Temporal dynamics of deep infralittoral macrobenthic fauna in a subtropical estuarine environment

Abstract

). In order to keep the Patos Lagoon main access channel at constant navigable depths, the Rio Grande Harbour Superintendence periodically executes maintenance dredging operations on this infralittoral area, but our multivariate analyses evidenced no significant difference between dredged and non-dredged sites regardless the year. Among the abiotic parameters analyzed here (temperature, percentage of fine sediments and salinity), the later was evidenced to be highly correlated to the biological data. Reductions in density and/or changes in the species composition could both be attributed to a natural macrobenthic response related to environmental variations. Along the year 2000 high salinity values decreased constantly through seasons to almost limnetic condition in spring, reducing diversity and abundance of marine species and densities of the dominant gastropod species Heleobia australis. On the other hand, salinity values along the year 2006 revealed the maintenance of brackish waters throughout seasons, favoring the input and survival of marine species from coastal adjacent areas inside the estuary, raising its macrobenthic diversity mainly by mollusks and polychaete worms.

Epidemiology of lobomycosis-like disease in bottlenose dolphins Tursiops spp. from South America and southern Africa

“…It receives freshwaters from the Keurbooms and Piesangs Rivers, considered of good quality with only some human-related disturbance (Department of Water Affairs, South Africa: www.dwa.gov.za/iwqs/ rhp/state_ of_ rivers .html). The T. aduncus sub-population inhabiting Plettenberg Bay was estimated to number be tween 1099 and 9492 individuals (95% CI, Phillips 2006). It is part of a larger population of over 16 000 individuals that ranges along the South African coastline (Reisinger & Karczmarski 2010).…”