Discard mitigation - what we can learn from waste minimization practices in other natural resources?

Solutions to the problem of discarding in fisheries have been debated for decades. Despite this attention, measures to ameliorate discarding have had limited success. Regulators, researchers, and industry continue to struggle with fisheries management and foregone yield in the face of the continued wastage of valuable resources due to discarding.Waste minimization and by-product utilization are powerful imperatives in other sectors that are also reliant on the harvest of natural resources. This paper considers the performance of these sectors in waste minimization and by-product utilization, with the aim of identifying practices and processes that may be applied to ameliorate discarding in fisheries.This paper describes the handling, utilization, and mitigation of discards and waste in the livestock farming, agriculture, mining, and waste management industries, and in particular, in forestry. In terms of biological impact, economic objectives, and management approaches the harvesting of trees has substantial similarities to industrialized fishing. However, the forestry sector has found ways to utilize almost 100% of the natural product harvest by establishing markets and new products. Analogous developments within the fishing industry could substantially improve sustainability through reduced levels of discarding and wastage. Based on the experiences of these sectors it is suggested that evaluations of potential Management Strategies are developed to specifically examine discard mitigation approaches on a broader scale than previously conducted.     

A preliminary investigation into the use of ochre as a remedial amendment in arsenic-contaminated soils

Ochre is an unwanted waste product that accumulates in wetlands and streams draining abandoned coal and metal mines. A potential commercial use for ochre is to remediate As contaminated soil. Arsenic contaminated soil (605 mg kg⁻¹) was mixed with different ochres (A, B and C) in a mass ratio of 1:1 and shaken in 20 mL of deionised water. After 72 h As concentration in solution was ca. 500 μg kg⁻¹ in the control and 1–2.5 μg kg⁻¹ in the ochre treated experiments. In a second experiment soil:ochre mixtures of 0.05–1:1 were shaken in 20 mL of deionised water for 24 h. For Ochres A and C, as solution concentration was reduced to ca. 1 μg kg⁻¹ by 0.2–1:1 ochre:soil mixtures. For Ochre B, as concentration only reached ca. 1 μg kg⁻¹ in the 1:1 ochre:soil mix. Sorption of As was best modelled by a Freundlich isotherm using As sorption per mass of goethite in the ochre (log K = 1.64, n = 0.79, R² = 0.76, p 0.001). Efficiency of ochre in removing As from solution increased with increasing total Fe, goethite, citrate dithionite extractable Fe and surface area.     

Using impacts of deep-level mining to research karst hydrology—a Darcy-based approach to predict the future of dried-up dolomitic springs in the Far West Rand goldfield (South Africa). Part 2: predicting inter-compartmental flow and final groundwater tables

Some of the world’s deepest goldmines operate below dolomitic karst aquifers in the Far West Rand (FWR) goldfield, South Africa. Associated impacts include the continuous dewatering of karst aquifers for over six decades and irreversible changes of the hydrogeological setting. Affecting an area of approximately 400 km² by drawing down the water table up to 700 m, these impacts, and the large amounts of data generated in the process, are used as unique research opportunities to better understand the complex karst hydrology. The focus of this study is on predicting final water table elevations in rewatered aquifers after mining ceases taking the fact that mines hydraulically linked previously disconnected aquifers into account. While part 1 of this series develops the conceptual model, this second part utilises large sets of pertinent data to calculate actual flow rates for predicting the fate of dried up springs after mine closure. Following a Darcy-based approach first applied by Swart et al. (Environ Geol 44:751–770, 2003a) it is not only predicted that the springs will flow again but also shown that linear relationships exist between flow rates through a combined system of karst-fractured aquifers overlying the mine void and the associated hydraulic head driving them. This suggests that—at this scale—porous media-based equations can be meaningfully used to predict flow in non-porous media.     

Ionospheric Scintillation and Dynamics of Fresnel-Scale Irregularities in the Inner Region of the Equatorial Ionization Anomaly

This paper reports differences in the occurrence statistics of global positioning system (GPS) L-band scintillations at observational sites located in the inner regions of the northern and southern crests of the equatorial ionization anomaly. Ground-based GPS data acquired at the closed magnetically aligned stations of Manaus (3.1°S; 59.9°W; dip lat. 6.2°N) and Cuiabá (15.5°S; 56.1°W; dip. lat. 6.2°S), Brazil, from December 2001 to February 2007 are used in the analysis. The drift dynamics of Fresnel-scale ionospheric irregularities at the southern station of Cuiabá are also investigated. Only geomagnetically quiet days with the sum of daily Kp < 24 were used in the analysis statistics and in the irregularity drift studies. The results reveal a clear dependence of the scintillation occurrence with the solar activity, but there exists an asymmetry in the percentage of scintillation occurrence between the two stations throughout the period analyzed. The nocturnal occurrence of the scintillations over Cuiabá is predominantly larger than over Manaus, but this scenario seems to change with the decline in the solar activity (mainly during local post-midnight hours). A broad minimum and maximum in the scintillation occurrence appears to occur over both the stations, respectively, during the June solstice (winter) and December solstice (summer) months. The dynamics of the Fresnel-scale irregularities, as investigated from the estimations of the mean zonal drift velocities, reveals that the amplitude of the eastward drifts tends to reduce with the decline in the solar activity. The magnitude of the zonal drift velocities during the December solstice months is larger than during the equinoxes, with the differences being more pronounced at solar maximum years. Other relevant aspects of the observations, with complementary data from a low-latitude ionospheric model, are highlighted and discussed.     

