ALBERT

Description: Coral-associated bacteria play an increasingly recognized part in coral health. We investigated the effect of local anthropogenic impacts on coral microbial communities on reefs near Jeddah, the largest city on the Saudi Arabian coast of the central Red Sea. We analyzed the bacterial community structure of water and corals (Pocillopora verrucosa and Acropora hemprichii) at sites that were relatively unimpacted, exposed to sedimentation & local sewage, or in the discharge area of municipal wastewaters. Coral microbial communities were significantly different at impacted sites: in both corals the main symbiotic taxon decreased in abundance. In contrast, opportunistic bacterial families, such as e.g. Vibrionaceae and Rhodobacteraceae, were more abundant in corals at impacted sites. In conclusion, microbial community response revealed a measurable footprint of anthropogenic impacts to coral ecosystems close to Jeddah, even though the corals appeared visually healthy.

Description: Altimetric data from Geosat and some critical hydrographic measurements were used to estimate in real time the mesoscale physical oceanographic environment surrounding the Joint Global Ocean Flux Study (JGOFS) 1989 North Atlantic Bloom Experiment. Three cyclonic eddies, including an exceptionally large one, evolved and interacted over the 10 weeks of observations. Subsequent analysis of all available hydrographic data confirmed the real time estimates and provided further quantitative information concerning the mesoscale and submesoscale structure of the upper ocean. Remotely sensed indicators of near-surface chlorophyll content reveal significant biological variability on these wavelengths. The altimetric and hydrographic data have been assimilated into a dynamical model to produce optimal estimates of physical fields of interest as they evolve in time for use in physical and biological process studies

Description: Estimates of significant wave height and period, together with tidal current speed over a semi-lunar cycle, were used to predict the area on the Australian continental shelf over which unconsolidated sediment was mobilised (threshold exceedance). These sediment-entraining processes were examined independently to quantify their relative importance on the continental shelf. Using observed grain size data, mobilisation from swell waves occurred on ∼31% and tidal currents on ∼41% of the continental shelf. Swell wave energy is sufficient to mobilise fine sand (0.1 mm diameter) to a water depth of 142 m on the Otway Shelf near the western entrance to Bass Strait. Tidal currents in King Sound (northwest shelf) are capable of mobilising large areas of medium sand (0.35 mm diameter) 100% of the time. Superimposing the distribution of threshold exceedance by wave and tidal currents indicates that there are areas on the shelf where either wave-induced or tidal currents dominate, some areas where waves and tides are of relatively equal importance and still other areas where neither is significant. We define six shelf regions of relative wave and tidal energy: zero (no-mobility); waves-only, wave-dominated, mixed, tide-dominated and tides-only. Our results provide a predictive, process-based understanding of the shelf sedimentary system that has applications to marine engineering projects and to regional studies of pollution dispersal and accumulation where significant shelf sediment mobilisation is a factor.

Description: Recently, researchers have begun to identify the prevalence of trait simplification, loss and reversal across all levels of biological organization. These studies have taken increasingly integrated approaches, incorporating phylogenetic, developmental and molecular methods, in the quest towards understanding the patterns and processes behind evolution in reverse. Here, we highlight the emerging interest in the reversibility of evolution by discussing a spectrum of studies examining both the genotypes and phenotypes of evolution in reverse. These integrative approaches have greatly increased our knowledge of the biological interactions that produce patterns of evolution in reverse and have led to promising new areas of research.