Debenest T.,Environment Canada |
Gagne F.,Environment Canada |
Burgeot T.,French Research Institute for Exploitation of the Sea |
Blaise C.,Environment Canada |
Pellerin J.,ISMER UQAR
Environmental Science and Pollution Research | Year: 2013
The purpose of this study was to examine the effects of pollution on DNA integrity in the feral soft-shell clam (Mya arenaria) in the Saguenay Fjord. Intertidal clams were collected downstream and upstream of the fjord at sites under anthropogenic pollution. DNA integrity was assessed by following changes in single- and double-stranded breaks, variation in DNA content and micro-nuclei (MN) incidence in hemocytes. The results revealed that clams collected at polluted sites had reduced DNA strand breaks (lower DNA repair activity), increased DNA content variation and MN frequency in hemocytes. The data revealed that DNA content variation was closely related to MN frequency and negatively with DNA strand breaks formation. Water conductivity was also related to reduced MN frequency and DNA content variation, indicating that, in addition to the effects of pollution, the gradual dilution of saltwater could compromise mussel health. © 2012 Her Majesty the Queen in Right of Canada.
Olivier F.,French Natural History Museum |
San Martin G.,Autonomous University of Madrid |
Archambault P.,ISMER UQAR
Polar Biology | Year: 2013
Since 2007, the ArcticNet and CHOne programmes have allowed researchers, through oceanographic surveys on the 'NGCC Amundsen', to collect yearly benthic samples in the Canadian High Arctic. From the Beaufort Sea to the Bay of Baffin, more than 262 samples have been collected and analysed to provide essential data to explain patterns of biodiversity in the Canadian Arctic archipelago. Whereas common species are well known, other more rare species belonging to a few minute species groups, with debatable taxonomy, were set aside for further analyses. Focusing on Syllidae (Annelida, Polychaeta), we found and describe here Streptospinigera niuqtuut sp. nov. from muddy habitats of bathyal Arctic and continental slope beds of northern Atlantic coasts of United States between depths of 169 and 707 m. S. niuqtuut differs from congeneric species by unique dorsal simple chaetae of 1-5 chaetigers dorsally curved and distally rounded, with some sub-distal serration. This species may have frequently been reported from the region as Syllides longocirrata Ørsted 1845 but in fact are species of the genus Streptospinigera Kudenov 1983. We also transfer Streptosyllis templadoi San Martín 1984 to this genus and provide herein a key for the identification of all species of the genus. © 2013 Springer-Verlag Berlin Heidelberg.
Corrosion inhibition of mild steel in natural seawater by snow crab (Chionoecetes opilio) peptidic extracts. Marine peptides as corrosion inhibitor [Inhibition de la corrosion de lacier doux en eau de mer naturelle par des extraits peptidiques de crabe des neiges (Chionoecetes opilio): Peptides marins comme inhibiteur de corrosion]
Tassel A.-C.,ISMER UQAR |
Doiron K.,ISMER UQAR |
Lemarchand K.,ISMER UQAR |
Simard S.,501 Boulevard Of Luniversite Est |
Materiaux et Techniques | Year: 2014
In Canada, about 30 000 tons of marine by-products from snow crab (Chionoecetes opilio) fisheries are generated annualy and currently disposed in landfills. These co-products contain biopolymers, such as peptide extracts, and some are known to interact with metallic surfaces and have an antibacterial activity. These properties suggest that snow crab peptide extracts (SCPE) could act as corrosion inhibitor, as well as by adsorption on the metallic surface as by the inhibition of microbially induced corrosion (MIC). Inhibition effect of SCPE has been investigated by electrochemical measurements and the covering of metal surface by corrosion products and biofilm was monitored by scanning electron microscopy. Corrosion inhibition efficiency of SCPE has been demonstrated over 10 days and architectural changes of biofilm were observed during the same period. This study shows that SCPE have potentially a direct effect by adsorption on the metal and an undirect effect by the structural modification of biofim which suggest that SPCE may modify MIC. © 2014 EDP Sciences.
Tassel A.-C.,ISMER UQAR |
Lemarchand K.,ISMER UQAR |
Doiron K.,UQAR |
St-Louis R.,UQAR |
EUROCORR 2013 - European Corrosion Congress | Year: 2013
Tons of marine by-products are available from snow-crab (chionocete opilio) fisheries and contain valuable biopolymers; among others snow crab peptide extracts (SCPE). Some of these biopolymers are known to interact with metallic surfaces and have an antibacterial activity. Fig: Evolution of Tafel curves for natural seawater (a) and seawater treated with dissolved biopolymers (b), for days 0, 1, 2, 4, 7, and 10. Both properties making them good candidates to inhibit corrosion, as well as by adsorption on the metallic surface as by the inhibition of microbial induced corrosion (MIC).An experiment conducted in three types of seawater (artificial, natural filtered on 0.22μm, and natural un-filtered) highlighted the connection between the dissolved biopolymers and the role of the microbial biofilm in corrosion inhibition. Thus, this study explored the potential of SCPE as corrosion inhibitor, by measuring different classic electrochemical variables, and following modifications of the microbial biofilm formation, on steel 1040 plates standing in natural seawater for 10 days. Corrosion current measurements showed that SCPE inhibited the corrosion of steel electrodes from day 1 and this inhibition persisted over 10 days (fig.). Moreover slopes of the two branches of the Tafel curves varied, indicating that the SCPE inhibitor is of the mixed type. The growth and the composition of the biofilm were modified by SCPE: biofilm reached maturity faster in the presence of SCPE, and the bacterial diversity was modified by the presence of SCPE. Further study was done by fractioning SCPE in three sub-fractions. An elemental analysis was performed on these fractions; the fraction with higher sulfur content was more effective than the two others. Only two amino-acids contain sulfur: cysteine and methionine. Thiol from cysteine is highly reactive and forms disulfide bonds which help SCPE biopolymers linking to the metal surface and could interfere with the biofilm formation. This study demonstrated that natural biopolymers extracted from snow crab by-products have the potential to be efficient corrosion inhibitors by both physicochemical and biological processes through the formation of a protective film on metallic surfaces and through the modification of the biofilm which stabilises the pre-existing protective film formed by SCPE at the surface of the metal.