Fish in Abbey Fields Lake

Abbey Lake covers an area of roughly 3.6 acres. Every spring fish are removed from the lake to reduce the numbers as there is no other means of escape for them. In 2018 there was a successful fish reduction and this year  it was hoped to reduce the current population by about 200 lbs to promote a healthy population.

Common and Mirror Carp are the predominant species within the lake, and when left unchecked these populations tend to increase steadily due to favourable breeding conditions and few natural predators, e.g. otters, cormorants. Once the population gets too large it is a temptation for illegal fishing but moreover it becomes unsustainable in the shallow lake, causing health problems for the fish, food shortages, depleted oxygen levels (particularly in the summer months) and sadly results in numbers of fish dying off, which is both unsightly and malodorous.

Images of some of the fish that have been seen in Abbey Fields Lake can be seen if you click here This will open in a new tab.

Why are the fish in Abbey Fields Gulping Air?

In times of hot weather, we often receive a number of messages from people who are worried about the fish in Abbey Fields especially when they see them apparently gulping for air.

Friends of Abbey Fields have checked with Warwick District Council who have responsibility for the management of all of the features of Abbey Fields and they have advised that they work with professional organisations that help us manage the lake, especially The Environment Agency and Leamington Angling Association.

The fish stocks are managed by removing as many fish as possible in late winter, (the lake is not stocked) and the removed fish are rehomed in local waters all under licence. This has been done for numbers of years, to everyone’s benefit, and they have not experienced a fish kill since the lake was dug.

We have contacted Warwickshire District Council (WDC) about fish gulping and fish dying  and they have advised that they and they have not experienced a fish kill since the lake was dug, however they pointed out that fish do come up to the surface to eat algae that floats on the surface also floating bread etc, as can be seen when you try to feed the ducks at the duck feeding station. This activity can be misinterpreted as ‘gasping for air’, but please remember that fishes do not breathe air in the same way that we do.  They extract oxygen from water by passing it through their gills.

WDC has checked the water oxygen and advised that this is OK. Previously, the Environment Agency have visited and checked the water quality, which means they check dissolved oxygen in the water the fish breathe, and for pollutants. In the hottest part of a previous year the levels of oxygen were all fine and no pollutants found on the several times the checks were made.

In the past, Leamington Angling have been asked to inspect the lake. They found the fish to be healthy and observed fish sucking invertebrates off the surface of the water, this, in their words, could be construed as fish gasping for air. The fishes were fed some carp food and were feeding happily

WDC are as interested as we are in ensuring that the lake stays healthy and to that end have made some enquiries about water aerators.  Commercial aerators such as would be required for Abbey Fields are expensive and power supplies would need to be provided.

WDC have advised that at present (2022) the lake is lower than normal and that they have contacted the Environment Agency about this. When the lake was re-established some years ago, WDC were advised by the Environment Agency to set the water feed from Finham Brook at a specific level about 8” / 20cm below the lake’s water outlet. This was done. However, when the water supply level falls below the minimum required for an inflow, no fresh water is fed into the lake. The result of this is that when we have prolonged period without rain, the level of the lake falls because of evaporation and in an extreme situation this could result in the lake drying out. In reality this can be a good thing as it re-sets the lake and removes all the fish however it is not so good for the fish population at that time. It should be noted that Abbey Fields Lake was not stocked with fish, they were introduced by nature after the lake was dug. The best wildlife ponds don’t have fish and dry out regularly.  It is a reality that with global warming and similar events a shallow lake as ours may well dry out at some point.

When we are in drought conditions no water flows into the lake. This was part of the design for the lake and was a planning constraint on the lakes construction /design.

As an observation, it is interesting to note that the fish are not stocked which indicates that they are surviving and breeding successfully and this would not happen if there were problems with oxygen levels or pollutants.

Fish removal Monday 21 March 2022

On Monday 21 March, 2022, a healthy quantity of fish were removed from Abbey Fields Lake.  This activity was completed under the direction of Fisheries Manager Jon Wall of Jon Wall Fisheries and Anthony Simmons  from Leamington Angling Association.

This is a task that is carried out approximately every year, although because of Covid it has not been possible to do so for the past two or three years.

As before the fish were carefully removed by Seine netting, and transported to John Wall Fisheries, in oxygenated 1 m3 tanks. Once there, the fish are sorted, health-checked, fed and prepared for distribution to restock ponds, lakes and pools in the area and potentially across the UK.

