Chalk Stream Creation

After over 8 years of research, the cause of a long standing and unsolved invertebrate population imbalance (characterised by very low freshwater shrimp numbers) in the beautiful chalk stream below Vitacress Salads’ St Mary Bourne operation has been identified. Natural mustard oils, released as watercress is prepared for packing, have been shown to cause sensitive invertebrate species to avoid them.

Responding to this, the company have engineered an environmentally sustainable solution by identifying, isolating and passing discharges tainted with mustard oils back through undisturbed watercress beds, where the oils are naturally broken down, rendering them harmless to chalk stream invertebrates.

Having solved what had hitherto been an intractable problem, work began in 2007 to provide a showcase for this pioneering breakthrough. Working with Technical Director Dr Steve Rothwell, Vitacress Conservation Trust trustee Tim Nevard sketched out an idea to open up over 100 metres of piped stream, which was further developed in consultation with angling author Terry Lawton, the Environment Agency and the Hampshire and Isle of Wight Wildlife Trust. Cain Bioengineering was engaged to re-create the topography and planting associated with a pristine chalk stream, with over 4,000 native marginal plants were used in the scheme, together with local provenance wildflowers and native trees – a celebration of sparkling, gin-clear water, fast flows and riffles brimming with biodiversity, in place of mown grass and underground pipes. Subsequent Environment Agency biological monitoring of the new stream and the carrier below shows many thousands of freshwater shrimps now thrive.

The factory and farm discharges now flow directly through the superb ‘Plunket Greene’ chalk stream, where school children can try pond dipping and fly fishermen have the opportunity to catch a wild Bourne Rivulet brown trout.

Wild Trout Trust Conservation Awards – 2008

The Vitacress Conservation Trust entered the ‘Plunket Greene Chalk Stream Restoration Project’ for this year’s prestigious Wild Trout Trust Conservation Awards and we were delighted to see it shortlisted as a finalist. But this isn’t the end of the story; the ‘Plunket Greene’ project, with support from the Bourne Rivulet Initiative and the Vitacress Conservation Trust’s Chalk Stream Headwaters Forum, also provided the inspiration for this year’s ‘Professional’ category runner-up, with our neighbour, Michael Malyon, also enlisting the services of Cain Bioengineering to restore his downstream reaches of the Bourne Rivulet.