assessment of status and threats of standing small water bodies

8/2/2019 Assessment of Status and Threats of Standing Small Water Bodies

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EEA/ADS/06/001 Water

Small water bodies - Assessment of statusand threats of standing small water bodies

Version: 1.1Date: 22. December, 2009

ETC/Water task.milestone.submilestone:Task 8

Prepared by / compiled by: ETC/W Organisation: IWRS

EEA Project manager: Niels Thyssen

Version HistoryVersion Date Author Status and description Distribution

1.0 01/07/2008 Lidija GlobevnikTina Kirn First draft Niels Thyssen

1.1 22/12/2009 Lidija GlobevnikTina Kirn

Final draft


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Acknowledgement

We would like to thank to all authors who contribute their articles for this briefing and to those who inform uson articles from other authors.Thanks to Andrew Hull for the book Pond & pond landscapes of Europe. Proceedings, InternationalConference of the Pond Life Project.


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Contents

1. INTRODUCTION ..................................................... ...................................................................................... 42. GENERAL CHARACTERISTICS AND SPATIAL EXTENT OF STANDING SMALL WATER BODIES WITHHISTORICAL OVERVIEW................................................................................................................ ................. 5

2.1. Lakes in Europe .................................................................................................................... ................. 52.1.1. Glacial mountain lakes ........................................................... ........................................................ 52.1.2. Glacial lowland lakes...................................................................................................................... 52.1.3. Karst lakes...................................... ................................................................................................ 62.1.4. Lakes by countries........................................................ ........................................................... ....... 7

2.2. Ponds..................................................... .............................................................................................. 122.2.1. Temporary ponds and pools............................................................. ............................................ 162.2.2. Kettle holes................................................................................................................................... 162.2.3. Farm ponds ................................................................................................................... ............... 182.2.4. Karstic ponds.................................. .............................................................................................. 192.2.5. Fish ponds.................................................................................................................................... 21

2.3. Springs................................................... .............................................................................................. 242.4. Mires, bogs and fens............................................................ ................................................................ 25

3. IMPORTANCE OF STANDING SMALL WATER BODIES (ECOSYSTEM SERVICES).............................. 283.1. Ecological importance - biology, hydrology, water quality ..................................................... ............... 28

3.1.1. Lakes............................................................................................................................................ 28

3.1.1.1. Glacial lakes ......................................................................................................................... 283.1.1.2. Karst lakes............................................................ ................................................................ 283.1.1.3. Fluvial lakes (floodplains) ..................................................................................................... 323.1.1.4. Shallow lakes........................................................................... ............................................. 33

3.1.2. Ponds ........................................................................................................................................... 363.1.2.1. Mountain ponds .................................................................................................................... 413.1.2.2. Temporary ponds and pools ................................................................................................. 433.1.2.3. Mediterranean ponds............................................................................................................ 453.1.2.4. Kettle holes.......................................................... ................................................................. 473.1.2.5. Farm ponds........................................................................................................................... 473.1.2.6. Karstic ponds........................................................................................................................ 533.1.2.7. Fish ponds ........................................................... ................................................................. 53

3.1.3. Gravel pits .................................................................................................................................... 563.1.4. Springs .................................................... ............................................................ ......................... 59

3.1.5. Mires, bogs and fens ............................................................................................................... ..... 653.2. Economic and social importance.......................................................................................................... 684. THREATS TO STANDING SMALL WATER BODIES.................................................................................. 74

4.1. Different threats.................................................................................................................................... 744.2. Hydromorphological alteration.............................................................................................................. 784.3. Water withdrawal.................................................................................................................. ................ 814.4. Pollution and water quality .................................................. ........................................................... ...... 824.5. Acidification.......................................................................................................................................... 944.6. Climate change ......................................................... ........................................................................... 974.7. Introduction of invasive alien species................................................................................................. 1004.8. Sedimentation .................................................................................................................................... 1024.9. Lack of management............................. ............................................................................................. 103

5. REFERENCES .................................................................................................................. ........................ 104


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1. INTRODUCTION

Small water bodies are ecologically very important. They support specific and important hydrological, chemicaland biological processes. Spatially small they are mainly neglected in national nature resources managementacitivities. In 2007 a briefing paper on assessment of status and threats of small water rivers was produced

with preliminary analysis of their spatial characteristics (by IWRS). In 2008 an extended technical paper withthe results of detailed spatial analysis of small rivers and an assessment of status and threats of other smallwater bodies was produced. A proposal for work for the assessment in 2008 has been developed in Oct 2007.The proposal how to produce the extended technical paper on the extent of small water bodies in Europe isdone by DHI separately.

The objective of work in 2008 is to rise awareness of the ecological importance of small water bodies inEurope. The purpose of work in 2008 is to produce an overview of the spatial distribution of small water bodiesin Europe and to describe their ecological importance in terms of their biology, hydrology and water quality,economic and social importance (ecosystem services) and their different threats. In 2009, an extract of thistechnical paper was produced.

For the purpose of this report, the following categores are used:

- tectonic lakes- volcanic lakes- glacial lakes- fluvial: oxbow lakes, floodplain lakes, river backwaters- karst lakes- coastal brackish lakes- saline lakes- limnocrenic and other springs- mires, bogs, fens, peatland, headwater wetlands, marches- river reservoirs (hydropower accumulations), water storages- gravel pit lakes- karstic ponds, ponds for cattle bredding, farm ponds- fish ponds

In this report a small standing water body has a surface area smaller than 1 km2. The most important smallwater bodies in Europe areglacial lakes in Boreal region and mountains (e.g. Alps),springs and karsticponds in karst regions,kettle holes in young moraine regions,farm ponds on agricultural land,fish ponds in Central Europe,temporary pools in the Mediterranean basin, andmires , bogs and fens in Northern,Western and Central Europe.Fluvial standing waters are important along all lowland rivers. On largeralluvial areas alsogravel pit lakes are numerous. In this study theirgeneral characteristics , ecologicalimportance in terms of their biology, hydrology and water quality,economic and social importance (ecosystem services ) and theirthreats are presented.


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2. GENERAL CHARACTERISTICS AND SPATIAL EXTENT OF STANDING SMALLWATER BODIES WITH HISTORICAL OVERVIEW

2.1. Lakes in Europe

Approximately 500 000 still water bodies over 1 hectare exist in Europe (EEA, 1995). This compares with anestimated figure of 8.3 million lakes worldwide (Pourriot & Meybeck 1995).The majority of natural lakes in Europe occur in Norway, Sweden and Finland. In terms of numbers, over 134000, 85 000 and 56 000 lakes over 1 hectare have been counted in Norway, Sweden and Finland respectively(Skjelkvle et al. 1997, EPA Sweden 1992, Wahlstrm et al. 1993). It has been estimated that over 9% ofFinland and Sweden are covered by freshwater lakes. Significant numbers of natural lakes also exist inIceland, Ireland and Scotland. Most of the largest European lakes are located in the Nordic countries and inthe Alpine regions.

Estimated numbers of still water bodies according to size

Sources of data: EEA (1996) and responses to EEA questionnaire for Dobris+3 report(1) Includes lagoons and reservoirs(2) Only natural lakes(3) Only reservoirsNI = no information(Leonard, Crouzet, 1999)

2.1.1. Glacial mountain lakes

Lakes of Alpine region

The Pyrenees also have an abundance of torrents, cascades andlakes . There are over 1,500 lakes above

1,000 m.The Carpathians contain numeroussmall lakes (many of glacial origin) and a dense network of rivers andstreams which are well nourished by the abundant rainfall.(Natura 2000 in the Alpine region, 2005)

2.1.2. Glacial lowland lakes

The Boreal region of the European Union includes most of Sweden and Finland, all of Estonia, Latvia andLithuania and much of the Baltic Sea.

With its endless expanse of coniferous forests,mires and lakes , the Boreal region forms part of a distinctband of vegetation which circles the entire northern hemisphere.


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Besides forests wetlands are the most common landscape feature. Around 10,000 years ago the entire Borealregion was covered in ice. As the massive ice sheet retreated after the last ice age, it carved shallowdepressions into the hard bedrock of granite and gneiss. This explains why there are such a large number oflakes , rivers and mires in the region today.Three quarters of Europes 600,000 natural lakes and some ofits largest bogs are found here. In parts of the far north, peatlands make up 50% of the land surface.

