Aquaculture practices and potential human health risks: current knowledge and future priorities

Annual global aquaculture production has more than tripled within the past 15 years, and by 2015, aquaculture is predicted to account for 39% of total global seafood production by weight. Given that lack of adequate nutrition is a leading contributor to the global burden of disease, increased food production through aquaculture is a seemingly welcome sign. However, as production surges, aquaculture facilities increasingly rely on the heavy input of formulated feeds, antibiotics, antifungals, and agrochemicals. This review summarizes our current knowledge concerning major chemical, biological and emerging agents that are employed in modern aquaculture facilities and their potential impacts on public health. Findings from this review indicate that current aquaculture practices can lead to elevated levels of antibiotic residues, antibiotic-resistant bacteria, persistent organic pollutants, metals, parasites, and viruses in aquacultured finfish and shellfish. Specific populations at risk of exposure to these contaminants include individuals working in aquaculture facilities, populations living around these facilities, and consumers of aquacultured food products. Additional research is necessary not only to fully understand the human health risks associated with aquacultured fish versus wild-caught fish but also to develop appropriate interventions that could reduce or prevent these risks. In order to adequately understand, address and prevent these impacts at local, national and global scales, researchers, policy makers, governments, and aquaculture industries must collaborate and cooperate in exchanging critical information and developing targeted policies that are practical, effective and enforceable.     

Distributions of heavy metals in the surface sediments of the Gulf of Saros, NE Aegean Sea

The Gulf of Saros in the northeastern Aegean Sea (Turkey) is a relatively unpolluted marine environment. There is almost no industry and only small settlements in the surrounding region. The main sources of fresh water and sediment to the Gulf are the Meric River in the northwest and the Kavak Creek in the east. It has an asymmetric bathymetry with a 10-km-wide shelf to the north and up to 15-km-wide, 700-m-deep trough in the south. Water circulation in the Gulf is characterized by longshore currents and anticyclonic eddies. The Black Sea waters, leaving the Sea of Marmara through the Canakkale Strait, are known to enter the southern Gulf during the summer. The surface sediments on the northern shelf consist mainly of sand, whereas those on the slope and the deep trough are mainly silt and clay. The ranges of Fe, Mn, Cu, Zn, Pb, Ni, and Hg contents of the surface sediments from the Gulf of Saros are 0.25 4.60%, 114 1740 ppm, 6-44 ppm, 23-154 ppm, 2-80 ppm, 14-145 ppm, and 10-130 ppb, respectively. These values are low compared to those from the other neighboring marine environments, indicating the pristine nature of the Gulf in terms of metal pollution. However, most metal and organic carbon (Corg) distributions in the Gulf sediments show the effect of anthropogenic and natural inputs to the northwestern and eastern shelf areas from the Meric River and the Kavak Creek and to the deep trough from the Black Sea waters.     

The Use of Natural Taraxacum officinale Wigg. Populations for Assessing the State of Technogenically Disturbed Areas

Russian Journal of Ecology -     

Heat wave vulnerability and exposure mapping for Osaka City,Japan

Heat waves and heat-related stresses are increasing environmental concerns in urban areas. The impact of heat waves is dependent on the intensity and duration of each event and on underlying environmental and socio-demographic factors which influence population vulnerability. In order to develop effective adaptation strategies, it is important to develop a method to clearly identify the most vulnerable areas based on these factors. The purpose of this study is to develop and map a heat wave vulnerability index combined with heat exposure analysis to identify areas where interventions can be targeted. The vulnerability index was derived from a principle component analysis of eight key variables that influence heat wave vulnerability. Eight proxy measures of vulnerability were obtained from 2010 census and land-use data for the 1904 census districts of Osaka City. Three principle components explained >77 % of the variance (age, employment and education; social isolation; density and lack of green space). The components were combined and weighted to produce a vulnerability score for each census district. The vulnerability scores ranged from 0 to 106, were categorised into eight vulnerability levels and were overlaid with fine-scale air temperature observations. The resulting output identified the distribution of population vulnerability and exposure. This assessment of vulnerability, combining exposure and sensitivity components, can provide precedent for efficient, targeted action to be taken to reduce the impact of heat waves at present and under climate change.     

