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Variation in recruitment rates of rocky shore intertidal invertebrates in response to alterations in physical forcings, chlorophyll-a concentration and temperature: the effect of cold fronts

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Author(s):
Ana Carolina de Azevedo Mazzuco
Total Authors: 1
Document type: Doctoral Thesis
Press: São Paulo.
Institution: Universidade de São Paulo (USP). Instituto Oceanográfico (IO/DIDC)
Defense date:
Examining board members:
Áurea Maria Ciotti; Paulo da Cunha Lana
Advisor: Áurea Maria Ciotti
Abstract

Marine communities are affected by oceanographic processes, which influence ecological interactions, such as recruitment rates, that are essential regulators of community dynamics. These relationships are not constant; they change in space and time or among taxa. We defend the thesis that oceanographic processes of climatic origin influencing larval abundance at the study region, regulate and establish the trends in settlement and recruitment of invertebrates (cirripeds and bivalves) at rocky shore intertidal. We first investigated the recruitment at different temporal scales and its relationships with physical forcings, chlorophyll-a concentration and sea surface temperature. Second, we focused on the spatial synchrony and contrasts of recruitment, and interspecific trends. Third, we described and evaluated the co-variation between cold fronts and the larval abundance and settlement. We concluded that there is a high degree of correlation between recruitment/settlement and the variation of the wind field, which set temporal trends. Cold fronts are important regulators of settlement, but higher recruitment was associated to NE-E winds. Barnacle recruitment is more susceptible to the environmental variations compared to bivalves. Regional recruitment is not spatially synchronic with differences in the scale of 100 km. This study highlights the importance of oceanic-climatic phenomena as predictors of spatio-temporal trends of recruitment showing that climatic fluctuations might have contrasting effects on rocky shore communities. (AU)

FAPESP's process: 11/12760-4 - Variation of reproductive output and recruitment of invertebrate groups on rocky shores in function of changes on sea level due storms and wave impact
Grantee:Ana Carolina de Azevedo Mazzuco
Support Opportunities: Scholarships in Brazil - Doctorate