74 research outputs found
"Hanging gardens" - comparing fauna communities in kelp farms and wild kelp forests
A growing need for food is causing increased interest for seaweed farming globally. This requires knowledge of the industryâs effects on the marine environment. We therefore aimed to explore the communities hosted by a kelp farm compared to that of wild kelp forests. The study was performed in mid-western Norway. Kelp associated fauna were collected from farmed kelp (Saccharina latissima and Alaria esculenta), in wild kelp forests (S. latissima, A. esculenta and Laminaria hyperborea), and from fauna traps in the water column. The study showed that the kelp farm had lower taxa abundance and richness and a lower biodiversity than the wild kelp forests. Nonetheless, the farmed kelp hosted many associated species, with communities different from what was found on ropes without kelp (i.e., in the water column). The fauna communities among the farmed kelp were more similar to what was found in the wild L. hyperborea kelp forest than to its wild counterparts. The difference between the fauna communities of âoldâ and âyoungâ farmed kelp (grown for 3 and 7 months, respectively) was not significant, but the fauna was dominated by the isopod species Idotea pelagica in the young forest and by amphipods, mainly belonging to the genus Caprella, in the older. The study contributes to our knowledge of kelp farmsâ ecological role in the marine environment, which is of importance for todayâs management as well as for ensuring a sustainable future development of the kelp farming industry.publishedVersio
Environmental and vegetation controls on the spatial variability of CH4 emission from wet-sedge and tussock tundra ecosystems in the Arctic
Aims
Despite multiple studies investigating the environmental controls on CH4 fluxes from arctic tundra ecosystems, the high spatial variability of CH4 emissions is not fully understood. This makes the upscaling of CH4 fluxes from plot to regional scale, particularly challenging. The goal of this study is to refine our knowledge of the spatial variability and controls on CH4 emission from tundra ecosystems.
Methods
CH4 fluxes were measured in four sites across a variety of wet-sedge and tussock tundra ecosystems in Alaska using chambers and a Los Gatos CO2 and CH4 gas analyser.
Results
All sites were found to be sources of CH4, with northern sites (in Barrow) showing similar CH4 emission rates to the southernmost site (ca. 300 km south, Ivotuk). Gross primary productivity (GPP), water level and soil temperature were the most important environmental controls on CH4 emission. Greater vascular plant cover was linked with higher CH4 emission, but this increased emission with increased vascular plant cover was much higher (86 %) in the drier sites, than the wettest sites (30 %), suggesting that transport and/or substrate availability were crucial limiting factors for CH4 emission in these tundra ecosystems.
Conclusions
Overall, this study provides an increased understanding of the fine scale spatial controls on CH4 flux, in particular the key role that plant cover and GPP play in enhancing CH4 emissions from tundra soils
The Organophosphate Chlorpyrifos Interferes with the Responses to 17ÎČ-Estradiol in the Digestive Gland of the Marine Mussel Mytilus galloprovincialis
BACKGROUND: Many pesticides have been shown to act as endocrine disrupters. Although the potencies of currently used pesticides as hormone agonists/antagonists are low compared with those of natural ligands, their ability to act via multiple mechanisms might enhance the biological effect. The organophosphate Chlorpyrifos (CHP) has been shown to be weakly estrogenic and cause adverse neurodevelopmental effects in mammals. However, no information is available on the endocrine effects of CHP in aquatic organisms. In the digestive gland of the bivalve Mytilus galloprovincialis, a target tissue of both estrogens and pesticides, the possible effects of CHP on the responses to the natural estrogen 17ÎČ-estradiol (E(2)) were investigated. METHODOLOGY/PRINCIPAL FINDINGS: Mussels were exposed to CHP (4.5 mg/l, 72 hrs) and subsequently injected with E(2) (6.75 ng/g dw). Responses were evaluated in CHP, E(2) and CHP/E(2) treatment groups at 24 h p.i. by a biomarker/transcriptomic approach. CHP and E(2) induced additive, synergistic, and antagonistic effects on lysosomal biomarkers (lysosomal membrane stability, lysosome/cytoplasm volume ratio, lipofuscin and neutral lipid accumulation). Additive and synergistic effects were also observed on the expression of estrogen-responsive genes (GSTÏ, catalase, 5-HTR) evaluated by RT-Q-PCR. The use of a 1.7K cDNA Mytilus microarray showed that CHP, E(2) and CHP/E(2), induced 81, 44, and 65 Differentially Expressed Genes (DEGs), respectively. 24 genes were exclusively shared between CHP and CHP/E(2), only 2 genes between E(2) and CHP/E(2). Moreover, 36 genes were uniquely modulated by CHP/E(2). Gene ontology annotation was used to elucidate the putative mechanisms involved in the responses elicited by different treatments. CONCLUSIONS: The results show complex interactions between CHP and E(2) in the digestive gland, indicating that the combination of certain pesticides and hormones may give rise to unexpected effects at the molecular/cellular level. Overall, these data demonstrate that CHP can interfere with the mussel responses to natural estrogens
En kunnskapsbasert finansnĂŠring
Prosjektet âEn kunnskapsbasert finansnĂŠringâ inngĂ„r som delprosjekt i det store nasjonale forskningsprosjektet âEt kunnskapsbasert Norgeâ som gjennomfĂžres ved HandelshĂžyskolen BI under ledelse av professor Torger Reve.
Norsk nÊringsliv er avhengig av en velfungerende finansnÊring. Denne nÊringen fungerer pÄ mange mÄter som et nav for de andre nÊringene i Þkonomien. For at nÊringslivet skal kunne skape vekst, mÄ det kanaliseres kapital til prosjekter som har hÞy lÞnnsomhet og evne til verdiskaping. Dersom bedriftene selv ikke har denne kapitalen tilgjengelig er det nÞdvendig med ekstern kapitaltilfÞrsel. Det er her finansnÊringen bidrar, bÄde med kapital og kompetanse om hvor kapitalen bÞr kanaliseres. Finansmarkedet fungerer ogsÄ som et korrektiv til bedriftenes atferd. Bedrifter som gjÞr det bra blir premiert gjennom hÞyere verdsetting pÄ bÞrs, mens de som gjÞr det dÄrlig opplever fallende kurser. PÄ denne mÄten fÄr eierne et tydelig signal om hvor godt bedriften er styrt og kan pÄ denne bakgrunn legge opp til endringer i bedriftens strategi. Videre spiller finansmarkedet en viktig rolle gjennom Ä ivareta bÄde nÊringslivets, husholdningenes og offentlig sektors behov for likviditet gjennom Ä tilby regulÊre banktjenester. NÊringen har ogsÄ en sentral oppgave gjennom Ä avdempe risiko gjennom ulike forsikringsprodukter. Sist, men ikke minst, har finansnÊringen en formidlerrolle gjennom Ä bistÄ aktÞrer i Þkonomien i Ä flytte verdier seg imellom. Vi snakker med andre ord om en nÊring med mange aktivitetsomrÄder og som i all hovedsak har forankret sine aktiviteter i andre aktÞrers Þkonomiske aktivitet
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