Water habitat surveys
Task 11: Water habitat surveys and rapid biodiversity assessment
Task 11
Water habitat surveys
This task involved discussing an Annex 1 water dominated habitat type, surveying of a pond and reporting on PSYM and newt surveying activity.
There are many different habitats that are dominated by water, with Annex 1 listing 8 different freshwater habitats. This doesn’t include marine habitats, or bogs/mires/fens. Each habitat is ecologically important in its own way. Below I describe one of the Annex 1 habitat types in more detail, before detailing rapid biodiversity surveying of ponds.
Freshwater habitats
3260 Water courses of plain to montane levels with the Ranunculion fluitantis and Callitricho-Batrachion vegetation
This habitat is defined by Ranunculus subgenus Batrachium (water crowfoots). River channels have floating mats of these species in early to mid-summer. They are ecologically important as they provide shelter and food for invertebrates and fish. They can also modify the flow of water and promote fine sediment deposition (Joint Nature Conservation Committee (JNCC), no date-a).
The substrate and dominant species (within the Ranunculus community) define the habitat sub-type:
Sub-type 1: Chalk substrates. Most have winterbourne stretches in their headwaters (Joint Nature Conservation Committee (JNCC), 2011), which run dry in summer. In these spring-fed headwaters, there will be pond water-crowfoot Ranunculus peltatus. The middle reaches will contain stream water-crowfoot R. penicillatus ssp. Pseudofluitans; and the river water-crowfoot R. fluitans will be found downstream.
Examples of this sub-type are rare across Europe, and in the UK is limited to where chalk is present i.e. south and east England.
Sub-type 2: Found on other substrates e.g. lime-rich substrates, sandstone and clay etc. Considerable variation across geographic regions. For example, fast flowing rivers over hard rocks have stream water-crowfoot Ranunculus penicillatus; rivers on sandstone have both R. penicillatus and river water-crowfoot R. fluitans.
Sub-type 3: This is a mesotrophic to oligotrophic community, found on hard rocks in the north and west. Stream water-crowfoot Ranunculus penicillatus, and other typical species include alternate water-milfoil Myriophyllum alterniflorum and intermediate water-starwort Callitriche hamulate.
Examples of these sub-types are found across the UK where the substrate is suitable.
This Annex 1 habitat type is covered by:
Phase 1 habitat: G2 Open water – Running water (Joint Nature Conservation Committee (JNCC), 2016, p. 62)
Containing NVC communities:
Callitriche stagnalis community A16
Ceratophyllum demersum community A5
Elodea canadensis community A15
Myriophyllum alterniflorum community A14
Nuphar lutea community A8
Persicaria amphibia community A10
Potamogeton natans community A9
Potamogeton pectinatus-Myriophyllum spicatum community A11
Potamogeton perfoliatus-Myriophyllum alterniflorum community A13
Ranunculus aquatilis community A19
Ranunculus fluitans community A18
Ranunculus peltatus community A20
Ranunculus penicillatus ssp. pseudofluitans community A17
Sources: Rodwell (2006, p. 62), NatureScot (2017)
UKHab: r2a5 Rivers with floating vegetation (H3260) (UKHab Ltd., 2023, p. 230)
In all cases, the amount of habitat has been reduced, due to nutrient enrichment e.g. sewage and agricultural run-off as well as modifications to river flows e.g. due to channelisation, over-widening, over-deepening etc. Reducing run-off and restoring natural river processes and connectivity are important to preserve this habitat.
Example
An example of this type of habitat can be found at the River Lambourn, which is designated as a Special Area of Conservation (SAC) for this habitat type (Joint Nature Conservation Committee (JNCC), no date-b). It is a chalk stream that discharges into the Thames. Part of its length it is a winterbourne, drying out in summer. It is one of the least-modified rivers of this type and is dominated by pond water-crowfoot Ranunculus peltatus. It should be noted that Annex II species at this site include Bullhead Cottus gobio and Brook lamprey Lampetra planeri.
Map of River Lambourn (SAC), from MAGIC Map (Defra, 2024).
