Category Archives: Management Reports – Netherfield Lagoons

Ouse Dyke Revitalisation

The Problem

The Ouse Dyke runs beside the Netherfield Lagoons Local Nature Reserve and historically has attracted kingfishers and herons to fish in it and grey wagtails and green sandpipers to hunt for insects along its banks. The floor of the stream supported a community of water plants and their associated invertebrates and the banks were vegetated with a wide assortment of native plants. Several species of fish, several as fry, were regularly seen in the stream.

Over a series of years Himalayan balsam colonised the banks. The banks were close enough together for the fully grown plants to meet over the top in an arch, cutting out most of the light from the stream bed, with the inevitable result of impoverishing the flora growing in it. The native plants growing on the banks were also out-competed with the result that in winter the banks were bare and lifeless, there was no longer the food to attract some of the birds. The balsam also started to spread away from the stream onto the reserve, especially where the seeds were carried as the Ouse Dyke flooded, which it does on a regular basis.

The Solution

Most of this land belonged to Severn Trent Water and was not the responsibility of the nature reserve owners, but, along the River Trent balsam was growing on reserve land. This was dealt with by pulling, making sure to break off the roots after it was pulled, or by mowing with a brush-cutter, leaving the roots in the ground. Both methods were effective but sites had to be regularly revisited as new seeds would germinate as the light penetrated to them. If all of the plants were dealt with before they could set seed there was very little growing the following year and the plants were eradicated in two years. However new plants arrive along the river banks each spring as the seeds are washed down from further upstream, but this is a small amount compared to what existed before the work started and is soon dealt with.

The Ouse Dyke was a much bigger problem as the balsam grew solidly along more than a mile of its length and large areas of washes on the nature reserve side were also thickly colonised. These washes were dealt with first by cutting with a scythe and pulling. As the first plants were removed light was allowed in and new seeds germinated, so that the process had to be repeated regularly.

The following spring the washes were again targeted but there were far fewer plants and so the Ouse Dyke adjacent to the reserve was also tackled, removing the source of colonisation for the washes.

In the subsequent spring the Ouse Dyke adjacent to the reserve was soon cleared and so up stream and downstream were also dealt with. Fortunately some volunteers came to help and most of the Ouse Dyke was cleared of balsam.

Next spring the Ouse Dyke should be virtually balsam free, except for downstream from the reserve, where it runs through Severn Trent land on both sides.

The Results

In the first spring after the balsam had been removed the submerged plant community in the Ouse Dyke began to develop again. Plants noted included stream water-crowfoot, fennel-leaved pondweed, curled pondweed, spiked water milfoil, Nuttall’s waterweed and water starwort. These plants have collected sediments so that the water moves more slowly over them but forms riffles around them. This provides more habitats for invertebrates and fishes and shoals of minnows are already being seen. The bottom of the stream is no longer flat and featureless and the overall covering of mud now has developed some patches of gravel. The banks are now clothed in green in the winter and hold invertebrates, which supply food for overwintering birds. Where the water plants have trapped sediments they form tiny islands which attract robins, blackbirds, dunnocks, wrens, grey wagtails and meadow pipits to search for food. This winter there were five overwintering Chiffchaffs, all feeding along the Ouse Dyke banks. Little egrets, herons and kingfishers are regularly seen and now the first green sandpiper is avidly being searched for.

Netherfield Lagoons – Manager’s Report – March

 As the brush cutting of the banks is now complete I have been digging out another dragonfly and amphibian pool, beside the Haven. Unfortunately some youths took exception to this and on 15th they had a go at a volunteer, who was working on his own by the Small Gravel Pit. They said the path cut their access to their favourite fishing and camping spot. The next week they set fire to the Haven, destroying a reed bed and a swan’s nest. Mark Glover has contacted a security firm to get an idea of how much it would cost for them to patrol the site. Some frogs have already spawned in the ponds that have been created.

The ‘Wader Scrape’ still has very little water in it and, on three consecutive mornings, there have been people excercising their dogs on it. They want to cross the Ouse Dyke bridge at this point rather than about a quarter of a mile further up as it is a more direct route around the reserve to the river bank.

I have been on a chainsaw course and now am qualified to prepare and maintain a chainsaw (CS30) and to fell and process small trees (CS31). The main purpose of obtaining these qualifications is to be able to remove the larger trees that are beginning to encircle the Deep Pit plus any other trees that become a problem on site. There are no large trees that we are likely to want to remove so I will not need to further pursue my chainsaw tutelage. Some trees could be dropped straight into the Deep Pit and allowed to rot there. This could create wet wood habitat which is uncommon nowadays as people tidy up dead trees that may pose the risk of blocking water courses. This habitat is valuable to several uncommon invertebrates.

I have done a survey to see how much balsam is coming up this year. So far the signs are good and very few seedlings have been found. When the plants have grown a little bit more and are easier to see I shall continue the eradication programme. The Ouse Dyke remains the source for recolonisation of the site and will also be tackled.

March has been a good month for raptors on the site, with two Rough-legged Buzzards seen on 11th, three Peregrines on15th and two Red Kites on 25th. Chiffchaffs, Blackcaps Sand Martins and Wheatears are summer migrants that have already been seen on site, the Chiffchaffs having already set up in territories.

Netherfield Lagoons – Manager’s Report – February 2012

 Most of my time has been spent on the Deep Pit banks again and they are now finished. I have also spent some time digging the dragonfly pools and a volunteer has been busy on these on many days this month. He has also opened up some areas that were formerly used for spawning by frogs. Whilst clearing the brush from the Deep Pit banks I came across good numbers of basal rosettes of Bee Orchids. It will be interesting to see if these flower this year.

We have been given an old bird table which we installed near the containers last month. I have kept it supplied with bird food and, although at first very little came, now there are good numbers of Reed Buntings and Chaffinches coming for food.

On 14th I received a phone call to say the swan on the Small Gravel Pit had fishing line dangling from its bill. I contacted Notts Wildlife Trust to see if they had anyone who they used to help them when these incidents occurred and they sent over the manager from Attenborough Nature Reserve. He brought a swan jacket and we soon caught the swan (it came for bread). Once restrained he soon had the fishing line out and it sat on the ground, unrestrained, between us, eating more bread. It didn’t bother getting up until all the bread was gone. Since then it has been seen several times and has flown between the Small Gravel Pit, river and Deep Pit, so it seems none the worse for its ordeal.

The week beginning 6th February was very cold and most of the pits froze over. A lot of the wildfowl moved away, although some stayed on the river. Since then it has all thawed again and the wildfowl are back, the Teal, Shoveler, Tufted Duck and Goldeneye in particularly good numbers. Otherwise it has been a quiet month for birds at the reserve but there have been some early signs of spring with a frog being seen on 24th February and a Red Admiral on the 1st March, plus Coltsfoot and Lesser Celandine coming into flower.

Lesser Cellandine
Lesser Cellandine