Teil 3: PCDD/F im Blutfett ausgewählter Personen

This study was designed to assess the degree of exposure to PCDD/F in 56 selected persons living in the vicinity of a former copper smelter located in Marsberg, Germany. The copper smelter was in operation until 1945. In 1991, high levels of PCDD/F were found particularly in materials from the slag dumps (10 000 – 100 000 ng TE/kg). The levels of PCDD/F in blood fat were used as parameters for individual PCDD/F exposure. Since only limited reference data for PCDD/F in human blood were available, blood samples of a reference group were analyzed in the same way. The criteria were collected from a group matched for sex, age (±3 years) and body mass. The median NATO/CCMS-Toxicity equivalency values (NATO/CCMS-TE-values) of the Marsberg group (43,2 pg NATO/CCMS-TE/g blood fat) and the reference group (43,0 pg NATO/CCMS-TE/g blood fat) were similar, whereas the arithmetic mean of the Marsberg group (52,7 pg NATO/CCMS-TE/g blood fat) was higher than that of the reference group (44,4 pg NATO/CCMS-TE/g blood fat). The frequency distribution of the individual TE-values of the Marsberg group was slightly shifted toward higher values. The individuals of the Marsberg group had significantly higher levels of PentaCDF, HexaCDF and HeptaCDF on average than the individuals of the reference group. On the basis of TE-values, the majority of the individuals from Marsberg did not have an increased body burden of PCDD/F. However, some individuals could be identified with TE-values exceeding background levels ranging up to 231 pg NATO/CCMS-TE/g blood fat. Although it must be assumed that the unusual congener pattern found in many of the test subjects is a result of ingestion of contaminated slag material or soil, the findings of this study could not verify this fact.     

<Emphasis Type="Italic">Sympagohydra tuuli</Emphasis> (Cnidaria,Hydrozoa): first report from sea ice of the central Arctic Ocean and insights into histology,reproduction and locomotion

Various cnidarians have adapted their life style to interstitial habitats of marine sediments. Recently, for the first time a hydroid was reported from the interstitial brine channel system of Arctic fast ice. Due to its derived features, the new genus and species Sympagohydra tuuli was introduced. Here we describe findings of S. tuuli in sea ice at several sites within the central Arctic Ocean. In our view the results of this study do not allow assignment of Sympagohydra to any known family and we, therefore, suggest the introduction of a new family Sympagohydridae which is placed within the hydrozoan subclass Hydroidolina, order Anthomedusae, suborder Capitata. A first detailed histological analysis of S. tuuli is presented. In vivo analysis of locomotion and reproduction revealed a remarkable convergent evolution in S. tuuli and distant meiobenthic relatives. Shared traits are a flagellated epidermis enabling the animals to glide within small interstices by means of flagellar beating as well as an internalised embryogenesis. In S. tuuli gametogenesis occurs in the absence of gonophores inbetween gastro- and epidermis clearly separated from the epidermis. Budding was observed as the vegetative mode of reproduction. Documentation of feeding behaviour identified copepod nauplii and rotifers as prey items and demonstrates a high trophical position of the hydroids within the sympagic food web. Occurrence of reproducing individuals and pronounced tolerances towards changing temperatures and salinities indicate S. tuuli as a truly sympagic species. Electronic supplementary material  The online version of this article (doi:) contains supplementary material, which is available to authorized users.     

STORM DISCHARGE,LOADS, AND AVERAGE CONCENTRATIONS IN NORTHWEST OHIO RIVERS, 1975–19951

ABSTRACT: A computerized technique was developed to identify storm runoff episodes and calculate storm discharges, storm loads, and storm average concentrations for each event in datasets with up to 10,000 records. This technique was applied to four watersheds within the Lake Erie drainage basin and identified between 160 and 250 runoff events in each. Storm event loads and storm event mean concentrations were calculated for each runoff event for suspended solids, total phosphorus, soluble reactive phosphorus, nitrate, and total Kjeldahl nitrogen. The basic characteristics of the resulting data are described, as are systematic differences as a function of watershed size, seasonal differences, and trends over time. Many of the results of this study reflect the importance of nonpoint processes and improvements in agricultural best management practices in these watersheds.     

