Publications
NIBIOs employees contribute to several hundred scientific articles and research reports every year. You can browse or search in our collection which contains references and links to these publications as well as other research and dissemination activities. The collection is continously updated with new and historical material.
2018
Abstract
A series of semi-continuous incubation experiments were conducted with the coccolithophore Emiliania huxleyi strain NIWA1108 (Southern Ocean isolate) to examine the effects of five environmental drivers (nitrate and phosphate concentrations, irradiance, temperature, and partial pressure of CO2 (pCO2// on both the physiological rates and elemental composition of the coccolithophore. Here, we report the alteration of the elemental composition of E. huxleyi in response to the changes in these environmental drivers. A series of dose–response curves for the cellular elemental composition of E. huxleyi were fitted for each of the five drivers across an environmentally representative gradient. The importance of each driver in regulating the elemental composition of E. huxleyi was ranked using a semiquantitative approach. The percentage variations in elemental composition arising from the change in each driver between present-day and model-projected conditions for the year 2100 were calculated. Temperature was the most important driver controlling both cellular particulate organic and inorganic carbon content, whereas nutrient concentrations were the most important regulator of cellular particulate nitrogen and phosphorus of E. huxleyi. In contrast, elevated pCO2 had the greatest influence on cellular particulate inorganic carbon to organic carbon ratio, resulting in a decrease in the ratio. Our results indicate that the different environmental drivers play specific roles in regulating the elemental composition of E. huxleyi with wide-reaching implications for coccolithophore-related marine biogeochemical cycles, as a consequence of the regulation of E. huxleyi physiological processes.
Authors
Trust Kasambala Donga Ole Martin EkloAbstract
The sugarcane industry is the third largest user of pesticides in Malawi. Our aim with this study was to document pesticide use and handling practices that influence pesticide exposure among sugarcane farmers in Malawi. A semi-structured questionnaire was administered to 55 purposively selected sugarcane farmers and 7 key informants representing 1474 farmers in Nkhata Bay, Nkhotakota and Chikwawa Districts in Malawi. Our results indicate that herbicides and insecticides were widely used. Fifteen moderately and one extremely hazardous pesticide, based on World Health Organization (WHO) classification, were in use. Several of these pesticides: ametryn, acetochlor, monosodium methylarsonate and profenofos are not approved in the European Union because of their toxicity to terrestrial and aquatic life, and/or persistence in water and soil. Farmers (95%) knew that pesticides could enter the human body through the skin, nose (53%) and mouth (42%). They knew that pesticide runoff (80%) and leaching (100%) lead to contamination of water wells. However, this knowledge was not enough to motivate them to take precautionary measures to reduce pesticide exposure. Farmers (78%) had experienced skin irritation, 67% had headache, coughing and running nose during pesticide handling. Measures are in place to reduce pesticide exposure in the large estates and farms operated by farmer associations. Smallholder farmers acting independently do not have the resources and capacity to minimize their exposure to pesticides. There is need to put in place pesticide residue monitoring programs and farmer education on commercial sugarcane production and safe pesticide use as ways of reducing pesticide exposure.
Authors
Nicholas ClarkeAbstract
No abstract has been registered
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Authors
Carl Gunnar FossdalAbstract
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Carl Gunnar FossdalAbstract
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Authors
Lillian ØygardenAbstract
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Authors
Jan Emblemsvåg Nina Pereira Kvadsheim Matthias Koesling Jon Halfdanarson Celine Rebours Annik Magerholm FetAbstract
Research is being poured into developing both potential products and the processes required to convert seaweed, or macroalgae, into products. So far, the results are products for high-end markets, such as restaurants, but in very modest volumes. To understand what it will take to create a large-scale seaweed industry, research is conducted into the strategic-, environmental- and economic realities such an industry would have to deal with as suppliers of fish-feed. The idea is that unless the industry has something to offer that competing products do not, in terms of cost, performance or environmental- and economic footprint, the seaweed industry will be delegated to small volumes for special needs and high value products. These topics are discussed below.
Authors
Arne Verstraeten Elena Gottardini Elena Vanguelova Peter Waldner Nicolas Bruffaerts Anita Nussbaumer Mathias Neumann Nicholas Clarke Karin Hansen Pasi Rautio Liisa UkonmaanahoAbstract
No abstract has been registered