Because the Lake is so shallow, the nets were laid from the boat and by people hauling them.  Once positioned, the net is then hauled into the edge of the lake from where the fish can be removed. Inevitably a lot of submerged branches and other debris has to be removed carefully so that the net is not damaged. This year as well as a haul of branches and twigs, a skateboard was recovered.

Laying out the net

Hauling in the net

Hauling in the net and cleaning it in the process

It looks like it is boiling, but it isn’t. It is the fish.

Photographs by David Emsley

Whilst talking with Anthony Simmons we learned that Finham Brook, which was running clear on Monday, has a population of Brown Trout and Signal Crayfish. The Brown Trout in Finham brook can grow up to about 30 cm but generally are a lot smaller.  The Signal Crayfish in Finham Brook can grow up to 5 to 7 cm. Elsewhere in the right conditions they can grow to 15 cm.

The native population of European Crayfish had been declining since the early 20th century and Signal Crayfish were introduced to the UK in the 70s. It was intended that they be farmed as food, especially for Sweden and Finland.  They are an aggressive invasive species and, unfortunately, also carry the disease that was eliminating the native European Crayfish. It does not help that Signal Crayfish are less likely to succumb to the disease whilst in European Crayfish it is generally fatal.

In the lake it is extremely unlikely that there are any Crayfish as they do not like the silty/muddy water. Similarly, there are no Brown Trout in Abbey Fields Lake.  They much prefer fast moving, well oxygenated, clean water as is found in streams and rivers.

Abbey Fields Lake has a variety of fish living in it, mostly Common Carp and Mirror Carp and these were what were netted on Monday. It seems that some other species do live in the Lake – a single Koi Carp was netted and there are reports of other types of fish living there as well.  It was even suggested that goldfish get ‘rehoused’ when they become too big or are no longer wanted.  It is not a good idea to ‘donate’ them to the Lake as they will not like the murky waters, and they also might introduce unwanted diseases to the healthy population of existing residents.

Jon Wall advised that he and his team were hoping to remove about 500 lbs /225 Kg of fish.  Because of the regular removals of the fish in previous years, the fish taken today were in good shape and size as well as being in a good range of sizes. Monday’s fish were anything up to about 5 pounds each, which is why we have seen the large mouths at the duck feeding station. Some of the Mirror Carp will be taken straight to Ryton Pools and the rest to Jon Wall’s offices for subsequent redistribution.

Removal of netted fish

Fish waiting to be moved to oxygenated tanks

Photographs by David Emsley

Please note:

  1. The fish are not harmed and are transported in special containers in oxygenated water to keep them healthy.
  2. Signal Crayfish, as any other wild creatures, will defend themselves and can give you a nasty nip or bite with their very strong claws.
  3. You need a licence from the Environmental Agency to catch Signal Crayfish.
  4. You are not allowed to handle European Crayfish without a license from Natural England and you will also need a licence from the Environment Agency.

Fish removal Wednesday 13 Feb 2019

On Wednesday 13th February, 2019, Countryside Management students from Moreton Morrell College came to Abbey Fields to help remove some of the fish from Abbey Lake under the direction of Fisheries Manager Jon Wall and Anthony Simmons  from Leamington Angling Association.

The fish were carefully removed by Seine netting, and transported to John Wall Fisheries, Melton Mowbray, in oxygenated 1 m3 tanks. Once there, the fish were to be sorted, health-checked, fed and prepared for distribution to restock ponds, lakes and pools in the area and potentially across the UK

This year, Jon Wall had brought a fish finder to see if the location of the fish shoals could be determined before laying out the nets. Unfortunately the shallowness of the water prevented a great deal of success and as a result the team had to complete two trawls with the seine nets.

Submerged branches from last year’s tree damage caused some issues with net retrieval.

A surprising number of visitors took interest in proceedings and we fielded questions whenever possible, in order to let everyone know what was going on.

Please click on the images for larger versions.

Image by David Emsley

Setting out the Seine Net

Photograph by David Emsley

Hauling in the Seine Net 1 – Jon Wall

Photograph by David Emsley

Hauling in the Seine Net 2

Photography by David Emsley

Jon Wall making sure that the fish do not escape under the Seine Net

Photograph by David Emsley

Andrew Simmons with Common Carp

Photograph by David Emsley

Andrew Simmons with Mirror Carp

Photograph by David Emsley

Jon Wall with fish about to be moved into transport tanks

Photograph by David Emsley

Fish being put into oxygenated transport tanks

Photographs by David Emsley

Fish Removal activities in previous years: