Wildlife Trust Derbyshire Wildlife Trust
East Mill, Bridge Foot, Belper, Derbyshire, DE56 1XH
Tel: 01773 881188 Fax: 01773 821826
E-mail: enquiries@derbyshirewt.co.uk

Heatherton Pond

Heatherton Pond



Derbyshire Wildlife Trust
East Mill
Bridgefoot
Belper
Derbyshire
DE56 1XH
A report for the Wild About Ponds Project
Prepared by Trevor Taylor
Local Wildlife Sites Officer (Planning)
Derbyshire Wildlife Trust

August 2012

Protecting Wildlife for the future

Regisered charity no. 222212
DWT is a company registered in England and Wales
with the Company Number 715675

Heatherton Pond

Background

Derbyshire Wildlife Trust was commissioned to survey the pond as part of the Wild About Ponds Project and provide management recommendations based upon the findings of the survey. It would also enable a comparison of survey results against data obtained as part of the 2004/5 Derby City Pond Survey.

Map 1 shows the location of the pond which is situated within an area of public open space to the south of Moorway Lane to the south of the suburb of Littleover near the south-west boundary of Derby City.

The pond was formed around 1998 as a balancing feature as part of the Sustainable Urban Drainage System (SUDS) associated with the nearby Heatherton housing development situated on the opposite side of Moorway Lane.

It is fed from a storm overload from Pastures Hill via an inflow into the south west corner of the pond and an outflow in the south-east corner returns water to the Hell Brook which runs along the southern boundary of the site.

The site is under the ownership of Derby City Council and the City Council Parks Department is responsible for site management. It also falls within the area covered by The Friends of Littleover Parks, a group actively involved in protecting and improving the parks of Littleover.

A path runs around the entire perimeter of the pond enabling access.

Survey objectives

The aim of the survey was to gather ecological information using the PSYM methodology in order to determine the current overall ecological quality of the pond.

Methodology

The survey followed the standard survey methodology known as PSYM developed by Pond Action (now Pond Conservation) and the Environment Agency. PSYM, the Predictive System for Multimetrics, (pronounced sim) was developed to provide a standard method for assessing the biological qualities of still waters in England and Wales.

The method uses a number of aquatic plant and invertebrate measures (known as metrics) which are combined together and fed into a computer model, along with basic environmental and location data, to obtain a single value which represents the waterbody's overall quality status.

The recommended time of year for carrying out PSYM pond surveys is during June, July and August. The pond was surveyed during August 2012.

The following information was gathered for the pond:

Calculating the pond metrics

The data collected from the surveys are used to calculate three plant metrics and three invertebrate metrics.

1. Number of submerged and emergent plant species

This is simply the number of submerged plant species plus the number of emergent plant species. The calculation does not include the number of floating-leaved species present. This is because the pond data suggest that the number of floating-leaved plants occurring at a site does not decline significantly with increasing degradation. The metric is therefore improved by omitting this plant group.

2. Trophic Ranking Score (TRS)

TRS is a measure of the average trophic rank for the pond. This is calculated by assigning each plant species with a trophic score based on its affinity to waters of a particular nutrient status. The trophic scores vary between 2.5 (dystrophic, i.e. very nutrient poor conditions) and eutrophic, i.e. nutrient rich conditions).

Unfortunately, not all plants have trophic scores. This situation has arisen because the current TRS values for standing waters (Palmer et al., 1992) are based only on analysis of lake data, and many plant species which are common in ponds occurred at too low a frequency in lakes to give them a score. Also, some plant species exhibit little nutrient preference.

The TRS value for a site is calculated as follows:

  1. The trophic scores from each plant species present at the site are summed together.

  2. The summed score is divided by the total number of plant species which have a trophic ranking score to give the TRS.

3. Uncommon Species Index

Uncommon species are those which have a rarity score of 2 or more. The number of these species is simply summed to give the number of uncommon species.

