Environmental contaminant concentrations in Canada goose (Branta canadensis) muscle: probabilistic risk assessment for human consumers.

The issue of food insecurity affects millions of people in the United States every year. Often these people rely on soup kitchens, food banks, and shelters for proper meals, and these organizations often depend on donations to meet needs. One of the most limited food resources is meat. To help alleviate this problem, the U.S. Department of Agriculture Wildlife Services donates more than 60 tons of wild game (deer, moose, feral hogs, goats, geese, and ducks) to a variety of charitable organizations each year. Although commercially produced meat routinely undergoes screening for contaminants, potential exposure to environmental contaminants from eating wild game is not well characterized. In this study, the concentration of 17 contaminants of concern in the breast meat of wild geese was examined. These concentrations were then used in a probabilistic model to estimate potential risk associated with consumption of this meat. Based on model predictions, more than 99 % of all adults were below exposure limits for all of the compounds tested. For all consumer age classes modeled, consumption of wild goose meat may expose a small fraction of these populations to levels of lead higher than the recommended exposure limits. Similarly, mercury exposure was predicted to be higher than the recommended limits when the meat was served as steaks. This information about concentrations of contaminants of concern in goose meat and potential exposures associated with meat consumption based on probabilistic models will enable others to make informed decisions about the risks associated with the consumption of wild meat.

Nutritional quality of salmon products available from major retailers in the UK: content and composition of n-3 long-chain PUFA.

In the present study, salmon products available from UK retailers were analysed to determine the levels of n-3 long-chain PUFA (LC-PUFA), a key determinant of nutritional quality. There was a wide variation in the proportions and absolute contents of EPA and DHA in the products. Relatively high contents of 18 : 1n-9, 18 : 2n-6 and 18 : 3n-3, characteristic of vegetable oils (VO), were found in several farmed salmon products, which also had generally lower proportions of EPA and DHA. In contrast, farmed salmon products with higher levels of 16 : 0 and 22 : 1, characteristic of fish oil (FO), had higher proportions of EPA and DHA. Therefore, there was a clear correlation between the levels of VO and FO in feeds and the proportions of n-3 LC-PUFA in products. Although wild salmon products were characterised by higher proportions of n-3 LC-PUFA (20-40%) compared with farmed fish (9-26%), they contained lower total lipid contents (1-6% compared with 7-17% in farmed salmon products). As a result, farmed salmon products invariably had higher levels of n-3 LC-PUFA in absolute terms (g/100 g fillet) and, therefore, delivered a higher 'dose' of EPA and DHA per portion. Overall, despite the finite and limiting supply of FO and increasing use of VO, farmed salmon continue to be an excellent source of and delivery system for n-3 LC-PUFA to consumers.

Dietary differences are reflected on the gut prokaryotic community structure of wild and commercially reared sea bream (Sparus aurata).

We compared the gut prokaryotic communities in wild, organically-, and conventionally reared sea bream (Sparus aurata) individuals. Gut microbial communities were identified using tag pyrosequencing of the 16S rRNA genes. There were distinct prokaryotic communities in the three different fish nutritional treatments, with the bacteria dominating over the Archaea. Most of the Bacteria belonged to the Proteobacteria, Firmicutes, Actinobacteria, and Bacteroidetes. The number of bacterial operational taxonomic units (OTUs) was reduced from the wild to the conventionally reared fish, implying a response of the gut microorganisms to the supplied food and possibly alterations in food assimilation. The dominant bacterial OTU in all examined fish was closely related to the genus Diaphorobacter. This is the first time that a member of the ß-Proteobacteria, which dominate in freshwaters, are so important in a marine fish gut. In total the majority of the few Archaea OTUs found, were related to methane metabolism. The inferred physiological roles of the dominant prokaryotes are related to the metabolism of carbohydrates and nitrogenous compounds. This study showed the responsive feature of the sea bream gut prokaryotic communities to their diets and also the differences of the conventional in comparison to the organic and wild sea bream gut microbiota.

Fourier transform infrared spectroscopy as a tool to study farmed and wild sea bass lipid composition.

BACKGROUND: The lipids of 16 farmed and wild European sea bass (Dicentrarchus labrax) samples were studied by Fourier transform infrared (FTIR) spectroscopy. The spectroscopic parameters which would be useful when distinguishing between both fish origins were analysed. RESULTS: It was shown, for the first time, that the frequency and the ratio between the absorbance of certain bands are efficient and reliable authentication tools for the origin of sea bass. Furthermore, relationships between infrared data and fish lipids composition referring to the molar percentage or concentration of certain acyl groups were also studied. It was proved that some infrared spectroscopic data (the frequency of certain bands or the ratio of the absorbance of others), are very closely related to the composition of sea bass lipids. It was shown for the first time that certain infrared spectroscopic data could predict, with a certain degree of approximation, the molar percentage, or concentration, of omega-3, docosahexaenoic (DHA) and di-unsaturated omega-6 (linoleic) in sea bass lipids. CONCLUSION: The consistency of the results confirms the usefulness of FTIR spectroscopy to detect frauds regarding sea bass origin, and to provide important compositional data about sea bass lipids from the nutritional and technological point of view.

