The brief
An extensive programme of sampling has taken place in the Stour and Orwell estuaries since 1997 for Harwich Haven Authority to monitor macrobenthic communities and biotopes. This forms part of the compensation, mitigation, and monitoring agreement under the 1998-2000 Capital Dredge Licence to investigate any impacts dredging may have on the benthic environment.
What we did
- Thomson has undertaken all surveys carried out since 1997 (1997, 2003, 2008-2025). We have analysed all samples taken, identified the benthic organisms present, and carried out particle size analysis (PSA) on the sediment samples.
- Every year, we have produced a report to summarise the findings of that year’s survey, and to detect and analyse any trends in community and biotope changes over the previous four years.
- Each year Thomson presents the findings of the reports to Harwich Haven and the members of their Environmental Steering Group.
The outcomes
Reports presenting results from Thomson’s analysis have shown both short and long-term changes in: biotopes, species abundance, biomass, number of taxa, diversity for the overall estuaries; as well as changes focused on key wildfowl prey species, rare/protected species, and non-native species.
These reports allow Harwich Haven Authority to monitor effectively the health of the ecosystems within the Stour and Orwell estuaries and therefore respond quickly to any significant changes. This work allows for the efficient management and protection of the estuaries and, in particular, the mudflats, which are significant to the Stour and Orwell estuaries designation as Sites of Special Scientific Interest (SSSI), Special Protection Areas (SPA), and Ramsar sites. It also allows for conservation groups to monitor the presence of prey items for birds present in the adjacent Special Protected Areas (SPAs).
Related case studies
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Harwich Haven AuthorityLocation
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Stour and Orwell estuaries, Suffolk
Services offeredWe have an excellent long-term collaborative relationship with Harwich Haven Authority through undertaking marine ecology surveys for over a decade and contributing to the environmental management of the port.Thomson project manager, for Harwich Haven -
Our other projects
We cover all aspects of environmental consultation – from smaller surveys through to strategic projects.
At Thomson, we strive to deliver a pragmatic and innovative approach to environmental compliance.
Working in partnership with our clients, our team of environmental specialists ensures objectives are met, with maximum efficiency for our clients, and minimal impact on the natural world.
