Toxic effects of copper on larval development of the barnacle Balanus amphitrite

Experiments were conducted to assess the effects of copper on larval development in the barnacle Balanus amphitrite. In the first experiment, we compared the sensitivity of three naupliar stages to copper stress. Molting inhibition occurred at copper concentrations ranging from 32 μg l⁻¹ in nauplius II to 128 g l⁻¹ in nauplius VI. EC₅₀ for molting ranged from 97 μg l⁻¹ in nauplius II to 129 g l⁻¹ in nauplius VI. Decreased survival occurred at 128 μg Cu l⁻¹ in all of the naupliar stages tested, with LC₅₀ ranging from 145 in nauplius II to 213 μg l⁻¹ in nauplius VI. In the second experiment, we examined effects of copper on the development from nauplius II to cyprid. The larvae reached cypris stage only in treatments of 16 μg Cu l⁻¹. Our study therefore showed that molting was a more sensitive endpoint than survival, nauplius II was the most sensitive naupliar stage, and that whole larval development assay was more sensitive than assays using a particular larval stage. The results were discussed with respect to the use of this species in toxicity tests.     

Rise of Buoyant Emissions from Low-Level Sources in the Presence of Upstream and Downstream Obstacles

Field and laboratory studies have been conducted to investigate the effect of surrounding buildings on the plume rise from low-level buoyant sources, such as distributed power generators. The field experiments were conducted in Palm Springs, California, USA in November 2010 and plume rise from a 9.3 m stack was measured. In addition to the field study, a laboratory study was conducted in a water channel to investigate the effects of surrounding buildings on plume rise under relatively high wind-speed conditions. Different building geometries and source conditions were tested. The experiments revealed that plume rise from low-level buoyant sources is highly affected by the complex flows induced by buildings stationed upstream and downstream of the source. The laboratory results were compared with predictions from a newly developed numerical plume-rise model. Using the flow measurements associated with each building configuration, the numerical model accurately predicted plume rise from low-level buoyant sources that are influenced by buildings. This numerical plume rise model can be used as a part of a computational fluid dynamics model.