Biological response of free-living mouse Mus spretus from Doñana National Park under environmental stress based on assessment of metal-binding biomolecules by SEC-ICP-MS.

A metallomic approach based on the use of size-exclusion chromatography (Superdex-75) with inductively coupled plasma mass spectrometry (ICP-MS) detection is combined with anion or cation exchange chromatography to characterize the biological response of the free-living mouse Mus spretus. The approach has been applied to contaminated and non-contaminated areas from Doñana National Park (southwest Spain) and the surroundings. Several areas affected by differential contamination from mining, industrial, and agricultural activities have been considered. The high presence of Mn, Cu, and Zn in liver and As and Cd in kidney is remarkable, especially in contaminated areas. The size exclusion chromatograms traced by Mn in liver cytosolic extracts are more intense than in kidney; a Mn-peak matching with the standard of 32 kDa (superoxide dismutase) is present in these organs, and its intensity is correlated with the concentration of Mn in the extracts. High-intensity peaks traced by Cu, Zn, and Cd at 7 kDa (matching with metallothionein I standard) in liver extract are triggered by the presence of contaminants. Other peaks related with molecules of 32 and 67 kDa traced by Cu and Zn can also be observed, although their intensity is higher in sites with low contamination. In kidney extracts, the presence of a Cd-peak with Mr of 7 kDa (tentatively Cd-metallothionein) with high intensity under the action of contaminants was observed, but high biological responses are also proven in the protected area of the Park, which denotes a progressive increase of diffuse contamination.

Assessment of lipid and essential fatty acids requirements of black seabream (Spondyliosoma cantharus) by comparison of lipid composition in muscle and liver of wild and captive adult fish.

The primary aim of the present study was to compare the contents of total lipid, lipid classes and their associated fatty acids in muscle and liver of wild and one-year captive black seabream (Spondyliosoma cantharus) adults, in order to elucidate the lipid and fatty acids requirements of this fish species of potential interest for aquaculture. The total lipid contents (TL) of muscle and liver of the captive fish were 2.5-fold greater than those of the wild fish. In consequence, contents of triacylglycerols were much higher in tissues of the captive fish. Distribution of fatty acids in total lipids and lipid classes of muscle and liver was also different between both groups of fish. For instance, percentages of 20:4n-6, 20:5n-6 and 22:6n-3 were considerably higher in the wild fish, whereas 18:1, 20:1, and 22:1n-9 as well as 18:2n-6 and 20:5n-3 were more abundant in the captive fish. These results suggest that the lipid composition of the commercial diet supplied to the captive black seabream differed greatly from that of the diet consumed by the fish in the wild, which hypothetically contains the desirable composition for the lipid nutrition of this fish species. Despite the good growth and survival achieved by the black seabream after one year in captivity, the significant accumulation of lipids and the imbalance of essential fatty acids in their muscle and livers, together with the absence of spawning, suggest that future research on the lipid requirements of this omnivorous species is necessary in order to establish whether the administration of currently available aquaculture formulated feeds is adequate for good black seabream performance and reproduction.

Daily energy expenditure of the grey mouse lemur (Microcebus murinus): a small primate that uses torpor.

We aimed to investigate the pattern of utilisation of torpor and its impact on energy budgets in free-living grey mouse lemurs (Microcebus murinus), a small nocturnal primate endemic to Madagascar. We measured daily energy expenditure (DEE) and water turnover using doubly labelled water, and we used temperature-sensitive radio collars to measure skin temperature (Tsk) and home range. Our results showed that male and female mouse lemurs in the wild enter torpor spontaneously over a wide range of ambient temperatures (Ta) during the dry season, but not during the rainy season. Mouse lemurs remained torpid between 1.7-8.9 h with a daily mean of 3.4 h, and their Tsk s fell to a minimum of 18.8 degrees C. Mean home ranges of mouse lemurs which remained normothermic were similar in the rainy and dry season. During the dry season, the mean home range of mouse lemurs showing daily torpor was significantly smaller than that of animals remaining normothermic. The DEE of M. murinus remaining normothermic in the rainy season (122 +/- 65.4 kJ x day(-1)) was about the same of that of normothermic mouse lemurs in the dry season (115.5 +/- 27.3 kJ x day(-1)). During the dry season, the mean DEE of M. murinus that utilised daily torpor was 103.4 +/- 32.7 kJ x day(-1) which is not significantly different from the mean DEE of animals remaining normothermic. We found that the DEE of mouse lemurs using daily torpor was significantly correlated with the mean temperature difference between Tsk and Ta (r2 = 0.37) and with torpor bout length (r2 = 0.46), while none of these factors explained significant amounts of variation in the DEE of the mouse lemurs remaining normothermic. The mean water flux rate of mouse lemurs using daily torpor (13.0 +/- 4.1 ml x day(-1)) was significantly lower than that of mouse lemurs remaining normothermic (19.4 +/- 3.8 ml x day(-1)), suggesting the lemurs conserve water by entering torpor. Thus, this first study on the energy budget of free-ranging M. murinus demonstrates that torpor may not only reflect its impact on the daily energy demands, but involve wider adaptive implications such as water requirements.