Spatial variation in concentrations and patterns of the PCDD/F and dioxin-like-PCB content in herring from the northern Baltic Sea

The purpose of the current study was to investigate spatial and seasonal variation of dioxin and dioxin-like PCB (dl-PCB) content in herring sampled along the northern Baltic Sea coast and map out risk zones for dioxins and dl-PCBs. We further aimed to investigate relationships between congener distribution (pattern) and sampling location and season. The results showed that there were distinct geographical differences in concentrations of dioxins, dibenzofurans and dl-PCBs along the Swedish coast, from the Bothnian Bay to north Baltic Proper, with the highest levels detected in the southern Bothnian Sea. The majority of the locations showed concentrations above the prescribed maximum for dioxin residues (4 TEQ pg g(-1) wet weight [w.w.]). If all the edible parts of the fish (muscle, subcutaneous fat and skin) are considered, the estimated concentrations exceeded the prescribed maximum level in the whole study area for herring collected during spring-summer. Concentrations in herring caught during spring-summer compared to concentrations in herring sampled in the autumn indicated seasonal variation. The pattern analysis showed a variation in relative congener concentration at the different sampling locations (spring-summer). Pattern differences were also noticed between seasons.     

Human impact on the fish diversity in the four largest lakes of Sweden

The four largest Swedish lakes, V?nern, V?ttern, M?laren, Hj?lmaren, host important commercial fisheries for char, salmon, trout, whitefish, vendace (cisco), perch, pike-perch, pike and eel, i.e. highly diverse biological resources. Case studies illustrate physical, chemical and biological impacts on some of these commercial species caused by constructions of dams and ship canals, eutrophication, and overexploitation. Although some original species have been lost and a few new species have been added, the recent human interference has basically caused major shifts in dominance of the fish community structures because of eutrophication, alterations in the abundance of eel or crayfish, and due to overfishing. The latter is in some cases caused by the Great Lake Fishery Paradox--in an environment with several predators and competitors, but with ample food resources, especially salmonid fish but also species like pike-perch may adapt a life history favoring growth over sexual maturation. If harvested at a conventional size these populations will decline rapidly due to too small spawning stocks.     

Temporal and spatial trends of PCBs,DDTs, HCHs,and HCB in Swedish marine biota 1969–2012

In the 1960s, the Baltic Sea was severely polluted by organic contaminants such as PCBs, HCHs, HCB, and DDTs. Elevated concentrations caused severe adverse effects in Baltic biota. Since then, these substances have been monitored temporally and spatially in Baltic biota, primarily in herring (Clupea harengus) and in guillemot (Uria aalge) egg, but also in cod (Gadus morhua), perch (Perca fluviatilis), eelpout (Zoarces viviparous), and blue mussel (Mytilus edulis). These chemicals were banned in Sweden in the late 1970s/early 1980s. Since the start of monitoring, overall significant decreases of about 70–90 % have been observed. However, concentrations are still higher in the Baltic Sea than in, for example, the North Sea. CB-118 and DDE exceed the suggested target concentrations (24 µg kg^?1 lipid weight and 5 µg kg^?1 wet weight, respectively) at certain sites in some of the monitored species, showing that concentrations may still be too high to protect the most sensitive organisms.     

The Swedish joint action method against drink driving—a study of suspected drink drivers' own experiences

Objective: In Sweden, a joint action method called SMADIT is in use, where the police quickly offer help from the social services or the dependency care and treatment service to suspected drink drivers. The objective of this article is to analyze the experiences of suspected drink drivers who accepted the offer of help and what it meant for them. The knowledge can be used to improve procedures and consultations. Furthermore, it can allow the basic premises of the method to be examined; for example, the importance of offering help quickly.

Methods: To enable comparisons over time, in-depth interviews were conducted with 12 suspected drink drivers on 2 occasions with 1 year between.

Results: To varying degrees the informants knew about their alcohol problems but were unsure whether they would have sought help by themselves. Therefore, the original ideas of the method with an initial contact with the social services or the dependency care and treatment service within 24 h was found to be important. However, the results also showed that some of the informants needed some time before the first meeting because they were in shock from the drink driving incident or in need of sleep. Therefore, the drink driver's situation and individual wishes always have to be considered. The article also shows that an encouraging attitude among the police, the social services, and the dependency care and treatment service is important for the success of the SMADIT method.

The informants are satisfied with the method and in retrospect the incident and the SMADIT offer of help are described as a turning point in their lives. One year after being offered help the informants were no longer focused solely on the personal consequences of drink driving, as they were shortly after the incident. Instead, they had gained insights into the harm they could have done to other road users when they drove while drunk.

Conclusions: One conclusion from this article is that SMADIT, as an innovative method that can be deployed more rapidly than other alcohol-impaired driving countermeasures, should be considered as a good complement to conventional methods to deal with drink driving. Based on the results, we recommend a trial of the joint action method against drink driving in other jurisdictions.     

瑞典四大湖中人类活动对鱼类多样性的影响

瑞典四大湖(维纳恩、韦特恩、梅拉伦和哈马伦湖)的鱼类资源极其丰富,分布有红点鲑、鲑、鳟、白鲑、河鲈、梭鲈,、白斑狗鱼和鳗鲡等经济物种.研究表明,筑坝、航运、富营养化和过度开发等所产生的物理、化学和生物因素会对湖中的经济物种产生影响,导致湖中原有物种资源的种类组成发生变化.由于近年来的人类活动的影响,上述湖泊中原有鱼类组成中的优势种群发生了变化,一些物种消失了,一些新的物种在湖中出现,其原因主要是富营养化、鳗鲡和龙虾丰度的改变以及过度捕捞.过度捕捞在某种情况下是大湖的渔业生产引起的--在一个捕食者和竞食者同时存在的环境中,如果食物资源非常充足,鲑科鱼类以及梭鲈等鱼类在生活史上会倾向于在性成熟状态下生长,但在常规可捕规格的选择性调控下,这些物种会因产卵群体太小而导致资源量急刷下降.