如何使农业食品供应链变得可持续：多国公司观点

联合利华公司简介 联合利华公司是一家多国公司,生产食品以及家庭和个人护理制品方面的名牌畅销消费品.联合利华公司食品占其业务量的略多于50%.农业(包括畜牧业和渔业)提供联合利华公司全部原材料的估计三分之二.     

Development of environmental thresholds for nitrogen and phosphorus in streams

Inputs of nutrients (P and N) to freshwaters can cause excessive aquatic plant growth, depletion of oxygen, and deleterious changes in diversity of aquatic fauna. As part of a "National Agri-Environmental Standards Initiative," the Government of Canada committed to developing environmental thresholds for nutrients to protect ecological condition of agricultural streams. Analysis of data from >200 long-term monitoring stations across Canada and detailed ecological study at ~70 sites showed that agricultural land cover was associated with increased nutrient concentrations in streams and this, in turn, was associated with increased sestonic and benthic algal abundance, loss of sensitive benthic macroinvertebrate taxa, and an increase in benthic diatom taxa indicative of eutrophication. Chemical thresholds for N and P were defined by applying five approaches, employing either a predetermined percentile to a water chemistry data set or a relationship between water chemistry and land cover, to identify boundaries between minimally disturbed and impaired conditions. Comparison of these chemical thresholds with biological thresholds (derived from stressor-response relationships) produced an approach for rationalizing these two types of thresholds and deriving nutrient criteria. The resulting criteria were 0.01 to 0.03 mg L(-1) total P and 0.87-1.2 mg L(-1) total N for the Atlantic Maritime, 0.02 mg L(-1) total P and 0.21 mg L(-1) total N for the Montane Cordillera, ~0.03 mg L(-1) total P and ~1.1 mg L(-1) total N for the Mixedwood Plains, and ~0.10 mg L(-1) total P and 0.39-0.98 mg L(-1) total N for the interior prairies of Canada. Adoption of these criteria should result in greater likelihood of good ecological condition with respect to benthic algal abundance, diatom composition, and macroinvertebrate composition.     

如何使农业食品供应链变得可持续：多国公司观点

联合利华公司简介 联合利华公司是一家多国公司,生产食品以及家庭和个人护理制品方面的名牌畅销消费品.联合利华公司食品占其业务量的略多于50%.农业(包括畜牧业和渔业)提供联合利华公司全部原材料的估计三分之二.     

Exploring the possibilities of seaward migrating juvenile European sturgeon Acipenser sturio L., in the Dutch part of the River Rhine

The water quality of the River Rhine has improved and might again suit the critically endangered European sturgeon A. sturio L, which was extirpated from the river by 1950. This study describes the tracking of 43 juvenile hatchery-reared A. sturio, in the Dutch part of the Lower Rhine and Delta, originating from an ex situ measure of the River Gironde population. Observing in situ juvenile downstream migration could help to identify essential habitats and potential threats, before actual stocking. Fish were implanted with transponders of the NEDAP Trail® system and released in two batches, in May (n?=?13) and June 2012 (n?=?30). Detections collected (n?=?26) exhibited no upstream movement. Test-fish moved downstream with the flow. Because the historic estuary is disconnected from the North Sea by a sea lock “Haringvlietdam”, the migration of the fish followed the re-directed river discharge into the Port of Rotterdam (161 km). 96 % (n?=?19) of the detections was collected from the harbor in brackish water, where fish presumably acclimatized to higher salinities. 14 % (n?=?6) of the sturgeons were recaptured in coastal waters by beam trawlers, five within 1 month after release. It is concluded that sustainable coastal fisheries is a key-condition for rehabilitation of the European sturgeon. Adapted management of the sea lock will reconnect the estuary to the North Sea and create more favorable conditions for the species in the Lower Rhine and Delta.     