Habitat types blend seamlessly into one another, creating a characteristic mosaic landscape of forests andwetlands. Along the coast, bedrock archipelagos intermingle withlow-lying brackish fens and meadows,providing ideal nesting grounds for hundreds of thousands of migratory birds.(Natura 2000 in the Boreal region, 2005)

There are hundreds of thousands of lakes in the region; at least 3/4 of the approximately 600 000 Europeannatural lakes larger than 0.01 km2 are located here.Most of them are small (less than 1 km 2).(The Boreal biogeographical, 2007)

Below the plains, there exists a moraine belt containing thousands oflakes, fens and mires around thePomeranian region in East Germany and Poland . This is one of the least populated areas of theContinental belt, due not only to the difficult terrain but also to its strategic location after the World Wars as a

border region between East and West.(Natura 2000 in the Continental region, 2005)

2.1.3. Karst lakes

Turloughs are the priority habitat type in the EU Habitats Directive. They are temporary lakes principally filledby subterranean waters and particular to karstic limestone areas. Most flood in the autumn and then dry upbetween April and July. However, some may flood at any time of the year after heavy rainfall and dry outagain in a few days; others, close to the sea, may be affected by the tide in summer. These lakes fill andempty at particular places. The soils are quite variable, including limestone bedrock, marls, peat, clay andhumus, while aquatic conditions range from ultra oligotrophic to eutrophic. The vegetation mainly belongsto the allianceLolio Potentillion anserinae Tx. 1947, but also to theCaricion davallianae Klika 1934.(Interpretation Manual of.., 2003)

Ireland: turloughs

Characteristics

Turloughs are depressions in karst areas, seasonally inundated mostly by groundwater and supportingvegetation and/or soils characteristic of wetlands (Working Group on Groundwater, 2004). Flooding annuallyin autumn through springs and fissures in the underlying limestone and draining in the springtime, oftenthrough the same fissures or swallow-holes. There may also be sporadic rises at other times in response tohigh rainfall. Some turlough basins retain standing water in channels,pools or small lakes when floodingsubsides. Although they harbour an aquatic fauna, they are not true lakes, since most drain in the summer,revealing fen or grassland vegetation which is frequently grazed by livestock. These karst wetland ecosystems

have been described as temporal ecotones.Number, distribution

Over 300 turloughs have been documented in Ireland. The greatest density of turloughs is in the western thirdof Ireland. The biggest turlough in Ireland is Rahasane in County Galway (ca. 260 ha).

Turlough loss by drainage

Roughly one third of turloughs over 10 hectares have been irreversibly damaged by drainage (Coxon, 1986).The impact of land drainage on groundwater resources is particularly acute in karst areas because of theunique characteristics of karstic aquifers. Arterial drainage, or drainage of river systems to dry out land withinthe catchment, of karst lowlands in Ireland since the mid-19th century has resulted in losses of recharge,lowering of water tables, drying up of turloughs, alteration of underground flow routes, and periodicgroundwater contamination (Drew and Coxon, 1988). Though large-scale drainage has ceased, it resulted inthe loss of at least 50% of flooded turlough area (Coxon, 1986; Goodwillie, 2001).(Sheehy Skeffington et al. , 2006)


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2.1.4. Lakes by countries

Countries/RBDs with small lakes (less than 50 ha) included in national WFD typology

In some regions where there are many SWBs, the general approach will need to be adopted. It may beappropriate to aggregate water bodies into groups for certain purposes. The lower size limit of surface waterbodies may be set lower than the ones prescribed in typology system A (lakes: the smallest size range: 0.5 - 1km2 surface area), in certain cases, i.e. if Member states decide that certain smaller water bodies aresignificant and require separate identification. This is of special ecological relevance for lakes. Otherwise,small elements of surface water are included as part of a contiguous larger water body, where possible.(WFD CIS Guidance Document No. 2, 2003; Guidance Document No. 10, 2003).

Ireland

The typology and risk assessment of Irish lakes for article 5 of WFD included all lakes greater than 0.5 km2 (large lakes) andlakes less than 0.5 km 2 (small lakes) if they were located in protected areas (e.g. inSpecial Areas of Conservation, or if they were used for water abstraction for drinking purposes) .(The Characterisation and Analysis, 2005)

Ireland: Western River Basin District (RBD)

The basin area of the Western River Basin District (RBD) of Ireland is rich in lakes,the highest number oflakes in the country , with a total of 5,638 lakes of which 69 are greater than 50 hectares. Only one percent oflakes are greater than 50 hectares in size, these include the Great Western lakes the Corrib, Mask, Conn andCuilin. Four percent are between 50 and 10 hectares, a further four percent between 10 and 5 hectares,fifteen percent between 5 and 1 hectare and seventy six percent are less than 1 hectare in size.

The water body is the reporting unit required by the WFD and it is also the management unit for futuremanagement of waters. There are 5,638 lake water bodies but only a selection (381) are reported on.

Although over 5,638 are located in the Western RBD area not all are required to be assessed under the WFD.

The Water Framework Directive requires the status of the following lakes to be reported:- greater than 50 hectares in size,- water abstraction lakes (with abstractions greater than 10 m 3 per day),- lakes that are associated with Special Areas of Conservation (SAC).

For SACs it is necessary to report on a representative number of lakes that reflect the status of waterbodieswithin the SAC. These are generally lakes of very small size (less than 1ha)

There are a total of 69 lakes greater than 50 ha in the Western RBD. When water abstraction lakes and lakesassociated with SACs are added this number increases to 381.(Western River Basin, 2005)

The UK

The identification of minor elements of surface water, such as garden ponds and artificial drainage ditches, asseparate water bodies would cause significant logistical difficulties, and stretch the resources available toimprove more significant elements of surface water. A balance is needed, so that the management process isnot overloaded and disabled by the creation of large numbers of very small management units. UK technicaladvisory group on the WFD suggest that small elements of surface water should be identified as separatesurface water bodies in certain cases, i.e. if they are designated as protected areas, which will also assist toachieve the objectives for these areas: (a) a SPA or candidate SPA under the Bird Directive and a SAC orcandidate SAC under the Habitat Directive; (b) drinking water protected area under Drinking Water Directive;(c) a nutrient-sensitive area under the Urban Waste Water Treatment Directive or the Nitrates Directive; (d) abathing water under the Bathing Waters Directive; (e) an area for the protection of economically significantaquatic species under the Shellfish Waters Directive or the Freshwater Fish Waters Directive.(Guidance on the identification..., 2003)


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Scotland

Surface water bodies have been identified using natural features as well as known pressures and existingwater quality information. As a result we have divided surface waters in the Scotland river basin district into2,005 river, 309 loch, 40 transitional and 449 coastal water bodies.

The Directive applies to inland surface waters, transitional waters, coastal waters and groundwaters, but forpractical purposes, we used size thresholds from the Directives typology system to initially identify river andloch water bodies. These thresholds are 0.5 km2 for the surface area of lochs and10 km2 for rivercatchment area. Water bodies identified using these thresholds are referred to as baseline waterbodies. Numbers presented throughout this report refer only to baseline water bodies. The length of baselinerivers is measured to their source mapped at 1:50,000 scale.

SEPA has identified and assessed additional small waters where justified by environmental concernsand to meet the requirements of regulatory legislation such as for drinking water supplies. These smallwaters represent the range of issues encountered for many other small waters. A total of 580 small rivers and200 small lochs have been identified for the Scotland river basin district . Better information is needed tocharacterise these and other small waters and this will be taken forward in future years.(Scotland River Basin District, 2005)

Northern Ireland

Table below lists the small lake water body types generated. The water bodies have been identified for thefollowing reasons:- Both environmental agencies in Ecoregion 17, the Environmental Protection Agency (EPA) and Environmentand Heritage Service (EHS), have agreed that all lakes above 10 ha are significant units in ecological termson the island of Ireland.- Small lakes identified or proposed by EHS Natural Heritage as supporting species or habitats of conservationinterest (Special Protection Areas (SPA), Special Areas of Conservation (SAC) and Areas of Special ScientificInterest (ASSI)).

Small water body types for lakesType Number Type 1:


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(River basins management, 2004)

Malta

All the identified water bodies are small. This is particularly evident for inland surface water bodies (rivers,lakes and transitional waters) which are also very similar in type within their respective categories. Malta hasconsidered a number of factors when designating and characterising these water bodies, includingdiscreteness, status and ecological significance. These sites also form part of candidate Natura 2000 sites.Thus the need for protection of these Maltese inland water bodies justifies their designation under thisDirective.

Typology of surface waters

Surface WaterCategory

Number of types created by thetypology

Number of water bodies occurringin each type in the watercatchment district*

Lakes 1 4 - calcareous, small (< 0.5 km2)

* The term water catchment district is the Maltese legislation equivalent to river basin district in theEuropean Directive.(Water Framework Directive, 2005)


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Denmark: SoE report

In Denmark there are 120,000 registered lakes. By far the majority are ponds and small lakes, however, andonly just over 2% are lakes larger than 1 ha.

