Overcoming obstructions
We may be a small environmental charity but our mission is mighty. Working with landowners, communities, corporate organisations and of course nature, our purpose is to protect the Tyne rivers and the ecosystems within them for present and future generations to enjoy. One such ecosystem is migratory salmonids…
The Tyne provides an excellent habitat for a wide range of fish, most notably salmon and sea trout. Angling tourism brings in millions to the local economy reflecting the financial gain of looking after the river, but more so the importance of protecting the delicate ecosystems beneath the water whose impact reaches far wider. Every year, salmon and sea trout return from the sea to the ‘Mouth of the Tyne’ and swim upstream to lay their eggs where they were hatched. The journey is known as fish migration. However, there are many obstructions which stop them from doing this and it is our goal to maximise both the production of migratory salmonids and the opportunity for them to do so since our inception in 2004.
Tyne Rivers Trust act as the voice of the river; the trust does not own any land or fishing but we host the Tyne Catchment Partnership which includes 26 different organisations that rely upon or use the Tyne rivers. Through this shared expertise and invaluable local knowledge we have built a picture of what the Tyne is capable of in terms of fish numbers. In the face of constant disturbance and detrimental change to their habitat through human activity and climate change, numbers of Atlantic salmon have greatly reduced. Over a 100,000 of thousands of migratory fish began their life spawning in the Tyne in the 1800s, that number today has dropped to well below 12,000, per year, giving a strong indication that something has gone wrong.
We are responsible for protecting the Tyne rivers and so it is we who champion and drive change, working in partnership with Government agencies, key funders, communities and locals to identify barriers to fish migration and put things right. Obstructions such as bridge footings, weirs and dams can prevent migratory species like salmon and sea trout from travelling upstream to spawn, thereby limiting population strength. To ensure the health and survival of fish populations, it is vital that obstructions are removed or altered to make them passable. In addition, it can reduce diversity and population robustness in non-migratory species such as brown trout. The weir at Hexham Bridge for example was a challenging leap for migrating salmon and sea trout especially in low water. Many of the leaps were unsuccessful and the fish could injure themselves by landing on the concrete. The energy wasted with these failed leaps also makes fish more prone to disease and they have less energy for spawning when they do eventually get upstream.
We began our first large scale intervention in the mid 2000s with detailed feasibility studies on the river to identify possible solutions to problems it faced. The result was the creation of a new fish pass to improve access and ecosystem services in the Tyne. With funding from Defra and others, and vital help from volunteers, Tyne Rivers Trust has led the design and construction of a range of fish passes throughout the catchment in the 20 years since. Across all of our fish passage and easement projects, monitoring the existing structure, flow regime, identifying land ownership and site access needs is a complex operation. Ensuring we provide value for money and create something that benefits multiple species is important too.
The nature of these fish passes varies from larger construction projects, such as that at Hexham Bridge, to highly innovative designs that blend into the natural environment, such as those at Darden where the fish easements were placed below and onto the obstructions, improving access by recreating a more natural flow regime.
Measuring impact is an ongoing challenge of its own, as nature has no neat schedule in which to make like-for-like comparisons, but we can and do take a tiny snapshot of what’s happening as a result of all our interventions, spotting trends and using methods like electro fishing to assess the positive impact of our works on river health and activity below the waterline.
Though a key part of our interventions at Tyne Rivers Trust, work on fish passes is not done in isolation. Instead it is part of a holistic view we take alongside riparian repairs, river restoration, habitat restoration and tree planting, when assessing how to better support and protect the river in the face of climate change, human activity and natural events such as flooding.
As our Fisheries Manager Aidan Pollard with over three decades of experience and local knowledge shares, ‘we’ve declined from an abundance of salmonids to a battle for survival. Our waterways need to be treated with respect and it is the duty of all of us to improve the habitat focussing beyond the short term.
