Working with water and ecology

Monitoring the health of our discharge points

In 2016, we asked an independent freshwater ecologist (Aquilina Environmental) to carry out an invertebrate survey at one of our discharge points.

Following the standard EA sampling protocol, aquatic macroinvertebrates were collected using a standard size FBA D-frame pond net from the major habitats along the stream (stands of different wetland plants, distinctive substrates, tree roots etc.). All the different habitats present were allocated a proportion of the overall sampling time (3 minutes) and different areas of the same mesohabitat were subsampled to ensure that as great a range as possible was sampled.

Each location was also searched for an additional minute looking for surface dwelling animals such as water skaters and whirligig beetles and inspecting submerged habitats such as logs and larger stones for attached animals.

We imagined that the results from our discharge points would be broadly similar, as the water quality is the same at each farm, however each of the surveys gave quite different results.  This was because each of the discharge points had different habitats with varying levels of shading and water flow.  The substrate also influenced the findings as in some locations there were gravel bases and others had a silty substrate.  It was evident that these environmental characteristics have a very significant effect on biodiversity when water quality is the same.
 

We have repeated that survey again this year with an addition of a further two testing locations.  We have seen an improvement in biodiversity over the two years and the report presenting this information in detail can be found at the foot of the page. 

This type of survey work will be carried out on a regular basis now that we have established some baseline levels, and any improvements can be recorded.

We have also carried out a survey on one of our farms upstream of any settlement facilities where the only water was that which has come from watercress beds. The aim of this study was to see which species were living in watercress discharge water without any outside influences, and to investigate what could be done to improve this biodiversity which will be monitored by further survey work in the future.  The results of this survey work are at the foot of the page. A video of this survey work, with explanations from Robert Aquilina can be found below.

 
 
 
 

Kick tests at the river with Tom Amery and Robert Aquilina. Robert explains how the water quality is tested then gets into the river to collect a sample of invertebrates to examine them.

Why we are under pressure and what we have
done to try and engage with local groups

 There has been significant pressure from the fishing community and local environmental groups, both on the watercress industry to reduce the levels of phosphate in the discharge water, and on the EA to regulate effectively.

We have met with Salmon and Trout Conservation UK and with local landowners to tell them what we have been doing to reduce our discharge levels. 

We also have representatives who attend meetings of the Upper Itchen Initiative, a group that has been meeting for over 10 years, concerned with the protection of the Upper Itchen river catchment and its tributaries. The group comprises of statutory bodies, riparian landowners, business interests and local stakeholders. This group is kept informed of our progress at each meeting. 

We also attend meetings of the Test and Itchen Catchment Partnership which brings together local people and organisations to plan and deliver positive actions that will improve our water environment and are a supporter of their lottery funded Watercress and Winterbournes project.

Over the past few years we have been working closely with the EA to formulate an action plan and to report to them on our progress. This successful working relationship has contributed to the success we have had with permit compliance in the first year of monitoring.

 
 

Macroinvertebrate Survey of Manor Farm outflow, Old Alresford , Hants

Report prepared by Robert Aquilina MSc MCIEEM

 

Macroinvertebrate Survey of three watercress farm outflows, Alresford , Hants

Report prepared by Robert Aquilina MSc MCIEEM

 
 

Macroinvertebrate survey of Drayton watercress farm outflow, Alresford, Hants

Report prepared by Robert Aquilina MSc MCIEEM

 

Watercress farming, A new era - by Ollie Bedford