Diatom stratigraphy in five offshore sediment cores from the northwestern Baltic proper implying large scale circulation changes during the last 8500 years

Five Holocene sediment cores from the northwestern Baltic proper were analysed for lithology, siliceous microfossil assemblages and geochemical parameters. The data indicate that surface water salinity and redox conditions below the halocline have changed drastically at least four times since the Baltic Sea changed from a fresh water lake (the Ancylus Lake) to a semi-enclosed brackish water sea (the Litorina Sea) c. 8500 yrs BP. These variations appear to be mainly effects of changes in water depth at the thresholds of inlet areas. Based on these changes, and earlier studies of the shoreline displacement in the inlet areas, we propose a tentative model for changes of large scale water circulation in the Baltic Sea during the last c. 8500 yrs.At the transition from fresh to brackish water 8500 ¹⁴C yrs BP, upwelling of nutrient rich bottom water started to occur, causing a slight increase in primary production. Diatom assemblages in sediments indicate a slow rise in surface water salinity during this period.At 7000-6500 ¹⁴C yrs BP, surface water salinity and primary production simultaneously increased, as anoxic bottom conditions were established at depth below the halocline. We suggest that high primary production was caused by increased input of oceanic water, leading to increased upwelling of nutrient rich bottom water. At the anoxic bottoms laminated sediments formed until 5000-4500 ¹⁴C yrs BP. This period (c. 7000-4500 ¹⁴C BP) was contemporaneous with the post-glacial transgression maximum in Öresund, and we suggest it represents the most saline phase of the Baltic Sea post-glacial history.Due to a regression in Öresund starting 4500 ¹⁴C yrs BP, upwelling decreased and the halocline was lowered, resulting in decreased primary productivity and hence oxic deep water conditions. The diatom assemblages of the sediments indicate a lowering of salinity at the beginning of this period.We suggest that the second period of anoxic bottom conditions c. 2000-1500 ¹⁴C yrs BP was caused by a change of dominating inflows from the Öresund to the Belt Sea. This resulted in decreased salinity of the inflowing water which did not penetrate to the deepest parts of the basin as frequently as before. The diatom record indicates both a second lowering of salinity and a change in the large scale water circulation at the beginning of this period.     

Magnetic susceptibility in sediment records of Lake Ådran,eastern Sweden: correlation among cores and interpretation

Magnetic susceptibility was used to test the representativity of the lithostratigraphy of a master sediment sequence from Lake Ådran, eastern Sweden. Five further sediment cores from the same lake were correlated and compared with the master sequence using magnetic susceptibility records. Mineral magnetic correlations are generally based on matching prominent susceptibility features but may be significantly improved by using slot sequence analyses. The result of these analyses show that the sediment in the Lake Ådran master sequence can be considered representative for the basin. The variations in the magnetic susceptibility in relation to pollen and diatom analyses also seem to reflect water level changes and shore displacement in the Baltic between 9900 ¹⁴C years B.P. and the isolation at 5900 ¹⁴C years B.P. The first emergence of scattered non-vegetated islands is characterised by high susceptibility values. Along with a continuous water lowering and the development of the vegetation during the Ancylus fresh water stage, susceptibility values gradually decrease. A rapid phase of the Ancylus regression between 9200 and 9000 ¹⁴C years B.P. is seen as an increase in magnetic susceptibility. During the following Baltic brackish water stage, the Litorina stage, susceptibility values are at their lowest, followed by higher values at the isolation from the Baltic with a maximum around 5000 ¹⁴C years B.P.Shore displacement between 9900 and 5900 ¹⁴C years B.P. is discussed based on the magnetic susceptibility measurements and their relationship to the pollen and diatom analyses.     

Traditional ecological knowledge and community resilience to environmental extremes: A case study in Doñana,SW Spain

Research in the last decade has emphasised the potential contribution of traditional ecological knowledge to cope with challenges from global environmental change. This research examines the role of traditional ecological knowledge and shared systems of beliefs in building long-term social–ecological resilience to environmental extremes. Data were collected from 13 villages of the Doñana region, southwestern Spain, through interviews, focus groups, and systematic reviews of historical archives. First, we assess adaptive practices to cope with environmental change. Then, we use historical records of religious ceremonies (1577–1956) to reconstruct collective responses to environmental extremes. Our results (1) show how environmental extremes could induce social and economic crises through declines in ecosystem services and (2) identify practices to cope with recurrent disturbance and institutional devices developed in response to environmental extremes. We conclude that traditional ecological knowledge and shared systems of beliefs can facilitate collective responses to crises and contribute to the maintenance of long-term resilience of social–ecological systems.     

The beginning of geography didactics in Norway

At the end of the 19th century geography became a mandatory subject in primary and secondary schools in Norway. Geography was seen as a useful subject that contributed to the modernization of society, but also as a subject that strengthened the national ideology. A need for better education in geography arose and consequently some authors of geography textbooks wrote about teaching geography. In order to strengthen teachers’ education, geography was taught at university level, and to develop the subject it became necessary to relate it to other subjects, especially geology. The author shows that there are several similarities between the content of geography taught in Norwegian schools in the late 19th century and geography taught in schools today.     

Killing Animals for Recreation? A Quantitative Study of Hunters’ Motives and Their Perceived Moral Relevance

Hunters in the Western world today do not need to hunt to obtain food and other animal products. So why do they hunt? This paper examines the motives of hunters, the motives ascribed to hunters by members of the general public, and the role motives play for the moral acceptability of hunting among members of the general public. It draws on a nationally representative survey of the general public (n?=?1,001) and hunters (n?=?1,130) in Denmark. People with a negative attitude to hunting are more likely to take motives into account when they consider the acceptability of hunting. Three clusters of motives defining distinctive hunting motivational orientations were identified: action/harvest, management/care, and natural and social encounters. The general public ascribed action/harvest motives to hunters more than hunters did. In a policy perspective, if hunters’ motives are misperceived, improved dialog may be needed to protect the legitimacy of recreational hunting.     

Investigating the Waterfront: The Entangled Sociomaterial Transformations of Coastal Space in Karnataka,India

Triggered by urbanization and changing land use, coastal transformation is a rapidly increasing phenomenon in the global south, driving dramatic livelihoods impacts. However, the existing literature on small-scale fisheries (SSF) has paid little attention to the way coastal transformations shape conditions for SSF livelihoods communities. This study proposes a new orientation in SSF studies by exploring the assemblage of entangled sociomaterial processes that account for coastal transformations by investigating waterfront transformation in a fishing community in Karnataka, India. Drawing on ethnographic fieldwork, we conclude that an entanglement of sociomaterial processes produces unequal outcomes among stakeholders that subsequently reinforce the political and economic marginalization of certain groups of waterfront users. Moreover, the investigated context-specific waterfront assemblage intimately connects to the broader context of national fishery policy, urbanization, and tourism, directing the way coastal space can and should be transformed. Such an analysis contributes to the understanding of changing livelihoods in SSF communities.     

Fourier transform infrared spectroscopy,a new method for rapid determination of total organic and inorganic carbon and biogenic silica concentration in lake sediments

We demonstrate the use of Fourier transform infrared spectroscopy (FTIRS) to make quantitative measures of total organic carbon (TOC), total inorganic carbon (TIC) and biogenic silica (BSi) concentrations in sediment. FTIRS is a fast and cost-effective technique and only small sediment samples are needed (0.01 g). Statistically significant models were developed using sediment samples from northern Sweden and were applied to sediment records from Sweden, northeast Siberia and Macedonia. The correlation between FTIRS-inferred values and amounts of biogeochemical constituents assessed conventionally varied between r = 0.84–0.99 for TOC, r = 0.85–0.99 for TIC, and r = 0.68–0.94 for BSi. Because FTIR spectra contain information on a large number of both inorganic and organic components, there is great potential for FTIRS to become an important tool in paleolimnology.