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On 18 April 1947, British forces set off the largest non-nuclear explosion in history. The target was a small island in the North Sea, thirty miles off the German coast, which for generations had stood as a symbol of Anglo-German conflict: Heligoland. A long tradition of rivalry was to come to an end here, in the ruins of Hitler's island fortress. Pressed as to why it was not prepared to give Heligoland back, the British government declared that the island represented everything that was wrong with the Germans: 'If any tradition was worth breaking, and if any sentiment was worth changing, then the German sentiment about Heligoland was such a one'. Drawing on a wide range of archival material, Jan Ruger explores how Britain and Germany have collided and collaborated in this North Sea enclave. For much of the nineteenth century, this was Britain's smallest colony, an inconvenient and notoriously discontented outpost at the edge of Europe. Situated at the fault line between imperial and national histories, the island became a metaphor for Anglo-German rivalry once Germany acquired it in 1890.Turned into a naval stronghold under the Kaiser and again under Hitler, it was fought over in both world wars. Heavy bombardment by the Allies reduced it to ruins, until the Royal Navy re-took it in May 1945. Returned to West Germany in 1952, it became a showpiece of reconciliation, but one that continues to bear the scars of the twentieth century. Tracing this rich history of contact and conflict from the Napoleonic Wars to the Cold War, Heligoland brings to life a fascinating microcosm of the Anglo-German relationship. For generations this cliff-bound island expressed a German will to bully and battle Britain; and it mirrored a British determination to prevent Germany from establishing hegemony on the Continent. Caught in between were the Heligolanders and those involved with them: spies and smugglers, poets and painters, sailors and soldiers. Heligoland is the compelling story of a relationship which has defined modern Europe.

The story of Heligoland, the North Sea island which for generations stood as a symbol of Anglo-German conflict. A fascinating microcosm of a long and often troubled relationship, covering two centuries and two world wars.

Bis zu 80 Individuen einer Stichprobe von der Insel Helgoland (Deutschland) wurden in 24 hämogenetischen Systemen untersucht (5 Erythrocyten-Antigensysteme, 6 Serumprotein-Polymorphismen, 12 Enzym-Polymorphismen der Erythrocyten). In der Clusteranalyse setzt sich die Helgoländer Stichprobe von benachbarten Bevölkerungen wie auch von europäischen Standarddaten deutlich ab. Diese Sonderstellung wird teilweise als im Laufe der Zeit entwickelte genetische Besonderheit, teilweise als Folge von Gendrift interpretiert.

Non‐tidal ocean loading (NTOL) signals are known to be a significant source of geophysically induced noise in gravimetric and geodetic observations also far‐away from the coast and especially during extreme events such as storm surges. Operationally available corrections suffer from a low temporal and spatial resolution and reveal too small amplitudes on continental stations. Dedicated high‐resolution sea‐level modeling of the North and Baltic Sea provides an improved prediction of NTOL signals. Superconducting gravimeter and Global Navigation Satellite Systems observations on the small offshore island of Heligoland in the North Sea are used for an evaluation of the model values revealing largely increased correlations of up to 0.9 and signal reductions of up to 50% during a storm surge period of one month in January and February 2022. Evaluations on additional continental superconducting gravimeter stations also show significant improvements through the recommended high‐resolution modeling for improved signal separation further away from the coast. Plain Language Summary Terrestrial gravimetry is a technique to monitor temporal variations of the gravity acceleration at the Earth's surface that are induced by mass variations and deformations caused by a large number of geophysical effects on very different temporal and spatial scales. Current applications of high social relevance are the estimation of terrestrial water storage variations under climate change conditions, for example, groundwater depletion or polar and alpine ice mass loss, as well as hazard and geothermal monitoring. Before analyzing such signals of interest, it is essential to separate all other signals included in the gravimetric observations usually on the basis of adequate models. Amongst these disturbing signals, NTOL is one of the smaller but still significant effects. Up to now, the available operational corrections show a weak correlation with gravimetric observations and their application does not lead to a significant reduction of the observational signal variation. This situation largely improves with a high‐resolution model for gravity observations on the North Sea island of Heligoland. The model results are also applied to gravity records that were observed further away from the coast to assess the benefits of the model for an improved signal separation even at continental stations. Key Points High‐resolution ocean model of the North and Baltic Sea provides improved non‐tidal ocean loading signals Model evaluation by geodetic observations on the island of Heligoland shows correlation of 0.9 and signal reduction of 50% Continental gravimetric stations further away from the coast benefit from high‐resolution model for an improved signal separation

In temperate and subarctic regions of the Northern Hemisphere, green algae of the genus Blidingia are a substantial and environment-shaping component of the upper and mid-supralittoral zones. However, taxonomic knowledge on these important green algae is still sparse. In the present study, the molecular diversity and distribution of Blidingia species in the German State of Schleswig-Holstein was examined for the first time, including Baltic Sea and Wadden Sea coasts and the off-shore island of Helgoland (Heligoland). In total, three entities were delimited by DNA barcoding, and their respective distributions were verified (in decreasing order of abundance: Blidingia marginata, Blidingia cornuta sp. nov. and Blidingia minima). Our molecular data revealed strong taxonomic discrepancies with historical species concepts, which were mainly based on morphological and ontogenetic characters. Using a combination of molecular, morphological and ontogenetic approaches, we were able to disentangle previous misidentifications of B. minima and demonstrate that the distribution of B. minima is more restricted than expected within the examined area. Blidingia minima, the type of the genus name Blidingia, is epitypified within this study by material collected at the type locality Helgoland. In contrast with B. minima, B. marginata shows a higher phenotypic plasticity and is more widely distributed in the study area than previously assumed. The third entity, Blidingia cornuta sp. nov., is clearly delimited from other described Blidingia species, due to unique characters in its ontogenetic development and morphology as well as by its tufA and rbcL sequences.

