Acidic Lake Trout
High altitude trout in bog lakes are generally small fish. But what they lack in size they make up for in attitude and numbers.
The lakes in higher areas of the country like Connemara, Killarney, Mayo or Wicklow are generally features of upland erosion as result of glaciation. Igneous granite bedrock and surrounding bogland usually result in acidic water forming streams, rivers and lakes in these areas. Coniferous forest planting can further acidify the water as can be seen in Connemara and Wicklow particularly.
Acidic water means implications for the life that tries to survive within. Brown trout that feature in such lakes never attain huge sizes and generally have shorter lifespans than their counterparts found in more fish friendly environments. One feature of water with a higher acidity level is an increase in dissolved metals in the water, namely aluminium. This can be mildly toxic to many plants and aquatic invertebrates. The inhibited plant and insect growth means the fish populations don’t have sufficient feed. Respiration becomes more difficult for the fish resulting in stress and shortened lifespans in comparison to fish from waters where acidification is not an issue.
The key with fishing these types of waters is not to expect monsters. The nature of trout means that some fish do cannibalise due to lack of available food sources and these fish will attain a higher average size than those that don’t. It is possible to find such fish in acidic waters but such instances are very much an exception rather than the rule. With this in mind I headed to a small water deep in Connemara to have a look at what could be caught.
I spent a couple of hours on the water, drifting and casting a team of three wet flies. The fish were obliging and although most of them were only a couple of ounces in weight, they provided tremendous sport and made for a very pleasant afternoon. I’m not sure how many fish I caught, I stopped counting after I made it to double figures. Successful flies included bibios and sooty olives and each fish hooked swam away quickly when returned to the water.
I called it a day when the wind dropped. The corduroy ripple that was present for the first few hours disappeared leaving the surface of the water like a mirror. Time to go home but where to next?