Complex sentence: A collaboration of the National Trust, Natural England, Environment Agency, East Sussex County Council and various other environmental and conservation groups has been set up, and is talking to local residents, businesses and visitors about how to manage the estuary in the future.
Split into simpler sentences: A collaboration of the National Trust, Natural England, Environment Agency, East Sussex County Council and various other environmental and conservation groups has been set up to manage the estuary. They are talking to local residents, businesses and visitors about how to proceed in the future.