There are around 120,000 lakes exceeding 100 m2, the majority of which are ponds and bogs, and only justover 2,500 exceed 1 ha in size. The important inland wetlands also include small ponds, bogs, raised bogsand periodically flooded meadows.The number of lakes has been decreasing for many years as a result of agricultural and urbandevelopment. This has mainly affected thesmall lakes , but the number of large lakes has also declinedconsiderably.For example, the number of lakes in Aarhus county decreased from 2,735 around 1900 to835 in 1980.In recent years the trend has reversed as small lakes are now encompassed by protection regulationstoo, and a number of lakes that had previously been drained have now been re-established. Moreover,the Counties are granting permission for the establishment of several hundred new lakes and ponds each yearand concomitantly refusing most applications to eliminate lakes.(Bach et al. , 2002)

Denmark: Odense Pilot River Basin: Provisional Article 5 ReportIn Denmark, all lakes larger than 100 m2 are protected by the Protection of Nature Act and are individuallyidentified. This protection is partly due to the fact that many small lakes were disappearing, and partly becausethe many small lakes are important natural elements in the very culturally influenced Danish landscape. Forexample, the small lakes and ponds together contain more species of macroinvertebrates such as worms,snails, mussels, crustaceans and insects than both the large lakes and watercourses (Fog & Wiberg-Larsen,2002).As a consequence, in Odense Pilot River Basin, all lakes larger than 100 m 2 have been identifiedas discrete water bodies. It is not practicable to investigate each of the more than 2 600 lakes, however. It ispermissible to aggregate lakes in relation to monitoring, reporting and management. The lakes are grouped onthe basis of lake type and catchment (assessed from GIS), and monitoring is carried out for a randomlyselected subgroup of the lakes.This aggregation and selection has not yet been carried out. (Odense Pilot River Basin, 2003)

There are 2 620 lakes larger than 100 m2 in Odense River Basin. Their combined area is 1.106 ha,corresponding to 1% of the whole basin.

Many of the existing lakes in Odense River Basin have arisen as a result of human activity, e.g. peat mining,clay, marl or gravel quarrying, or as a result of dams etc. especially for operating mills.

Millponds derived from damming watercourses are classified as heavily modified water bodies. Lakes createdthrough human activity in a location where there has not previously been a water body are classified asartificial water bodies. This particularly applies to peat mine, gravel quarry and marl/clay quarry lakes, duckponds, and, to a certain extent, also to village ponds and fire reservoirs.

Of 66 investigated lakes in the basin, nearly half (45%) arose as a result of peat mining, and only 18 (27%) arenatural.

18 lakes are characterized as natural, 44 as artificial water bodies (peat mine and marl, clay and gravel quarrylakes, village ponds, fire reservoirs, etc.) and 4 as heavily modified water bodies (dams and millponds). Of thelarger lakes (>5 ha), however, nearly all are natural.

Origin of 66 investigated lakes in Odense River BasinOrigin No. of lakes %Natural 18 27Peat mine 30 45Marl/clay quarry 7 11Gravel quarry 4 6Village pond, etc. 3 5Dam/millpond 4 6Total 66 100

Unlike natural lakes, artificial and heavily modified lakes do not have to achieve good ecologicalstatus, but rather good ecological potential. Correspondingly, reference conditions do not have to beestablished for these lakes, but rather a maximum ecological potential.


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Over the years, many lakes have been exposed to various physical pressures in the form of waterlevel regulation, reclamation etc. In some places, moreover, water abstraction has reduced water flow to thelakes. Conversely, new lakes have arisen through damming and excavation.

A very large proportion of the typically small, shallow lakes have completely disappeared over thepast 100 years or so as a result of drainage and lowering of the water level. For example, the numberof lakes in the Lake Arreskov catchment area has decreased by 76% from 276 around the year 1890 to65 in 1992.(Odense Pilot River Basin, 2003)

Estonia

The lakes, which area is bigger than 0.5 km2 have been taken into account in the first place. Lakes, which aresmaller than this, are identified as water bodies connected with the river, into which catchment area theybelong (these can be small lakes from where or through which small rivers or streams flow, or even lakes withno outlet in the abovementioned catchment area). According to the definition, small lakes, which areconnected with a bigger lake than 0.5 km2, form a single water body with the bigger lake.(Compliance with the Requirements, 2005)


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2.2. Ponds

Definitions of the term pond vary and there is no universal agreement of what a pond is.

Surface area

Ponds can vary in surface area from about one metre squared to a few hectares.For example the lower size limit of the cupular pools from the Island of Gavdos in Greece is less than onesquare metre.The upper size limit that differentiates ponds from lakes is two hectares in the UK and one hectare inGermany.The Ramsar definition of temporary pools includes waterbodies up to 10 hectares.The size of man-made fish ponds can be much higher: for example the biggest fish pond in Europe, in theCzech Republic, is 490 hectares in surface area.

Depth

Ponds can vary in depth from a few centimetres to many metres. Mediterranean temporary pools, for example,are defined as being a few centimetres in depth. Hell Kettles pond in Derbyshire (UK) is said to be bottomless!

Water duration

Some ponds hold water all year round, but many go through cycles of wetting and drying. Somehighly ephemeral pools may only remain wet for a few weeks after rainfall.

Origin

Ponds can either beman-made or natural in origin. Natural processes have created pondsthroughout geological time. Examples include topographical depressions created following glaciations,floodplain backwaters, or ponds created by tree falls or animals (e.g. wild boar).

Unfortunately, natural ponds are not as common in the European landscape as they once were, mainly due tohuman activities such as agricultural intensification, river regulation and drainage.

For the last few thousand years people have also artificially created ponds for industry, agriculture and to

provide beauty in the landscape.Ponds are now increasingly being created for ecosystem services and leisure activities (e.g. ongolf courses).

Worldwide, ponds occur in all biogeographical regions, from desert to tundra pools in the Arctic Circle. Pondsare often found in clusters, forming a network of patches or pondscapes. These are particularly common onfloodplains , but ponds can also occur naturally at high densities in other types of landscapes, such as somehigh altitude zones of the Alps. Examples of natural ponds which occur at high density include thekettle-holes of northern Europe which run from Denmark, through northern Germany and Poland, to Belarus.

Other pond landscapes are of human origin, such as those in the north west of England and northeast Germany which were dug to extract lime-rich marl used to fertilise surrounding fields.(The Pond Manifesto, 2008)

Pondscape

The effective pond landscape (pondscape) includes the pond and its immediate catchment, but also theterrestrial matrix of land between ponds. As a result, land management activitiessome distance away from the waterbody may threaten individual ponds or complexes in bothrural and urban locations (Boothby 1997). This has considerable importance when considering thedispersal of aquatic organisms (such as aquatic insects and amphibia) from their birth pond and thecolonization of new or adjacent ponds. In the case of amphibians, the pondscape matrix also stronglyinfluences foraging activity and the availability of suitable winter hibernation sites (Griffiths 1997).

Origin of ponds

Ponds have been created by a variety of natural processes such as glaciation, land subsidence,river action and tree falls, although in the contemporary landscape anthropogenic activities are widelyacknowledged as the dominant force influencing their creation and elimination in temperate latitudes


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(Rackham 1986). Ponds are naturally more common in areas with impervious geologies, where surfacewaters easily collect in depressions. However, this pattern is not always clear, since large numbers ofirrigation, livestock and dew-ponds have historically been created in areas underlain by highly porous rock(e.g. chalk and limestone) where natural surface waters are uncommon, to ensure reliable water sources foragriculture (Beebee 1997; Stanton 1995).

Land use

Ponds occur in almost allland-use types , including mountainous uplands, moorlands, woodlands,grasslands, coastal margins and in all agricultural settings.(Wood et al. , 2003)

The UK: number, distribution and pond loss (historical changes)

Ponds account for around 97 per cent of the total number of standing water bodies in the UK, but only14 per cent of the total surface area (Bailey-Watts et al. 2000).

The total number of ponds in the UK is not known, although Rackham (1986) estimated that around 800 000ponds existed in England and Wales in 1880, based on detailed analysis of Ordnance Survey maps and

applying a correction factor for ponds less than six metres in diameter that would have not been surveyed.A similar survey for the 1920s estimated that around 340 000 ponds existed, although there was considerablespatial variability across England and Wales.The lowest density of ponds occurred in upland areas andthe highest in areas of ancient woodland and agricultural land in Norfolk, Suffolk and Cheshire . TheLowland Pond Survey 1996 estimatedthe number of lowland ponds in Great Britain to be around 228 900 (Williams et al. 1998).

Pond loss

The destruction of pond habitats has three components: straightforward loss of habitat, increasedfragmentation of the remaining habitat and reduced habitat quality.Fragmentation can be defined as the remaining habitat of fixed total area that is located within increasinglysmaller and more isolated discrete fragments (patches) (Hanski 1999).Habitat loss and fragmentation usually occur together and have undoubtedly led to greater pressure on a

number of pond species due to a reduction in dispersal and colonization opportunities (Mller 2003; Godreauet al. 1999).

