The work to protect wildlife on the rivers of Essex

Gentle streams, trickling springs and running rivers are idyllic features of British landscapes. Aside from their beauty, rivers play a functional role as they travel from source to sea. In the UK, around 3,000 species rely on rivers, 200 of which are listed as rare, endangered or vulnerable. Find out how Essex Wildlife Trust is working to protect these vital freshwater habitats and the wildlife that relies on them

Over centuries, the importance of rivers has become paramount. For people, rivers provide drinking water, irrigation for farming, aid with the transportation of goods for businesses, link together communities and are people’s livelihoods. For wildlife, they are an essential support system, providing a habitat to live, breed, feed, swim and shelter within.

Great British Life: Cooks Mill - an example of a barrier Credit: Essex Wildlife Trust Cooks Mill - an example of a barrier Credit: Essex Wildlife Trust

There are around 42 native species of freshwater fish in the UK such as carp, brown trout, flounder and lampreys, to name a few. Some of these species are migratory, using rivers as breeding grounds before returning to the sea in adulthood. Eels are especially known for living parts of their extensive life cycle in our rivers.

Kingfishers, with their unmistakable bright blue and orange colourations, rely on rivers for finding this food source. Herons too, with big, wide wings, will stand statue-still in the riverbank reeds, waiting for an unsuspecting fish to appear. But birds are not the only wildlife that rely on rivers for food. Otters are semi-aquatic mammals, dipping below the waterline in search of their dinner. In the thick vegetation that borders our rivers, water voles leave nibble-sized marks in grasses before burrowing in steep banks to nest.

Rivers at risk

Great British Life: Old Stratford River Weir Credit: Essex Wildlife Trust Old Stratford River Weir Credit: Essex Wildlife Trust

Sadly, river biodiversity is under threat. Over many years, Essex’s freshwater network has been fragmented and industrialised. Rivers have become drains for waste and chemicals, and man-made barriers such as weirs, locks, dams, and mills have substantially reduced the flow of rivers. Although built for a purpose at one time, many of these artificial barriers are no longer in use, leaving 97% of our river network interrupted. Fish navigating through a once-flowing river network are now unable to continue along migratory paths. This has a huge impact on wildlife, affecting the diversity and population of migratory fish that are no longer able to access suitable spawning sites. Recovery for these species can be dangerously slow if fish cannot move back upstream, which also affects their predators like the hungry kingfisher, heron, and otter.

The Essex Fish Migration Roadmap

Great British Life: A completed fish passage Credit: Essex Wildlife Trust A completed fish passage Credit: Essex Wildlife Trust

Essex Wildlife Trust has been working in collaboration with the Thames Estuary Partnership and the Environment Agency to create The Essex Fish Migration Roadmap. By working together, a map of Essex rivers has been created, with 400 obstructions to fish passage also identified. Work has now commenced to remove or adapt each barrier, in an ambitious, decade-long project. Preferably, fish passages will be entirely removed and rivers can resume their flow. However, this can be complicated and expensive, considering factors such as maintaining water levels and the risk of flooding. If a barrier cannot be removed, a bypass may be a secondary solution. So far, 3 Reconnecting rivers

Great British Life: The Essex Fish Migration Roadmap showing the blockages to fish migration (in red) and free migration (green) Credit: Essex Wildlife Trust Caption: The Essex Fish Migration Roadmap showing the blockages to fish migration (in red) and free migration (green) Credit: Essex Wildlife Trust Caption:

A freshwater network

There are around 42 native species of freshwater fish in the UK, such as carp, brown trout, flounder and lampreys, to name a few. Some of these species are migratory, using rivers as breeding grounds before returning to the sea in adulthood. Eels are especially known for living parts of their extensive life cycle in our rivers.

Kingfishers, with their unmistakable bright blue and orange colourations, rely on rivers for finding this food source. Herons too, with big, wide, wings, will stand statue-still in the riverbank reeds, waiting for an unsuspecting fish to appear. But birds are not the only wildlife that rely on rivers for food. Otters are semi-aquatic mammals, dipping below the waterline in search of their dinner. In the thick vegetation that borders our rivers, water voles leave nibble-sized marks in grasses before burrowing in steep banks to nest.