Age and source material of the Kingash ultramafic-mafic massif,East Sayan

The REE distribution patterns and Nd whole-rock and mineral isotope ratios of the Kingash ultramafic-mafic massif enabled us to propose a multistage history for its evolution at 1410 and 875 Ma. These stages reflect the magmatic evolution of the Siberian paleocontinent margin during the Late Precambrian. The age of metamorphism of the massif during collision and accretion in the Early Paleozoic (∼500 Ma) was obtained based on a Sm-Nd mineral isochron from rheomorphic veined albitite. The Nd and Sr isotopic compositions of rocks from the Kingash massif suggest mantle sources for picritic and basic magmas, which are thought to have originated by mixing of different proportions of depleted (PREMA or DM) and enriched (EM) melts. The initial isotope ratios of the parental melts transformed during interaction with Sr-rich material from the host metasedimentary complexes.     

Estimating water balance components of tropical wetland lakes in the Pantanal dry season,Brazil

Abstract

Water balance studies with stable water isotopes have rarely been conducted in remote and tropical wetland areas. As such, little is known regarding the water balance and groundwater–surface water interaction in the Pantanal, one of the largest and most pristine wetlands in the world. We applied MINA TrêS, a water balance model utilizing stable water isotopes (δ¹⁸O, δ²H) and chloride (Cl^-) to assess the dry-season hydrological processes controlling groundwater–surface water interactions and the water balance of six floodplain lakes in the northern Pantanal, Brazil. Qualitatively, all lakes exhibited similarity in hydrological controls. Quantitatively, they differed significantly due to morphological differences in controlling groundwater inflow and lake volume. Our approach is readily transferable to other remote and tropical wetland systems with minimal data input requirements, which is useful in regions with sparse hydrometric monitoring.

Editor Z.W. Kundzewicz     

Uranium and lead gain of detrital zircon studied by isotopic analyses and fission-track mapping

Besides Pb and U loss and mixing of crystals of different age, U gain is considered a possible cause of discordant U-Pb ages of zircons. However, whether U gain without new zircon growth occurs in nature had not been proven, so far. In order to test this possibility, two detrital zircon populations were studied for which the absence of later zircon overgrowth after deposition could be demonstrated. The samples were separated from a metaquartzite near a large pegmatite body and from metaquartzite inclusions found in the pegmatite (Martell Valley, Italian Alps). The distribution of neutron-induced fission tracks reveals distinct accumulation of U in the rims of more than 90% of the zircon grains of the inclusions (total U in the crystals: 540–850 ppm), whereas in the country rock only some of the grains show similar but weaker patterns (total U: 155–320 ppm). From the isotopic data and from additional U-Pb and Rb-Sr analyses of minerals and whole-rock samples of the pegmatite, the marginal accumulation and the higher concentration of U in the zircon grains of the inclusions are interpreted as the result of episodic U gain during the intrusion of the pegmatite and/or during a later metamorphism. From the concentration levels of common Pb, an addition of Pb - and possibly other elements - to the zircon grains is inferred.     

Studies of temperature effects of dust storms

We studied the temperature variations of the lower air layer caused by dust content using a dust storm in Dushanbe in November 2007 as an example. Quantitative estimates of air cooling and a decrease in the diurnal temperature difference due to a diminishing horizontal visibility range are given. Observations of air temperature variations due to the dust content of the atmosphere in an arid zone are presented. The critical value of aerosol concentration for toggling between the greenhouse and antigreenhouse effects is determined. The long-term effect of dust aerosol on climate is analyzed.     

Longshore variations in nearshore wave processes at magilligan point,northern ireland

Magilligan Point is a recurved cuspate foreland at the mouth of Lough Foyle. Two wave regimes intersect in the estuary mouth and the manner of their interplay controls shoreline changes. Ocean swell waves from the N and NE are refracted around the recurve, losing both height and energy longshore. Width of the surf zone decreases and waves tend to steepen, although both these changes and wave refraction owe something to nearshore geometry. Angle of wave approach becomes more acute and a westerly flowing longshore current moves sand S and SW along the beach. Estuary waves from the S and SW are wind-driven with high-frequencies and steepnesses. They generate a northeasterly current which returns material N, but dies out as the waves become obliterated by nearshore attenuation and breaking of swell. It is possible to identify a time-averaged null-point where shoreline wave power is balanced, although this tends to shift over short periods causing rapid morphological changes. The existence of two independent, but counteractive cells ensures the long-term maintenance of the foreland, without requiring major or continuous supplies of fresh sediment.