Attempts to quantify pond loss are difficult, since the total number of ponds in the UK is unknown. It is widelyacknowledged that natural succession, agricultural land drainage and developments for urban housing,industry or transport infrastructure have significantly reduced the number of ponds over the last 150 years(Boothby and Hull 1997).

Regional estimates of loss vary widely from 90 per cent for parts of London (Langton 1985) to six per cent forurban ponds in Edinburgh (Jeffries and Mills 1990). However, direct comparison between studies is not alwayspossible, since many only provide an estimate of pond number, or rates of pond loss, rather than definitivefigures.Pond loss appears to have been greater in the last two decades than during any other period (Boothby et al. 1995). Data from the Lowland Pond Survey 1996 (Williams et al. 1998) indicate thatmostponds lost between 1990 and 1996 were from arable land, while there was a net increase on pastoralland.


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Estimates of pond loss from different parts of the UK

(Wood et al. , 2003)

The UK: Lowland pond survey

The Lowland Pond Survey in England, Wales and Scotland was carried by Pond Conservation in 1998.The number of ponds in lowland Britain was estimated and the first national estimate of pond ecologicalquality was provided, in terms of the variety of plants and invertebrates living in them.

Main findings- It was estimated there were 228,900 ponds in lowland areas.- Between 1990 and 1996 there was a high turnover of ponds, with an estimated 17,000 ponds lost but anestimated 15,000 new ponds made.- More than a third of the ponds were seasonal and were dry in the summer. Of the permanent ponds, 40 %were very shallow with an average water depth of less than 25 cm.(Lowland pond survey, 2008)

The UK: ponds (see the whole section of Pond Priority Habitat Proposal under ecological importance)

Habitats at riskPonds are vulnerable to loss and damage by a wide range of factors including nutrient enrichment and infilling.The 1996 Lowland Pond Survey (LPS96) shows that at least 50% of ponds in the wider countryside arehighly degraded and that there is widespread evidence of enrichment and other diffuse pollutionimpacts. Temporary ponds are believed to be more degraded than permanent ponds. There is also growingconcern that even ponds in semi-natural landscapes are at risk fromair-borne pollution (e.g. acidification,nutrient-enriched rainfall) andclimate change , to which shallow ponds are recognised as being particularly

vulnerable.Pond numbers in the UK are probably at an historic low, with the loss of about 70% of theponds existing in 1880. Much of the loss appears to have occurred in the second half of the 20thcentury as a result of agricultural change and urbanisation. In addition, LPS96 and Countryside Survey2000 data show that, although pond numbers arenow beginning to stabilise , there is an exceptionallyhigh turnover of ponds, with 1% of the total resource both destroyed and created each year. There iscurrently no indication of the quality of ponds lost compared to those gained. However, LPS96 suggests thatmost new ponds are created (a) with stream inflows - a practice discouraged in many other Europeancountries, since most inflows are polluted, and (b) as fishing lakes. Both trends are worrying. Recent evidenceshows that many high value ponds are seriously at risk from the spread of alien invasive species of plants andanimals. With increased emphasis on access to the countryside, this risk is likely to increase.(Nicolet et al. , 2007)

In the UK, there are about 400,000 ponds, which are defined as being between 0.0025 and 2 hectaresin area. This represents 97 percent of the number of all discrete standing waterbodies.(The Pond Manifesto, 2008)


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Ponds in Cheshire, North West England

There are nearly 17,000 pond sites inCheshire , and it is claimed that the county has one of the highest ponddensities in north-west Europe (Hull et al. 1992). The county is predominantly agricultural, and much of it stillcomprises a medium to small scale field pattern bordered by hedgerows, with small copses and ponds (Hulland Boothby 1996).

The majority of ponds are unprotected, in private ownership and on farmland over which there is very littlecontrol in respect of changes of use or intensification.Over 24 year period between 1969 and 1993,agriculture accounted for 2 out of every 3 ponds which were lost. However, a significant percentage isattributable to development activities of various kinds. Development activities come under the control oflocal planning authorities.

Reasons for pond loss in Cheshire between 1969-1993Pond sites lost

Ponds lost to: No. %Transport infrastructure 205 3.0Industry and commerce 764 11.2Housing 794 11.7Recreation 517 7.6Agriculture 4489 66.0Total lost ponds 6769 100.0From Boothby and Hull (1997)(Marshall et al. , 1999)

A census of ponds in Cheshire, North West England

Of the 41 564 small water bodies (ponds) identified on Ordnance Survey maps of Cheshire in ca 1870,61% had disappeared by the early 1990s.Pond loss has taken place across the county and is associated with a number of different replacement land-uses; loss rates are highest in areas of urban development.Using aerial photography, only 45% of extant ponds show areas of open water, many being completelyovershaded by trees or with substantial emergent vegetation.The effects of pond loss are now being felt in increasing fragmentation of the total resource; the density of wetponds over the entire county has fallen from 17.8 km-2 (ca 1870) to 3.25 km-2 (1992/93), and theconnectedness of the pond landscape has been similarly reduced.(Boothby, Hull, 1997)

A survey of pond loss in Essex, South-east England

An extensive survey used only maps while a smaller, intensive survey combined maps with a field study.In total, 283.43 km2 were surveyed, approximately 7% of the total area.Fifty-five per cent of the ponds present in 1870 had disappeared by 1960 with the greatest lossoccurring between 1920 and 1960.Loss of ponds in agricultural locations contributed most to this because of their high initial number and theirhigh rates of loss. Percentage losses of large and small ponds were greater than for medium-sized ponds.A field survey showed that a further 23% of a random sample of ponds shown on maps of 1960 couldnot be found in 1989. Overall loss rates for the period 1870-1989 are estimated to be 68.6% for theextensive area and 54.8% for the intensive area. (Heath, Whitehead, 1992)

Malta: ponds, pools, water tanks

Malta with surface are of less than 300 km2 is mostly limestone, and before 1830s had much surface water:marshes, pools, ponds, rivers, springs, etc with species that are typical of (undamaged) limestone in southernEurope (e.g. Sicily, S. Italy, S. France). Because of sever land drainage and abstraction, the island is now verydry as nearly all Malta's surface water have been removed, yet, surprisingly, some ponds remain. There aresummer ponds in rivers; spring pools, natural and constructed; freshwater rock pools; and constructed watertanks, etc.


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Ecosystems services

Irrigation has been spreading fast, using water from river impoundments, partly-treated sewageeffluent, springs and domestic supply, as well as groundwater. In Malta, most surface waters are used- and indeed created - for irrigation, since human impact became severe. Management is for irrigationwater, flood hazards, and to look clean and tidy (dredging of rivers).

Summer ponds in river and stream beds in the dry season (most with springs) are mostly dammed/ impounded. Impoundments have been dug since 1890s, usually with dams. The major ones were sited onsprings, puddled with clay, and presumably often on previous pools. Only a few are now summer-wet andmany are no longer even winter-wet. The vegetation is very poor and is even worse if the water is polluted aswell. River pools are distinctive landscape of much value, often within steep river valleys.

Spring pools are still fairly frequent. Many have been dried, and others have been altered, e.g. locked awaybehind doors. Of those left, some are small pools within caves. The remainder have mostly been dug out, andperhaps stoned. Vegetation ranges from nothing to diverse, with rare species.

Freshwater rock pools occur on the hard Caralline limestone, usually in sheltered places, and now usually inremote ones. Pools persist water for at least several months. The water quality is good, deriving from springsor rain. The vegetation is still diverse.

Water tanks (constructed reservoirs) are frequent, and filled by one or more spring water, borehole(aquifer) water and run-off. Most belong to individual farmers, though a few are larger for general supply.Some are merely temporary stores for (maybe polluted) run-off. They have little habitat value, but add to thediversity of the Maltese landscape and are important aesthetic landscape feature (pale limestone tanks,mostly on slopes).

Disused quarries are increasing and some bear water much of the year. The habitat is harsh: thougheventually it may ameliorate.(Haslam, 1999)

2.2.1. Temporary ponds and pools

Temporary pools as Ramsar wetland typeTemporary pools are usually small (< 10 ha in area) and shallow wetlands which are characterized by analternation of flooded and dry phases, and whose hydrology is largely autonomous.

