Biomonitoring in the Boulder River Watershed, Montana, USA: Metal Concentrations in Biofilm and Macroinvertebrates, and Relations with Macroinvertebrate Assemblage

Portions of the Boulder River watershed contain elevated concentrations of arsenic, cadmium, copper, lead, and zinc in water, sediment, and biota. We measured concentrations of As, Cd, Cu, Pb, and Zn in biofilm and macroinvertebrates, and assessed macroinvertebrate assemblage and aquatic habitat with the objective of monitoring planned remediation efforts. Concentrations of metals were generally higher in downstream sites compared with upstream or reference sites, and two sites contained metal concentrations in macroinvertebrates greater than values reported to reduce health and survival of resident trout. Macroinvertebrate assemblage was correlated with metal concentrations in biofilm and macroinvertebrates. However, macroinvertebrate metrics were significantly correlated with a greater number of biofilm metals (8) than metals in invertebrates (4). Lead concentrations in biofilm appeared to have the most significant impact on macroinvertebrate assemblage. Metal concentrations in macroinvertebrates were directly proportional to concentrations in biofilm, indicating biofilm as a potential surrogate for monitoring metal impacts in aquatic systems.     

Effects of elevated atmospheric CO2 and tropospheric O3 on tree branch growth and implications for hydrologic budgeting

The forest hydrologic budget may be impacted by increasing CO₂ and tropospheric O₃. Efficient means to quantify such effects are beneficial. We hypothesized that changes in the balance of canopy interception, stem flow, and through-fall in the presence of elevated CO₂ and O₃ could be discerned using image analysis of leafless branches. We compared annual stem flow to the results of a computerized analysis of all branches from the 2002, 2004, and 2006 annual growth whorls of 97 ten-year-old trees from the Aspen Free-Air CO₂ and O₃ Enrichment (Aspen FACE) experiment in Rhinelander, WI. We found significant effects of elevated CO₂ and O₃ on some branch metrics, and that the branch metrics were useful for predicting stem flow from birch, but not aspen. The results of this study should contribute to development of techniques for efficient characterization of effects on the forest hydrologic budget of increasing CO₂ and tropospheric O₃.     

Accidental release: Fuzzy selection of adequate formal model

Risk assessment of a chemical process plant requires the application of a variety of consequence models in order to estimate the potential physical effects of accidental releases. The types of models required vary depending upon the substance under consideration and the circumstances of a release. The objective of this study was the development and application of a system based upon ‘fuzzy logic’, for the selection of a computer model to be used in consequence analysis in specific situations where only certain types of consequence models can be used. The collection of data for modelling purposes from different kinds of computer model and application of fuzzy methods were also important aims of the study.     

The synaptosomal membrane bound ATPase as a target for the neurotoxic effects of pyrethroids,permethrin and cypermethrin

Pyrethroids are used widely as insecticides both in agriculture and in households. A cellular target of pyrethroids is the sodium channel in the membrane. In the present study, the activity of the membrane bound integral protein ATPase was studied as a biomarker for the membrane effect of the pyrethroids permethrin and cypermethrin. Male Sprague-Dawley rats were used for cerebral synaptosome preparation. The isolation of synaptosomes was performed with the Percoll gradient method. Both total ATPase and Mg(2+) activated ATPase were studied by determining inorganic phosphate liberated from the substrate ATP. One hour exposure to permethrin (Biokill) and cypermethrin (Ripcord) insecticide products affected ATPase activities. The activity of Na(+), K(+) ATPase decreased dose-dependently in 10-50 microM concentrations of permethrin, and Mg(2+) activated ATPase increased over twofold in the same concentrations of the active components. The effect of the cypermethrin compound Ripcord was not clearly dose-dependent. The activity of total ATPase was almost entirely lost in the concentrations of 100 microM of permethrin and cypermethrin. The results support the idea that membrane ATPases are one target of the neurotoxic effect of pyrethroid compounds.     

