Up to 60-100% of the vegetation has been lost over the last century in some areas, e.g. along the northern part of the Swedish west coast (Baden, Gullstrom, Lunden, Pihl, & Rosenberg, 2003, Waycott et al., The biodiversity of seagrass communities are essential for ensuring high levels of ecosystem function (Duffy, Moksnes, & Hughes, 2013). Declines in seagrass abundance and distribution have negative effects on the biomass of fish and the sequestration of nutrients.