Biodiversity in Hampshire’s rivers

Hampshire’s rivers are teeming with wildlife. Otters chatter with each other while kingfishers perch on the riverbanks waiting for fish to swim by. 85% of the world’s chalk streams are in England, and many of these are in Hampshire, including the rivers Itchen, Test and Meon. These rivers are fed by spring water from the chalk aquifer (an underground layer of rock that can hold water) rather than from rain, which means they’re mineral rich, cold, and clear. This distinctive type of river provides the perfect habitat for the diverse range of animals that all spend time on, in, or near, our rivers.

Unfortunately, due to an increase in pollution, water usage, and population growth, three quarters of our chalk streams aren’t in good health. For more information about how you can save water and help protect our wildlife, read Hampshire & Isle of Wight Wildlife Trust's top tips.

Read on to find out more about Hampshire’s river residents.

Otters

For years it was thought that otters had become extinct in Hampshire. Fortunately, due to recent reductions in river pollution, less intensive farming, and the Meon Valley Partnership’s river restoration, the River Meon’s otter population is growing. These adorable animals are a wonderful part of Hampshire’s rivers and a sign that the local ecosystem is healthy. Otters can also be spotted in the River Itchen following their reintroduction in 1994.

Water voles

While water voles are endangered, Hampshire is home to the largest water vole reintroduction project held within a river valley. In 2013, 2,548 water voles were released within the Meon Valley by the South Downs National Park Authority and the Meon Valley Partnership, supported by the Wildlife Trust. Recent surveys have shown that the water voles are doing well in their new home and are now well established. Their burrows can be spotted on the riverbanks, and as water voles start to breed in the spring, there’s a chance you might spot some babies.

In fact, last summer we caught sight of this rare creature on one of our hidden walks.

White-clawed crayfish

White-clawed crayfish are small, bronze-coloured crustaceans with pale cream or rose undersides of their claws and are UK’s only native freshwater crayfish species. They use mineral-rich water to strengthen their exoskeleton, much like humans use calcium to fortify our bones. This makes our chalk streams the perfect habitat for these interesting invertebrates.

Unfortunately, white-clawed crayfish are increasingly rare due to the introduction of non-native North American signal crayfish. This invasive species has brought with them a disease called crayfish plague that has destroyed populations of white-clawed crayfish. Efforts are being made to boost populations, including a release in late 2022 of just under 200 white-clawed crayfish into the River Itchen, so hopefully they will be a much more common sight soon.

Atlantic salmon

Hampshire’s rivers, including the River Test, are home to Atlantic salmon – the clear, crisp freshwater providing the perfect habitat for the silvery fish. The ‘King of Fish’ can live for up to 13 years and spend a lot of their lives at sea. However, they’ll return to the area of the river or stream where they hatched to spawn their own young. The younger fish will then stay in that area for six years before they head back to the sea. While we’re not entirely sure how they find their way back to the stretch where they hatched, it’s definitely impressive.

Kingfishers

Kingfishers can be found in Hampshire’s rivers year-round, particularly by the banks of the River Itchen. These spaces give them the chance to hunt for fish and aquatic insects from perches on branches that hang over the water. So, if you’re on a stroll by the waterside, you might spot the colourful turquoise and orangey-copper birds diving from their spots into the water to catch a small fish!

These rare and interesting species are a valuable part of Hampshire’s countryside. So, when you’re out and about enjoying the sunshine on a summer’s stroll, please follow the countryside code to help protect them.

Find a walking route that follows one of our rivers and send us photos of the wildlife you spot along the way on Facebook and Instagram. You can also sign up to our newsletter for more information about how to get involved with Hampshire’s countryside this year.