Flat-stalked Pondweed (Potamogeton friesii)
Key Details
| Taxonomic Groups: | Vascular plant > flowering plant > Aquatic plant |
| Red List Status: | Near Threatened (Not Relevant) [NT(nr)] |
| D5 Status: | Included in the baseline Red List Index for England (Wilkins, Wilson & Brown, 2022) |
| Section 41 Status: | (not listed) |
| Taxa Included Synonym: | (none) |
| UKSI Recommended Name: | Potamogeton friesii |
| UKSI Recommended Authority: | Rupr. |
| UKSI Recommended Qualifier: | (none specified) |
| Red List Citation: | in Stroh et al., 2014 |
| Notes on taxonomy/listing: | (none) |
Criteria
| Question 1: | Does species need conservation or recovery in England? |
| Response: | Yes |
| Justification: | Potamogeton friesii expanded through the canal network, and has subsequently declined as canals became disused or dominated by pleasure-boat traffic. It is also found in slow-flowing rivers, fenland lodes, and other open waterbodies. It is assessed as VU in England, and NT in GB, although the latter category is likely to change to VU following a revision of the GB Red List (Stroh et al., in prep). |
| Question 2: | Does recovery/ conservation depend on species-specific actions? |
| Response: | Yes |
| Justification: | A decline in water quality combined with an increased use in boat traffic along canals, and succession in ditches and moderate eutrophication, are the most likely causes for the ongoing decline of this species. |
| Question 3: | At a landscape scale, would the species benefit from untargeted habitat management to increase habitat mosaics, structural diversity, or particular successional stages? |
| Response: | Yes |
| Justification: | Untargeted measures would likely not lead to the recovery of this species at a landscape scale. A decline in water quality combined with an increased use in boat traffic along canals is the most likely cause for the ongoing decline of this species, and so specific actions are required. |
Species Assessment
| Current step on the Species Recovery Curve (SRC): | 4. Autecology and pressures understood |
| Recovery potential/expectation: | Medium-high |
| National Monitoring Resource: | Opportunistic - insufficient |
| Species Comments: |
Key Actions
Key Action 1
Proposed Action: Prepare an ecological profile to inform future conservation actions.
Action targets: 4. Autecology and pressures understood
Action type: Scientific research
Duration: 1 year
Scale of Implementation: Unknown
High priority sites: This action involves a thorough ecological profile of the species, and so no specific site actions are required here
Comments:
Key Action 2
Proposed Action: Introduce speed limits for boat traffic on a selection of canals, and along selected sections of these canals, where the species is extant or has been present this century, with the speed limit designed to be slow enough to stop the development of a bow-wave or the uprooting of plants. Support a move away from propeller-driven craft to jet-propelled craft.
Action targets: 5. Remedial action identified
Action type: Pressure mitigation
Duration: 3-5 years
Scale of Implementation: ≤ 5 sites
High priority sites: Montgomery Canal; Allington, Kennet+Avon Canal; Grand Union Canal; Grantham Canal
Comments:
Key Action 3
Proposed Action: Monitor the results of Action 2 along stretches of canals that have speed limits in place, and also areas along the same canal that do not have speed limits, to collect information on the presence/spread of the target species and the success or otherwise of the targeted action (2).
Action targets: 6. Recovery solutions trialled
Action type: Scientific research
Duration: 3-5 years
Scale of Implementation: Unknown
High priority sites: Montgomery Canal; Allington, Kennet+Avon Canal; Grand Union Canal; Grantham Canal
Comments:
Acknowledgment:
Data used on this website are adapted from Threatened species recovery actions 2025 baseline (JP065): Technical report and spreadsheet user guide (Natural England, 2025). Available here.