Bird Island
Research undertaken prior to construction, identified the necessity for undisturbed roosting areas to assist the numorous overwintering birds in the area. An adaptive design to maximise ‘attractiveness to birds’, whilst, further to discussion with Natural England, allowing its future height to increase in size to accomodate sea level rise.
Undisturbed high-tide roosts play a fundamental role in supporting waders during their non-breeding season. Close vicinity of these roost sites to feeding areas is pivotal to success, some advantages being:
• Other species may colonise or utilise the roost.
• Island reduces wave energy, creating saltmarsh habitat in the lee.
• Aestheticly pleasing focal feature in the harbour.
• A useful way to educate the community on wading birds.
• Aids with localised establishment of saltmarsh.
The bird island may require future shingle recharges, increasing its height to accommodate sea level rise; this has been incorporated within the design.
Innovative and accessible approaches to on going engagement will include: increasing appreciation of the bird life and reducing social exclusion by introducing braille to the interpretation boards allowing blind and partially sighted people to read by touch, guided by RNIB; use of QR codes which link to sound recordings of individual birds calls, allowing people to identify hard to spot birds by their sounds.
The design refined using hydrographic models.
It was engineered to reuse construction material to build island’s core.
The concept of the design was developed to be replicated elsewhere.
Environmental
Improvements at the Noth Portsea Coastal Scheme
The North Portsea Coastal Scheme is a local authorityled flood and coastal erosion risk management scheme comprising five distinct phases. Phase 4 (Eastern Road), completed September 2024, comprises hard engineering in the form of a concrete flood wall, with associated landscaping and public realm improvements. This phase implemented a varied suite of innovative environmental initiatives, including the UK’s first large-scale Ecoformliner, a reuseable mould that generates a textured finish on concrete structures and a high-tide wader roost island. Other initiatives include stepped tidal pools, wildflower meadows, bee posts and more, which together greatly exceeded legislative and national/local policy requirements.
PORTSMOUTH
NORTH PORTSEA
Before - Bird Island under construction
After - Bird Island completion
Oystercatcher By Tobias Hopp
Black headed gull By Stephen Tafra
Dunlin By Bob Brewer
Ringed Plover By Emad Tahaei
Ecoformliner
The Ecoformliner is a bespoke habitat creating solution, devised where there was nothing on market that could be scaled up effectively. The textured design is based on PhD level, scientific research by Glasgow University. An ecological survey of the local foreshore refined the design to target specific local marine life, creating ‘niches for species’ and to encourage colonisation of the seawall. The uniqueness of this design improves biodiversity, creating future habitat potential that would otherwise be devoid of life, whilst allowing some species protection from being ‘grazed off’ by other species.
Small scale trials were undertaken prior to construction to ensure the structure was going to be buildable on a larger scale. The design then covered the whole wall, encouraging colonisation to continue over its 100-year design life.
Process of colonisation is not linear, although green algae are quick to colonise, this is removed by grazers and replaced with long-lasting species such as fucoid algae and or barnacles, depending on tidal height.
The image (left) shows 1.5km of the 2km extent of the Ecoformliner wall during construction (the northern extent is marked by the red arrow), with Langstone Harbour to the right of the photo and Portsea Island to the left. At the base of the wall, a few of the 132 stepped tidal pools. The high-tide wading bird roost island (Cockleshell Island – named by a public naming competition) is shown in the foreground, adjacent to a section of landward realigned seawall which created an area of new intertidal foreshore between Cockleshell Island and the land.
Design & Buildability
Future Proofing
The unique texture of the surface delivers a range of ecosystem services, including:
• Seaweed growth to encourage carbon storage.
• Encouraging invertebrates in the seaweed, providing feeding resources for birds and fish.
• Promoting seaweed growth to filter pollutants, helping to improve water quality.
• Improving asset resilience where seaweeds help to reduce weather-related deterioration.
• The Ecoformliner wall is designed with no long term maintenance requirements.
• The design is integral to the wall with no fixings and no risks of it becoming loose or degraded over time.
• Design life of wall is 100yrs and over time inspections via laser scanning will identify any maintenance issues.
• There will be localised clearance of growth if further investigations are required.
By working with nature, the biological growth on the wall will slow down deterioration caused by weather and tide movements, at the same time as protecting thousands of homes from flooding.
The texture and attractive appearance of the sea wall was specifically designed to maximise colonisation potential for years to come and will likely increase with rise in sea levels.
A long term monitoring programme has been developed with the University of Portsmouth UG and PG students, which is incorporated into the Marine Biology degree course to provide lasting independent academic rigour. The programme aims to assess rates of colonisation and assembly of communities on the wall; identify background environmental conditions influencing colonisation; identify improvements in the design and methods of construction of coastal infrastructure as well as critically enthuse and train the next generation of marine scientists, focusing on Greening the Grey.
This photograph demonstrates how impactful the tectured Ecoformliner has been in providing valuable habitat compared to a smooth seawall.
Before - 50m length section of the old sea wall in 2017
After - the same section of the seawall in 2023 with the Ecoformliner texture
EARLY DESIGN
TRIAL FORMLINER TRIAL MOULD
STRIKING TEXTURE ACHIEVED FULL SIZE FORM REMOVING THE FORM RESULT
