Environmental and biological characteristics along a transect in Kongsfjorden (Svalbard Islands)
| Autor: | Caruso G., Madonia A., Bonamano S., Miserocchi S., Giglio F., Maimone G., Azzaro F., Decembrini F., La Ferla R., Piermattei V., Piazzolla D., Marcelli M., Azzaro M. |
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| Jazyk: | angličtina |
| Rok vydání: | 2017 |
| Předmět: | |
| Zdroj: | XXIII Congresso AIOL, Cagliari, 26-29/09/2017 info:cnr-pdr/source/autori:Caruso G., Madonia A., Bonamano S., Miserocchi S., Giglio F., Maimone G., Azzaro F., Decembrini F., La Ferla R., Piermattei V., Piazzolla D., Marcelli M., Azzaro M./congresso_nome:XXIII Congresso AIOL/congresso_luogo:Cagliari/congresso_data:26-29%2F09%2F2017/anno:2017/pagina_da:/pagina_a:/intervallo_pagine |
| Popis: | In the Kongsfjorden site (Svalbard Islands) glaciers retreat is one of the most evident signs of global warming. Such evidence has strong implications on the marine ecosystem. An oceanographic cruise was performed within the ARCA (ARctic: present Climatic change and pAst extreme events) Project in May 2016 to study the chemical-physical, biochemical and biological characteristics of superficial waters along a transect of 7 surface stations in inner Kongsfjorden until the Kronebreen glacier (stations 4-5-14-6-23-7 and 8, glacier). Station 4 was also sampled from surface to 100 m. The studied parameters were: temperature, salinity, dissolved oxygen, turbidity, nutrients, chlorophyll-a (Chl-a), Total Suspended Matter (TSM), chromophoric Dissolved Organic Matter (c-DOM) absorption, total bacterioplankton abundance and its respiring fraction, heterotrophic bacteria on Marine agar, extracellular enzymatic activity (leucine aminopeptidase - LAP, beta-glucosidase -GLU and alkaline phosphatase -AP). Temperature and salinity values decreased from station 4 to station 8 (near the glacier) and an opposite trend was observed for turbidity and nutrients values. TSM also peaked at station 8 while reduced concentrations of Chl-a characterized the surface waters. Ammonia, nitrite+nitrate and orthophosphate ranges were 0.45-1.44 µmol/l, 0.12-5.60 µmol/l, 0.10-0.48 µmol/l, respectively. CDOM absorption slope values (range 275-295 nm) varied from 0.0077 to 0.0109 nm-1. Total and respiring bacterioplankton counts were in the magnitude order of 106 and 104 cells/ml respectively and of 10^2 Colony Forming Units/ml. Enzymatic activity patterns were in the order AP>LAP>GLU, with rates lower than 1.78, 1.25 and 0.25 nmol respectively. Temperature affected negatively nutrients, TSM and turbidity, positively GLU. AP was associated to the heterotrophic bacteria (Pearson r=0.59). AP and c-DOM absorption spectra were significantly related (r=0.71), as well as LAP and Chl-a (r=0.97), suggesting fresh material stimulated enzymatic synthesis. |
| Databáze: | OpenAIRE |
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