Abstract Bacterioplankton dynamics at Helgoland Roads (54°11.3′N, 7°54.0′E) in the North Sea over the winter–spring transition were investigated. The bacterial community was analyzed and correlated with phytoplankton community data and abiotic parameters. The community structure was analyzed by ribosomal intergenic spacer analysis (RISA) and by denaturing gradient gel electrophoresis (DGGE) of 16S rRNA genes followed by DNA sequence analysis. The linkage of abiotic and biotic environmental factors and bacterial community as well as phylotypes (sequenced DGGE bands) was analyzed by the ordination technique of canonical correspondence analysis (CCA). Generally, an influence of temperature and phytoplankton on the bacterial community during the sampling period was observed. Additionally, multivariate analysis by factors revealed an influence on specific bacterial phylotypes of these factors. Overall, results indicate that changes in the bacterial community were caused not only by abiotic factors but also by the phytoplankton community.

Bacteria of the genus Vibrio are an important component of marine ecosystems worldwide. The genus harbors several human pathogens, for instance the species Vibrio parahaemolyticus , a main cause for foodborne gastroenteritis in Asia and the USA. Pathogenic V. parahaemolyticus strains emerged also in Europe, but little is known about the abundance, pathogenicity and ecology of V. parahaemolyticus especially in Northern European waters. This study focuses on V. parahaemolyticus and its close relative Vibrio alginolyticus in the North Sea (Helgoland Roads, Germany). Free-living, plankton-attached and shellfish-associated Vibrio spp. were quantified between May 2008 and January 2010. CFUs up to 4.3 × 10 3  N l −1 and MPNs up to 240 N g −1 were determined. Phylogenetic classification based on rpoB gene sequencing revealed V. alginolyticus as the dominant Vibrio species at Helgoland Roads, followed by V. parahaemolyticus . We investigated the intraspecific diversity of V. parahaemolyticus and V. alginolyticus using ERIC-PCR. The fingerprinting disclosed three distinct groups at Helgoland Roads, representing V. parahaemolyticus , V. alginolyticus and one group in between. The species V. parahaemolyticus occurred mainly in summer months. None of the strains carried the virulence-associated genes tdh or trh . We further analyzed the influence of nutrients, secchi depth, temperature, salinity, chlorophyll a and phytoplankton on the abundance of Vibrio spp. and the population structure of V. parahaemolyticus . Spearman Rank analysis revealed that particularly temperature correlated significantly with Vibrio spp. numbers. Based on multivariate statistical analyses we report that the V. parahaemolyticus population was structured by a complex combination of environmental parameters. To further investigate these influences is the key to understanding the dynamics of Vibrio spp. in temperate European waters, where this microbial group and especially the pathogenic species, are likely to gain in importance.

The aim of the present study was to compare preservation, staining and preparation techniques to assess the influence of different sample treatments and analyses on the accuracy of benthic foraminiferal assemblage data from NE Atlantic shelf seas. Replicate surface samples from the SE North Sea were preserved with ethanol-rose Bengal or formalin, some were stained after processing, or foraminifera were concentrated by flotation. Coloration of living specimens was different between samples treated with an ethanol-rose Bengal solution and those stained after washing. In the latter case, only the last two or three chambers were stained. The aliquot sample preserved with formalin showed dissolution features in agglutinated and porcellaneous species. Population density varied between different preservation, picking modes and investigators. The accuracy of picking was in the range of ±2% (1σ), while external reproducibility ranged from -34 to +16%. There was no significant difference between wet and dry picking. Samples that were concentrated by flotation generally yielded a lower number of specimens. Agglutinated species were under-represented in samples that were stained after washing and in the flotation concentrate. Size fractions showed a reduction of population density and Fisher alpha diversity index with increasing mesh size. Only half of the specimens and less than two-thirds of the species are captured if the >125 µm rather than >63 µm fraction is analysed. In oxygen minimum zones, where small-sized species dominate the assemblage, the recovery in larger size fractions could be lower.

The battle of Heligoland Bight was the first major action between the British and German fleets during World War I. The British orchestrated the battle as a warning to the German high command that any attempt to operate their naval forces in the North Sea would be met by strong British resistance. Heligoland Island guarded the entrance to the main German naval anchorage at Kiel. Fought on August 28, 1914, the engagement was complicated by dense fog, the piecemeal engagement of German forces, and the unexpected appearance in the area of additional British ships, which were hard to distinguish from foe. Initial British damage was significant; however, fearing that the protracted battle would allow the bulk of the German fleet to join the battle, the British brought in their battle cruiser reinforcements and won the day, inflicting heavy losses on the Germans. The battle was significant for its political and strategic ramifications for the two sides. The Germans became reluctant to engage large forces in an attempt to gain a decisive maritime victory. After this defeat, any plans for large-scale fleet operations had to be approved by the Kaiser, which hampered the German fleet's effectiveness. This left the North Sea to Great Britain for much of the war.