This year saw the second year of fish surveys undertaken by the Trust.  A more comprehensive presentation of results will be forthcoming. As well as our wider fish survey programme to understand the presence and health of different fish species at different locations, we took the opportunity to survey  RTCT’s recently completed, Environment Agency funded nature-like fish pass channel at Stadhampton.

It’s hard to believe that only 18 months ago this was a brand new, freshly constructed channel in what was previously a field. During our October survey, we noted characteristic chalk stream plants are now well established, and flourishing in the margins and channel, and saw that the geomorphological processes had created natural stream bed conditions – clean, coarse gravel bars with other areas of finer sediment – which allied with diverse depths and flow velocities provide the range of conditions needed to support a diversity of plants, invertebrates and fish.

Those diverse conditions were reflected in our electric fishing results, with brown trout, gudgeon, dace, chub, bullhead, minnows, stickleback, stone loach and perch all being present.

The presence of perch in the bypass channel was particularly promising. Our fish surveys elsewhere in the Thame catchment, and anecdotal reports from anglers indicate that perch are currently very scarce. Thus, the finding of high numbers of young-of-the-year perch in the new channel was encouraging. One hypothesis is that perch, a phytophilic species (one which spawns on plants), have been able to capitalise on the extensive presence of submerged plants present in the new channel (initially planted out as part of the project, but now thriving of their own accord).

Another species likely to benefit from the new channel is trout. The flow characteristics and clean gravel look to be ideal trout spawning. With the trout spawning period upon us, we’ll be keeping a close eye on Stadhampton channel to look for spawning activity.

The Stadhampton bypass channel is a testament to what can be achieved through river restoration projects and nature’s remarkable ability to adapt. If you build it, they will come! This project highlights the vital role that tributaries, like the Chalgrove Brook, play as the arteries of our rivers, providing essential habitats that support fish at different stages of their lifecycle and across the seasons. Fish surveys, like those conducted here, are crucial for understanding fish populations and evaluating the effectiveness of restoration efforts. By systematically incorporating baseline and follow-up surveys into our projects, we can better evidence their impact and continue to refine our approach. In the coming weeks, we’ll be analysing the electric fishing results gather across multiple tributaries more fully and sharing a detailed report—keep an eye out for further insights.

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