Chichester Harbour Oyster Partnership Initiative
Working to achieve sustainable oyster fishing on England’s South Coast: an ecosystem approach...
Chichester Harbour has held a long standing population of the native oyster (Ostrea edulis) since records began. This population is not only a valuable resource for the fishing industry, it also holds a high cultural value due to its contribution to the historic development of the harbour and plays an important role in marine biodiversity and ecosystem functioning.
Unfortunately, over the past few years the productivity of the Chichester Harbour Oyster Fishery has declined. This decline is of concern to those within the industry as well as to environmental organisations. This species of oyster and its habitat is listed in the Sussex Biodiversity Action Plan which looks to maintain and increase the distribution and abundance of the species.
The Chichester Harbour Oyster Partnership Initiative (CHOPI) was started in 2010 through a partnership consisting of local oyster fishermen, Sussex Inshore Fisheries & Conservation Authority, Chichester Harbour Conservancy and Natural England. The project looked to establish 2-3 small areas of seabed within the harbour where oysters can be moved and left to establish as “breeding stock”. It is hoped this will facilitate the re-colonisation of the area. Under a voluntary agreement these areas will then be closed to fishing.
Ecosystem Service Benefits:
Creating sustainable oyster stocks within the harbour will allow a consistent market share to be established, ensuring the long term survival of the oyster fishing industry and provision to local buyers.
The presence of oysters within coastal marine environments lowers the level of turbidity, suspended sediment, nitrogen, microbial production and phytoplankton biomass present in the water. In addition there is likely to be an increase in the amount of submerged aquatic vegetation which is beneficial in creating habitats for other species and providing oxygenation for the sea water.
The presence of oysters increases submerged aquatic vegetation and this will provide habitat for a diverse range of species including epibenthic invertebrates which provide a sustainable food source for native fish populations.
The shells of oysters retain CO₂ and as such are a useful asset in lowering greenhouse gas concentrations.
Flood Alleviation/Coastal Flooding:
Reefs of oysters encourage sedimentation and are in effect a living breakwater which can rise at rates in excess of any predicted sea level rises and as such assist in stabilising shoreline erosion as well as habitat loss. To what extent this can be utilised and the monetary value of such schemes is still being investigated.