Salmon

The fish ladder at Pitlochry Dam, on the River Tummel within the River Tay catchment, has provided one of Scotland’s most important and consistent salmon monitoring points since it opened in 1951, with counts maintained by SSE Renewables and the River Tay District Salmon Fisheries Board. Over the decades, the numbers of salmon passing up through the ladder reveal a striking and deeply concerning long‑term trend. In the 1970s, annual counts typically stood between 5,500 and 7,000 fish, a robust baseline that began to slip noticeably through the 1980s, falling to around 4,000 by the early 1990s. By the turn of the millennium, the figure had dropped further still, averaging roughly 2,000 to 2,600 salmon each year — a decline of more than half from the levels of fifty years before. Since 2015, numbers have remained stubbornly low, fluctuating between approximately 1,500 and 2,400 fish annually, with no sign of a sustained recovery to the historic highs. The overall picture is clear: roughly two‑thirds fewer salmon pass Pitlochry Dam today than in the 1970s, and while there are encouraging ups and downs from one year to the next, the long‑term trajectory remains unmistakably downward.

This decline is driven by a complex web of pressures, both in the river and far out at sea. Changing ocean conditions, warming seas, and shifting food availability have all reduced survival rates during the salmon’s marine phase, while in the river, climate change has altered flows and temperatures, and barriers to migration and the siltation of spawning grounds continue to present challenges. The impacts of aquaculture — including sea lice and genetic interactions with farmed escapees — remain significant concerns, and increasing numbers of predators such as seals, cormorants, goosanders and mergansers also take their toll. Restrictions on coastal netting have helped stem the decline somewhat, but they have not been enough to reverse it, and the fish that do return now arrive in far smaller numbers than in generations past. The ladder at Pitlochry thus stands not only as a gateway to the spawning grounds of the Tay and Tummel, but as a quiet, consistent witness to a profound change in our rivers — one that underscores the urgent need for continued monitoring, protection, and restoration across the entire salmon lifecycle.