| 1. |
|
|
| 2. |
|
|
| 3. |
|
|
| 4. |
|
|
| 5. |
|
|
| 6. |
- Torgersen, T., et al.
(författare)
-
Profiles and levels of fatty acid esters of okadaic acid group toxins and pectenotoxins during toxin depuration, Part I: Brown crab (Cancer pagurus)
- 2008
-
Ingår i: Toxicon. - : Elsevier BV. - 0041-0101. ; 52:3, s. 407-417
-
Tidskriftsartikel (refereegranskat)abstract
- In 2002, two outbreaks of diarrhetic shellfish poisoning (DSP) occurred in Norway, which was later confirmed to be caused by the consumption of brown crab (Cancer pagurus) contaminated predominantly by esters of okadaic acid (OA) after feeding on toxic blue mussels (Mytilus edulis). In addition to OA-group toxins, pectenotoxins (PTXs) are commonly detected in the toxin-producing algae (i.e. Dinophysis). In this paper, an experiment was set up to study the fatty acid ester profiles and depuration rates of OA-group toxins and PTXs from C. pagurus after feeding on M. edulis containing these toxin groups. CA, DTX1, DTX2 and PTX2 SA were all detected primarily in the form of fatty acid esters in the crab hepatopancreas (HP). Crabs preferentially assimilated toxins of the OA group after feeding on the mussels for 1 week. Detailed analysis of the fatty acid ester profile in crabs and mussels showed that the ester profiles in the crabs differed slightly from profiles of the fatty acid esters in M. edulis, but neither ester profile nor ester to free toxin ratio appeared to change in the crabs during the first 2 weeks of deputation. Calculations of deputation rates of the free forms of toxins resulted in similar reduction rates for OA and DTX2, whereas the depuration rate of DTX1, PTX2 and PTX2 SA was considerably faster. From the industrial perspective, the PTX-compounds are of minor importance compared to the OA group toxins in crabs, considering (1) the uncertainty regarding the oral toxicity of the PTXs, (2) the preferential ingestion of OA-group toxins compared to PTXs and (3) the faster depuration of PTXs. (C) 2008 Elsevier Ltd. All rights reserved.
|
|
| 7. |
- Torgersen, T., et al.
(författare)
-
Profiles and levels of fatty acid esters of okadaic acid group toxins and pectenotoxins during toxin depuration. Part II: Blue mussels (Mytilus edulis) and flat oyster (Ostrea edulis)
- 2008
-
Ingår i: Toxicon. - : Elsevier BV. - 0041-0101. ; 52:3, s. 418-427
-
Tidskriftsartikel (refereegranskat)abstract
- Bivalve molluscs accumulate toxins of the okadaic acid (OA) and pectenotoxin (PTX) groups, which are frequently found in Dinophysis spp. Transformation of the OA-group toxins into fatty acid ester derivatives (often designated "DTX3") is common in many bivalve species but the degree to which these toxins are transformed vary between species, and is also depending on the parent toxin involved. In this paper, detailed profiles and levels of fatty acid esters of OA, DTX1, DTX2 and PTX2 SA were studied in blue mussels (Mytilus edulis) and European flat oysters (Ostrea edulis), collected during a bloom of Dinophysis spp. and after 3 and 6 weeks of depuration. Analysis of samples by HPLC-MS/MS and HPLC-MS2 revealed some differences in identity and abundance of fatty acid moieties of the OA-group esters between species, but the 16:0 fatty acid esters dominated in both oysters and mussels, which is in accordance with the free fatty acid profiles in these species. A wider range of FM SA-esters were detected compared to esters of the CA-group toxins in both mussels and oysters, and in oysters, both 14:0, 18:4 and 20:5 fatty acid side chains were more common than 16:0. OA-group toxins were esterified to a larger degree in oysters (83-93%) compared to mussels (21-41%), and in mussels a higher proportion of OA was esterified compared to DTX1 and DTX2. Contrary to what was observed for CA-group toxins, PTX2 SA was esterified to a larger degree in mussels (81%) compared to oysters (64%). Calculations of depuration rates for all individual esters of each parent compound showed that the esters of DTX1 depurated significantly slower from both mussels and oysters compared to esters of OA, DTX2 and PTX2 SA, but overall the deputation rates of esters of both toxin group were highly similar for both species. This indicated that differences in depuration rates are not causing the large species-specific differences in levels and profiles of these toxins. Instead, the results for the CA-group toxins suggested that a higher rate of esterification in oysters is the main factor causing the observed differences in the proportion of esters to free toxin. For FM SA, large differences in ester profiles and a higher proportion of esters of PTX2 SA in mussels compared to oysters suggested differential assimilation and metabolic rate processes for the PTXs compared to OA-group toxins between these species. Hence, although produced by the same Dinophysis species, conclusions about the dynamics of one toxin group based on results from the other group should be avoided in future studies. (C) 2008 Elsevier Ltd. All rights reserved.
|
|
| 8. |
- Wrange, Anna-Lisa, 1981, et al.
(författare)
-
Japanska jätteostron – främmande nykomling i västsvenska vatten.
- 2008
-
Ingår i: Havsmiljön. ; 2008
-
Tidskriftsartikel (övrigt vetenskapligt/konstnärligt)abstract
- Hösten 2007 upptäcktes en helt ny art av ostron på svenska västkusten. Känd för att vara en invaderande art som världen över lett till allvarliga konsekvenser för den marina miljön, är det japanska jätteostronet här för att stanna.
|
|
| 9. |
- Wrange, Anna-Lisa, 1981, et al.
(författare)
-
Massive settlements of the Pacific oyster, Crassostrea gigas, in Scandinavia.
- 2009
-
Ingår i: Biological Invasions. - 1387-3547.
-
Tidskriftsartikel (refereegranskat)abstract
- The Pacific oyster (Crassostrea gigas) is an important aquaculture species world-wide. Due to its wide environmental tolerance and high growth rate, it has also become a successful invader in many areas, leading to major ecosystem changes. Low water temperatures were previously believed to restrict the establishment of Pacific oysters in Scandinavia. However, recent surveys reveal that the Pacific oyster is now established in many areas in Scandinavia. We present data on the current distribution, abundance and age-structure in Denmark, Sweden and Norway. The biomass of oysters in the Danish Wadden Sea increased from 1,056 to 6,264 tonnes between 2005 and 2007. Massive settlements were observed along the Swedish west coast in 2007, with densities >400 oysters per m−2. In Norway, populations are established on the southern coast, and specimens have been found as far north as 60°N. The potential impacts and probable causes of this recent large-scale establishment are discussed.
|
|
