This warning from the Harbour Conservancy has been prompted by a new planning document issued by Havant Borough Council, which has major implications for the harbour.

In a detailed reaction to the borough's blueprint, conservancy members homed in on a suggested wind turbine in the Broadmarsh area of Langstone, next to a special protection area for birds.

Reports issued by the conservancy said there was grave concern over the idea of a 'landmark' turbine which could also be a tourist attraction, close to Chichester Harbour.

"This is likely to be an incongruous feature which will detract from the landscape of the area of outstanding natural beauty and be harmful to designated sites for nature conservation," they added.

The use of renewable energy was supported in principle, but the conservancy did not see the need to make a wind turbine a landmark/tourist attraction in this sensitive location.

A tidal renewable energy system suggested at the entrance to the harbour, close to Sandy Point, could have a detrimental effect on the safe passage of boats and safety of navigation.

It was uncertain what visual impacts might arise from shoreside infrastructure for tidal energy, as no details of the proposal were given in the Havant document – the local development framework core strategy 'issues and options' paper.

It was possible changes in tidal dynamics might result in damage to salt marsh habitat, wildlife and other nature conservation features.

An 'array' of photovoltaic panels – used to generate energy from sunlight – proposed for sites in the area were likely to have a detrimental visual impact on the AONB, depending on where they were located and their scale.

The conservancy would object to any proposal that compromised the 'naturalness' of the AONB.

'Grave concerns' were also expressed over proposed new housing development in the open gap between Emsworth and Havant, which is partly in the harbour AONB.

"This part of the landscape is mainly exposed, and part of the distinctive character of the AONB," said the conservancy reports.

It was an area which was highly sensitive to change.