Unique partnership to fight threat to Hampshire’s chalk streams

The University of Southampton has joined the Vitacress Conservation Trust, the Wessex Chalk Stream and Rivers Trust, the Test and Itchen Association, the Environment Agency and CPRE Hampshire (the county branch of the Campaign to Protect Rural England) to collaborate to provide positive proof of how damaging phosphorous pollution can be tracked. The Vitacress Conservation Trust is providing £60,000 and the Test and Itchen Association £10,000 to commission a PhD study led by Dr Pete Shaw of the University of Southampton, designed to identify the key factors in phosphorous pollution of Hampshire’s chalk streams.

The new research aims to identify and measure sources of phosphorous entering headwaters, including the three headwaters of the Upper Itchen (the Candover, Arle and Cheriton/Tichborne), plus the Bourne Rivulet, the Dever and the Upper Test. The research will also investigate the emerging threat from septic tanks identified at the recent fourth annual Chalk Stream Headwaters Forum, where Dr Linda May’s research indicated under-recording of phosphorous pollution from this source by the Environment Agency of up to 95 per cent.

The results of the PhD study will assist the Environment Agency and Southern Water in identifying targets and mechanisms to reduce the input of phosphorus into chalk streams. CPRE Hampshire’s support will ensure a wider understanding among those closely involved in rural planning issues.

Dr Shaw says: “There are problems to be solved in these iconic streams and we hope to produce scientific evidence that will show us where problems arise and guide us towards solutions. Having a broad group of committed partners will help us immeasurably in achieving our aims.”

To support the project, the Environment Agency will be providing auto-sampling equipment and river keepers associated with the Wessex Chalk Stream and Rivers Trust will be collecting multiple samples in the catchments of the rivers Test and Itchen. Symptoms of phosphorous-induced ‘chalk stream malaise’ are evident in both the Test and Itchen, and include:

• Proliferation of river bed algae which smothers the young shoots of aquatic plants such as Ranunculus
• Blanket weed which entangles and chokes aquatic plants

An earlier University of Southampton MSc research project, carried out last summer, has already measured phosphorous levels in the three headwaters of the River Itchen as well as the Itchen itself. The study found high levels of phosphorous in the Arle.