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(Reference retrieved automatically from Web of Science through information on FAPESP grant and its corresponding number as mentioned in the publication by the authors.)

Environmental and grazing influence on spatial variability of intertidal biofilm on subtropical rocky shores

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Christofoletti, Ronaldo A. [1] ; Almeida, Thiago V. V. [2] ; Ciotti, Aurea M. [2]
Total Authors: 3
[1] Univ Sao Paulo, Ctr Biol Marinha CEBIMar USP, BR-11600000 Sao Sebastiao, SP - Brazil
[2] Univ Estadual Paulista, Unidade Sao Vicente, BR-11330900 Sao Vicente, SP - Brazil
Total Affiliations: 2
Document type: Journal article
Source: MARINE ECOLOGY-PROGRESS SERIES; v. 424, p. 15-23, 2011.
Web of Science Citations: 18

Epilithic biofilm on rocky shores is regulated by physico-chemical and biological factors and is important as a source of food for benthic organisms. The influences of environmental and grazing pressure on spatial variability of biomass of biofilm were evaluated on shores on the north coast of Sao Paulo State (SE Brazil). A general trend of greater abundance of microalgae was observed lower on the shore, but neither of the environmental factors evaluated (wave exposure and shore level) showed consistent effects, and differences were found among specific shores or times (September 2007 and March 2008). The abundance of slow-moving grazers (limpets and littorinids) showed a negative correlation with chlorophyll a concentration on shores. However, experimental exclusion of these grazers failed to show consistent results at small spatial scales. Observations of divergent abundances of the isopod Ligia exotica and biomass of biofilm on isolated boulders on shores led to a short exclusion experiment, where the grazing pressure by L. exotica significantly decreased microalgal biomass. The result suggests that grazing activities of this fast-moving consumer probably mask the influence of slow-moving grazers at small spatial scales, while both have an additive effect at larger scales that masks environmental influences. This is the first evaluation of the impact of the fast-moving herbivore L. exotica on microalgal biomass on rocky shores and opens an interesting discussion about the role of these organisms in subtropical coastal environments. (AU)

FAPESP's process: 06/00559-4 - Trophic ecology of the crab Pachygrapsus transversus (Gibbes, 1850) (Brachyura: Grapsidae) and its influence on sessile communities of rocky shores of Ubatuba, SP
Grantee:Ronaldo Adriano Christofoletti
Support Opportunities: Scholarships in Brazil - Post-Doctoral