Evaluation of the stocks of Hypnea musciformis (rhodophyta: gigartinales) on two beaches in Bahia, Brazil

Abstract

A B S T R A C THypnea musciformis occurs widely in the northeast coast of Brazil, and it is one of the most important natural sources of k-carrageenan, which is used in food and cosmetic industries. Despite its potential for exploitation little is known about its ecology. The aim of this study was to investigate the biology and ecology of H. musciformis in Brazil through analyses of biomass stock and accompanying flora. Two populations of H. musciformis were analyzed: those on the beaches of Stella Maris and Itacimirim (Bahia, Brazil). Eight samplings were conducted between 2007 and 2009 during the dry and rainy seasons. The algae were sampled along transects (20 m) using quadrats (0.04 m²) in three different hydrodynamic regions of the reefs (TP, PRR and FRR). The t-Test, Dunn's Test and parametric and nonparametric ANOVA were used for statistical analyses. 17 host species and 41 associated species were identified. The highest biomass stock was observed during the dry season. On Stella Maris, the region with the highest biomass stock was FRR; on Itacimirim, TP had the highest biomass value. This study permits the assumption that seasonality, microhabitat, hydrodynamic and micro scale factors contribute to variation in biomass stock in H. musciformis populations. R E S U M OHypnea musciformis ocorre amplamente na costa nordeste do Brasil, sendo uma das mais importantes fontes naturais de k-carrageenana que é utilizado nas indústrias alimentícia e cosmética. Apesar do potencial de explotação, pouco se sabe sobre sua ecologia. O objetivo deste estudo foi conhecer a biologia e ecologia de H. musciformis no Brasil através da análise do estoque de biomassa e da flora acompanhante. Duas populações de H. musciformis foram analisadas nas praias de Stella Maris e Itacimirim (Bahia, Brasil). Oito amostragens foram realizadas entre 2007 e 2009, durante as estações seca e chuvosa. As algas foram coletadas ao longo de transectos (20 m) utilizando quadrados (0,04 m²) em três diferentes regiões hidrodinâmicas dos recifes (TP, PRR e FRR). t-Test, Teste de Dunn e ANOVA paramétrica e não-paramétrica foram utilizados para a análise estatística. Foram identificadas 17 espécies hospedeiras e 41 espécies associadas. O maior estoque de biomassa foi observado durante a estação seca. Em Stella Maris, a região com maior estoque de biomassa foi FRR, e em Itacimirim, TP apresentou biomassa maior. Este estudo permite supor que sazonalidade, microhabitats, hidrodinamismo e fatores em microescala contribuem para a variação no estoque de biomassa em populações de H. musciformis.

The Bostrychietum community of pneumatophores in Araçá Bay: an analysis of the diversity of macrofauna

“…Several genera found on pneumatophores in the Bostrychietum, such as Ceramium and Amphiroa, are also common on rocky shores (e.g. The presence of Hypnea only in the winter samples can be explained by the timing of the reproductive cycle of members of this genus, which occurs in the drier seasons (autumn and winter) in south-eastern Brazil (Caires et al, 2013). Overall algal dry weight was higher during summer and lower during winter, probably in response to their reproductive cycles, availability of nutrients, and moisture.…”

Hypnea musciformis: alternative or complement to the production ofKappaphycus alvareziiintroduced in tropical countries?

“…This fact, plus the occurrence of strong wind velocity (more than 6 m s À1 ), may be the limiting factor in growing this native carragenophyte on the southeastern Brazilian coast. The negative effect of strong seawater movement on red algae is known (Kain & Norton 1990), including severe storms that have caused the loss of H. musciformis biomass on natural beds in different regions of the Brazilian coast (Schenkman 1989;Wallner, Lobo, Boccanera & Silva 1992;Berchez, Pereira & Kamiya 1993;Reis & Yoneshigue-Valentin 1998;Caires et al 2013). Berchez et al (1993) and Reis, Barros-Barreto, Caldeira and Miranda (2005) commented that the seawater movement is one of the main factors that negatively affects the growth of this species in southeastern Brazil.…”

“…(Faccini & Berchez ; Reis, Yoneshigue‐Valentin & Santos ; Caires et al . ). The northeastern beds are being depleted by harvesting (Pellizzari & Reis ; Hayashi et al .…”

“…In Brazil, H. musciformis occurs in the protected infralittoral from the northeastern to the southern regions (Creed, Fujii, Barreto et al 2010;Caires, Costa, Jesus, Matos, Pereira-Filho & Nunes 2013), mainly as an epiphyte on Sargassum spp. (Faccini & Berchez 2000;Reis, Yoneshigue-Valentin & Santos 2008;Caires et al 2013). The northeastern beds are being depleted by harvesting (Pellizzari & Reis 2011;Hayashi et al 2013).…”

Definindo espécies e sua distribuiação: um estudo de caso em Hypnea (Gigartinales, Rhodophyta)

“…Studies with Hypnea emphasize that morphological characters undergo variation in relation to the environmental conditions and habitat of the specimen (Yamagishi & Masuda 2000, Lucio 2006, Jesus 2013b. The color of the thallus is highly variable for some species, but has been more homogeneous for others.…”