6 minute read
Discover Southmoor
This coastal nature reserve near Portsmouth is changing with the tides – quite literally. Since its sea wall was breached in 2020, the habitats at Southmoor have begun a fascinating transformation which is off ering new opportunities for wildlife and visitors.
Two years ago, a summer visit to Southmoor Nature Reserve in Havant would mean strolling through a coastal marshland prolific with flowering orchids, wading birds and grazing cattle.
Since then, a dramatic and irreversible transformation has taken place. The waders happily remain but, sadly, the orchids are no more and the cattle are yet to return.
In August 2020, the deteriorating sea wall that defended Southmoor against the tides of Langstone Harbour succumbed to a series of fierce storms and was breached. The nature reserve was completely flooded.
The deteriorating sea wall before it was breached...
...sea water floods into the nature reserve after the wall’s defences fail.
Initially, there was real concern the entire site would be lost to the sea forever. Mercifully, those fears receded thanks to an outlet that allows some fl oodwater to drain away. However, the sea wall was so badly damaged that parts of the reserve are now completely underwater at each high tide. Trust staff have even found seaweed hanging from the top strands of barbed wire that was previously Southmoor’s cattle fencing.
Opportunities for wildlife
All is not lost at Southmoor. The sea wall’s failing has resulted in a remarkable shift in habitat and opportunity has arisen from the change. What used to be coastal grazing marshland is now in the process of becoming saltmarsh, which is attracting new wildlife.
Joe Rackstraw, the Trust’s reserves offi cer at Southmoor, says: “The reserve was already an important site for nature, but it has become even more special because of the sea wall breach and the potential for new wildlife it could bring.
“It was sad losing the orchids but these fl owers, plus others that were killed off , are slowly being replaced by saltwater specialist plants like glassworts (also known as marsh samphire).
“As a saltmarsh, Southmoor will attract wading birds like lapwing, avocet, redshank, greenshank, godwit, curlew and plover, as well as ducks like gadwall, wigeon and shelduck.”
Haven for birdlife
At high tide, when much of the eastern half of Southmoor becomes completely submerged, only a few islets of scrubland remain exposed. These have been readily accepted as ideal roost sites for gulls and terns as they are safely out of reach of predators like foxes.
Even before the breaching event, Southmoor was a known birding hotspot. Since its transition to saltmarsh, that has become even more apparent. Last winter, the Trust’s ecology team carried out several bird surveys at the reserve and recorded over 1,400 birds of 35 diff erent species.
This included protected species such as curlew, dunlin and ringed plover, which feature on the ‘red list’ of Birds of Conservation Concern.
Carmen Green, Senior Ecologist at the Trust, says: “Southmoor is a haven for overwintering birds in the Solent and attracts an abundance of winter ducks and waders.
“With the fantastic habitats of Langstone Harbour and Farlington Marshes Nature Reserve either side of Southmoor, it’s possible to see a range of species here.
“It’s particularly good to fi nd several rare and notable bird species at Southmoor and though we didn’t see one in our surveys, I’ve heard short-eared owl have been sighted at the reserve.”
TOP TIP: Southmoor is a great vantage point for spotting black-necked grebes, red-breasted mergansers and great northern divers in Langstone Harbour.
Going with the tide
The Trust wants to use the breaching event at Southmoor to better understand how habitats can change when nature takes over. Thankfully, the flooding has not been detrimental to local wildlife at Southmoor. However, other coastal nature reserves that support a larger number of protected species, like Farlington Marshes, face a far greater risk from the impact of climate change.
These coastal habitats play an important role in helping to mitigate the impact of urban fl ooding from rising sea levels and more extreme storms. Ensuring that we can fi nd suitable compensatory space really does have multiple benefi ts for people and wildlife. The challenge is fi nding those substitute habitats, and this is something we want to work with local authorities on to safeguard the future of our precious coastal wildlife.
Glasswort, or sea asparagus, is one plant species that could thrive in the new saltmarsh environment.
NOW YOU DO IT
Visit Southmoor Nature Reserve
KNOW BEFORE YOU GO
Location: Southmoor Lane, Havant, Hampshire, PO9 1JW OS Maps grid reference: SU709051 Parking: Parking available on Southmoor Lane. Nearest bus stop: Langstone Business Park, Penner Road, 10-minute walk to Southmoor. Getting around: The reserve features several public footpaths and permissive paths across the site, some are unsurfaced and can be muddy when wet. Please keep to paths to avoid disturbing sensitive wildlife.
TOP WILDLIFE TO SPOT
Skylarks: These ground nesting birds, renowned for their distinctive display fl ight and song, use Southmoor as a breeding site. Red-breasted merganser: Look out for these handsome birds with their long, serrated bills at the reserve and in Langstone Harbour. Curlew: Southmoor off ers good habitat for this protected wading bird, with its unmistakeable downcurved bill and evocative ‘cur-lee’ call.
HABITAT OVERVIEW: SALTMARSH
Saltmarshes are coastal wetlands that are fl ooded and drained by salt water brought in by the tides. The ecosystem provides important breeding and feeding sites for waders and waterfowl and nursery areas for fi sh species. As well as supporting huge biodiversity, saltmarshes also protect us from coastal erosion and storm surges and help to combat climate change. One hectare of saltmarsh can capture two tonnes of carbon a year and lock it into sediments for centuries.