Uncommon species refers to species which can be best described as "local", "nationally scarce" or "Red Data Book". The rarity status values for Scarce and Red Data Book species are based on existing definitions derived from the Red data Books and other authorities. The definition of "local" has been used to define species which are not uniformly common and widespread in Britain: with plants this refers specifically to species recorded from between 100 and 700 10x10 km squares in England, Wales and Scotland.

4. Average Score per Taxon (ASPT)

The ASPT is calculated by summing the BMWP scores for all taxa present at the site and dividing by the total number of BMWP taxa present.

BMWP (Biological Monitoring Working Party) scores are assigned to taxa depending on their known tolerance to organic pollution, a higher score indicating lower tolerance. The scores were defined by Maitland in 1977.

5. Number of dragonfly and alderfly families.

This metric is the sum of the number of dragonfly (Odonata) and alderfly (Megaloptera) families.

6. Number of beetle families

This metric is the sum of the number of beetle (Coleoptera) families present at the site. The metric has a relationship with bank quality as well as water quality.

Results

The pond was surveyed using the PSYM methodology enabling an assessment of its biological quality to be made together with a comparison with other ponds in the area.

The PSYM scores are placed in four categories which reflect the ecological quality of the pond:

0-25% is very poor, 26-50% is poor, 51-75% is fair, and 76-100% is good


Site and sample details

Grid reference: SK 32458 32430

Site Name: Heatherton Pond

Location: Heatherton, south of Littleover

Owner/site access details: Derby City Council

Survey Date: 9th August 2012Surveyors: Trevor Taylor (Derbyshire Wildlife Trust)

Environmental Data

Altitude: (m)53m aslpH:8.94
Shade: % pond overhung:8%% emergent plant cover10%
Inflow (absent = 0, present = 1):1Pond area (m2)16,054m2
% of pond margin grazed:0

Pond base: categories into one of three groups; 1=0%-32%, 2=33%-66%, 3=67%-100%

Clay/silt:2Sand, gravel, cobbles:2Bed rock:1
Peat1Other1

Emergent plantsRarity ScoreTrophic Ranking Score
 
Caltha palustris, Marsh-marigold17
Carex pendula, Pendulous Sedge1-
Cardamine pratensis, Cuckooflower1-
Carex otrubae, False Fox-sedge1-
Deschampsia caespitosa, Tufted Hair-grass1-
Epilobium hirsutum, Great Willowherb1-
Glyceria fluitans, Floating Sweet-grass1-
Iris pseudoacorus, Yellow Iris1-
Juncus articulatus, Jointed Rush1-
Juncus effusus, Soft Rush1-
Juncus inflexus, Hard Rush1-
Phragmites australis, Common Reed17.3
Schoenoplectus lacustris, Common Club-rush27.7
Scrophularia auriculata, Water Figwort1-
Solanum dulcamara, Bittersweet110
Sparganium erectum, Branched Bur-reed18.5
Typha latifolia, Bulrush18.5
Veronica beccabunga, Brooklime110
 
Submerged plants
 
Ceratophyllum demersum, Rigid Hornwort210

Number of emergent and submerged species - 19
Number of uncommon species (with a rarity score of 2 or more) - 2

Trophic Ranking Score - 8.63


Macroinvertebrates

Group 4 taxa (BMWP: 6)
Gammaridae - Crustacean (shrimp)
Coenagriidae - Damselfly (Ischnura elegans)

Group 5 taxa (BMWP: 5)
Planariidae - Flatworm
Gerridae - Water bug (water skater)
Pleidae - Water bug
Corixidae - Water bug (Lesser Water Boatman)
Group 6 taxa (BMWP: 4)
Baetidae - Mayfly

Group 7 taxa (BMWP: 3)
Lymnaeidae - Snail
Hydrobiidae - Snail (Jenkin's Spire Shell)
Physidae - Snail
Glossiphonidae - Leech (Helobdella stagnalis)
Asellidae - Crustacean (Water slater)

Group 8 taxa (BMWP: 2)
Chironomiidae - Fly (non-biting midge)

Group 9 taxa (BMWP: 1)
Oligochaeta - True worm

Total No. Of taxa14
Total BMWP Score54
ASPT3.9
No. OM taxa1
No. Coleopt taxa0

Index of Biotic Integrity (PSYM Score %) = 50. As such the pond would be considered to be in poor ecological condition. This represents a slight decrease in ecological condition when compared with the survey results obtained in 2004/05 when the pond achieved a PSYM score of 61%.

