National Trust ‘shores up’ to protect vital saltmarsh habitat

National Trust ‘shores up’ to protect vital saltmarsh habitat - National Trust

Northey Island from the air. Credit - Terry Joyce

A significant conservation project to help retain vital saltmarsh habitat in the Blackwater Estuary over the next century is underway at Northey Island in Essex.

Saltmarsh, due to its ability to store carbon, is one of the key habitat types that needs protecting to help tackle the climate crisis. Often referred to as blue carbon, saltmarsh and seagrass represent the largest sedimentary carbon store of the coastal and marine habitats.

This coastal habitat is also very unique, less than half a per cent (0.5 per cent) of the landmass in the UK, and is currently at risk due to rising sea levels due to the climate crisis.

Northey Island, cared for by the National Trust, is the single largest block of saltmarsh in the Blackwater Estuary and this latest phase of work will protect and strengthen the saltmarsh and wider habitats by applying a range of innovative management approaches over the next few years.

The current stage of the project includes improving and extending the existing central bank made of clay using material obtained from the creation of a freshwater pond and drainage system on the Island.

This improved bank will protect the north of the Island from flooding and allow for the managed creation of new saltmarsh to the southeast, over the next few years.

The new freshwater pond and drainage system will also provide an important water source for birds to drink and wash the salt from their feathers.

The project continues vital work started by the National Trust 30 years ago when Northey Island was the first site ever in England to carry out managed realignment[4] to its shoreline in efforts to recreate saltmarsh habitat.

In 1991 and 2018/19 work undertaken by the conservation charity resulted in two areas of healthy saltmarsh, approx. 1.7 hectares, which are now thriving with an amazing variety of wildlife.

Daniel Leggett, Coastal Projects Manager at the National Trust says: “Without management the whole 90 hectares of saltmarsh at Northey will be lost in the next 70-100 years. The saltmarsh on the island, which comprises 80 per cent of the current land mass, is shrinking due to wave erosion and stronger tidal flows, which are the result of sea level rise - one of the impacts of climate change. With higher tides, the saltmarsh and creek margins are eroding and sea water is overtopping the banks and flowing over the top of the saltmarsh more frequently. The changes are impacting wildlife. Some of the plant species found in the lower saltmarsh, such as sea aster, are dying out as the area is frequently under water, but are also creeping further up the shoreline encroaching on the areas where ‘higher’ saltmarsh plants, such as shrubby sea blite and golden samphire grow. With sea levels rising the plants are running out of space and being squeezed out of existence between the rising tides and fixed man-made defences. Although we will inevitably lose some areas of saltmarsh due to sea level rise, this work should help us protect at least 50 to 60 hectares, create 10 hectares of new saltmarsh and raise a further five hectares to a sustainable height above the tides.”