Intertidal macroalgae species distribution along the Northwestern Iberian coast in 2020/2021

Study Extent

Data were collected between the autumn of 2020 and the summer of 2021. Sampling was carried out at 71 wave-exposed rocky shore locations along the Northwestern Iberian coast, covering the three major rocky stretches of shoreline in the Northern, Central Portuguese regions and in Galicia.

Sampling

Specimens in this dataset were collected in field work carried out between the autumns of 2020 and the summer of 2021. Observations derives from visual surveys done along the Northwestern Iberian coast. A semi-quantitative estimation of abundance was assigned to each taxa identified during the survey. We used a modified version of the scale established by Crisp and Southward 1958 — SACFOR, where abundances were encoded from 6 to 0 (where 6 means Superabundant; 5, Abundant; 4, Common; 3, Frequent; 2, Occasional; 1, Rare; and 0, not found).

Quality Control

In addition to AlgaeBase (Guiry and Guiry 2021), authoritative identification guides and keys for the Eastern Atlantic and Mediterranean were used. Specifically, Araujo et al., 2009; Araújo et al., 2011; Aziza et al., 2008; Bárbara, 2009, 2013; Benita et al., 2018; Bunker et al., 2017; Campbell et al., 1994; Chapman & Goudey, 1983; M Edwards et al., 2012; Faes & Viejo, 2003; Molenaar et al., 1996; Poza et al., 2017; Stuart et al., 1999; Vieira et al., 2010. All scientific names were standardized against the WoRMS - The World Register of Marine Species using the Taxon Match tool available at http://www.marinespecies.org/aphia.php?p=match (accessed on: 2021-07-07).

Method steps

1. The steps that led to the final release of the dataset were as follows: (1) In-situ identification of species and attribution of a semi-quantitative abundance SACFOR score; (2) standardisation of taxonomy against the World Register of Marine Species.

A total of 35 seaweed species were surveyed (20 Ochrophyta, 13 Rhodophyta and 2 Chlorophyta): Ascophyllum nodosum, Asparagopsis armata, Calliblepharis ciliata, Chondrus crispus, Codium adhaerens, Delesseria sanguinea, Desmarestia ligulata, Dictyopteris polypodioides, Dilsea carnosa, Dumontia contorta, Fucus serratus, Fucus spiralis, Gelidium corneum, Grateloupia turuturu, Halidrys siliquosa, Halopithys incurva, Himanthalia elongata, Hypnea musciformis, Laminaria ochroleuca, Laminaria hyperborea, Laminaria sp., Leathesia marina, Padina pavonica, Palmaria palmata, Pelvetia canaliculata, Petalonia fascia, Phycodrys rubens, Phyllophora crispa, Saccharina latissima, Saccorhiza polyschides, Sargassum flavifolium, Sargassum muticum Treptacantha baccata, Undaria pinnatifida and Valonia utricularis.

1. Rodophyta
   rank: phylum
2. Ochrophyta
   rank: phylum
3. Chlorophyta
   rank: phylum

Northwestern Iberia