Informing policy to protect coastal coral reefs: Insight from a global review of reducing agricultural pollution to coastal ecosystems

The continuing degradation of coral reefs has serious consequences for the provision of ecosystem goods and services to local and regional communities. While climate change is considered the most serious risk to coral reefs, agricultural pollution threatens approximately 25% of the total global reef area with further increases in sediment and nutrient fluxes projected over the next 50 years. Here, we aim to inform coral reef management using insights learned from management examples that were successful in reducing agricultural pollution to coastal ecosystems. We identify multiple examples reporting reduced fluxes of sediment and nutrients at end-of-river, and associated declines in nutrient concentrations and algal biomass in receiving coastal waters. Based on the insights obtained, we recommend that future protection of coral reef ecosystems demands policy focused on desired ecosystem outcomes, targeted regulatory approaches, up-scaling of watershed management, and long-term maintenance of scientifically robust monitoring programs linked with adaptive management.     

Laser Ablation In Situ Silicon Stable Isotope Analysis of Phytoliths

Silicon is a beneficial element for many plants and is deposited in plant tissue as amorphous bio‐opal called phytoliths. The biochemical processes of silicon uptake and precipitation induce isotope fractionation: the mass‐dependent shift in the relative abundances of the stable isotopes of silicon. At the bulk scale, δ³⁰Si ratios span from ?2 to +6‰. To further constrain these variations in situ, at the scale of individual phytolith fragments, we used femtosecond laser ablation multi‐collector inductively coupled plasma‐mass spectrometry (fsLA‐MC‐ICP‐MS). A variety of phytoliths from grasses, trees and ferns were prepared from plant tissue or extracted from soil. Good agreement between phytolith δ³⁰Si ratios obtained by bulk solution MC‐ICP‐MS analysis and in situ isotope ratios from fsLA‐MC‐ICP‐MS validates the method. Bulk solution analyses result in at least twofold better precision for δ³⁰Si (2s on reference materials ≤ 0.11‰) over that found for the means of in situ analyses (2s typically ≤ 0.24‰). We find that bushgrass, common reed and horsetail show large internal variations up to 2‰ in δ³⁰Si, reflecting the various pathways of silicon from soil to deposition. Femtosecond laser ablation provides a means to identify the underlying processes involved in the formation of phytoliths using silicon isotope ratios.     

Field Studies on the Fate and Transport of Pharmaceutical Residues in Bank Filtration

Bank filtration and artificial ground water recharge are important, effective, and cheap techniques for surface water treatment and removal of microbes, as well as inorganic, and some organic, contaminants. Nevertheless, physical, chemical, and biological processes of the removal of impurities are not understood sufficiently. A research project titled Natural and Artificial Systems for Recharge and Infiltration attempts to provide more clarity in the processes affecting the removal of these contaminants. The project focuses on the fate and transport of selected emerging contaminants during bank filtration at two transects in Berlin, Germany. Several detections of pharmaceutically active compounds (PhACs) in ground water samples from bank filtration sites in Germany led to furthering research on the removal of these compounds during bank filtration. In this study, six PhACs including the analgesic drugs diclofenac and propyphenazone, the antiepileptic drugs carbamazepine and primidone, and the drug metabolites clofibric acid and 1-acetyl-1-methyl-2-dimethyl-oxamoyl-2-phenylhydrazide were found to leach from the contaminated streams and lakes into the ground water. These compounds were also detected at low concentrations in receiving public supply wells. Bank filtration either decreased the concentrations by dilution (e.g., for carbamazepine and primidone) and partial removal (e.g., for diclofenac), or totally removed PhACs (e.g., bezafibrate, indomethacine, antibiotics, and estrogens). Several PhACs, such as carbamazepine and especially primidone, were readily transported during bank filtration. They are thought to be good indicators for evaluating whether surface water is impacted by contamination from municipal sewage effluent or whether contamination associated with sewage effluent can be transported into ground water at ground water recharge sites.     

