The impact of block and chain swing mooring damage to the seabed within seagrass (Zostera marina) meadows; Jersey, Channel Islands

Boating activities, such as moorings, anchors and boat propellers, are one of the leading
threats to seagrass meadows and the ecosystem services they provide. Mooring damage to
seagrass, Zostera marina, beds has been recorded across its distribution. Evidence of this
damage can be seen in aerial imagery of Jersey’s most extensive Z. marina meadow, in St
Catherine’s Bay, where traditional block and chain moorings have created patches of bare
sand within the meadow, known as mooring ‘scars’. Shallow core seabed samples, of 160mm
depth, were taken inside and outside mooring scars, within the St Catherine’s Bay Z. marina
meadow, to assess what impact the mooring has had on the seabed. Including changes in
infaunal species assemblages, carbon content and sediment characteristics, in addition to the
loss of seagrass plants in these areas. Species diversity, richness and abundance was
significantly lower within the scars. However, there was no significant difference in the
percentage of organic carbon or the sediment characteristics.