A conductivity test to measure the total quantity of chemicals dissolved in the water returned a reading of 460µS/cm. This figure indicates that the pond is on the borderline with regard to contamination. Where conductivity is 500-1000 + µS/cm this is usually a sign of some kind of pollution and a perfectly clean water pond would have a figure of 100µS/cm or less.


Survey Results

A large triangular shaped pond with a small central island and a small area of wet woodland at the northern tip comprised mainly of Grey Willow, Salix cinerea, with occasional Goat Willow, Salix caprea, Osier, Salix viminalis, Crack Willow, Salix fragilis and Alder, Alnus glutinosa. An area of established Phragmites reedbed is present at the northern end within which Brooklime, Veronica beccabunga, is a frequent component together with a smaller reedbed area in the south-east corner. A largely continuous band of Grey Willow and occasional Goat Willow and Osier trees is present around the perimeter of the pond with consequently very few areas of open bank. Whilst the pond supports a reasonable overall range of aquatic plant species, apart from Phragmites australis, Common Reed, they are all somewhat limited in quantity, largely as result of the lack of availability of suitable areas of open bank for the establishment of emergent aquatic vegetation. In suitable open areas, emergent aquatic vegetation comprises occasional stands of Bulrush, Typha latifolia, along with clumps of Great Willowherb, Epilobium hirsutum, and Hard Rush, Juncus inflexus. The uncommon plant species Common Club-rush, Schoenoplectus lacustris, is confined to the occurrence of a few stems in one location on the western bank and a few stems within the wet woodland. The limited occurrence of this uncommon plant at the site makes it somewhat vulnerable to any swim clearance operations by anglers.

The surrounding habitats comprise unmanaged created grassland of relatively low species diversity with areas of immature plantation woodland.

The presence of fish was recorded in the pond during a survey carried out by David Rogers Associates in 2010, as part of the Wild About Ponds project, to assess its suitability for selection as an ark site for white-clawed crayfish. The survey concluded that the pond was not suitable as an ark site for white-clawed crayfish due to its link with the River Trent which is known to contain signal crayfish.

During the 2012 survey, a number of large carp were observed, mainly in the shallows at the northern end, together with at least one large conspicuous goldfish/koi carp. Some clearance of bankside trees and shrubs was noted to enable access for informal angling activities.

The pond supports a good number of waterfowl, including mute swan, Canada goose, mallard, moorhen and coot, all of which were confirmed to have successfully bred during both 2005 and 2012. Little grebe, tufted duck and domestic ducks also occur. The reedbed and wet woodland also provides suitable habitat for reed warbler, sedge warbler and reed bunting.

The 2012 survey confirmed that the ecological condition of the pond has slightly decreased since the surveys undertaken in 2004 and 2005. The most obvious changes to the pond since that time has been the decrease in the range of aquatic invertebrates associated with the pond, particularly the number of dragonflies and water beetles and the number of sizeable fish that are now present in the pond. It is likely that the introduction of fish has contributed to the decline in the number of dragonflies and water beetles now present in the pond. The lack of stands of aquatic vegetation which would provide shelter also makes the aquatic invertebrates more vulnerable to fish predation

The reasonably high conductivity reading is not surprising given the presence of fish, notably large carp, large numbers of waterfowl and the run-off from urban areas, all of which have potential to result in nutrient enrichment.

No evidence of amphibians was found at the pond during torchlight surveys undertaken in 2004 and 2012.

As part of the Wild About Ponds project, during 2011 and 2011, The Conservation Volunteers began the clearance of willows along sections of the bank to encourage the establishment of aquatic vegetation.


Heatherton Pond

Above: Cleared section of bank - 2011


Management recommendations













Heatherton Map