Temporal and spatial variability in coral recruitment on two Indonesian coral reefs: consistently lower recruitment to a degraded reef

Corals are the primary reef-building organisms, therefore it is key to understand their recruitment patterns for effective reef management. Coral recruitment rates and juvenile coral abundance were recorded in the Wakatobi National Marine Park, Indonesia, on two reefs (Sampela and Hoga) with different levels of environmental degradation (12.5 vs. 44 % coral cover with high and low sedimentation rates, respectively) to examine consistencies in recruitment patterns between years and seasons. Recruitment was measured on multiple panels at two sites on each reef (6–7 m depth) and cleared areas of natural reef. Although coral recruitment was twofold higher in 2008–2009 than in 2007–2008, and seasonal differences were identified, consistent significant differences in recruitment rates were found between the two reefs even though they are separated by only ~1.5 km. Recruitment rates and juvenile abundance were lower on the more degraded reef. These patterns are likely a consequence of differential pre- and post-settlement mortality as a result of the high sedimentation rates and degraded conditions and possibly reduced larval supply.     

Isoproturon degradation as affected by the growth of two algal species at different concentrations and pH values.

Metabolism of [14C-u-phenyl]isoproturon [3-(4-isopropylphenyl)-1,1-dimethylurea] by two soil and freshwater microorganisms, green alga Chlorella kesslerei and cyanobacterium Anabaena inaequalis, was studied as a function of pH, pesticide concentration, and incubation time. Metabolized isoproturon, in the media, ranged from 0% (Chlorella at pH 5.5 after 1 d) to 22% (Anabaena at pH 5.5 after 10 d). Twenty-five percent faster degradation of isoproturon by Anabaena occurred at pH 5.5 versus pH 7.5, when measured over 10 d. Increased 14C incorporation into tissue, with time and at lower pH, was due mainly to bioaccumulation of [14C]isoproturon and/or its metabolites in the cells. Metabolic degradation resulted in four identifiable (by TLC) metabolites. Based on this, a degradation pathway is proposed, involving mono- and di-N-demethylation, hydroxylation of the isopropyl moiety, and hydrolysis to 4-isopropylaniline. Similarity in the metabolites produced suggests that the enzyme systems responsible for metabolizing isoproturon are almost identical in both photosynthetic micro-algae.     

Modelling local and synoptic scale influences on ozone concentrations in a topographically complex region of Southern Italy

A modelling study with the on-line coupled Eulerian chemical-weather model WRF/Chem for the Southern Italian region around Cosenza (Calabria) was conducted to identify the influences of synoptic scale meteorology, local scale wind systems and local emissions on ozone concentrations in this orographically complex region. Four periods of 5–7 days were chosen, one from each season, which had wind pattern characteristics representative of typical local climatological conditions, in order to study the local versus non-local impacts on ozone transport and formation. To account for the complex terrain, the horizontal resolution of the smallest modelling domain was 3 km. Model results were compared with measurements to demonstrate the capability of the model to reproduce ozone concentrations in the region. The comparison was favourable with a mean bias of ?1.1 ppb. The importance of local emissions on ozone formation and destruction was identified with the use of three different emission scenarios. Generally the influence of regional emissions on the average ozone concentration was small. However during periods when mountain-sea wind systems were well developed and synoptic scale winds were weak, the influence of local emissions from the urban area was at its greatest. The maximum influence of local emissions on ozone concentrations was 18 ppb.