during the previous autumn before the sea froze up, the April data were excluded from further quantitative analyses. The collected material was packed and kept frozen. In the laboratory, the species composition in each sample was determined. As wrack specimens were often fragmented and detailed identification was impossible, morphologically very similar species were treated as one group. The filamentous brown algae Ectocarpus siliculosus (Dillwyn) Lyngbye and Pilayella littoralis (Linnaeus) Kjellman were not separated. All characeans except Tolypella nidifica (O.F. Müller) Leonhardi were determined as Chara spp. Higher plants with similar morphology such as Zannichellia palustris L., Ruppia maritima L. and Stuckenia pectinata (L.) Börner were treated as one group. The biomasses of Fucus vesiculosus L. and Furcellaria lumbricalis (Hudson) J. V. Lamouroux and the rest of the sample were separated and weighed after drying at 60°C to constant weight. Biomass (grams dry weight) was calculated per square metre [g d.w. m−2]).