Liste des habitats menacés et/ou en déclin de la Convention OSPAR

’Kelp forests’ are defined as complex habitats created by large brown seaweeds mostly in the order Laminariales and some species of the order Tilopteridales (Bolton, 2016; Wernberg & Filbee-Dexter, 2019). They typically occur from the low intertidal down to shallow subtidal zones (approximately 40 m depth, depending on the water clarity with a depth limit at around 10% of incoming irradiance; Lüning, 1990) of temperate and polar coastal waters. As surface seawater temperature increases towards lower latitudes, kelp forests become excluded from shallow areas and restricted to deeper, cooler water (Graham et al., 2007; Marzinelli et al., 2015).
A kelp forest has a canopy formed by kelp stipes that hold fronds tens of centimetres to several metres above the substratum. This modifies the local environment to support a specific and distinct associated understorey and epibiotic community, which would not persist without the canopy (Flukes et al., 2014; Leclerc et al., 2015; Teagle et al., 2017). A forest exhibits dense stands with the fronds forming an almost complete canopy (often referred as Leaf Area Index > 1; Pehlke & Bartsch, 2008) equivalent to having a stipe density of at least 3-5 adult stipes m-² for the kelp species of the North-East Atlantic. Depending on the latitude and environmental conditions, kelp forests have different kelp species assemblages and may show density variations for example after storms or winter die-back of annual sporophytes. Six canopy-forming species that may be locally dominant or occur in mixed assemblages with varying densities and are able to form dense canopies are considered here: the Laminariales Alaria esculenta, Laminaria digitata, L. hyperborea, L. ochroleuca, Saccharina latissima (formerly Laminaria saccharina), and the Tilopteridale Saccorhiza polyschides.

I, II, III, IV, V

II, III, IV

OSPAR 2008. Descriptions of habitats on the OSPAR List of threatened and/or declining species and habitats. OSPAR Commission. OSPAR Agreement 2008-07 updated 2021, 15 pp. (Source)

OSPAR 2008. Liste OSPAR des espèces et des habitats menacés et/ou en déclin. Commission OSPAR. Accord OSPAR 2008-06 révisé 2021, 6 pp. (Source)

OSPAR 2008. OSPAR List of threatened and/or declining species and habitats. OSPAR Commission. OSPAR Agreement 2008-06 updated 2021, 5 pp. (Source)

de Bettignies T., de Bettignies F., Bartsch I., Bekkby T., Boiffin A., Casado de Amezúa P., Christie H., Edwards H., Fournier N., García A., Gauthier L., Gillham K., Halling C., Harrald M., Hennicke J., Hernández S., Kilnäs M., Martinez B., Mieszkowska N., Moore P., Moy F., Mueller M., Norderhaug K. M., Ó Cadhla O., Parry M., Ramsay K., Robertson M., Russel T., Serrão E., Smale D., Sousa Pinto I., Steen H., Street M., Walday M., Werner T., La Rivière M. (2021). Background document on kelp forest habitat. OSPAR 788/2021, 67 pp. ISBN 978-1-913840-15-0

de Bettignies T., Hébert C., Assis J., Bartsch I., Bekkby T., Christie H., Dahl K., Derrien-Courtel S., Edwards H., Filbee-Dexter K., Franco J., Gillham K., Harrald M., Hennicke J., Hernández S., Le Gall L., Martinez B., Mieszkowska N., Moore P., Moy F., Mueller M., Norderhaug K. M., Parry M., Ramsay K., Robuchon M., Russel T., Serrão E., Smale D., Steen H., Street M., Tempera F., Valero M., Werner T., La Rivière M. (2021). Case Report for kelp forest habitat. OSPAR 787/2021, 39 pp. ISBN 978-1-913840-16-7