Electrofishing Survey – Four Springs Lake
Just prior to the opening of the brown trout season, the Service conducted a single, one day survey of the trout population at Four Springs Lake. This survey was undertaken to supplement the information gathered during an earlier survey in March 2015.
A total of 51 trout were collected using the Service’s electrofishing boat for just over 2 hours effort. Approximately 10 percent of the catch were rainbow trout from a range of size classes. Of the 46 brown trout collected, the average weight was 1.1 kg although this result was heavily influenced by the recent stocking of adult fish transferred from Great Lake in early June 2015, with these fish weighing between 0.6kg and 1.2 kg. Of those brown trout that were deemed not to be from this stocking, that is fish over 460mm, the average weight was almost 1.6kg.
The graph above distinctly shows the stocked adult fish from 2015 at around 420 – 440 mm length and the 2014 & 2013 adult stocking at 460 – 500 mm length. The 2013 adult fish could easily be distinguished as the adipose fin on their back was clipped before being released in May 2013.
A report of the results from the 2013, March 2015 and July 2015 surveys will be published when completed later in the year.