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Wildlife and Conservation at Cowes Harbour

Wildlife and Conservation

The River Medina lies in a wide shallow valley bordered by mudflats and areas of saltmarsh, which are essential to the estuary’s ecosystem. The estuary’s mud is full of tiny creatures, marine worms and snails, which provide a rich food source for resident and visiting waterbirds. The estuary is also full of fish, and cormorants can be seen all year diving underwater to feed. In winter they are joined by little grebes, goldeneye, and in summer months by the spectacular terns.


Areas of saltmarsh provide a safe haven for young birds in summer and are important resting and feeding sites for birds throughout the tidal cycle. They contain rare and vulnerable plants and provide important nutrients for wildlife. Saltmarsh is also economically important as it is part of the natural capital, or the world’s natural assets, that provide ‘ecosystem services’ that benefit people. Saltmarsh provides ecosystem services such as flood management, nursery sites for commercial fish species and support for our recreational uses. It also absorbs and binds carbon from the atmosphere and nutrients from the water, effectively reducing pollution.

There is a relatively small amount of saltmarsh habitat in the Medina Estuary, but it is a very important feature of our local marine protected area. Annual photographic monitoring of the saltmarsh in the Medina Estuary takes place in June to record the extent and composition of saltmarsh and any change in the height or level of the banks. The monitoring is done to show any change that might require management. Over the past few years there has been a reduction in the area of saltmarsh in the estuary, so work is underway to help to prevent further loss and encourage growth.

Saltmarsh monitoring
Saltmarsh monitoring

Resident and overwintering birds are an important feature of the estuary and the international designations that help conserve it. Large parts of the Medina are developed, which leaves fewer areas where birds can roost at high tide. Cowes Harbour Commission (CHC) has been working with the Hampshire and Isle of Wight Wildlife Trust to improve habitat for use by birds at high water. This has included the removal of scrub vegetation both within a field and along its edge to allow a clear line of sight between the birds and the estuary. This line of site allows the birds to see danger and an escape route and is important so they can conserve energy.

Chawton Field
Chawton Field


Another important habitat within CHC’s jurisdiction is seagrass, also known as eelgrass. This fascinating species is the only marine flowering plant and forms lush underwater meadows. The complex ecosystem around it supports a wide range of marine wildlife. Seagrass beds provide food and shelter for fish and other animals, from tiny invertebrates to marine mammals and waterfowl. It is important as a nursery, spawning and refuge area for fish, including commercial species. The plants themselves stabilise the sediment and absorb nutrients from the surrounding seawater. Healthy seagrass beds store significant amounts of carbon from the atmosphere, helping reduce the impact of climate change. Beds of seagrass have been called the rainforest of the marine world!

Despite its value, seagrass is one of the most rapidly declining habitats on earth and is a critically endangered, red-listed habitat and a UK habitat of principal importance. It is under pressure from many of our activities, smothering from increase algal growth and climate change.

Nudibranch on seagrass - Credit ReMedies ProjectCowes Harbour is fortunate to have both intertidal and subtidal species of seagrass and CHC are working with Natural England, the Green Blue and other partners on a project to try to conserve it. The project will:
• work on practical ways to manage the habitat for rare protected species, such as seahorses, stalked jellyfish and seaweeds;
• be the first to collect seed and replant seagrass at this scale in England;
• provide solutions, such as Advanced Mooring Systems to reduce harm to these seabed habitats;
• raise awareness with the boating community and encourage better care of seabed habitats.

For more information about how you can help to protect seagrass by careful anchoring visit The Green Blue.

To find out more about local marine life and habitats see Hampshire and Isle of Wight Wildlife Trust or their local project ‘Secrets of the Solent’.

Seagrass - Credit Fiona Crouch
Seagrass - Credit Fiona Crouch

Marine Protected Areas

CHC is a competent authority and a relevant authority as set out in Regulation 6 of the Conservation of Species and Habitats Regulations 2010. This means that CHC has responsibilities for the sites that are designated for nature conservation within and, to some extent, adjacent to its jurisdiction.

There are four marine protected areas with components within CHC’s jurisdiction:
• The Solent & Southampton Water Special Protection Area (SPA) and Ramsar Site, which both recognise the importance of the intertidal and estuarine areas for overwintering and breeding waterfowl.
• The Solent Maritime Special Area of Conservation (SAC), which forms a complex of interlinked sites of importance for a range of marine, coastal and maritime habitats.
• The Solent and Dorset Coast SPA, which is designated to help protect tern feeding areas.

The Management Scheme for the Solent sites is referred to as the Solent Marine Sites Management Scheme (or SEMS). As a relevant authority, CHC is part of the management group with the secretariat being provided by the Solent Forum (a Coastal Partnership). CHC has to monitor activity within its jurisdiction and report back to the management group. The group then looks at any potentially damaging activities, either new or increasing and if necessary, refers them to the SEMS Natural Environment Group to develop management measures.

For more information about our local Marine Protected Areas see Solent Forum and Natural England.

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