Light,stratification and zooplankton as controlling factors for the spring development of phytoplankton in Lake Constance

The patterns of phytoplankton growth and decline during the spring bloom and the following clear-water phase in Lake Constance have been studied on the basis of cell counts with short-term sampling intervals and related to light climate, stratification and zooplankton pressure.     

Peperite formed by lava flows over sediments: An example from the central Paraná Continental Flood Basalts,Brazil

Pahoehoe flows interbedded with sediments have been identified in the superior portion of Paraná Continental Flood Basalts (PCFB), west portion of Paraná State, southern Brazil. In the study area peperites are generated by the interaction between lava flows and wet lacustrine sediments (silt and clay). Evidence that the sediments were unconsolidated or poorly consolidated and wet when the lava flowed over them includes vesiculated sediment, sediment in vesicles and fractures in lava flow and in juvenile clasts in the peperite and soft sediment deformation. Hydrodynamic mingling of lava and wet sediments (coarse mingling) is predominant and volcanic rocks and textures related to explosive phase of Molten Fuel Coolant Interaction (MFCI) are not observed in study area. Locally centimeter-sized areas display direct contact between ash-sized juvenile clasts and sediments formed by the collapse of a vapor film. The textures of fluidal peperites in the central PCFB indicate that the relevant factors that led to a coarse mingling between lava/sediment are (1) lava properties (low viscosity); (2) fine grained, unconsolidated or poorly consolidated wet sediment; and (3) a single episode of interaction between lava flows and sediment.     

Open and closed magnetospheric tail configurations and their stability

The asymptotic theory valid for magnetospheric tail configurations that vary only weakly in the antisolar direction is used to derive a number of explicit properties. The conditions under which the magnetopause converges to form a closed magnetosphere or diverges (open magnetosphere) are identified and discussed. It is shown that the presence of the high latitude low pressure tail lobes guarantees the open solution. The large value of the Mach-number of the unperturbed solar wind is the reason for the slow variation of the plasma and field quantities along the tail. Criteria for (two-dimensional) stability are discussed and it is shown that they can be expressed in terms of simple topological properties of the equilibria. Closed magnetopheres turn out to be stable, open magnetospheres with sufficiently stretched field lines are subject to an instability which — as shown earlier —may be the cause of magnetospheric substorms.     

Technological capability and transfer for achieving South Africa's development goals

Technological capability and technology transfer both play important roles in achieving low-carbon development targets and the concepts of both have appeared in national development and climate policy debates. Yet, they differ. Improving capabilities and transfer mechanisms are two differing approaches to technological development. Technology transfer is associated with a key political dynamic within international climate policy, in that developing countries request support from industrialised countries. Whereas technological capability focuses on building internal capabilities and is often framed in the context of national industrial policy plans rather than relying on external support. We argue that technology development, a combination of these approaches, can contribute to South Africa's low-carbon development through innovation and technology-based mitigation actions that increase domestic technological capabilities. Technological capability needs to become a determinant of mitigation action to effectively contribute to achieving South Africa's low-carbon development goals. International technology transfer and cooperation should contribute to boosting domestic capabilities to advance technological development. Technology transfer based on pure sales will not contribute to achieving long-term low-carbon development goals.     

