Cultivating Palmaria palmata - Bord Iascaigh Mhara

2.2 Geographical distribution
Palmaria palmata is a cold temperate species of the North Atlantic and North Pacific Oceans. The area of
distribution in the North Atlantic stretches from Spitzbergen and Greenland in the Arctic (80°N) to Portugal and
New Jersey (40°N). Palmaria palmata is also found along the Pacific coasts of Canada and the USA from Alaska
to northern California, and along the cold-temperate coasts of eastern Russia (Sakhalin and the Kuril Islands)
and northern Japan (Hokkaido; Lüning, 1990). It is a common constituent of many rocky shores in Ireland and
the UK (Bunker et al., 2010; Hardy & Guiry, 2003).
2.3 Habitat and ecology
Palmaria palmata grows in the lower intertidal and shallow subtidal zone to a maximum depth of 20 metres. In
European waters, the alga is a frequent epiphyte on stipes of Laminaria hyperborea or L. digitata, but it is also
found occasionally on Fucus species or on rocks and mussel shells (see Fig. 2.2). Palmaria prefers sheltered to
semi-exposed sites with a moderate to strong water current. A good water flow has a very positive effect on
growth, probably because of its impact on nutrient exchange. Young fronds of Palmaria are normally free of
epiphytic growth, but older fronds are frequently covered by bryozoans and other organisms. Older thalli also
frequently contain small endophytic algae, which are visible as dark brown dots in the tissue, and marine fungi.
14
2cm
Fig. 2.2. Palmaria palmata in its natural habitat. Clockwise from top left: Palmaria growing on the stipes of
Laminaria digitata at spring low tide in Strangford Lough; Palmaria at spring low tide submerged; P. palmata
growing on stipes of Laminaria hyperborea at spring low tide at Ballyrisode Beach, South West Cork; recruits of
Palmaria palmata on a stipe of L. digitata in June.