Diversity and turnover in a rocky shore intertidal community of an upwelling region (Arraial do Cabo, Brazil).

JOEL C. DE PAULA,WANDERSON F. DE CARVALHO,AMANDA C.S. CORAÇÃO,LUCIANO N. DOS SANTOS,ROBERTA P. SILVA,ERICK A.P. LOPES-FILHO

doi:10.1590/0001-3765202020181096

Abstract

The present study describes the community diversity and gives a seasonal distribution of an intertidal macroalgal assemblage at Prainha Beach, Arraial do Cabo City in Rio de Janeiro state, Brazil. Sampling was performed during four seasons of a 1-year period. Organisms were sampled and photographed using photoquadrats to quantify relative coverage. Ninety-six taxa of macroalgae were registered, including 23 chlorophytes, 19 ochrophytes, and 54 rhodophytes, while three barnacles, seven mollusks, one isopod, and one polychaete were recorded among the zoobenthos. In the upper intertidal zone, the coverage was frequently dominated by invertebrates. Macroalgae always dominated the middle and lower zones, covering almost 100 % in both zones. The highest values of species diversity (H'), richness (S), and turnover rates were found during the transition from spring to summer, which coincided with the upwelling period. A comparison with the 1980's flora revealed that the major changes in the macroalgal assemblage were among species belonging to the same genera, unless new additions were provided. The combination of photoquadrats and minimally destructive sampling allowed a detailed description of the composition and structural characteristics of the intertidal zone, a methodology that should be applied to study protected marine areas.

Highlights

Rocky shores are dynamic coastal environments that are considered to be zones of transition between aquatic and terrestrial ecosystems and are inhabited predominantly by specially adapted marine organisms (Ros et al 1985)
The upper zone of the rocky shore was dominated by invertebrates, which made up more than half of the Community Components (CCs) in all seasons, and the invertebrate cover was higher during winter, summer, and autumn, whereas algae had a higher coverage than invertebrates in the spring (Figure 1)
Community components with less percentage coverages were identified during the year and included taxa such as Tetraclita stalactifera Lamarck 1818 (TET), Amphibalanus amphitrite Darwin 1854 (AMA), Perna perna Linnaeus 1758

Summary

Introduction

Rocky shores are dynamic coastal environments that are considered to be zones of transition between aquatic and terrestrial ecosystems and are inhabited predominantly by specially adapted marine organisms (Ros et al 1985). The diversity and productivity of rocky shores are associated with the presence of marine macroalgae, which are the main primary producers and serve as substrate, shelter, and reproduction sites for many vertebrates and marine invertebrates (Széchy et al 2001, Tano et al 2016). The presence of a variety of organisms there may serve as indicators of environmental conditions (Murray et al 2006, Pinedo et al 2007, Borja et al 2012). Ulvophyceae may present higher coverage or be favored in anthropogenic disturbed sites (Faveri et al 2010, Teichberg et al 2010, Scherner et al 2013), while the coverage of Phaeophyceae is reduced or locally absent under these conditions (Oliveira & Qi 2003, Menconi et al 2012, Széchy et al 2017). Zonation patterns and natural fluctuations are broadly investigated concepts at different rocky shores worldwide (Masi et al 2009, Goméz & Huovinen 2011, Stevčić et al 2017, Vinagre et al 2017, Little et al 2018).

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