Seasonal dynamics and annual production of &lt;i&gt;Cystoseira crinita&lt;/i&gt; (Fucales: Ochrophyta)-dominated assemblages from the northwestern Mediterranean

Marta Sales,Enric Ballesteros

doi:10.3989/scimar.03465.16d

Seasonal dynamics and annual production of <i>Cystoseira crinita</i> (Fucales: Ochrophyta)-dominated assemblages from the northwestern Mediterranean

Marta Sales, Enric Ballesteros

Open Access

https://doi.org/10.3989/scimar.03465.16d

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Abstract

Algae of the genus Cystoseira are the main engineering species on Mediterranean shallow rocky bottoms. Cystoseira crinita is an endemic species which grows in shallow and rather sheltered environments throughout the entire Mediterranean Sea. In order to investigate its role in structuring benthic assemblages and as a primary producer, three localities were sampled every two months during one year in Menorca (Balearic Islands). The total biomass of Cystoseira crinita -dominated assemblages showed a seasonal pattern mainly due to temporal changes in the biomass of the dominant alga. The assemblages also showed seasonality in their species richness (number of species per sample). Both total biomass and species richness peaked in summer, and their lowest values were recorded in winter. Despite these temporal patterns, C. crinita -dominated assemblages from Menorca showed reduced seasonality compared to C. crinita -dominated assemblages in other areas in the western Mediterranean, as C. crinita specimens kept their branches throughout the entire year. Total annual production of Cystoseira crinita branches and cauloids was around 1230 g dwt m –2 , which is higher than that of other Cystoseira species living in sheltered areas but much lower than that of Cystoseira species growing on exposed shores. Production was highly seasonal, and was highest in spring and null in winter and late summer.

Highlights

Algae in the orders Laminariales and Fucales are the main engineering species in sublittoral rocky bottoms of all temperate areas in the world (Ribera et al.1992, Steneck et al 2002)
The assemblages showed seasonality in their species richness. Both total biomass and species richness peaked in summer, and their lowest values were recorded in winter
The majority of shallow rocky temperate coasts are occupied by Laminariales, commonly known as kelps (Dayton 1985, Steneck et al 2002), while in the Mediterranean Sea these areas are occupied by algae of the genus Cystoseira (Fucales) (Giaccone 1973, Ballesteros 1992)

Summary

Introduction

Algae in the orders Laminariales and Fucales are the main engineering species in sublittoral rocky bottoms of all temperate areas in the world (Ribera et al.1992, Steneck et al 2002). They are very important primary producers in coastal areas (Mann 1973) where they dominate structurally complex and diverse assemblages (Duggins 1980, Reed and Foster 1984, Graham 2004). The majority of shallow rocky temperate coasts are occupied by Laminariales, commonly known as kelps (Dayton 1985, Steneck et al 2002), while in the Mediterranean Sea these areas are occupied by algae of the genus Cystoseira (Fucales) (Giaccone 1973, Ballesteros 1992). The seasonal dynamics and annual production of Cystoseira-dominated assemblages have been studied by several authors (e.g. Ballesteros 1988a, 1989, 1990a,b, Pizzuto 1999), and have been found to show marked seasonality in the abundance of the dominant species and overall species composition

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