Environmental impact assessment of salmonid feeds using Life Cycle Assessment (LCA)

Understanding the environmental burdens associated with aquafeeds is a critical component for assessing and improving the environmental performance of aquaculture. The aim of the study was to assess the environmental impacts associated with feeds for rainbow trout production in France, using Life Cycle Assessment (LCA). The stages assessed are: the extraction of the raw materials, the production and transformation of the primary ingredients used, the manufacturing of the feeds, the use of the feeds at the farm, transport at all stages, and the production and use of energy resources. The assessment revealed that the use of fishery resources (such as biotic resource use) and nutrient emissions at the farm (such as eutrophication potential) contribute most to the potential environmental impacts of salmonid aquafeeds. Improvements in feed composition and management practices seem to be the best ways for improving the environmental profile of aquafeeds.     

Characterization of biological responses under different environmental conditions: A hierarchical modeling approach

A natural river system is organized as a nested hierarchy of interconnected habitats with specific environmental conditions to which the biological community has adapted. Due to this hierarchical structure, identifying the role of different stressors on the biological community is a formidable task. Efforts trying to link stressors to biological integrity have always been bound to the geographic scale of the selected study area, leading to scale-specific results. In this research, an attempt is made to lift this limitation and develop a hierarchical, scale-sensitive methodology that can identify the significant environmental stressors to the biological community at different scales. Sites with similar background environmental conditions are clustered using self-organizing maps (SOM). This is used to identify stressors which affect the biological community throughout the area of study - called environmental gradients or large-scale stressors. Subsequently, these clusters of similar observations (sampling sites) are progressively sub-divided using environmental variables with a significant but localized effect on the biological community - called small-scale stressors. A parent group of sites is split only when the resulting sub-groups have significantly different biological responses. At the end of this recursive sites decomposition procedure, the original set of observations is organized as a tree of environmentally homogeneous groups of observations characterized by unique biological responses to multiple stressors with different geographic extents. The developed hierarchical analysis methodology has been validated using a large-size dataset of environmental observations from the State of Ohio. Our results show that habitat degradation and increased nutrient loading are the large-scale stressors with a widespread impact in Ohio. Other stressors, such as heavy metals, pH or nitrate concentrations have significant albeit localized effects on biological integrity.     

Assessing the Effectiveness of Winter Cover Crops for Controlling Agricultural Nutrient Losses

A nutrient loss reduction strategy is necessary to guide the efforts of improving water quality downstream of an agricultural watershed. In this study, the effectiveness of two winter cover crops, namely cereal rye and annual ryegrass, is explored as a loss reduction strategy in a watershed that ultimately drains into a water supply reservoir. Using a coupled optimization-watershed model, optimal placements of the cover crops were identified that would result in the tradeoffs between nitrate-N losses reduction and adoption levels. Analysis of the 10%, 25%, 50%, and 75% adoption levels extracted from the optimal tradeoffs showed that the cover crop placements would provide annual nitrate-N loss reductions of 3.0%–3.7%, 7.8%–8.8%, 15%–17.5%, and 20.9%–24.3%, respectively. In addition, for the same adoption levels (i.e., 10%–75%), sediment (1.8%–17.7%), and total phosphorus losses (0.8%–8.6%) could be achieved. Results also indicate that implementing each cover crop on all croplands of the watershed could cause annual water yield reduction of at least 4.8%, with greater than 28% in the months of October and November. This could potentially be detrimental to the storage volume of the downstream reservoir, especially in drought years, if cover crops are adopted in most of the reservoir's drainage area. Evaluating water yield impacts, particularly in periods of low flows, is thus critical if cover crops are to be considered as best management practices in water supply watersheds.     

The effects of field-realistic doses of imidacloprid on Melipona quadrifasciata (Apidae: Meliponini) workers

Environmental Science and Pollution Research - The presence of Brazilian native bees can improve tomato production by increasing pollination effectiveness. However, the extensive use of pesticides...     

Short communications normal fetal growth despite persistent amniotic fluid leakage after genetic amniocentesis

Two women not only lost relatively large amounts of amniotic fluid immediately following genetic amniocentesis, but continued to lose fluid for the remainder of their pregnancies. Periodic ultrasonographic assessment confirmed normal fetal growth and presence of some amniotic fluid. Both women were delivered at term of normal offspring who showed no evidence of fetal deformations. Although amnionitis is a risk, cautious surveillance may permit continuation of pregnancies complicated by copious or persistent amniotic fluid leakage following genetic amniocentesis.     

A new apparatus for force measurement in marine bioadhesion

In an experimental study on the effect of parrotfish (probably Scarus taeniurus) grazing on the structure of benthic reef communities, fishes in densities of 0.6 to 1.5 parrotfish per m² or 9 to 17 g wet weight of fish per m² of feeding surface were found to have an optimum effect, resulting in the greatest benthic species richness and biomass on 2-dimensional surfaces. The presence of refuges (3-dimensional habitats), however, has a greater impact on bemthic community structure (number of species and biomass) than does just the density of parrotfish in such an experimental system. Coral recruitment is enhanced by the presence of refuges and, like coralline algae, is more successful under increased grazing pressure. These optimum densities of parrotfishes relate well to observed field densities where, in a collection from a Hawaiian patch reef, there were 1.1 fish or 10.8 g wet weight of parrotfish per square meter of collection area. The success of coralline algae and corals under high grazing pressure may have important consequences for the stability and structure of modern coral reefs.