The minke whale is the last of the great whale species to be hunted in significant numbers. Effective management must include an understanding of how genetic diversity is divided and distributed among putative local populations, and as for many migratory species, this is complicated for the minke whale by large-scale seasonal movement among geographic regions. The problem is that the geographic identity of breeding populations is not known, and instead these whales are predictably found and hunted where different breeding stocks may mix on seasonal feeding grounds. Here we use microsatellite DNA and mtDNA markers to investigate minke whale population structure across the species' range in the North Atlantic. We found no evidence of geographic structure comparing putative populations in recognized management areas, although some limited structure had been indicated in earlier studies. However, using individual genotypes and likelihood assignment methods, we identified two putative cryptic stocks distributed across the North Atlantic in similar proportions in different regions. Some differences in the proportional representation of these populations may explain some of the apparent differentiation between regions detected previously. The implication would be that minke whales range extensively across the North Atlantic seasonally, but segregate to some extent on at least two breeding grounds. This means that established stock boundaries in the North Atlantic, currently used for management, should be re-considered to ensure the effective conservation of genetic diversity.
Category: Branches
Icelandic streams with mean annual temperatures of less than 5 ° C, which receive the cationic products of basaltic rock weathering, were found to host mats of iron-cycling microorganisms. We investigated two representative sites. Iron-oxidizing Gallionella and iron-reducing Geobacter species were present. The mats host a high bacterial diversity as determined by culture-independent methods. β-Proteobacteria, Actinobacteria, α-Proteobacteria, and Bacteroidetes were abundant microbial taxa. The mat contained a high number of phototroph sequences. The carbon compounds in the mat displayed broad G and D bands with Raman spectroscopy. This signature becomes incorporated into the weathered oxidized surface layer of the basaltic rocks and was observed on rocks that no longer host mats. The presence of iron-oxidizing taxa in the stream microbial mats, and the lack of them in previously studied volcanic rocks in Iceland that have intermittently been exposed to surface water flows, can be explained by the kinetic limitations to the extraction of reduced iron from rocks . This type of ecosystem illustrates key factors that control the distribution of chemolithotrophs in cold volcanic environments. The data show that one promising sample type for which the hypothesis of the existence of past life on Mars can be tested is the surface of volcanic rocks that, previously, were situated within channels carved by flowing water. Our results also show that the carbonaceous signatures of life, if life had occurred, could be found in or on these rocks.
Corn snack fortified with 7% fish protein powder made from saithe (Pollachius Virens) surimi was selected by expert panel from industry for consumer studies in Iran and Iceland. They hedonically screened products with 3%, 5%, 7% and 9% fish protein powder. Snack containing 9% fish protein powder (FP) had significantly lower liking for odor, texture, flavor, and overall acceptability than the other three prototypes. Snacks fortified with 3%, 5%, and 7% FP had similar sensory attributes. Therefore, snack with the highest level of FP (7%) was selected for acceptance tests. It was seasoned with cheese powder, vegetable oil, salt, and colorant. The amount of protein, moisture, fat, ash and salt in fortified corn snack (FCS) was 12%, 2%, 31%, 3%, and 2% respectively. Consumers' acceptance was studied using a central location test method. Consumers were 6–16 years old children in two communities (Iceland and Iran). They liked FCS but Iranian children favored it more than Icelandic children. Majority of parents of the participants expressed their willingness to choose this product when buying snacks.
Bacteria inhabiting crystalline rocks from two terrestrial Icelandic volcanic lava flows of similar age and from the same geographical region, but differing in porosity and mineralogy, were characterized. Microarray (PhyloChip) and clone library analysis of 16S rRNA genes revealed the presence of a diverse assembly of bacteria in each lava flow. Both methods suggested a more diverse community at the Dómadalshraun site (rhyolitic / andesitic lava flow) than that present at the Hnausahraun site (basaltic lava flow). Proteobacteria dominated the clone library at the Dómadalshraun site, while Acidobacteria was the most abundant phylum in the Hnausahraun site. Although analysis of similarities of denaturing gradient gel electrophoresis profiles suggested a strong correlation of community structure with mineralogy, rock porosity may also play an important role in shaping the bacterial community in crystalline volcanic rocks. Clone sequences were most similar to uncultured microorganisms, mainly from soil environments. Of these, Antarctic soils and temperate rhizosphere soils were prominent, as were clones retrieved from Hawaiian and Andean volcanic soils. The novel diversity of these Icelandic microbial communities was supported by the finding that up to 46% of clones displayed <85% sequence identities to sequences currently deposited in the RDP database.
Aims: Campylobacter jejuni isolates from various sources in Iceland were genotyped with the aim of assessing the genetic diversity, population structure, source distribution and campylobacter transmission routes to humans.
