The reproductive phenology and cultivation of Palmaria palmata on the west coast of Ireland

• Main Author: Whelan, Susan
• Other Authors: Johnson, Mark P., Edwards, Maeve D.
• Format: Thesis
• Language: unknown
• Published: NUI Galway 2023
• Subjects: Science and Engineering; Science; Natural Sciences; Palmaria palmata; Seaweed; cultivation; Colour parameters (L*; a*; b*); High-quality protein; Phenology; Holdfast; Pacific; North Atlantic
• Online Access: http://hdl.handle.net/10379/17907; https://doi.org/10.13025/18024

The Rhodophyte Palmaria palmata (Linnaeus) Weber and Mohr, 1805 is part of the Palmariaceae family. The Palmariaceae family can be found in cold waters of the North Atlantic and North Pacific (Morgan et al. 1980; Lüning 1990), but P. palmata is found only in the North Atlantic where it can be observed as far south as Portugal (Faes and Viejo, 2003; Grote, 2019). In Ireland and the British Isles P. palmata is commonly distributed, apart from the Norfolk coastline in the East and a small area on the West coast of England (Lancashire) (Irvine and Guiry, 1983). P. palmata grows in the lower subtidal and intertidal zones of rocky shores and can be found on hard surfaces such as rock and mussel shells (Irvine and Guiry, 1983) and as an epiphyte of Fucus spp., L. hyperborea, and L. digitata (Lüning, 1990; Edwards, 2007). It can also be noticeably abundant on shores where Sabellaria alveolata reefs are present in Ireland (personal observation). In the wild, the alga attaches and grows with a small, disc-like holdfast which then forms a short stipe and palmate (resembling a hand with fingers) thallus (frond). Fronds usually grow up to 10-40 cm but can reach up to 100 cm in length in some conditions (personal observations). The colour of the fronds are purple, crimson, or brownish-red, which turn yellow to pink after drying and bleaching in the sun (Mouritsen et al., 2013). Individuals that are greater than a year old can have a more leathery texture. New growth is produced within the meristematic tissue of P. palmata found around the apical tips of the frond. In older individuals, these regions sometimes also produce new growth in the form of proliferations (small bladelets) around the edges of the frond (Titlyanov et al., 2006; Grote, 2019; Schmedes and Nielsen, 2020a) There are several morphotypes of P. palmata recorded in Ireland (Kraan and Guiry, 2006). Typical individuals have a broad flat palmate frond, however other morphotypes that exist have much more finely dissected thalli and are usually referred to as P. ...