The marine algal (seaweed) flora of the Azores: additions and amendments

Abstract

Thirteen species of benthic marine algae are reported new for the isolated mid-Atlantic Azores archipelago and five older records are confirmed. Seven (Bangia atropurpurea, Codium fragile spp. tomentosoides, Ectocarpus fasciculatus, E. siliculosus, Porphyrostromium ciliare, Ulothrix flacca and Ulvaria oxysperma) are widespread amphi-Atlantic species some of which extend in distributional range south to the Canary Islands. Cryptonemia seminervis, Ctenosiphonia hypnoides and Phyllophora sicula are known from the northeastern Atlantic Ocean only and also occur in the Canary Islands. The Azores archipelago is the western limit of distribution of Codium fragile ssp. atlanticum, Bostrychia scorpioides, Bryopsis cupressina, Erythroglossum laciniatum, Haliptilon squamatum and Phyllophora sicula, and the southern limit of C. fragile ssp. atlanticum and E. laciniatum. The tropical species Phyllodictyon anastomosans, Valonia macrophysa and Wurdemannia miniata reach their northern limit of distribution there. Asparagopsis taxiformis is now less common possibly due to competition with the non-native A. armata; subspecies of the non-native C. fragile now occur widely in the Azores. The status of Fucus vesiculosus, Ulva (Enteromorpha) clathrata and Rhizoclonium tortuosum is clarified and other species have been removed from the flora. The continuing addition of new species records for the Azores shows the archipelago to be floristically richer than other Atlantic islands except for the Canary Islands.

Adaptation of macroalgal indexes to evaluate the ecological quality of coastal waters in oceanic islands with subtropical influence: the Azores (Portugal)

“…The R/P (Rhodophyta/Phaeophyceae) ratio varies between 1.0 and 2.0 in temperate waters, and may reach 4.3 in tropical waters (Witman & Roy, 2009). In the present study, the calculated R/P ratio was between 1.4 and 2.8 for the different water bodies, reinforcing the suggestion of Titley & Neto (2005) that the algal communities of the Azores present characteristics of a temperate water flora, though also having tropical influences. Even though the R/P ratio is not considered to be a very precise biotic index (Marques et al, 2009), this ratio has been used as an indicative in water quality classification, showing some separation between different water bodies conditions.…”

“…Four of the main ecological indexes using macroalgae as bioindicator created for European coastal waters were tested in the Azores at six sampling sites located in different islands of the archipelago. The metrics of the different indexes were adapted according to the characteristics of the Azorean marine flora, i.e., poorer than continental floras in terms of number of species (Titley & Neto, 2005) and of mixed nature with strong components of cold water floras with few tropical and subtropical elements (Neto 1997). Also taken into consideration were the different characteristics of the archipelago coastal lines that are difficultly accessed by land and highly exposed to waves.…”

Species diversity and biogeographical patterns of Laurencia sensu stricto (Rhodophyta) in the Atlantic Ocean

“…Distribution: Lusitania: azorEs islands: Santa María Island and Pico (Tittley et al, 2009). canary islands: El Hierro, Fuerteventura, Gran Canaria, La Palma, Lanzarote, and Tenerife .…”

Species diversity and biogeographical patterns of Laurencia sensu stricto (Rhodophyta) in the Atlantic Ocean

“…Distribution: Lusitania: azorEs islands: Santa María Island and Pico (Tittley et al, 2009). canary islands: El Hierro, Fuerteventura, Gran Canaria, La Palma, Lanzarote, and Tenerife (Gil-Rodríguez et al, 2012).…”