To perform a rapid biodiversity survey of a restored pond, a number of considerations need to be taken into account:
1. Timing: Depending on the taxa being surveyed, certain times of the year will be preferable to perform the survey as it may be harder to identify organisms outside of these times, or to ensure standard survey methods e.g. Common Toad and Common Frog surveys should be performed in March or April (Freshwater Habitats Trust, no date)
2. Health and safety: Working in/next to water can be dangerous and appropriate health and safety measures should be followed. Ideally lone working is discouraged. Dangers from waterborne diseases such as leptospirosis (Weil’s disease) need to be mitigated e.g. by ensuring no open wounds when working near water, cleaning hands after surveying etc.
3. Expertise: The person(s) undertaking the survey should have appropriate expertise and knowledge for the survey to reduce any errors. If surveying multiple taxa at the same time, then having experts on each taxon may be advantageous.
4. Methodology: The survey methodology should be determined prior to the survey, using a standardised and recommended method so that results can be compared to other survey results. If the purpose of the survey is to determine the overall ecological quality of the pond then the PSYM method may be used (Freshwater Habitats Trust, 2019), see PSYM survey for more details.
5. Equipment: Appropriate equipment and clothing should be selected for the survey e.g. nets, trays, waders, sunhats, warm clothes, waterproof clothes etc.
6. History: If previous surveys have been performed, then a checklist of know species is a good place to start. If there are any rare, or Priority, species present/expected then it is useful to be aware of this. An understanding of the management of the site, if there are livestock grazing etc. will aid to overall understanding.
7. Fauna/Flora: Different fauna/flora may have different considerations such as surveying methodologies, timings, legislation etc. For example, for protected species such as Great Crested Newts Triturus cristatus, a license is required to perform a full survey. See Newt surveying for more details. For invertebrates, surveys may only require identifying to family level not species.
Rapid biodiversity survey: ponds
Experience
I have gained some practical experience with surveying ponds, including a session on PSYM and also newt surveying. Please follow the links for more details.
References
Defra (2024) MAGIC Map. Available at: https://magic.defra.gov.uk/MagicMap.aspx (Accessed: 20 May 2024).
Freshwater Habitats Trust (2019) Predictive System for Multimetrics (PSYM). Available at: https://freshwaterhabitats.org.uk/advice-resources/survey-methods-hub/psym/ (Accessed: 04 June 2024).
Freshwater Habitats Trust (no date) Amphibian surveys. Available at: https://freshwaterhabitats.org.uk/advice-resources/survey-methods-hub/amphibian-surveys/ (Accessed: 04 June 2024).
Joint Nature Conservation Committee (JNCC) (2011) UK BAP Priority Habitat Descriptions (Rivers & Streams) (2008, revised 2011). Available at: https://hub.jncc.gov.uk/assets/01d6ab5b-6805-4c4c-8d84-16bfebe95d31#UKBAP-BAPHabitats-45-Rivers-2011.pdf (Accessed: 04 June 2024).
Joint Nature Conservation Committee (JNCC) (2016) Handbook for Phase 1 habitat survey: A technique for environmental audit. Available at: https://hub.jncc.gov.uk/assets/9578d07b-e018-4c66-9c1b-47110f14df2a (Accessed: 17 May 2024).
Joint Nature Conservation Committee (JNCC) (no date-a) Habitats: 3260 Water courses of plain to montane levels with the Ranunculion fluitantis and Callitricho-Batrachion vegetation. Available at: https://sac.jncc.gov.uk/habitat/H3260/ (Accessed: 04 June 2024).
Joint Nature Conservation Committee (JNCC) (no date-b) River Lambourn. Available at: https://sac.jncc.gov.uk/site/UK0030257 (Accessed: 04 June 2024).
NatureScot (2017) SNH Commissioned Report 766 - Manual of terrestrial EUNIS habitats in Scotland - correspondence tables. Available at: https://www.nature.scot/sites/default/files/2020-04/Publication%202017%20-%20SNH%20Commissioned%20Report%20766%20-%20Manual%20of%20terrestrial%20EUNIS%20habitats%20in%20Scotland%20-%20correspondence%20tables_0.xls (Accessed: 04 June 2024).
Rodwell, J. S. (2006) NVC Users' Handbook. Peterborough: JNCC.
UKHab Ltd. (2023) UK Habitat Classification Version 2.0. Available at: https://www.ukhab.org (Accessed: 07 May 2024).