Temporary pools can occur in many different parts of the world, but are particularly well represented in karstic,arid, semi-arid, and mediterranean-type regions.(The Ramsar Convention., 2002)

Mediterranean temporary ponds as habitat type by Natura 2000

Mediterranean temporary ponds are very shallow temporary ponds (a few centimetres deep) which existonly in winter or late spring, with a flora mainly composed of Mediterranean therophytic and geophytic speciesbelonging to the alliancesIsoetion, Nanocyperion flavescentis, Preslion cervinae, Agrostion salmanticae,Heleochloion and Lythrion tribracteati. (Interpretation Manual of.., 2003)

Temporary ponds are common throughout Europe, including Northern and Alpine regions, but they are aparticularly important pond type on the mainland and islands of the Mediterranean basin . Indeed,temporary ponds are the commonest and most characteristic freshwaters in North Africa.(The Pond Manifesto, 2008)

2.2.2. Kettle holes

In Germany, the young moraine region ofNortheast Germany has the highest density of natural ponds, theso-called kettle-holes created by the last glaciations. The estimated number of kettle-holes between 0.01 and1 hectare is about 167,000 in a 30,800 km2 area, compared to 4,901 lakes (> 1 hectare).(The Pond Manifesto, 2008)


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Young moraine landscapes are characterised by regions with internal catchments. Glacially shaped kettleholes are depressional small lentic waters or wetlands respectively (< 0.01 km2) within the sinks of thesecatchments. InNortheast Germany , kettle holes are high distributed (more than 150,000), mostly withinarable land.(Kalettka et al. , 2005a)

Wet depressions are important habitats in the agricultural landscape. InNE Germany, many of thesedepressions are morainic kettle holes containing temporary or permanent water bodies. Such kettle holeswere formed at the end of the last glaciation, about 12,000 year ago, by slowly melting blocks of buried deadice.(Frielinghaus, 1998)

Germany: historical overview, threats (drainage, agriculture intensification)

In the young-moraine landscapes ofNortheast-Germany , wide-flat drainage and the intensification ofagriculture have caused the degradation or destruction of numerous ponds.Currently in the study area ofBarnim (Northeast of Berlin, 3 km2) 40 ponds exist. The number decreased from 60 ponds 150 yearsago, as identified on an old map

(Urmetischblatt 1839).(Schneeweiss, Beckmann, 1999)

Poland: historical overview, threats (agriculture intensification, melioration)

Historical analysis in occurrence of mid-field ponds situated in the area of younger plaistocene landscapes ofPomerania in Poland was analysed. The analysis was based on the comparison of topographical maps inscale 1 25 000 from 1888 and 1980 covering the area of 9039 km2. In addition, loss of the ponds wasanalysed in relation to respective mesoregions and the character of surface features, taking into considerationthe water surface size and melioration works conducted in the drainage basin area. Mid-field ponds located inthe areas which usage in compared periods has not changed were chosen.

Characteristics of pondsThe landscape of Northern Europe is created by various postglacial forms, amongst them interior terraindepressions filled with water, refereed as water ponds. They are located both north as well as south of the linedetermining the maximum range of the Baltic glaciation. They are the most characteristic for the areas ofmoraine plateaus - ground and end moraine in the range of the last Baltic icing, whereas they havedisappeared on the older areas. The area of the ponds varies between 0.1 to 1.0 ha.

Threats

All of the water ponds and especially the midfield ponds undergo the process of land formation, which to thegreat extend was modified by human activities. Accelerated filling of depressions appeared already duringintensive settling phases, as a result of introduction of listers skids and ploughs in early medieval age.Afterthe Second World War on the area of Pomerania agriculture intensification and creation of large area

farms was started. The shaping of the agrarian sphere was at that time directed to creation of verylarge crop rotation fields without any other agricultural land use. It lead to elimination of all obstacles,water ponds were amongst those obstacles.

Melioration had as well influence on mid-field ponds and marshes disappearance. Particularintensification of melioration works in Pomerania took place in the twenties and thirties of the 20thcentury, when majority grasslands were meliorated.

All of the above activities led to disappearance of the substantial number of ponds, which in turn entailed aseries of negative phenomena within aquatic biocenosis, both in flora and fauna. Up till now in Poland midfieldponds were ranked as wastelands, but their more and more documented biocenotic and phytocenotic rolecaused that presently activities are being undertaken in order to preserve them.

ResultsMid-field ponds at the end of the 19 th century accounted for 59.4% of all small water bodies plotted onthe maps. In comparison with the ponds located within the forested areas, meadows and in inhibitedareas they were subject to land forming processes to much greater degree, therefore their share in a


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group of all small water bodies during the period of less than hundred years dropped to 39.4%.Average disappearance of mid-field ponds between the end of the 19 th and second half of the 20 th century on the whole area researched was estimated at 70.2%. To a lesser degree disappeared pondslocated on the meadows (65.5%), in the forests (63.0%) and in inhibited areas (39.5%).

The smallest ponds were primarily turned into farmlands this was due to their susceptibility for dryingand possibility of ease for levelling the basin. During the time period of less than one hundred years 80.1%of the smallest ponds were taken over for farmlands, whereas over half of larger dried out ponds (0.5-1.0 ha)reminded as unused dry depressions. Dry depressions are abundant in the areas where melioration workswere conducted in the past-war period.

In the case of drying out of the mid-field ponds reminding from the late 19-hundreds it was observed thatthewater surface has diminished significantly in respect of larger basins. Amongst ponds 0.5-1.0 ha (stateas of 19th century) in over 80% cases decrease of the water surface was ascertained. Larger water bodies,even though during hundred years disappeared to the lesser degree, went through processes leading tocomplete disappearance.

Disappearance of mid-field ponds (D) depending on water surface (A)

Larger degree of mid-field ponds disappearance was ascertained on the fields with land meliorationconducted during post-war years (6.3% difference). The biggest difference between meliorated and nonmeliorated areas (22.0%) occurred in the area of Nowogard Plain, which as compared to the analysed LakeDistrict area - has worst soils. Loss of mid-field ponds in this mesoregion on farmlands, which are not coveredwith melioration works, amounted to 49%, while in meliorated areas 71%.

Diversification of mid-field ponds disappearance between meliorated and non meliorated areas in relation tosurface features allows to assume that the greatest influence of the melioration works conducted took placeon richly formed areas of the frontal moraine and a plateau with a large number of melt-out areas, and smallereffect on surface moraine and levels of Pyrzyce ice-dammed basin.(Piekowski, 2003)

2.2.3. Farm ponds

Italy: Loss of ponds in three different area of Tuscany

The past and present uses of ponds in three different areas of Tuscany (the Chianti Hills; the Florence north-west lowland; the coastal lowland close to Orbetello lagoon) were studied, with particular reference toamphibian populations to show human-induced environmental changes with consequent endangering ofwildlife.

A widespread progressive pond loss is a phenomenon that since the end of the last century has touched manycountries, especially the more developed.

ThreatsIn the recent past the main causes of loss of these habitats were drainage and changes in farmingpractice. Today the increased habitat fragmentation by roads and similar infrastructures can beconsidered the biggest problem.


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In the past in the Chianti Hills southwards of Florence, the water bodies most used by amphibians breedingwere generally man-made like tanks, fountains, wash-pools, watering places, small ponds, etc., and weredistributed everywhere, especially near each small group of farm houses.

Most of the water bodies were neglected not only because of the changes in agriculture and cattlebreeding but also because in the 50 and 60 farmers moved to the towns (urban migration). During thelast two decades, some old farm houses were restored, generally to be used as summer houses. Theresults of these two processes has been to endanger the water bodies, because of lack ofmanagement, water collection, redesigning with artificial features, introduction of fish, and deliberateinfilled. About 35 % of the old water bodies are now completely lost, and 40 % severely endangered.

Piana Fiorentina is the only lowland near Florence. At the beginning of this century, large parts of the arableland were still swampy. The situation worsen progressively. Many of drainage channels made wereconstructed with concrete walls. Florence airport, factories, trade centres and houses were erected. Many newroads, motorways and railways now cross the area, forming ecological barriers for amphibians and otherterrestrial species (Scoccianti and Cigna, 1996).

Lowland close to Orbetello lagoon was until recent past time a wetland. Because of reclamation, a very largepart of this area was used for agriculture and cattle breeding. In this last period many portions of this land stillflooded during the year and there was great number of ponds for cattle breeding.

Today this area is almost completely reclaimed. A motorway and new buildings along it have replacedthe old coastal road. Cattle breeding has decreased and many ponds have been lost. The result is that12.5 % of ponds are lost for deliberately infilling. About 50 % lack management to the degree that theyare almost completely covered by vegetation; only 37.5 % are still present.

Like in many other parts of Italy, at the end of 1960s and 1970s many newlakes for irrigation wereconstructed in the Chianti Hills and Lowland close to Orbetello lagoon. The new water bodies made forirrigation are not good for most amphibian species because of physical features, their incorrect managementand, especially, the introduction of fish.(Scoccianti, 1999)

Farm ponds and dams of Andalusia, Southern SpainThe Mediterranean climate of Andalusia and its traditional farming activities have determined theproliferation of farm water storages (dams or ponds). Agricultural intensification has increased inSpain for the last four decades. This has determined changes in territory, such as the increase ofirrigated land and creation of farm water storages, which has increased exponentially. Water storageshave a wide range of flooding due to natural or human causes, but their management is unknown becausethey belong to private properties and their use is not monitored.

