Environmental Impact Assessment, Port of Harwich

The brief

Harwich Haven Authority is responsible for the maintenance of the Port of Harwich. This includes routine operations such as dredging the navigation channel, disposal of residue and foreshore recharge to mitigate against erosion, as well as potential new developments, most notably at Bathside Bay.

Ecological surveys are required for all these processes, as they have the potential to impact on the marine environment. To date, Thomson Unicomarine, Thomson’s marine division, has written more than 70 reports for HHA, detailing different aspects of the marine biology of the area and likely impacts of different operations. We also gave expert witness evidence at the public enquiry for Bathside Bay.

What we did

• We monitored changes in the marine ecology of the area through regular fish and benthos surveys, including detailed biotope mapping, boat and shore based sampling of fish and benthos and in situ records.
• Reports detailed likely reasons for any changes to benthos, through comparison of maps and statistical analyses.
• We recorded and published on the arrival of newly recorded non-native species such as the Oriental shrimp (Palaemon macrodactylus) and Japanese skeleton shrimp (Caprella mutica).
• We also recorded changes in the abundance of different fish species over time.

The outcome

All surveys and reports were completed on time and budget and, in later years, results were presented at annual Regulators Group meetings by our staff. Recorded changes to the biological communities were considered to be due to factors outside the control of HHA and essential port maintenance has continued.

The proposed expansion at Bathside Bay was approved after the public enquiry and agreement to ecological monitoring and mitigation measures. Since then development has been postponed for reasons outside ecology.

Our work within the Stour and Orwell estuaries on behalf of the Authority is still ongoing.