Swimming Upstream is the story of Patsy Peril, who was born in a small fishing community near Shannon in Ireland, where his family caught fish using hemp nets. In 1929 the local hydro-electric station opened, to provide nearly all of the country’s electricity.
But even before it opened, there were concerns over how the station would block salmon from swimming upstream to spawn, and these concerns were well-founded as numbers have dived ever since.
Now there are also fish farms in the Shannon estuary, where disease and parasites are rampant amid tightly crowded fish. This is his story of how to protect wild salmon, a subject he has covered for decades, working with the North Atlantic Salmon Conservation Organisation.
Ecological Roles of Wild Salmon
When salon return to spaw in freshwater streams, they transport essential nutrients from the ocean. Their spawning (and death) releases nitrogen and phosphorus, which are crucial for aquatic plants and algae. This supports the entire food web, from microscopic life to larger fish that feed on them.
Salmon are also a main diet for many creatures, including bears, eagles, otters and seals. Other fish (like trout) depend on salmon eggs for food). So more salmon means a thriving wildlife population, along with the growth of plankton and other aquatic plants.
When salmon die off in large numbers after spawning, the decomposing bodies nourish the surrounding forests, enhance soil quality and plant growth.
Threats to Wild Salmon Populations
Over-fishing a major threat, as populations can’t recover. Other threats are urban development, pollution and climate change (which alters the water temperature and flow patterns). That’s why it’s really important to restore degraded waterways, reduce pollution runoff and help to prevent climate change.
