Lower Reservoir – Fish Survey

Following the fish kill at the bottom reservoir at Harold Road earlier this year, members of the Environment Agency fisheries team attended the reservoir today (Tuesday 27/11/2018) to carry out a survey in order to assess the remaining fish stocks. The survey results are below:

Clive Vale Lower Reservoir Survey

Survey method:
Single sweep with a 75m seine net set by hand. The net was walked around the lake and drawn into the western bank.

Findings:
Allowing for fish missed by the net and a percentage that will have escaped due to the lead line lifting on various unavoidable submerged features it would be reasonable to assume that our sample was representative of the overall stock in both health and diversity. A number of species, such as Tench, are difficult to net due to their tendency to hug the lake bed, likewise larger perch have a tendency to hide amongst the dense marginal vegetation. This should be taken into account when assessing the stock – just because we didn’t catch them doesn’t mean they aren’t there!

All fish caught in the survey appeared to be in very good health. There were no obvious outward signs of parasitic infestation or the lesions or gill necrosis that may indicate some diseases. None of the fish appeared visually malnourished or stunted.

Species found on the survey are as follows, with details of size and numbers below;

Roach, Rudd, Bream, Perch, carp (mirror & common) and hybrids (carpxcrucian / brown goldfish)

Species Numbers Weights
Carp (mirrors & commons) 24 3lb – 15lb 4oz (16 of these were 5lb or above)
Brown Goldfish / Crucian Hybrids (also known as F1’s) 70 1-3.5lb

Mixed smaller fish (roach, rudd, skimmer bream, perch, roach/bream hybrids) 56 x nets full (approximate 7lb per net) 392 – 400lb

Using some very rudimentary maths It is estimated that in a single net we had around 630-640lb of fish. If we make the very optimistic estimation that that could be around 40% of the total stock (realistically it was likely to be lower than that) we could estimate that the stocking density of the lake could be in the region of 1,600lb. Although this is in no way an exact science I would certainly say that there is a perfectly sufficient stock for it to continue to be a thriving fishery. It could be that the volume of fish removed by the unfortunate events of the summer has actually benefitted the remaining stock.

All in all, an excellent result

              

Selection of Pictures taken on the day