Body size and reserve protection affect flight initiation distance in parrotfishes

Flight initiation distance (FID), the distance at which an organism begins to flee an approaching threat, is an important component of antipredator behavior and a potential indicator of an animal’s perception of threat. In a field study on parrotfishes, we tested the predictions that FID in response to a diver will increase with body size, a correlate of reproductive value, and with experience of threat from humans. We studied a broad size range in four species on fringing reefs inside and outside the Barbados Marine Reserve. We used the Akaike's Information Criterion modified for small sample sizes (AICc) and model averaging to select and assess alternative models. Body size, reserve protection, and distance to a refuge, but not species, had strong support in explaining FID. FID increased with body size and generally remained two to ten times fish total length. FID was greater outside the reserve, especially in larger fish. Although we were not able to completely rule out other effects of size or reserve, this study supports predictions of an increase in FID with reproductive value and threat from humans.     

Functional connectivity from a reef fish perspective: behavioral tactics for moving in a fragmented landscape

Functional connectivity, the degree to which the landscape facilitates or impedes movement, depends on how animals perceive costs and benefits associated with habitat features and integrate them into a movement path. There have been few studies on functional connectivity in marine organisms, despite its importance for the effectiveness of Marine Protected Areas. In this study, we asked how open sand and conspecific distribution affected functional connectivity of longfin damselfish (Stegastes diencaeus) on fringing reefs in Barbados. We translocated 102 individuals to sites varying in sand gap width and in configuration: Continuous (solid reef between release site and territory); Detour (sand along the direct path between release site and territory, but an alternative, continuous solid U-shaped reef path); and Patch (sand between release site and territory, but an alternative stepping stone path). We visually tracked and mapped every homing path. We found no evidence of a barrier to movement in the Continuous configuration, but sand was a partial barrier in Detour and Patch configurations. The probability of crossing the sand gap dropped below 50% when its width was > 1.85 m in Detour and > 3.90 m in Patch configuration. Damselfish avoiding large gaps took detours that approximated the route maximizing travel over reef, but they crossed more short sand gaps and fewer conspecific territories, suggesting avoidance of agonistic interactions. This study quantifies for the first time the size and steepness of a barrier to movement in a marine organism, and it provides evidence for effects of both landscape configuration and conspecific distribution on functional connectivity.     

Adsorption and transport of arsenic(V) in experimental subsurface systems

The adsorption and transport of As(V) in a heterogeneous, iron oxide-containing soil was investigated in batch and column laboratory experiments. The As(V) adsorbed rapidly to the soil over the first 48 h, but continued to adsorb slowly over the next several weeks, clearly indicating the potential for rate-limited transport. The equilibrium As(V) adsorption isotherm was markedly nonlinear, further indicating the potential for nonideal transport. A model developed for the adsorption of As(V) to hydrous ferric oxide (HFO) was able to predict the pH-dependent adsorption of As(V) to the soil in batch experiments within 0.116 to 0.726 root mean square error (RMSE). Arsenic(V) was significantly retarded in column transport experiments. The column transport experiments were modeled using the one-dimensional advection-dispersion equation, considering both linear and nonlinear adsorption equilibrium. Although the nonlinear local equilibrium model (NLLE, RMSE = 0.273) predicted the data better than the linear local equilibrium model (LLE, RMSE = 0.317), As(V) breakthrough occurred more rapidly than predicted by either model due to adsorption nonequilibrium. However, due to the presence of an irreversible or slowly desorbing fraction, the peak aqueous As(V) concentration (0.624 mg L(-1)) and the total amount of As(V) recovered (44%) was lower than predicted based on the two equilibrium models (NLLE and LLE). For the conditions used in this study [1 mg L(-1) As(V), pH 4.5 and 9,0-0.25 mM PO4, 0.53-1.6 cm min(-1) pore water velocity], the effect on As(V) mobility and recovery increased in the order pH < pore water velocity < PO4.