Quality Assessment of Southeast Nile Delta Groundwater for Irrigation

The Nile Delta aquifer has deteriorated in the quality of the groundwater due to domestic, agricultural and industrial activities. In order to examine this, a dataset of thirty-one shallow groundwater samples and four surface water samples were collected in May 2014. The objective of our study is to investigate the hydrochemical characteristics of the groundwater at El-Khanka region in El-Qalubia governorate, southern Nile Delta to discuss the possibility of groundwater use for agricultural purpose. Groundwater types were defined, and the suitability for use in irrigation was evaluated. The factor analysis was conducted to investigate the relationship between the thirteen variables for exploring the loading of them in the model. Then, the principal component analysis was performed to identify the linear combination of variables that account for the greatest amount of common variance. Results showed that groundwater samples are mainly alkaline with an average pH value of 8.60. The total dissolved solids (TDS) range from 350 to 1456 mg/L. The highest concentrations of the anions and cations are sulfate (\(\rm{SO}_4^{2-}\)) and sodium (Na⁺) respectively. The residual sodium carbonate (RSC) is less than 1.25 meq/L. Also, all groundwater samples are located in good and permissible salinity with TDS < 1500 mg/L. In addition, all samples are located in the low sodium hazard zone where sodium adsorption ratio (SAR) is less than 10. Therefore, it is concluded that, the groundwater is suitable for irrigation use in El-Qalubia Governorate. Four factors with Eigenvalues above 1.0 which correlated to each other contributed to the model with 81% of the total variance and governed the spatial variability of the aquifer.     

Reconstructing rates and patterns of colluvial soil redistribution in agrarian (hummocky) landscapes

Humans have triggered or accelerated erosion processes since prehistoric times through agricultural practices. Optically stimulated luminescence (OSL) is widely used to quantify phases and rates of the corresponding landscape change, by measuring the last moment of daylight exposure of sediments. However, natural and anthropogenic mixing processes, such as bioturbation and tillage, complicate the use of OSL as grains of different depositional ages become mixed, and grains become exposed to light even long after the depositional event of interest. Instead, OSL determines the stabilization age, indicating when sediments were buried below the active mixing zone. These stabilization ages can cause systematic underestimation when calculating deposition rates. Our focus is on colluvial deposition in a kettle hole in the Uckermark region, northeastern Germany. We took 32 samples from five locations in the colluvium filling the kettle hole to study both spatial and temporal patterns in colluviation. We combined OSL dating with advanced age modelling to determine the stabilization age of colluvial sediments. These ages were combined with an archaeological reconstruction of historical ploughing depths to derive the levels of the soil surface at the moment of stabilization; the deposition depths, which were then used to calculate unbiased deposition rates. We identified two phases of colluvial deposition. The oldest deposits (~5 ka) were located at the fringe of the kettle hole and accumulated relatively slowly, whereas the youngest deposits (<0.3 ka) rapidly filled the central kettle hole with rates of two orders of magnitude higher. We suggest that the latter phase is related to artificial drainage, facilitating accessibility in the central depression for agricultural practices. Our results show the need for numerical dating techniques that take archaeological and soil-geomorphological information into account to identify spatiotemporal patterns of landscape change, and to correctly interpret landscape dynamics in anthropogenically influenced hilly landscapes. © 2019 The Authors. Earth Surface Processes and Landforms Published by John Wiley & Sons Ltd.     

Contaminants and habitat choice in the Baltic Sea: Behavioural experiments with the native species, Monoporeia affinis, and the invasive genus, Marenzelleria

The invasive polychaete genus, Marenzelleria and the native amphipod, Monoporeia affinis are food and habitat competitors in the Baltic Sea. Previous studies have shown that moderate densities of Marenzelleria can affect the behaviour of M. affinis. To examine the short-term interactive effects of interspecific habitat choice and environmental contaminants a series of habitat colonisation experiments were performed. The contaminants examined included harbor sediments and sediment spiked with the antifouling substances, Cu, Zn and Irgarol. Polychaetes and amphipods were exposed to contaminants in single-species and two-species experiments. In spiked-sediment experiments, M. affinis showed clear dose-dependent response. These experiments verified that behavioural response of M. affinis to different habitats is a sensitive method for testing toxicity under controlled conditions. In experiments with three different harbor sediments and reference sediment both species showed the lowest preference for the reference sediment. This sediment also had the lowest content of quality food, indicating that factors such as food quality and quantity may override the disturbing effects of contaminants in natural sediments. The presence of Marenzelleria spp. did not affect amphipod habitat choice, indicating no short-term effects, which implies that both species can co-exist provided sufficient food is available.