An inventory carried out by the regional environmental protection agency (CMA) has recorded more than16,500 water storages with individual surface area > 700 m2, of diverse types according to the high diversity offarming productive systems in the region.Dams in small streams and off-stream excavations dominate inextensive farming systems, andartificial substrate ponds made of concrete or made waterproof withpolyethylene dominate in the more intensive systems.(Casas et al. , 2008; Len et al. , 2008)

2.2.4. Karstic ponds

Italy: Karstic ponds and pools in the Karst of Trieste

Pond characteristics

The ponds and pools located in the dry karstic plateau near Trieste (NE Italy - SW Slovenia) represented forcenturies the only surface water resource for human activities (Polli & Alberti, 1969; Pagnini Alberti, 1972).The more natural surface water basins in the karstic landscape are ephemeral puddles and rock-pools onlimestone banks (Ranzoli et al., 1979). Unfortunately, most of rock-pools have a diameter smaller than 1.5 mand retain water only during rainy seasons (autumn and spring). The other ponds and pools were artificiallycreated by man who had to face with natural scarcity of surface waters in a karstic land.


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Karstic ponds have a surface area > 20 m2, whereas pools have a surface area of between 2 and 20 m2, filledwith water at least 4 months/year. The average surface of ponds in the Karst of Trieste is 211,7 m2, whereasthe average depth is 90 cm.

Historical changes

The Natural History Museum in Trieste has undertaken an ecological survey of the karst ponds since 1969including creation of pond database and publication of a pond cadastre.In the Province of Trieste from 1969 to 1985, 122 ponds and rock-pools were registered in a cadastre (Polli &Alberti, 1969; Alberti et al., 1981; Polli & Polli, 1985), whereas in 1998, 33 ponds and 11 pools remained. Therate of pond loss in the last decades has been high;66 % of ponds and 78 % of pools of the Karst nearTrieste disappeared between 1979 and 1998.

Threats

The traditional economic activities connected with karstic water bodies stopped after World War II, and theconsequent lack of management lead to a drastic infilling of the basins and to subsequent disappearance ofmany ponds. Some additional drinking troughs were constructed during the last 20 years in the game-reservesusing concrete, but they are usually very small (less than 4 m diameter) (Polli & Polli, 1987, 1989).

The main causes of pond loss are, in order of importance:a) the lack of management due to the construction of the new aqueducts and the decline of traditionalagricultural and zootechnical activities, as well as of ice production, during the second half of this century, anda consequent natural ecological succession towards a terrestrial environment.b) human activity (construction of buildings, reclamation),c) use of ponds as dumps.(Bressi, Stoch, 1999)

A survey of ponds and their loss in umberak-Samoborsko gorje Nature Park, northwest Croatia

A field research into the ponds in umberak-Samoborsko gorje Nature Park and aquestionnaire survey of 54people living in 43 villages within the border of the Park was conducted in 2005.

Nature park characteristics

The umberak-Samoborsko gorje Nature Park covers 333 km2 and is situated in the northwest of the Republicof Croatia and comprises a hilly area to the southwest of the Pannonian plain bordered by the rivers Sava,Krka and Kupa. Altogether, various kinds of karst landscape cover around 90% of the Parks territory, which isapprox. 300 km2 (BRKI et al., 2002.).

Historical changes and threats

As a part of pond inventarisation 164 present ponds were recorded. Through questionnairesat least 178 more ponds were identified that were here in the past. The loss trend has been quantifiedat 2.5 ponds per year or 0.74% per year. If 2.5 ponds are lost per year, in 65 years from now there willno be ponds in this area. Exceptions will be temporary ponds that came into existence from streamoverflows and other natural ponds. If the average loss of 0.74% of ponds per year is considered, thesituation is somewhat better, but still the trend of disappearance of ponds is very big. Some 60 yearsago there were at least 342 ponds in this area or approximately 1 pond per square kilometre. Morethan a half of all ponds have been lost in the last 60 years. Of the 115 lost ponds, for which therespondents recall the time of disappearance, most of them were lost in the period between 11-30years ago.

This time period can be connected with the declines in the numbers of livestock. Over the lastdecades, and especially in the 1990s, animal husbandry has been seriously declining in the Park(UPANI, 1996). Abandonment of agricultural land is in evidence. All demographic indicators showthat the remaining population is ageing (CRKVENI, 2002). Between 1991 and 2001, the populationhas decreased by 31%. Approximately 37% of the people living in the Park are more than 60 years old(CBS, 2001).

Data from literature (UPANI, 1996; FRANKOVI et al., 2004; KIPSON, 2003; VRBEK & BUZJAK, 2002,

2003) show that due to emigration of the inhabitants and abandoment of the rural way of life, all of the habitatsand species whose survival depends on regular maintenance will gradually disappear within the climate-zonalvegetation growth.


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In recent times, most of ponds are threatened as a consequence of lack of management as well as of somenegative influences such as intensive agriculture, filling and introduction of alien species.The abandonment of the ponds led to natural processes of succession and they were gradually filledwithsediments and overgrown with neighbouring vegetation. The problem of overgrown ponds is connected withwaste management in umberak-Samoborsko gorje Nature Park (ZLATAR, 2004).

The main threat to the ponds is their being overgrown with plant life, caused by the decline in humanand livestock population. Park inhabitants agreed with these as the main threats.

Because the primary function (water supply for livestock) of the ponds has decreased, the main role in theprotection will have to be taken over by the park authority in concert with the local inhabitants.(Janev Hutinec, Struna, 2007)

2.2.5. Fish ponds

Remark: fishponds can be very large, so not all fishponds are small water bodies.

The Czech Republic: FAO Fishery Country Profile

There are few natural lakes in the Czech Republic, mostly small waterbodies at high elevation, with littlesignificance for fisheries.

Aquaculture production in the Czech Republic is characterized by extensive and semi-intensive fish farming inponds, and has a very long and reputable tradition. Nowadays, of the52 000 ha available,41 000 ha are usedfor fish production. Production averages around 450 kg/ha, with individual farms ranging between 200 and 800kg/ha. The average yield from ponds depends on many factors such as management measures, altitude, etc.and ranges very broadly from 150 kg in highland extensive ponds to more than one tonne per ha in lowlandregions. Annual fish production currently fluctuates between 19 000 to 20 000 tonnes. Common carp is thedominant fish produced (88 percent). Other cultured fish includes grass carp, silver carp, tench, whitefish andpredators such as pike, zander, wels, catfish perch and salmonids such as trout.

An overwhelming majority of carp production is based on natural food - zooplankton and zoobenthos.Recently, the use of manure has been restricted due to enormous eutrophication (algal blooms caused byhigh nutrient concentrations). Nowadays, organic manure is applied in very small amounts only and lime ismainly used to counter the negative effects.

History

The first information on fishponds in the Czech Republic appears in documents from the tenth-elenventhcenturies. However, the annual yield in the early ponds was very low (10-20 kg per ha) and it was harvestedonce every 4-6 years. In the late fourteenth century there were already 75 000 ha of ponds with an estimatedproduction of 2 250 tonnes. At the turn of the sixteenth seventeenth century, the area of ponds had reachedup to 180 000 ha and the crop was over 5 000 tonnes. The level of pond farming technologies wascomparatively high at that time. Subsequently, fishpond farming started to decline due to frequent wars andthe rapid development of agriculture. As a result many ponds were drained, dried and converted into fields. Inthe early 1930s, the area of ponds was about 45 000 ha with a yield of 3 700 tonnes. This began to increasein recent years towards the level of approximately 17 000-20 000 tonnes today.

Distribution

The pond farming areas are located in all regions of the Czech Republic, except for northern Bohemia. Pondsurface area ranges from 143 ha to the largest at 7 428 ha . There are 25 companies or owners producingpredominantly carp. The largest Czech fishpond farming companies operate in the area of South Bohemia,where more than 70 percent of the total pond area is situated.

Trout farming is usually carried out in flow-through concrete and earthen canals and ponds. The farms arelocated at higher altitudes.(The Czech Republic, 2005; The Czech Republic, 2008)


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The Czech Republic: Fish farming in fish ponds

The research underFRAP- Development of a procedural framework for action plans to reconcile the conflictbetween large vertebrate conservation and the use of biological resources: fisheries and fish-eatingvertebrates as a model case

In the Czech Republic there is an old tradition going back to the 13th century to grow carp in shallow(up to 2 m deep) ponds. Currently there are more than 50.000 ponds with a total area of about 520 km 2.Among the members of the Federation of European Aquaculture Producers (FEAP) the CzechRepublic is the second largest carp producer in Europe (after Poland) with about 17,000 tonnes ofcarp production per year. Carp is farmed for human consumption within the country and abroad. In manyfamilies they serve as the traditional Christmas meal similar to turkey or geese in other countries and thereforethey have also some cultural and emotional dimension for people.

