TOLKA VALLEY PARK – I USED A VOIGHTLANDER 40mm LENS
Today I walked to Broombridge along the Royal Canal [about 7km] and then returned to Bolton street via Tolka Valley Park and Griffith Avenue. I do not know what the total distance was but I was exhausted by the time I returned home.
To begin with the Voigtlander 40mm lens worked perfectly but when it suddenly got colder I began to notice that the edges of the images captured by my camera were becoming blurred at the edges and as time passed the problem got much worse. After examining my equipment in detail I discovered that there was condensation inside the lens [why I don’t know]. I do not know how to prevent this happening in future especially as my apartment is very dry, maybe too dry.
Tolka Valley Park is an important regional park of about about 50 hectares. The river valley is rich in plant and animal life, a haven for biodiversity within the city, and local history. The Park is situated over a former city landfill, creating challenges to its management and design.
One of the interesting projects here is the ‘integrated constructed wetlands’ which were created in 1999 as a novel way of treating the incoming waters of the Finglaswood Stream. This Stream was polluted by misconnected domestic drains. This project was jointly initiated by Dublin City Council Parks and Landscape Services Division, Drainage division and National Parks and Wildlife Service. Wastewater from dishwashers, showers, washing machines, kitchen waste, oils, car washings together with surface water runoff from roads and houses was flowing to an artificial pond in the Park, by the now culverted Finglaswood Stream, before ultimately flowing into the nearby Tolka.
The pollution from these surface water sewers resulted in algae and scum, foul odours and an unpleasant appearance to the pond. Phosphates and Ammonia from household detergents were also contributing to ‘eutrophication’, a term used to describe the excess application of nutrients, in the Tolka river. Oxygen was low in the river and there was ‘weedy’ plant and algal growth that blocked light and choked streams – thereby worsening the environment for fish, including Salmon (Salmo salar) and Trout (Salmo trutta).
The construction of the wetland has been a success on many fronts: trapping pollution, reducing bad odours, making the pond more pleasant, and creation of new wetland habitat for local biodiversity.
The Council had a survey conducted of the wildlife in the wetlands in 2008. Perhaps the most exciting discovery of this survey was the presence of the Common Frog Rana temporaria. The frog is one of only three amphibian species in Ireland. While it is one of Ireland’s most familiar animals, its fortunes have declined in recent times. It is listed as ‘Internationally Important’ in the Red Data Book (Whilde, 1993) and more recently was determined to have a poor conservation status due to a decrease in both its range and population (NPWS, 2008). This is primarily due to the loss of habitat as a result of the widespread drainage of wetlands in recent times. It is protected under Annex V of the EU’s Habitats Directive.
The wetlands at Tolka Valley Park can be seen to be making a valuable contribution to the conservation status of this important species in Europe.