Environment and development in the Republic of the Marshall Islands: Linking climate change with sustainable fisheries development

The Republic of the Marshall Islands (RMI) is a major custodian of one of the ocean's major natural resources: tuna. The commercial tuna fisheries sector is the most important economic sector in the RMI and is thus a substantial contributor to this tiny island nation's GDP. Tuna catch and its associated revenues has fluctuated in line with climatic events such as the El Niño/La Niña Southern Oscillation (ENSO) and, in the last decade, national fisheries development policies have begun to capitalize on the positive effects that ENSO warm events have had on the tuna populations. However, global warming is expected to have a significant impact on ENSO, and not necessarily in positive ways. This paper will focus on the relationship between environment and economic development in the RMI fisheries sector. In particular, the linkages between global warming and its effects on the tuna fisheries sector must be better understood and uncertainties accounted for so that impacts are appropriately addressed and integrated into sustainable fisheries development policies. Conclusions reached are that new fisheries development strategies that emphasize environmental‐based planning are required. The emerging ecosystem‐based approach to fisheries management is a start, as are the various international initiatives in furthering our understanding of the linkages between climate and ocean systems currently underway.     

Assessment of Residential Rain Barrel Water Quality and Use in Cincinnati,Ohio1

The collection, storage, and reuse of rainwater collected in rain barrels from urban rooftop areas assists municipalities in achieving stormwater management objectives and in some areas also serves as an adjunct resource for domestic water supplies. In this study, rainwater reuse and levels of select microbial indicators were monitored for six residential rain barrels located in the Shepherd Creek watershed of Cincinnati, Ohio. Water from rain barrels typically had poor microbial quality and was used for watering indoor and outdoor plants. Rain barrel water chemistry was slightly acidic, exhibited wide ranges in conductivity, turbidity, and total organic carbon (TOC) concentrations and gave no evidence of the presence of cyanobacterial microcystin toxins. Selected microbial water‐quality indicators indicated that counts of total coliform and enterococci were consistently above U.S. Environmental Protection Agency standards for secondary recreational contact water‐quality standards. Residential rain barrels can provide water appropriate for low‐contact reuses (such as plant watering), although there may be transient periods of high levels of indicator bacteria in the collected water.     

Piperonyl butoxide potentiates the synaptosome ATPase inhibiting effect of pyrethrin

Pyrethrins are widely used insecticides in both agriculture and households. In many commercial formulations piperonyl butoxide (PBO) is used with pyrethrins. PBO is a well-known synergist of pyrethrins, used to intensify their effects. One of the cellular targets of pyrethrins is the sodium channel in the membrane. In the present study, the activity of the membrane-bound integral protein ATPase was studied as a biomarker for the membrane effects of pyrethrin and PBO. Cerebral synaptosomes of rat brain were used in the study. The isolation of synaptosomes was performed with the Percoll gradient method. Both total ATPase and Mg2+ activated ATPase were studied by determining inorganic phosphate. Exposure to 0.1-1000 microM of pyrethrin and to 0.4-4000 microM of PBO decreased ATPase activity dose-dependently. The most efficient mixture was the one consisting of one part of pyrethrin and four parts of PBO. The activity of total ATPase decreased 15% in concentrations of 0.1-10 microM pyrethrin, and a 50% decrease was found at 100 microM pyrethrin. The mixture of pyrethrin and PBO caused a 15-60% decrease in the total ATPase activity at 0.1-10 microM pyrethrin and 0.4-40 microM PBO. A 85% decrease was found after exposure to the mixture of 100 microM pyrethrin and 400 microM PBO. PBO alone had no effect at 0.4-40 microM concentrations, but a marked effect was seen at over 40 microM concentrations. The results indicate that PBO is an effective synergist of pyrethrin and that it is very toxic in high concentrations. The results also confirm that neuronal sodium homeostasis is one target of the neurotoxic effect of pyrethroid compounds.