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NIBIOs ansatte publiserer flere hundre vitenskapelige artikler og forskningsrapporter hvert år. Her finner du referanser og lenker til publikasjoner og andre forsknings- og formidlingsaktiviteter. Samlingen oppdateres løpende med både nytt og historisk materiale. For mer informasjon om NIBIOs publikasjoner, besøk NIBIOs bibliotek.

2021

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Sammendrag

Surface water runoff can export pesticides from agricultural fields into adjacent aquatic ecosystems, where they may pose adverse effects to organisms. Constructed wetlands (CWs) are widely used to treat agricultural runoff contaminated by pesticides, but the removal of hydrophilic pesticides is usually low. In this study, we suggest superabsorbent polymer (SAP), a cross-linked hydrophilic polymer, as a supplement to substrates of CWs and tested the hypothesis that SAP results in an enhanced removal of hydrophilic pesticides. Therefore, batch experiments were conducted to study the retention capacity of water-saturated SAP (w-SAP) for several hydrophilic pesticides. Retention of the pesticides on w-SAP was related to the ionization state and water solubility of the pesticides. The retention of neutral pesticides, imidacloprid, metalaxyl and propiconazole, was about 20% higher than that measured for anionic pesticides, bentazone, glyphosate and MCPA. The retention of the pesticides by w-SAP mainly resulted from their distribution in the gel-water phase of w-SAP, while less water soluble pesticides might have also been adsorbed on the molecular backbone of SAP. Furthermore, we tested the efficacy of w-SAP for treatment of runoff water contaminated by pesticides in lab-scale horizontal subsurface flow CWs. SAP in CWs improved the removal of the pesticides, including the recalcitrant ones. The removal enhancement was owing to the increase of hydraulic retention time and improvement of biodegradation. The removal of the pesticides in SAP containing CWs was > 93% for MCPA, glyphosate, and propiconazole, 62 – 99% for imidacloprid, 50 – 84% for metalaxyl, and 38 – 73% for bentazone. In the control gravel CWs, the removal was > 98% for glyphosate, generally > 83% for MCPA and propiconazole, 46 – 98% for imidacloprid, 32 – 97% for metalaxyl, and 9 – 96% for bentazone.

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The common smooth-hound shark, Mustelus mustelus, is a widely distributed demersal shark under heavy exploitation from various fisheries throughout its distribution range. To assist in the development of appropriate management strategies, the authors evaluate stock structure, site fidelity and movement patterns along the species’ distribution in southern Africa based on a combination of molecular and long-term tag-recapture data. Eight species-specific microsatellite markers (N = 73) and two mitochondrial genes, nicotinamide adenine dehydrogenase subunit 4 and control region (N = 45), did not reveal any significant genetic structure among neighbouring sites. Nonetheless, tagging data demonstrate a remarkable degree of site fidelity with 76% of sharks recaptured within 50 km of the original tagging location. On a larger geographic scale, dispersal is governed by oceanographic features as demonstrated by the lack of movements across the Benguela-Agulhas transition zone separating the South-East Atlantic Ocean (SEAO) and South-West Indian Ocean (SWIO) populations. Microsatellite data supported very shallow ocean-based structure (SEAO and SWIO) and historical southward gene flow following the Agulhas Current, corroborating the influence of this dynamic oceanographic system on gene flow. Moreover, no movements between Namibia and South Africa were observed, indicating that the Lüderitz upwelling formation off the Namibian coast acts as another barrier to dispersal and gene flow. Overall, these results show that dispersal and stock structure of M. mustelus are governed by a combination of behavioural traits and oceanographic features such as steep temperature gradients, currents and upwelling systems.