Ecological effects of offshore wind farms on Atlantic cod (Gadus morhua) in the southern North Sea

Evaluating the ecological effects of the rapid expansion of offshore renewables at local, regional and ecosystem-wide scales is essential to understand the overall socio-ecological trade-offs also for other sectors such as fisheries. Hence, little is known about the ecological impact on demersal fish. To shed light on this topic, we studied the effects of an offshore wind farm in the southern North Sea on different life stages of Atlantic cod (Gadus morhua) using a combination of sampling methods at varying spatial and temporal scales. Our investigations of diet composition and trophic niches indicate that cod utilizes wind turbine piles with scour protection as feeding grounds. Furthermore, collected information on cod adults and early life stages during winter spawning season suggest that spawning activity occurred in winter across the wider wind farm area. We conclude that wind turbine foundations with a scour protection can function as artificial reefs that have local positive effects on the resilience of local cod populations. With our study we contribute to urgently needed observational evidence regarding the ecological impact of offshore wind farm installations to inform area-based management and future monitoring activities.

Diving into the vertical dimension of elasmobranch movement ecology

Knowledge of the three-dimensional movement patterns of elasmobranchs is vital to understand their ecological roles and exposure to anthropogenic pressures. To date, comparative studies among species at global scales have mostly focused on horizontal movements. Our study addresses the knowledge gap of vertical movements by compiling the first global synthesis of vertical habitat use by elasmobranchs from data obtained by deployment of 989 biotelemetry tags on 38 elasmobranch species. Elasmobranchs displayed high intra- and interspecific variability in vertical movement patterns. Substantial vertical overlap was observed for many epipelagic elasmobranchs, indicating an increased likelihood to display spatial overlap, biologically interact, and share similar risk to anthropogenic threats that vary on a vertical gradient. We highlight the critical next steps toward incorporating vertical movement into global management and monitoring strategies for elasmobranchs, emphasizing the need to address geographic and taxonomic biases in deployments and to concurrently consider both horizontal and vertical movements.

Extensive oceanic mesopelagic habitat use of a migratory continental shark species

The identification of movement and behaviour patterns, as well as inter- and intra-population connectivity is crucial in order to implement effective and functional management and conservation measures for threatened migratory species such as tope (Galeorhinus galeus). Yet, previous studies struggled to elucidate clear and consistent movement and depth usage patterns of adult tope in the Northeast Atlantic, suggesting a high plasticity in the migration and behaviour. We deployed pop-up satellite archival tags on adult tope during their seasonal summer aggregations in the inner German Bight of the south-eastern North Sea and near a presumed mating site in southwest Scotland. Depth distribution and migration pathways were derived from time series data with location processing. Four individuals followed migration trajectories leaving coastal areas and crossed the European shelf slope into oceanic areas of the Northeast Atlantic, remaining fully pelagic for the rest of the deployment duration. These sharks showed far-ranging migration trajectories and undertook regular and frequent diel vertical migrations, reaching daytime depths of over 700 m. Vertical migration patterns closely overlapped with biological mesopelagic habitat structures and closely tracked the diel migration of organisms from deep scattering layers derived from hydroacoustic recordings. It is hypothesized that adult tope regularly utilize oceanic habitats, foraging on mesopelagic layers in an environment generally considered of low prey density.

Diet composition and feeding of European anchovy Engraulis encrasicolus in Kiel Bight, western Baltic Sea

Diet composition of the expanding southern species European anchovy Engraulis encrasicolus in the western Baltic Sea was investigated. Results revealed an interesting case of bentho-pelagic coupling with potential implications for local fish species through competition for food resources.

The fos gene product undergoes extensive post-translational modification in eukaryotic but not in prokaryotic cells

To investigate the properties of the fos oncogene, we have constructed bacterial and yeast vectors which express the entire fos-coded protein (Fos) and two C-terminal deletion products. In Escherichia coli, Fos proteins were expressed from the phage lambda pL promotor under the control of the temperature-sensitive lambda repressor. In vitro transcription/translation studies indicate that these vectors produce Fos proteins of the expected sizes. However, in vivo, Fos protein accumulation is observed only in hosts with the Lon- phenotype. In Saccharomyces cerevisiae, the fos gene was expressed from the PHO5 promoter which is induced under low-phosphate conditions. In contrast to the situation in E. coli, in which the heterologous proteins appeared as single major products when subjected to sodium dodecyl sulfate - polyacrylamide gel electrophoresis, the Fos proteins in S. cerevisiae displayed extensive Mr heterogeneity. Pulse-chase analyses indicated that this heterogeneity was a consequence of extensive post-translational modification. These modifications occurred to an equivalent extent on the products coded by the fos gene with C-terminal deletions and thus appear not to be controlled by the missing domain.

Molecular cloning and regulated expression of the human c-myc gene in Escherichia coli and Saccharomyces cerevisiae: comparison of the protein products

mRNA from human HL-60 cells was used to prepare a cDNA library, from which two full-length clones that encompass the complete c-myc coding region were isolated. One clone, pM1-11, contains all three exons of human c-myc. The second clone, pM4-10, represents a relatively rare transcript that initiated in the first intron and includes the coding exons 2 and 3. The cDNA insert in pM1-11 was used to express the human c-myc protein in both prokaryotic and eukaryotic cells. Insertion of the coding sequences in exons 2 and 3 into the appropriate expression vectors yielded detectable c-myc protein in Escherichia coli lacking the Lon protease and in Saccharomyces cerevisiae upon induction. The protein produced in E. coli has an apparent size of 60 kDa and appears to be unmodified, as it is identical in size to the protein synthesized in an in vitro system. In contrast, yeast cells synthesize two myc proteins, of 60 kDa and 62 kDa. The difference in apparent molecular mass between the two proteins appears to be due, in part, to phosphorylation. Subcellular fractionation of yeast cells showed that the c-myc phosphoprotein is located predominantly in the nuclear fraction.

HTLV-III env gene products synthesized in E. coli are recognized by antibodies present in the sera of AIDS patients

The envelope gene of HTLV-III, the retrovirus directly linked to AIDS, encodes a protein of 856 amino acids. Our sequence analysis of the cloned HTLV-III (HXB-3) env gene and its comparison with other isolates reveal significant divergence, especially in the external portion of this protein. A large segment of the env gene (1800 bp) was inserted into the expression vector pEV-vrf3, and a corresponding 68 kd protein, which encompasses both the extracellular and the membrane-associated regions of the native protein, was produced in E. coli. Several smaller polypeptides, which appear to be internal initiation products, were also produced. All 50 AIDS patient sera obtained from different locations in the United States specifically recognized the bacterially synthesized envelope proteins, as judged by Western blots. This suggests that these proteins will be useful for the diagnosis of HTLV-III infection and possibly as a vaccine against AIDS.