Tito Almeida has completed his PhD at the age of 37 years from Federal University of Sao Carlos – Sao Paulo/ BRAZIL and postdoctoral studies from UNIVALI. He is Associated Professor of UNIVALI since 2001 and responsible for the Community Ecology Laboratory. He has published more than 26 papers in reputed journals and has been serving as an editorial board member Brazilian Journal of Environmental Technology.
Little is known about the effects of dredging activities upon indirectly affected areas like river margins. On an urbanized subtropical estuary in southern Brazil, benthic macrofauna was sampled throughout two dredging events on control and impacted areas. Granulometry and river discharge were also accessed. Univariate PERMANOVAs with five factors (Time, Area, Event, Station, Sector) were applied on Euclidean distance matrices of abundances for the most representative taxa (H. similis, H. australis, K. schubartii, N. fluviatilis, Polydora sp. = 91% total abundance) to test the null hypothesis of no differences in population densities upon dredging. Results evidenced small scale disturbances, indicating that dredging along with environmental variations affects studied populations; effects differ between the two margins and the resilience times range from 3 to 9 months. Greatest overall abundance was recorded during dredging operations, when river discharge readings showed the lowest values, indicating that dredging should be performed during periods of low river discharge.
Ilana Rosental Zalmon has completed his PhD in 1995 from University of Sao Paulo, Brazil and postdoctoral studies from University of California at Santa Barbara. She is a Professor and marine researcher on community ecology at the Centre of Bioscience and Biotechnology from the University of North Rio de Janeiro. She has published more than 45 papers in reputed journals and has been serving as a referee member of repute.
Artificial reefs were deployed on a flat bottom, 9 m deep and 5 km area offshore Southeast Brazil, and changes on composition and structure of the associated fish assemblages were assessed over a period of 15 years. Fishes were collected through bottom gillnets at 1 month, 6 months, 1 year, 6 years, 7 years, 10 years, 13 years, 14 years and 15 years after artificial reef settlement. A total of 552 fishes, 45 species and 19 families were caught, with C. chrysurus (Carangidae) and C. nobilis (Haemulidae) as the prevalent species and Sciaenidae as the richest family (11 species). Fish abundance, richness and biomass varied significantly with time, increasing gradually until the sixth-seventh years and lowered subsequently. The same unimodal response was recorded for the abundance and biomass of planktivorous and invertivorous fishes and for Haemulidae, suggesting that this family accounted for most of the temporal variation recorded for the whole-fish assemblage descriptors. The abundance and biomass of sharks decreased gradually after the first year but apparently recovered up to the fifteenth year. Fish usage of artificial reefs seems to be modulated by a continuous species turnover with time, since no single species occurred throughout the surveys and an arch effect was observed from the detrended correspondence analysis performed on the species abundance matrix. This study stresses the importance of long-term assessments on marine artificial reefs in order to incorporate the successional patterns of fish colonization into management actions and thus to optimize the effects of large-scale habitat manipulation programs.