Abstract
Storms, associated with strong winds and heavy rains, are often the most severe physical disturbances in shallow coastal areas causing instability to sedimentary environments. We hypothesized herein that if storms influence short-term assemblage structure of macrofauna, then assemblages should change after storms, while remaining relatively stable over calm weather conditions. The study was conducted at the subtropical Paranaguá Bay, in southern Brazil. We selected four 700 m² sites, at the estuarine outlet, to monitor changes in number of species, number of individuals and Shannon diversity. Sampling was arranged considering the weather forecast so that both before and after conditions could be recorded. Data of each site was tested separately to access the significance of specific (before/after) comparisons using t tests. There were no clear effects of storms on macrofaunal species richness, abundance and diversity at the four sampled sites. Conversely, we showed that short-term variation in abundances occurred regardless of weather conditions. Increased dispersal may be the most common process associated with storms instead of mortality. Storms that intermittently affect the southern coast of Brazil can be thus seen as minor driving forces of shallow-water estuarine macrofauna. Effects of extreme meteorological events remain to be assessed.
Highlights
Unconsolidated soft sediments, ranging from intertidal shores and estuaries to oceanic abyssal depths, are the most extensive environments on the planet (MURRAY et al 2002)
Shallow coastal areas are a mosaic of benthic patches where sediment properties and faunal components vary considerably (THRUSH 1991, HEWITT et al 2008)
The role played by such storms in structuring benthic associations in the inner platform shelf and other shallow coastal areas remains to be assessed (GALLUCCI & NETTO 2004)
Summary
Unconsolidated soft sediments, ranging from intertidal shores and estuaries to oceanic abyssal depths, are the most extensive environments on the planet (MURRAY et al 2002). Despite their apparent homogeneity, shallow coastal areas are a mosaic of benthic patches where sediment properties and faunal components vary considerably (THRUSH 1991, HEWITT et al 2008). Shallow-water benthic species may be, to a degree, adapted to erosion or deposition (BOCK & MILLER 1995), but tolerance to disturbance varies considerably among taxa and recovery to predisturbance conditions may not occur, especially after large scale physical disturbances (UNDERWOOD 1999).
Sign-in/Register to view highlights & summary Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