Methods and Results: A collection of 584 Campylobacter isolates were collected from clinical cases, food, animals and environment in Iceland in 1999–2002, during a period of national Campylobacter epidemic in Iceland. All isolates were characterized by pulse field gel electrophoresis (PFGE), and selected subset of 52 isolates representing the diversity of the identified PFGE types was further genotyped using multilocus sequence typing (MLST) and fla-SVR sequencing to gain better insight into the population structure.
Conclusions: The results show a substantial diversity within the Icelandic Campylobacter population. Majority of the human Campylobacter infections originated from domestic chicken and cattle isolates. MLST showed the isolates to be distributed among previously reported and common sequence type complexes in the MLST database.
Significance and Impact of the Study: The genotyping of Campylobacter from various sources has not previously been reported from Iceland, and the results of the study gave a valuable insight into the population structure of Camp. jejuni in Iceland, source distribution and transmission routes to humans. The geographical isolation of Iceland in the north Atlantic provides new information on Campylobacter population dynamics on a global scale.
Fish protein isolate (FPI) made from haddock (Melanogrammus aeglefinus) cut-offs by the pH-shift process was added to haddock mince to make two groups of fried fish balls. The proportions (%) of mince to isolate were 100: 0 (control group), 75:25 and 50:50. All groups were air packed and kept frozen at −18C. The sample groups were evaluated by sensory evaluation 1 day after processing and after 2, 4 and 8 weeks of storage at −18C. The results indicated that added FPI to mince and frozen storage affected the odor, flavor, texture and appearance of fish balls significantly, possibly because of chemical and biochemical changes of all groups. This study also revealed that most negative features are attributed to the groups containing 50% mince and 50% isolate. The results can be considered for product development of FPI.
Sensory characteristics of farmed cod exposed to low or conventional stress levels prior to slaughter were evaluated by a trained sensory panel. Consumers in two different settings, central location test (CLT) and home-use test (HUT), also tasted the products and rated them according to overall liking on a 9-point hedonic scale and sensory attributes on a 9-point intensity scale. Differences were observed in texture attributes of the two cod groups by the trained sensory panel. Consumers in the CLT distinguished between the two cod groups whereas consumers in the HUT setting did not. Consumers in the CLT scored the products lower with regard to liking, and evaluated sensory attributes differently from consumers in the HUT setting. The results indicated that the cooking method chosen by consumers in the HUT setting influenced the consumer evaluation of cod. Similar cooking methods used in CLT and HUT produced similar results of liking.
Sensory characteristics of cod products available to consumers were analyzed, and different ways to analyze sensory results were viewed. Ten cod samples of different origin (wild and farmed cod), storage time (short and extended) and storage method (stored fresh, frozen or packed in modified atmosphere) were evaluated with quantitative descriptive analysis by a trained sensory panel. Signal-to-noise analysis, p * MSE (discrimination and repeatability) and line plots proved to be very useful in studying panelists' performance. Most sensory attributes described significant differences between the products, and principal component analysis provided an overview of the differences and similarities between the products with regard to sensory characteristics. Farmed cod had different sensory characteristics compared to wild cod, such as more meat flavor, and rubbery and meaty texture. Different storage methods had minor influence on sensory characteristics of cod fillets after short storage time, but after extended storage, the groups were different with regard to most attributes.
The effects of Fucus vesiculosus extract and fractions towards haemoglobin- (Hb-) catalysed lipid oxidation in washed cod muscle system and cod protein isolates during ice storage were examined. The extract and fractions were characterized in terms of total phlorotannin content (TPC), 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging activity, ferrous ion-chelating ability and reducing power. Progression of oxidation was followed by determining rancid odor, thiobarbituric acid reactive substances (TBARS), redness and volatile oxidation compounds by gas chromatography (GC). In both washed cod muscle and protein isolates, phlorotannin-enriched ethyl acetate (EtOAc) fraction showed higher inhibitory effect than crude 80% ethanol (EtOH) extract. The addition of oligomeric phlorotannin-rich subfraction (LH-2) separated by Sephadex LH-20 chromatography, completely inhibited the initiation of lipid peroxidation in both systems throughout the entire study period (8 days). Its effectiveness at 300 mg / kg level was comparable to that of 100 mg / kg propyl gallate (PG), a highly effective synthetic antioxidant in muscle foods. Although polymeric phlorotannin-rich subfraction (LH-5) had similar level of TPC and chemical antioxidant activities as oligomeric subfraction LH-2, it was far less efficient in model systems. These results suggest that other factors rather than the intrinsic reactivity toward radicals could be responsible for the inhibitory effect of phlorotannins on lipid oxidation in fish muscle. This study highlights the great potential of oligomeric phlorotannins as novel natural antioxidants in fish and fish products.