Reviving the River Adur: a path to thriving kelp forests
The Adur estuary at Shoreham. © Shoreham Society 2023
Thinking ‘More Joined Up’
Supporting the River Adur to recover from the top of the catchment to the sea creates the best opportunities for ‘bigger, better and more joined up’ landscapes and restoration outcomes, many of which extend well beyond the river itself. A great example of this is the Adur’s close connection to the historic kelp forests off the Sussex coast.
The Adur reaches the sea at Shoreham, which forms the easternmost point of the designated Sussex kelp recovery area. Sadly, by 2019 only 4% of the once-thriving, 20th century kelp beds remained.
Kelp washed up on Worthing beach in the 1960s. © David Nicholls.
Kelp in Crisis
One of the key pressures facing Sussex kelp is sedimentation and excess nutrients. Sediment enters the sea as runoff from agriculture and urban development. This intensifies existing sediment pressure from commercial bottom-trawling and dredging.
Surplus sediment smothers kelp and scours the rocky substrate that kelp attaches to. Simultaneously, increased water turbidity from sediment and excess nutrients reduces light in the water column, inhibiting kelp photosynthesis - and therefore growth.
New kelp growth off the Sussex coast provides habitat and food for fish. ©Sussex Wildlife Trust
Adur Recovery to the Rescue
Reducing sediment erosion and runoff is vital for terrestrial and freshwater habitats, but the kelp proves that it is essential for marine systems as well. Here at Adur River Recovery, two of our core aims are to revive floodplains and improve water quality. Healthy and functional floodplains absorb and retain more water than degraded (such as incised or channelised) rivers, by slowing the flow of floodwaters and minimising erosion downstream. This helps to lower some of the sediment pressure threatening the restoration of kelp. Additionally, improving water quality reduces nutrient loading and eutrophication, which is important for maintaining sufficient light into the water column.
A flooded River Adur valley. ©Knepp Wildland Foundation
Joining up…to us!
The recovery of the Adur provides brilliant opportunities to connect-up inspiring projects and partners across the region. Restoring kelp across the Sussex coast will bolster fish nurseries and habitats, with countless benefits for coastal communities and fisheries. As the Adur recovers, and the river regains many of its’ vital functions and services, we look forward to following more emergent and unexpected benefits to our communities and stakeholders – let the good times flow!
Whelk fishery. © Geoffrey Lee