Protecting Wildlife for the futureRegisered charity no. 222212
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.
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.
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:
Environmental and location data including grid reference, altitude, pH, pond area, percentage of shade, percentage of pond edge grazed by livestock, pond base, presence of inflow/outflow, percentage of emergent plant cover, details of surrounding land use, evidence of management.
A complete list of wetland plant species present within the outer boundary of the pond.
A list of the macroinvertebrates, identified to family level, recorded from the pond according to the survey method used for PSYM. This involved a three minute hand-net sampling method. The number of mesohabitats present at the site was identified and the three minute sampling time was divided equally between the number of mesohabitats present. Each mesohabitat was netted vigorously to collect macroinvertebrates. A further one minute was spent searching for animals which might have been missed by the three minute hand-net sampling such as creatures on the water surface or under stones or logs.
The data collected from the surveys are used to calculate three plant metrics and three invertebrate metrics.
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.
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:
The trophic scores from each plant species present at the site are summed together.
The summed score is divided by the total number of plant species which have a trophic ranking score to give the TRS.
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.
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.
This metric is the sum of the number of dragonfly (Odonata) and alderfly (Megaloptera) 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.
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
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 2012||Surveyors:||Trevor Taylor (Derbyshire Wildlife Trust)|
|Altitude: (m)||53m asl||pH:||8.94|
|Shade: % pond overhung:||8%||% emergent plant cover||10%|
|Inflow (absent = 0, present = 1):||1||Pond 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:||2||Sand, gravel, cobbles:||2||Bed rock:||1|
|Emergent plants||Rarity Score||Trophic Ranking Score|
|Caltha palustris, Marsh-marigold||1||7|
|Carex pendula, Pendulous Sedge||1||-|
|Cardamine pratensis, Cuckooflower||1||-|
|Carex otrubae, False Fox-sedge||1||-|
|Deschampsia caespitosa, Tufted Hair-grass||1||-|
|Epilobium hirsutum, Great Willowherb||1||-|
|Glyceria fluitans, Floating Sweet-grass||1||-|
|Iris pseudoacorus, Yellow Iris||1||-|
|Juncus articulatus, Jointed Rush||1||-|
|Juncus effusus, Soft Rush||1||-|
|Juncus inflexus, Hard Rush||1||-|
|Phragmites australis, Common Reed||1||7.3|
|Schoenoplectus lacustris, Common Club-rush||2||7.7|
|Scrophularia auriculata, Water Figwort||1||-|
|Solanum dulcamara, Bittersweet||1||10|
|Sparganium erectum, Branched Bur-reed||1||8.5|
|Typha latifolia, Bulrush||1||8.5|
|Veronica beccabunga, Brooklime||1||10|
|Ceratophyllum demersum, Rigid Hornwort||2||10|
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
|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 taxa||14|
|Total BMWP Score||54|
|No. OM taxa||1|
|No. Coleopt taxa||0|
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.
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.
Above: Cleared section of bank - 2011
Continue to remove willows from sections of the bank to provide open areas of bank to encourage the establishment of emergent aquatic vegetation. The work should be carried out during the autumn and winter periods between October and February to avoid disturbance to nesting birds. Ideally, any cut stumps should be treated with herbicide to prevent re-growth. The establishment of aquatic plants should be allowed to colonise naturally and it is not envisaged that any planting will be required.
Explore the option of involving a reputable angling organisation to regulate the angling activities on the site in order to encourage responsible use of the site to maintain and enhance its wildlife interest. Access restrictions should be placed upon the reedbed and woodland areas during the bird breeding season to prevent disturbance to nesting birds as part of any angling club agreement.
Annual PSYM surveys should be undertaken during the period June to August to monitor the ecological condition of the pond. The results would give some indication of management success and the need for further bankside tree removal. The results of the surveys should be forwarded to Derby City Pond Warden Association and the Derbyshire Wildlife Trust.