Exorbitant mortality of hatchery-reared Atlantic salmon smolts Salmo salar L., in the Meuse river system in the Netherlands

Stocking Atlantic salmon Salmo salar L. in the Meuse river system is unsuccessful, since hardly any adults return upstream. To investigate problems during seaward migration, individual salmon smolts were tracked in the Dutch part of the river Meuse, using the Nedap Trail® system. The study included a comparison for two seasons, one with high (2010) and one with low (2011) discharge conditions. Cultivated smolts (Loire-Allier strain, n = 100 per year) were implanted with telemetry tags and released in the tributary Roer in March, at the beginning of the natural smolt run. The study area was split into four river sections each characterized by different conditions: tributary Roer, main river Meuse extensively dammed, main river Meuse free flowing and the estuary. Mortalities differed considerably between sections. In the free flowing river Meuse the mortalities were relatively low (10 and 25 %). Mortalities were high in the tributary (44 and 45 %), the dammed river (46 and 49 %) and in the estuary (89 and 90 %). Only 2 and 3 % of the smolts escaped into the North Sea. Results are discussed in relation to environmental factors light and discharge and the presence of man-made obstacles: weirs, hydropower plants and a sea lock. A lack of current and delays at man-made obstacles result in disorientation of fish, a higher risk of predation and disturbance of the smolt run timing. Mortality causes must decrease for sustaining a salmon population in the Meuse.     

Using fatty acids to fingerprint biofilm communities: a means to quickly and accurately assess stream quality

The assessment of lotic ecosystem quality plays an essential role to help determine the extent of environmental stress and the effectiveness of restoration activities. Methods that incorporate biological properties are considered ideal because they provide direct assessment of the end goal of a vigorous biological community. Our primary objective was to use biofilm lipids to develop an accurate biomonitoring tool that requires little expertise and time to facilitate assessment. A model was created of fatty acid biomarkers most associated with predetermined stream quality classification, exceptional warm water habitat (EWH), warm water habitat (WWH), and limited resource (LR-AMD), and validated along a gradient of known stream qualities. The fatty acid fingerprint of the biofilm community was statistically different (P?=?0.03) and was generally unique to recognized stream quality. One striking difference was essential fatty acids (DHA, EPA, and ARA) were absent from LR-AMD and only recovered from WWH and EWH, 45 % more in EWH than WWH. Independently testing the model along a stream quality gradient, this model correctly categorized six of the seven sites, with no match due to low sample biomass. These results provide compelling evidence that biofilm fatty acid analysis can be a sensitive, accurate, and cost-effective biomonitoring tool. We conceive of future studies expanding this research to more in-depth studies of remediation efforts, determining the applicable geographic area for the method and the addition of multiple stressors with the possibility of distinguishing among stressors.     

Periphyton as an indicator of water quality in the St Lawrence River (Québec, Canada)

The performance of various algal indices to document improvements in water quality across a low nutrient concentration gradient was assessed during 2 years in the St Lawrence River (Quebec, Canada). Water-quality variables and periphyton samples were collected on navigational buoys near Montreal during the spring, summer and fall of 1994 and 1995. Exposure to urban wastewater varied widely within the sector surrounding the island of Montreal, with some areas upstream receiving no direct effluents and areas further downstream receiving treated and untreated wastewater. Faecal coliform concentrations provided a good tracer of effluents and were significantly correlated to nutrient concentrations (r = 0.33-0.72, p < 0.001) and water transparency (r = 0.70, p < 0.001). Despite a strong gradient in faecal coliform concentration (< 2 to > 20 000 UFC/100 ml), algal biomass and diversity did not reflect differences between sites with varying levels of urban wastewater. Taxonomic composition of periphyton communities, particularly the presence of the cyanophyte Plectonema notatum Schmidle, was related (r = 0.48, p = 0.004) to exposure to urban effluents. Variables describing seasonal changes (temperature, Julian day, river discharge, conductivity, NO2-NO3) explained a large fraction of total variance (38-52% of total variance) and thus exerted the predominant influence on algal biomass and species composition in the St Lawrence River. Variables describing the presence of effluents explained 1-22% of the variance in compositional data. Subtle changes in periphyton species composition were the only response to different levels of exposure to urban wastewater in the Montreal area, which represented relatively small differences in comparison to natural seasonal variability.