Nuttall’s Waterweed	Status LU: established. 1st record: LU & ITW 1975.
	Schmuelbliedereg Waasserpescht	Status Eur.: established. 1st record: BE 1939. IAS of EU concern (2017).
	Elodée de Nuttall	RA: ISEIA: A3, Black List. Harmonia+: 0,42
	Schmalblättrige Wasserpest	Wikipedia: | Wikispecies: | CABI
	Smalle waterpest	Back to the list of neophytes

Report the species

→ Report Elodea nuttallii to the National Museum of Natural History.

Brief description

Elodea nuttallii (Planch.) H. St. John is an aquatic plant that thrives in various types of freshwater habitats, from still to slow-flowing systems and from very shallow to deep waters. It is very tolerant to water pollution and prefers warm eutrophic and calcareous waters; it is often found in species-poor macrophyte communities. This submerged perennial makes dense monospecific populations which often colonise whole water bodies, restrict water movement, cut off light, produce anoxic conditions and trap sediments in the system. Due to its quick nutrient uptake and very high growth rate, the species has been reported to outcompete several native aquatic plants (Branquart et al. 2019).

IAS of Union concern

In 2017, Elodea nuttallii (Planch.) H. St. John was added to the list of invasive alien species of Union concern (Anonymous 2017) which implies that member states shall take all necessary steps to prevent it’s unintentional introduction or spread.

Status and distribution in Luxembourg

Elodea nuttallii (Planch.) H. St. John has been first documented by Paul Verheggen in the Upper Sûre lake near Boulaide in 1975 (Parent 1983 cit. in Diederich 1984: 39)¹. The species, observed since 1941 in the Netherlands, was harvested in 1939 in northern Belgium, but was only identified later (around 1967). It tends to locally supplant Elodea canadensis Michx. (Lambinon & Verloove 2012: 790).

Elodea nuttallii (Planch.) H. St. John is so far less common in Luxembourg than the Canadian waterweed. 

An identification sheet of the species has been published by the MECB in French and German.

Management

Action plan

The action plan dedicated to Nuttall’s Waterweed was published September 2020:

→ Finalised Action Plan for Elodea nuttallii (Pfeiffenschneider & Hoppe 2020).

Risk assessment

ISEIA protocol

A3 (3+3+3+3) = Black List (Ries et al. 2013: 18).

Harmonia+ protocol

Overall risk score 0,42 = (Overall Invasion score 0,71 x Overall Impact score 0,60) (Ries et al. 2020).

Worldwide distribution

Bibliography

• Anonymous, 2017. Commission implementing regulation (EU) 2017/1263 of 12 July 2017 updating the list of invasive alien species of Union concern established by Implementing Regulation (EU) 2016/1141 pursuant to Regulation (EU) No 1143/2014 of the European Parliament and of the Council. Official Journal of the European Union L 182: 37-39 (13.7.2017).
• CABI, 2019. Elodea nuttallii. In: Invasive Species Compendium. Wallingford, UK: CAB International. URL: www.cabi.org/isc [accessed 2020-02-28]
• Branquart, E., I. Stiers, L. Triest, S. Vanderhoeven, W. Van Landuyt, F. Van Rossum, F. Verloove, 2019. Harmonia database: Elodea nuttallii (Planch.) H. St. John. Harmonia version 1.2, Belgian Forum on Invasive Species. URL: http://ias.biodiversity.be [accessed on 2019-10-09]
• Diederich, P., 1984. Les monocotylédones aquatiques (excl. Potamogeton s.l.) du Grand-Duché de Luxembourg. Dumortiera 29-30: 34-41. [PDF 5 MB].
• Lambinon J. & F. Verloove, 2012. Nouvelle flore de la Belgique, du grand-duché de Luxembourg, du Nord de la France et des régions voisines. Sixième édition. Avec la collaboration de L. Delvosalle, B. Toussaint, D. Geerinck, I. Hoste, F. Van Rossum, B. Cornier, R. Schumacker, A. Vanderpoorten et H. Vannerom. Jardin botanique national de Belgique, Meise. CXXXIX + 1195 pp. ISBN : 9789072619884.
• MNHNL, 2000-. Elodea nuttallii (Planch.) H. St. John in Recorder-Lux, database on the natural heritage of the Grand Duchy of Luxembourg. Musée national d’histoire naturelle, Luxembourg. URL: https://mdata.mnhn.lu [Accessed 2019-09-05]
• MNHNL, iNaturalist & GBIF, 2019. Elodea nuttallii (Planch.) H. St. John in MNHNL-mdata, online portal combining species observation from Recorder-Lux, iNaturalist and GBIF. National Museum of Natural History, Luxembourg. URL: https://mdata.mnhn.lu [Accessed 2019-09-06]
• Oly, M., 2022. Kartierung invasiver gebietsfremder Wasserpflanzen im Großherzotum Luxemburg, Untersuchungen zur Verbreitung von invasiven gebietsfremden Wasserpflanzen in einer beispielhaften Auswahl an Stillgewässern, Musée national d’histoire naturelle, Luxembourg. 117 pp. 
• Parent, G. H., 1983. Données floristiques inédites tirées de l’herbier du docteur Paul Verheggen. Dumortiera 25 : 12-21.
• Pfeiffenschneider, M. & F. Hoppe, 2020. Plan d’action pour espèces exotiques envahissantes au Grand–Duché de Luxembourg : Elodéede Nuttall, Elodea nuttallii (Planch.) H. St. John. Version 23/09/2020. Administration de la nature et des forêts, Luxembourg. 22pp.
• Ries, C. & Y. Krippel, 2021. First records of 56 invasive alien vascular plants in Luxembourg. Bulletin de la Société des naturalistes luxembourgeois 123: 115-127. [PDF 241 KB]
• Ries, C., Y. Krippel & M. Pfeiffenschneider, 2020. Risk assessment after the Harmonia+ protocol of invasive alien vascular plant species in Luxembourg. Bull. Soc. Nat. luxemb. 122: 197-205. [PDF 132 KB]
• Ries, C., Y. Krippel, M. Pfeiffenschneider & S. Schneider, 2013. Environmental impact assessment and black, watch and alert list classification after the ISEIA Protocol of non-native vascular plant species in Luxembourg. Bull. Soc. Nat. luxemb. 114: 15-21. [PDF 652 KB]