Chichester Harbour Projects

© Sussex IFCA

Sussex IFCA conducts research to gather data and information to support the decision making processes of the Authority. We work in partnership with a wide range of organisations. Below are highlights from our project partnership work in Chichester Harbour.


Oyster Stock Monitoring
There is a small-scale but locally important fishery for native oysters in Chichester Harbour. Fishing by dredging used to take place for a couple of weeks each November but unfortunately stock levels have been too low in recent years to allow any fishing activity. We conduct an annual stock assessment to inform flexible  management measures.  We also work with the environmental health officers from the local councils to gather catch per unit effort and length-frequency data. We are working with the  Native Oyster Network  and the Solent Oyster Restoration Project to explore options for oyster restoration.

The History of Oyster Fishing in Chichester Harbour 
We commissioned a maritime historian, Dr Ian Friel, to research the history of oyster fishing in Chichester Harbour.

A few key points include:

  • There is evidence of oysters being cultivated in the Harbour during Roman times.
  • There has been oyster dredging in the Harbour since the 14th century.
  • During the 1600 and 1700s, Chichester Harbour had a significant oyster fishery, supporting local fishers, with oysters eaten locally and exported. There is some evidence that at this time the fishers were restocking, using spatting ponds and laying cultch.
  • From the start of the 1800s, larger vessels from Kent, Essex and elsewhere came into the Harbour and took large amounts of oyster, including breeding stock to be relaid on other beds. Land reclamation attempts also damaged the oyster beds.
  • In the mid-1800's, extensive offshore oyster beds were discovered and fished intensively until all the oysters had been harvested.
  • Several Orders (private oyster beds) were established in the 1870s within Chichester Harbour but by this time, the oyster stocks were very low. Poaching, lack of cultch, lack of funding and disputes between the members of the co-operatives did not help matters.
  • In the 1890s, sewage works contaminated the Harbour's shellfish and an outbreak of typhoid in 1902 was blamed on the oysters.
  • Oyster fishing improved in the 1910s and 1920s but the increase in the slipper limpet population led to another decline in oysters.
  • There was somewhat of a revival in the 1950's with relaying of oysters from France and other parts of the UK, as had been done periodically in the past. Some Pacific oysters were laid in the Harbour in the 1980s.
  • Oyster stocks have been low and declining since at least 2010. There has been a 95% decline in oyster populations across Europe.

Read the report: The Real Natives - A Study of the History of Oyster Fishing in Chichester Harbour by Dr Ian Friel

Chichester Harbour Oyster Partnership Initiative

The Chichester Harbour Oyster Partnership Initiative (CHOPI) is a partnership of fishers and local authorities, set up in 2010 with the aim to promote the native oyster fishery. There is a small wild population of native oysters in Chichester Harbour and there has been an oyster fishery there for hundreds of years. Various research projects have been undertaken since the set up of CHOPI, including broodstock relaying, collection of length frequency and catch per unit effort data in partnership with local environmental health officers, pre-season catch per unit effort assessment, a valuation of the value of Chichester Harbour shellfisheries and promotion of better water quality. CHOPI has been part of the development of the Sussex Inshore Fisheries and Conservation Authority (IFCA) Oyster Permit Byelaw (2015). The Byelaw has restrictions on size of dredges, amount of time fishing and a harvest control threshold. This means that when the fleet average catch per unit effort for the day falls below 15 kg per hour per 1m dredge width, the fishery closes.


Valuing Chichester Harbour Shellfisheries
Sussex IFCA has worked with the Environment Agency to improve the evidence base for the valuation of the Chichester Harbour oyster fishery. An economic analysis of the fishery was carried out together with the creation of a model. The model predicts the potential value of the shellfishery under different water quality scenarios. The project was delivered by the New Economics Foundation. The results obtained demonstrate that better water quality leads to higher gross added value (GVA) as a result of an increased oyster harvest. The evidence from this sudy can be integrated into future cost benefit analyses, which in turn may encourage investment in environmental protection and fisheries enhancement. The model created can be used for any shellfishery where data exists. Please note that the report and model were updated on the 4th October 2018.

The full report can be viewed here
The model (Excel) can be viewed here


Clear Seas, Chichester Harbour
Sussex IFCA and the Environment Agency have worked with partners including Southern Water, The Sussex Wildlife Trust, Chichester Harbour Conservancy to produce a simple guide to looking after the Chichester Harbour marine environment for boat users. Take a look at the posters and leaflets from the link below to see how you can take some simple steps to protect Sussex seas for wildlife and future generations.

Clear Seas


SeaView Chichester Harbour: an environmental regulation stock check
Sussex IFCA, in partnership with the Environment Agency, have produced a report which provides an overview of the marine environment and the targets underpinned by local, national and EU legislation within Chichester Harbour. It is hoped that by collating and condensing the available information in to one report, the actions required to push for an improved environment can become clearer for all relevant bodies and partnerships.

See the full report here


Small Fish Surveys
We work with partner organisations to conduct surveys of small and juvenile fish in estuarine and inshore areas in our District. These areas are important as nursery grounds for many fish species, in particular those which are of commercial importance. Fish are also an important part of marine food webs and as indicators of ecosystem health. Surveys are carried out to European Water Framework Directive standards. There is more information on the research page .

Chichester Harbour small fish survey 2018
Chichester Harbour small fish survey 2016
Chichester Harbour small fish surveys 5 year analysis 2010-2014
Application of the Environment Agency's Transitional Fish Classification Index to Chichester Harbour small fish survey data 2010-2014

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