Lowering the Embankment at Northey Island

Blog by David Mason, National Trust - Suffolk and Essex Coast Ranger

April 2023 was an exciting month for the Northey Island Coastal Adaptation Strategy and the LIFE on the Edge project. After several years of planning and preparation the final parts of the embankment were lowered on April 28th and the tide came into the new starter creek, finally overtopping onto the Eastern fields at high tide on the 4th of May. Hurrah!

We have timelapse cameras on site to record progress and these are quite useful in comparing before and after photos.

Embankment in Winter 2022/23 (c) National Trust

​​This photo shows the ‘before’ of the pond the water voles were translocated from, with Brent Geese settled in the field. The area on the right is the location of the first managed realignment in England carried out in 1991, which laid the foundation for later realignment projects around the country.

Embankment in May 2023 (c) National Trust

​This is the same view after the embankment was removed, showing the tide coming over the 1991 realignment.

Embankment in October 2023 (c) National Trust

​On particularly high tides the incoming water covers the lowered embankment and spills into the pond. Here little egrets and other wading birds can be seen in the shallows.

Eastern field in May 2023 (c) National Trust

​May the 4th be with you. The forces of nature take charge at Northey as the first high tide overtops the new starter creek onto the Eastern field.

Saltmarsh plants growing on Eastern field (c) National Trust

​Saltmarsh plants have already begun growing in the Eastern field, predominantly along the edges of the creek and scrape, whilst birds including lapwing, little egret, redshank and greenshank make use of the new intertidal area

Bank Reprofiling

Reprofiling the bank (c) National Trust

The bank in the Northern field has been reprofiled with a shallow back slope to make it more resilient to overtopping by the tide during storm surges.  Capped with topsoil from on site this will quickly regenerate and forms part of a new circular walk around the site, open April through to September. A new borrowdyke has been dug out further inland.  This drains the field and links to an outlet pipe with flap valve that takes excess water into the saltmarsh.  The ditch contains a deeper pond area for freshwater wildlife. The field has been re-fenced and will continue to be used for hay making and grazing which keep the grass in good condition for brent geese, lapwing and curlew to use in the winter.

Water vole update-
As the landscaping work has finished, the fencing to keep the water voles in their new pond has been removed.  It now looks like part of the landscape and the voles are free to roam into the network of freshwater ponds and ditches.

The new Water vole pond (c) National Trust

Fish survey training

​National Trust staff undertook fish survey training with Steve from the Institute of Fisheries Management.  After laying out fyke nets in the creeks at low tide, we trawled a tidal pool with a seine net while waiting for the tide to rise and bring the fish in to the creeks.  The seine net caught a range of small fish including common goby, bass, thin lipped grey mullet, gold grey mullet, stickleback, prawn and shrimp.  Larger bass were caught in the fyke net nearest the seaward end of the creek. The surveyed marine life were returned to the creeks and scrapes following identification to continue their journeys around the estuary and further afield.
 

Laying out seine net in a tidal lagoon (c) National Trust

Examining the catch (c) National Trust

Small fish caught in the seine net kept in an aerated water bucket (c) National Trust

Gold grey mullet in measuring vessel (c) National Trust

Laying out a fyke net in the new creek, also showing the vegetation changing due to flooding (c) National Trust

Links to previous blogs about Northey Island
​Part 1:  www.projectlote.life/news/northey-island
Part 2:  www.projectlote.life/news/ntconservationadaption
Part 3: https://www.projectlote.life/news/ntwatervoles​
Part 4: www.projectlote.life/news/northey-update