Ponds may vary considerably in size ranging from less than 0.1 ha to several 100 ha. Pondsestablished decades and centuries ago usually have very natural banks providing cover and dens forotters as well as habitat for other otter prey than commercial fish. Ponds are usually stocked in springand harvested in autumn. During the winter some ponds (23 %) remain empty and both juvenile and oneyear old carp and carp not sold yet are kept in a few ponds for over wintering. Such ponds have to providespecial conditions in respect of water quality and depth in order to guarantee the survival of carp in good

condition for the next season, when they are redistributed in other ponds for growing.During the last three decades, many new ponds were built and old ones were reactivated. Theseponds work in the same way as the old ones, just their appearance is more artificial due to a lack ofold trees along the banks etc. They also provide suitable habitat for otters and this development hasincreased the carrying capacity of otters considerably.

Ponds are usually scattered throughout the landscape according to prevailing natural water suppliessuch as streams and rivers. In many cases they are organised in cascades of ponds, which createclusters of water bodies. The productivity of these ponds varies between 300 and about 600 kg /10.000 m2.

Differences in productivity also reflect the two contrasting carp farming areas of the country: theLowlands along the River Lunize in the south of the country (T ebo Biosphere Reserve) and theHighlands found northeast of T ebo (Czech Moravian Highlands). In both areas otters are presentand cause conflict, though with different accents. In the highlands carp farming is rather suboptimaldue to climatic reasons and losses of fish stock are more common (Kranz 2000). This and geo-morphological aspects are responsible that small sized ponds prevail there.

One consequence of fish farming is a 20 to 100 folds increase of readily available fish biomass for otterscompared to the landscape without fish farming. However, there is a pronounced seasonality in the availabilityof these fish. From spring to autumn they are available in all ponds (e. g. 120 ponds / 100 km2), but from theharvest in autumn to the stocking in spring fish are concentrated in a approximately 80% of the ponds andtheir access may be hindered by ice.

Apart from the traditional carp farming other fish may be reared in these ponds, namely pike (Esoxlucius), pike-perch (Stizostedion lucioperca) and tench (Tinca tinca).Rainbow trout (Oncorhynchus mykiss )are produced in other ponds and other regions than the former due to their special demands forcolder water and higher oxygen supply. These ponds are usually smaller and located in upstreamrivers in the highlands and Border Mountains of the Czech Republic.(Polednkov et al. , 2006)

The Czech Republic and Germany: Fish farming in fishponds (see under ecological importance)

Hungary: FAO Fishery Country Profile

About 2 000 ha of small water areas such as ox-bow lakes, gravel pits and small reservoirs are underintensive, pond-like management, while 30 000 ha are utilized only for recreational purposes.

Fish production represents only a minor part of the Hungarian economy, in terms of production value itcorresponds to 2-2.5 percent of the gross value of animal production. However, Hungarian aquaculture

possesses some special characteristics, for example, its world-wide reputation in carp breeding, the value ofits R&D (Research and Development) and its special role in water management, nature conservation, water-related tourism and rural development. Total fish production from both aquaculture and capture fisheries was


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18 324 tonnes in 2002, the proportion from aquaculture being approximately 63 percent or 11 574 tonnes. Themajority (93 percent) of aquaculture production derives fromfish ponds , where both extensive and semi-intensive technologies, based on the utilisation of natural food, are commonly applied. The total area coveredby fish ponds in Hungary is approximately28 000 ha with the major species farmed being common andChinese carps, common carp (Cyprinus carpio ) represents 74 percent of the total fish production in Hungary.

The cultivated species contributing to the largest volume of production is the common carp, which occursextensively in the natural waters and is the traditional species for cultivation.Pond based fish farms are still the main production units in the Hungarian aquaculture, however, thediversification of pond fish production has been observed recently as a consequence of the socio-economicchanges in Central and Eastern Europe. Besides the conventional common carp dominated polyculturesystems in fertilised ponds, various other integrated technologies have been developed and practised inHungary, including fish-duck culture and sewage-fed pond culture.

History

The first fish farms in Hungary were established in the 1890s modelled on German and Bohemian practicesand the first selected carp varieties were also obtained from these countries. The total area covered by fishponds was about 9 200 ha in 1938. As a result of a new fish pond construction programme following theSecond World War, the total fish pond area reached 22 000 ha by 1975.

In the past, almost all ponds were managed either by state farms or agricultural cooperatives. Within theseunits, pond farming was closely integrated with cereal crop production which supplied the feed for fish. Thissituation completely changed in the early 1990s. In 1986, only 187 ha of pond area were managed by privateowners; however, in 1995, the ownership structure of the pond area in operation was as follows: state-owned30%, cooperative 17%, associations 6%, private ownership 47%.

Distribution

Fish production in earthen ponds is the traditional and most common form of aquaculture in Hungary. Fishfarms have been built in those areas where soil quality is not suitable for economical agricultural production,paddy field type ponds on the Great Plain region and contour ponds on the Trans Danubian region are typicalexamples.

The geographical, water and climatic conditions in Hungary are favourable for traditional pond fish husbandryand in some cases for intensive fish production. Ponds have been constructed mainly on marginal agriculturalland and their individual sites are not suitable for up-to-date intensive management. In 1995, technical andfinancial problems partly caused by privatization meant that only 17 545 ha of ponds were in operation out of atotal of 20 363 ha. (The Republic of Hungary, 1996; Hungary. National Aquaculture, 2008)


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2.3. Springs

Springs in general

Groundwater-fed springs constitute a unique interface between surface and groundwater ecosystems (Webbet al. 1998) and are geographically and functionally relatively isolated from each other (Williams and Williams1998). Karst springs, permanent or temporary, usually appear at the contact zone between fractured and lessfractured limestone or dolomite rock, or in the valleys, where impermeable sediments or saturated zonesappear (Gams 2003).(Mori, Brancelj, 2006)

The most often used typology includes three categories of spring types based on groundwater flow rate andtopography of the groundwater source area: helocrene, rheocrene and limnocrene springs (e.g. Danks &Williams, 1991; Smith, 1991).In helocrenes, groundwater percolates through a layer of detritus or vegetation into a marshy holding area,whereas in rheocrenes emergent groundwater flows rapidly over a gravel or sand substrate. In limnocrenes astenothermic ground water pool is formed at the point of discharge. Helocrenes often form diverse springcomplexes, including all the spring habitat types described above (Lindegaard, 1995). Gerecke & Di Sabatino(1996) used the extended terms rheohelocrene and rheopsammocrene for such spring complexes, which forma mosaic of lentic and lotic habitats and groundwater seepage, with either organogenic or minerogenicmaterial as the groundwater seeping substrate.(Ilmonen, Paasivirta, 2005).


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2.4. Mires, bogs and fens

Peatlands in Europe

Peatlands are the most widespread of all wetland types in the world, representing 50% to 70% of the globalwetlands. They cover over four million km or 3% of the land and freshwater surface of the planet. Peatland isan area with a naturally accumulated peat layer at the surface.Peat deposits, i.e. peatlands have more than 0.3 m peat and along with mires with thick peat layers they alsoinclude some forest types, drained mires, and peat extraction areas.

The majority of peatlands in Europe are concentrated in the northern half of the continent. Russia and theNordic countries alone provide more than 60 % of the European peatland resource, and Estonia, Latvia andLithuania fall within the top 20 peat-rich nations (Bragg, Lindsay, 2003).

Mires are one of the wetland types. It is an area of land that is constantly or periodically waterlogged and thatsupports vegetation that is characteristically peat-forming.In Latvia mires reach about 316 712 ha of the total land area, Estonia - 300 000 ha but Lithuania 352 000 ha(Bragg, Lindsay, 2003).

Two hydro-morphological mire types are distinguished:- minerogenous (minerotrophic) mires (fens and transition mires) are supplied by underground water rich innutrients and precipitation;- Ombrogenous (ombrotrophic) mires (raised bogs) rely entirely on rainfall for their water and nutrient supplies.(Pakalne, 2004)

Bogs, fens, mires of Bioreal region (see also under glacial lowland lakes)

Over most of the Boreal region, wetlands such asmires, bogs and fens form characteristic landscapeelements in mosaics with various forest types. In parts of northern Finland, mires cover almost 50 % of thesurface area. Peat-rich mires are still abundant in Estonia and Latvia (Baltic Environment Forum, 2000), whileLithuania has lost around 70 % of such wetlands over 30 years.(The Boreal biogeographical, 2007)

The UK: Active raised bogs and degraded raised bogs still capable of natural regeneration (habitattype Natura 2000)

Countries known to hold significant concentrations ofActive raised bogs include Finland, Sweden, the UKand Ireland. Raised bogs are widespread but unevenly distributed in the UK. There are notable concentrationsin several areas, including the Central Belt in Scotland, the Solway region on the England/Scotland border,north-west England and Northern Ireland.