Production of soybean ethanol-based biodiesel using CaO heterogeneous catalysts promoted by Zn,K and Mg

This article focuses on the optimization of the production of fatty acid ethyl esters from soybean oil using CaO-based heterogeneous catalysts. Three different catalytic promoters were evaluated: Magnesium, zinc, and potassium. The reaction has evaluated the promoter content (promoter to calcium molar ratio), catalyst load, alcohol to oil molar ratio, and temperature. Response surface methodology (RSM) was used to evaluate the influence of each variable on the yield of biodiesel. The addition of K₂O or MgO in the catalyst has enhanced the yield in fatty acid ethyl esters, while the use of ZnO as a promoter was not successful.     

Clam shell catalyst for continuous production of biodiesel

Continuous flow transesterification of waste frying oil (WFO) with methanol for the biodiesel production was tested in a laboratory scale jacketed reactive distillation (RD) unit packed with clam shell based CaO as solid catalyst. The physiochemical properties of the clam shell catalysts were characterized by X-ray Diffraction (XRD), Brunauer–Emmett–Teller (BET), Scanning Electron Microscopy (SEM), and Energy Dispersive Atomic X-ray Spectrometry (EDAX). The effects of the reactant flow rate, methanol-to-oil ratio, and catalyst bed height were studied to obtain the maximum methyl ester conversion. Reboiler temperature of 65°C was maintained throughout the process for product purification and the system reached the steady state at 7 hr. The experimental results revealed that the jacketed RD system packed with clam shell based CaO showed high catalytic activity for continuous production of biodiesel and a maximum methyl ester conversion of 94.41% was obtained at a reactant flow rate of 0.2 mL/min, methanol/oil ratio of 6:1, and catalyst bed height of 180 mm.     

Biogas production from pistachio (Pistaciavera L.) de-hulling waste

Pistachio processing wastes create significant waste management problems unless properly managed. However, there are not well-established methods to manage the waste generated during the processing of pistachios. Anaerobic digestion can be an attractive option not only for the management of pistachio processing wastes but also producing renewable energy in the form of biogas. This study investigated anaerobic digestibility and biogas production potential of pistachio de-hulling waste from wet de-hulling process. Best to our knowledge, this is the first report on biogas production from pistachio de-hulling waste. The results indicated that (1) anaerobic digestion of pistachio de-hulling wastewater, solid waste, and their mixtures in different ratios is possible with varying levels of performance; (2) 1 L of de-hulling wastewater (chemical oxygen demand concentration of 30 g/L) produced 0.7 L of methane; (3) 1 L of de-hulling wastewater and 20 g of pistachio de-hulling solid waste produced 1.25 L of methane; and (4) 1 g of de-hulling solid waste produced 62.6 mL of methane (or 134 mL of biogas).     

Improving invasive species management by integrating priorities and contributions of scientists and decision makers

Managing invasive species is a major challenge for society. In the case of newly established invaders, rapid action is key for a successful management. Here, we develop, describe and recommend a three-step transdisciplinary process (the “butterfly model”) to rapidly initiate action for invasion management. In the framing of a case study, we present results from the first of these steps: assessing priorities and contributions of both scientists and decision makers. Both scientists and decision makers prioritise research on prevention. The available scientific knowledge contributions, however, are publications on impacts rather than prevention of the invasive species. The contribution of scientific knowledge does thus not reflect scientists’ perception of what is essentially needed. We argue that a more objective assessment and transparent communication of not only decision makers’ but also scientists’ priorities is an essential basis for a successful cooperation. Our three-step model can help achieve objectivity via transdisciplinary communication.     

Conceptualizing and communicating management effects on forest water quality

We present a framework for evaluating and communicating effects of human activity on water quality in managed forests. The framework is based on the following processes: atmospheric deposition, weathering, accumulation, recirculation and flux. Impairments to water quality are characterized in terms of their extent, longevity and frequency. Impacts are communicated using a “traffic lights” metaphor for characterizing severity of water quality impairments arising from forestry and other anthropogenic pressures. The most serious impairments to water quality in managed boreal forests include (i) forestry activities causing excessive sediment mobilization and extirpation of aquatic species and (ii) other anthropogenic pressures caused by long-range transport of mercury and acidifying pollutants. The framework and tool presented here can help evaluate, summarize and communicate the most important issues in circumstances where land management and other anthropogenic pressures combine to impair water quality and may also assist in implementing the “polluter pays” principle.