Over half of England’s estuaries are at risk of losing essential habitats. A combination of rising seas, lower drought river levels and new weirs and dams are shrinking these vital habitats.
Locally, estuaries play host to many species of wader but also to the breeding and nursery stages of many commercially important fish. They are also important globally, as a carbon store and water filter for nutrients, contaminants and sediment.
Normally, saltwater being pushed into freshwater tidal zones would naturally be rectified by moving the zone further inland. However, man-made river structures to guard against flooding are preventing this natural process from working.
In the same way, as intertidal zones vanish permanently beneath the waves, the beach line would naturally retreat, the shoreline being relandscaped. This though, due to artificial sea defences, simply cannot happen and means that the intertidal zones disappear altogether.
This “estuarine squeeze” has been coined and researched at Nottingham Trent University. They have shown that some zones have already been lost, such as in the Tees, Mersey and Tyne. Furthermore, 57% of estuaries in England are bounded by upstream barriers, leaving them at significant risk.
If we want to continue to see wader species in our estuaries, more research and understanding are required to ensure these areas are future proofed. One solution is to create more habitats at the top of estuaries, but the key message is that we must conserve what is already there.
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