g. Bučas et al. 2009) differs somewhat. We believe that beach wrack learn more sampling is both efficient and cost-effective. Indeed, we mostly found more macrophyte species from
beach wrack samples compared to data collected by divers or using underwater cameras (Table 3). The higher species diversity recorded in beach wrack samples than in seabed samples can be explained by the higher accuracy of laboratory analysis of beach wrack samples compared to the in situ visual assessment of seabed communities. Additionally, some better floating specimens (e.g. Zostera marina L., F. vesiculosus) might have been carried from more distant areas. Zostera marina was found in the beach wrack samples but not in the seabed samples in all areas. Z. marina was previously found in the Kõiguste area ( Möller & Martin, 2007). In the Sõmeri area, the
closest known site of Z. marina is 7 km and at Orajõe 15 km away (database of the Estonian Marine Institute). Also, the higher abundance and occurrence of F. vesiculosus in beach wrack samples compared to the nearshore area indicate that the plant material in the wrack originates Palbociclib from a somewhat larger sea area than the very narrow in situ sampling transects. Therefore, sampling of beach wrack can give a more accurate estimate of species diversity than underwater visual observation in heterogeneous areas. As diving is time-consuming and expensive, only a limited number of diving transects are sampled during ordinary biodiversity assessments (e.g. environmental monitoring, inventories of marine protected areas). However, the small number of transects may not be sufficient for adequately assessing the biodiversity of large and heterogeneous marine areas. Sampling of beach wrack has the potential to improve biodiversity assessments as the method enables biodiversity information to be obtained from much larger areas compared to the sparse in situ seabed sampling. Variation of species occurrences between methods in the samples described can be explained by the different distribution of vegetation along the wrack line or sea bottom. The variations
in the data sets of beach cast samples were smaller as the species originating at different depths were bunched together Tangeritin by the nearshore wave action. Data collected by the diver have a greater variation of species distribution at different depths along the depth gradient of the transect. Coherence between the samples of beach wrack and submerged vegetation is hydrodynamically possible because (1) the alongshore currents in the practically tideless Estonian coastal sea are meteorologically driven and generally niether persistent nor strong; the material on the beach originates from the adjacent sea areas; (2) high sea level and wave events occur on an almost regular basis at least every 10–30 days, providing fresh beach wrack material. In general, the stronger the storm event, the richer the wrack.