Within GB, the Lowland Raised Bog Inventory (LRBI) lists 800 former and existing raised bogs, covering atotal area of nearly 700,000 ha. However, all of these sites have been modified to some extent by humanactivity. Peatland in Northern Ireland has been classified and mapped using air photographs (Cruickshank &Tomlinson 1988). This identified 2,270 ha of intact lowland peatland and 20,042 ha of cut-over peatland.

Degraded raised bogs still capable of natural regeneration are widely distributed in Europe, and are foundin most EU Member States. Degraded raised bogs occur throughout the range of raised bogs in the UK.Degraded raised bogs are certainly more extensive than 7110 Active raised bogs. Representation ofDegraded raised bogs within the UK SAC network is particularly high in England. This reflects the fact that agreater proportion of the English raised bog resource has been affected by human activities than in other partsof the UK.(SAC Interest Features, 2008)

Bogs of Atlantic region

The heavy rainfall and low evaporation of the Atlantic region has also encouraged the formation ofcharacteristicblanket bog and raised bog habitats. The UK and Ireland host some of the largest and mostsignificant tracts of blanket bogs in Europe. This is however only a fraction of what originally existed.Up to90% has already been lost through large-scale extraction, afforestation and drainage schemes.(Natura 2000 in the Atlantic region, 2005)


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UK: headwater peat wetlands

Around 13% of the UK is peat wetland. Most (90%) of the UKs peat-land is found in Scotland.(Haigh, 2006)

The Netherlands: Marshes, bogs and swamps

Characteristics

Marshes, bogs and swamps are waterlogged to wet areas consisting of open water, terrestrialising vegetation,reedbeds, thickets and swamp woodland. The Netherlands has many such areas as it is on the delta formedby the Rijn and the Maas.

Habitat fragmentation

There are almost 1500 marshes, bogs and swamps in the Netherlands, but over 80% of them are smaller than10 ha (upper figure) and a sizeable proportion of the total area of this habitat is in areas smaller than 100 ha(lower figure). The total area of marshes, bogs and swamps considered here is approximately 50% of the totalarea; open water, waterlogged grassland and similar have been excluded.

In the small areas, species are much more at risk of disappearing, especially if the small marsh, bog or swampis very isolated from other similar areas. Even the largest areas of this habitat (1000 to 5000 ha in size) aretoo small to be able to guarantee the long-term survival of all the characteristic species in them. However, theeffects of habitat fragmentation can be countered by physically linking marshes, bogs and swamps.

Historical changes

Marsh, bog and swamp is one of the few ecosystems thatincreased in area between 1950 and 1990 (by over9%). In about 1990 the total area of marsh, bog and swamp was over 47 000 hectares, compared with over 43000 hectares in about 1950. The increase is largely because of the creation of the Oostvaardersplassen in thenewly reclaimed polder province of Flevoland and the closing off of tidal inlets (for example, Lauwersmeer),which resulted in saltmarsh becoming marsh. A further increase is anticipated because of habitat creationprojects, particularly those around the river region.(Guidance Marshes, bogs and swamps, 2008)


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The Netherlands: Heathland, fens and raised bogs

The area of wet heathland is much smaller than that of dry heathland.Schamine et al. (2001) assume thatin 1930-1950 about 10% of the heathland was wet, compared with about 6% in 1990-2000. Wetheathland is verysensitive to the effects of water draw-down, which results in the invasion of purple moor-grass.

Historical changes (raised bogs)There is much less raised bog than there used to be, primarily because of peat digging and drainage.In 1900there was approximately 90 000 ha of raised bog, but by 1990 only 5200 ha remained. Most of the areathat remains is degraded raised bog in which peat formation has ceased.Only 15 ha of living raised bogremains. The current low level of alkaline water and the heavy atmospheric deposition of nitrogen arehindering the growth of Dutch raised bogs.(Guidance Heathland and fens, 2008)

Bogs of Continental region (see also under glacial lowland lakes)

Typical wetland habitats of Continental region include a large number oflakes and bogs as well as extensivefreshwater marshes andfens . The Biebrza river valley, in north-eastern Poland, is one of the largest and leastdisturbed marshlands in Central Europe with large tracts of naturalbogs extending over some 90,000 ha.

Only the habitats on poorer soils, such asbogs , marshes and heaths escaped major transformation. Thesewere managed extensively instead, if at all. Such is the case for the region around Pomorania or in the MassifCentral in France. Both still harbour large areas of valuablebogs , marshes, forests and grasslands.(Natura 2000 in the Continental region, 2005)


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3. IMPORTANCE OF STANDING SMALL WATER BODIES (ECOSYSTEM SERVICES)

3.1. Ecological importance - biology, hydrology, water quality

3.1.1. Lakes

3.1.1.1. Glacial lakes

Many of the Boreal lakes are young, succeeding the glaciation period. Most of them are rathershallow, cold,clear, and oligotrophic with very low natural nutrient loads . Only the largest lakes and those in mountainareas have mean depths exceeding 20 m.

Most boreal lakes are covered by ice for several months each year, develop sharp temperature profiles duringsummer, and have pronounced turnover of water in spring and autumn.

Many of the small lakes associated with forests or mires are heavily influenced by peat deposits and have adystrophic character with high humus content.

Oligotrophic lakes are specifically mentioned as habitat types of priority for conservation in the EU habitatsdirective and by the Bern convention. In the Boreal region this applies in particular to lakes poor in dissolvedinorganic carbon, so-called Lobelia lakes, which contain a suite of characteristic macrophyte species such asisotids (plants with basal rosettes growing on the bottom of shallow waters in clear, naturally oligotrophiclakes). The occurrence of isotids is used as a quality indicator. Sweden estimates still to have around 8 000naturally oligotrophic lakes, but the occurrence of Lobelia is decreasing.

With the extensive bogs and mires, lakes and forests present in many river catchments of the region, there isa huge natural water storage capacity , resulting in a generally slow water release. However, the river flow inthe Boreal region has heavy floods in spring and early summer, due to snow melt, while the flow is lowest inwinter during the ice-bound period.

Biodiversity

Species such as osprey (Pandion haliaetus ), European beaver (Castor fiber ) and European mink (Mustela lutreola ), which used to be fairly widespread in Europe, now tend to have their major or only populations in

association with lakes and rivers of the Boreal region, where they may encounter introduced populations ofCanadian beaver (Castor canadensis ) and American mink (Mustela vison ).

The ringed seals (Phoca hispida saimensis and Phoca hispida ladogensis ) of lakes Saimaa and Ladogarepresent endangered subspecies, which may be considered post-glacial relicts.

Boreal waterbodies are important breeding habitats for numerous birds, several of high conservation valueand sensitive to disturbances, such as divers (Gavia stellata, Gavia arctica ) and water birds like whooperswans (Cygnus cygnus ), bean goose (Anser fabalis ) and smew (Mergus albellus ).

Boreal freshwater habitats are inhabited by substantial populations of economically important fish species ofthe families Salmonidae, Cyprinidae, and Percidae, as well as pike (Esox lucius ) and burbot (Lota lota ). Thereis a rich fauna of freshwater invertebrates, but few of these have been of substantial economic or conservationinterest. The crayfishAstacus astacus and the musselMargaritana margaritifera provide exceptions. Both ofthese species have been under traditional and partly modern exploitation with dangers of over-harvesting andare also under threat from changes in their habitat. Several invertebrate species have been used as indicatorsof environmental changes in freshwater, especially for acidification or eutrophication.(The Boreal biogeographical, 2007)

3.1.1.2. Karst lakes

Ireland: Turloughs: biodiversity

Turloughs are grass- or sedge-dominated basins which sometimes have a marsh or occasionally a permanentpond in the centre. They are notable for the absence of trees or shrubs (Praeger, 1932) which are controllednot only by grazing but also by duration of flooding (Praeger, 1932; Goodwillie, 1992, 2003). They are priorityhabitats in the EU Habitats Directive supporting a variety of wet grassland and fen type vegetation with rarewetland species.


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Characteristic invertebrate species include some aquatic species-often benefiting from the absence of fish-,and many wetland terrestrial species, including carabid beetles that are rare on a European scale. Due to theirshallow nature and the full vegetation cover of the basin, turloughs can host internationally significant numbersof visiting winter wildfowl, particularly whooper swans. Amphibians are also widespread in turloughs.

The variety of plant and invertebrate communities between turloughs is primarily due to differenthydrogeomorphological characteristics, but also depends on the range of grazing practices on turloughs.Since these often vary within a turlough basin, this helps maintain within-turlough biodiversity.Though it is clear that turloughs support a number of unusual plant and invertebrate communities, knowledgeon their biodiversity is far from complete.(Sheehy Skeffington et al. , 2006)

Ireland: Turloughs: groundwater dependent terrestrial ecosystems by WFD

Wetlands encompass a continuum of aquatic to terrestrial environments including groundwater dependentecosystems. As turloughs occur mainly in Ire

assessment of status and threats of standing small water bodies

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