Chichester Harbour shellfish valuation

NEF Consulting and the New Economics Foundation (NEF) were commissioned by the Environment Agency and Sussex IFCA to determine the economic value of the Chichester Harbour shellfish beds.


Chichester Harbour is a large estuary and natural harbour located to the south west of the city of Chichester, comprising around 44km² of navigable water, the vast majority of which is intertidal. Chichester Harbour is a large estuary and natural harbour located to the south west of the city of Chichester, comprising around 44km² of navigable water, the vast majority of which is intertidal.

The productivity of the Solent stock, including Chichester Harbour oyster fishery has been declining for a number of years. It is thought that the recruitment failure for three consecutive years is due to low fertilisation success, as a result of low oyster density on the shellfish beds, which is a key requirement for successful reproduction.

Alongside the socio-economic impacts of the declining fishery, the reduction of the oyster stock has also meant a reduction in the water filtration capacity and biogenic habitat provided, which can act as a nursery area. This is in addition to the array of other services which functional shellfish/oyster beds provide.

Our methodology

A model was developed to assess the potential Gross Value Added (GVA) from oyster harvesting under different water quality scenarios in the Chichester Harbour area, both in economic and employment terms.

During December 2017, five different scenarios were developed in consultation with Sussex IFCA and the Environment Agency. These scenarios ranged from doing nothing to improvements to all shellfish beds to specific standards.


The results demonstrate that better water quality leads to a higher direct and indirect GVA as a result of the increases in oyster harvest. As there is a higher harvest and more oysters are sold locally (and local retails make a profit at a greater price) instead of them being exported.

Improvements in shellfish waters would also mean Thorny Channel could be re-opened and harvested.

Click here to read our report in full.

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by @nefconsulting