News

Friday, May 24, 2013

Marine Art II at Fort Napoleon

Part of the Marine Art exhibition was displayed at Fort Napoleon, Ostend. The exhibition took place from May 18 to June 9. 

 

Celebrating World Oceans Day, Marine@UGent members made presentations on the science behind the art, that served as an inspiration for it. Speakers were: prof. Ann Vanreusel on deep-sea research, prof. Colin Janssen about invisible threats to ocean life (microplastics), prof. Peter Troch about waves, and dr. Nancy Fockedey about overfishing and jellyfish. 

 

Read more about it: http://www.marine-art.be/.

Friday, May 24, 2013

Electrofishing

Trawl fishing on shrimp and sole results in seabed disturbance and produces high discards of which the majority of animals do not survive. Recently, the European Commission decided to strongly reduce these discards, warranting the need for research on alternative fishing techniques with less environmental impact in terms of seabed disturbance and discards.

 

Electrofishing uses electrodes towing over the sea floor and inducing electrical pulses, which elicit an upward movement of the shrimp and fish enabling their catch with much less spading of the bottom. Although this technique is promising, only little information is available on the possible adverse effects and the actual factors determining the extent of these unwanted effects on marine organisms.

 

The research of PhD students Marieke Desender and Maarten Soetaert ambiates to remediate this knowledge gap by assessing their impact on different marine species and lifestages. Cod (Gadus morhua) is alleged to be by far the most sensitive species in the pulse trawl catches. Therefore, from April until July 2013, Marieke and Maarten are performing studies on cultivated cod in Norway (NOFIMA, Tromsø), where they can make use of the infrastructure and expertise present. Eggs, larvae, juveniles and adult fish will be included in this research. Possible anomalies regarding development and behavior will be analysed as well as any macroscopical and histological abnormalities. Additionally, X-rays will be taken to discern fractures. These studies are supported by the Institute for Innovation by Science and Technology (IWT), AQUAEXCEL, the European Fisheries Fund, ILVO-Fisheries and UGent. The promotors are Prof. Koen Chiers (UGent), Prof. Annemie Decostere (UGent) and dr. ir. Hans Polet (ILVO).

Friday, May 24, 2013

Biodiversity and function of nematodes in the deep sea

The deep sea (> 200 m water depth) is one of the most extensive habitats on Earth. It hosts a large fraction of global biodiversity and encompasses a considerable supply of minerals, and natural food and energy sources. Anthropogenic activities, such as pollution, exploitation of fish and oil, as well as global change may change deep-sea properties and processes. It is therefore of paramount importance that we gain more insight into the functioning of the deep-sea ecosystem to support sustainable ecosystem management.

 

The international and multidisciplinary research projects HERMES (“Hotspot Ecosystem Research on the Margins of European Seas”; http://www.eu-hermes.net/), HERMIONE (“Hotspot Ecosystem Research and Man’s Impact ON European Seas”; http://www.eu-hermione.net/) en BIOFUN (“BIOdiversity and ecocystem FUNctioning in southern European deep-sea environments: from viruses to megafauna”) were erected to gain more knowledge on the structure, functioning and dynamics of deep-sea ecosystems. These projects were the framework for the PhD study of Ellen Pape of the Marine Biology Research Group of Ghent University. For her research, Ellen concentrated on nematodes or round worms, which form the dominant phylum within the meiofauna; bottom-dwelling animals between 0.032 and 1 mm large. These organisms are the most abundant, diverse and ubiquitous metazoans that live within the deep-sea bed. Nevertheless, it is not known which role nematodes fulfil within the ecosystem, what the importance is of their high biodiversity, and which factors drive this high diversity.

 

Specifically, Ellen investigated which environmental factors influence nematode diversity and what the effect is of the composition and diversity of nematode assemblages on carbon assimilation and remineralisation. Her results showed that the amount of available energy (food), the degree of chemical (e.g. high concentrations of toxic substances like sulphide) and physical (e.g. hydrodynamic activity) stress, and habitat heterogeneity play an important structuring role in deep-sea nematode communities. The environmental context not only impacts the structure but also the function of nematode assemblages. Finally, Ellen’s research indicated that a climate-regulated surface water process such as primary productivity influences the structure, diversity and functioning of nematodes. This finding suggests that global change is affecting, and will continue to affect, nematodes communities in the deep sea.

Wednesday, May 22, 2013

Defended PhD by Pieter Boets (Laboratory of Environmental Toxicology & Aquatic Ecology)

Besides habitat fragmentation, the introduction of invasive species is considered to be one of the greatest threats to global biodiversity. Due to increased global trade, habitat degradation and climate change the number of species introductions has increased spectacularly during the last decades. This has led to changes in structure and functioning of ecosystems worldwide.

 

In this study, the impact and spread of alien macroinvertebrates in surface waters in Flanders was investigated. A detailed study on the distribution of alien macroinvertebrates in Flanders revealed that in total, 65 alien macroinvertebrates are established of which 40 are regularly encountered in fresh and slightly brackish inland waters. Most alien taxa belonged to the crustaceans and molluscs originating from North America and the Ponto-Caspian region. Many alien species were first discovered in the east of Flanders from where they started the colonisation of the central and western parts of Flanders. Changes in the macroinvertebrate composition were discovered during the last two decades as a result of changing environmental conditions and the introduction of alien species.

 

When analysing the factors that favoured the establishment and spread of alien macroinvertebrates it was found that shipping, hydro-morphological and physical-chemical factors were detrimental for the success of alien macroinvertebrates. Canals, harbours and the polder waters were hot spots for alien species introductions. Small streams were less invaded by alien macroinvertebrates probably because of a higher biotic resistance and the lack of proper vectors. 

 

The knowledge gathered during the case studies was used when making predictions on the future distribution of alien macrocrustaceans in Flanders. Based on data-driven classification and regressions trees it was found that alien macrocrustaceans prefer large rivers and canals with a good chemical water quality and that with increasing conductivity the abundance and species richness of alien macrocrustaceans increases in the brackish water environment. When incorporating the improvements in water quality, it was found that the number of alien species (alien species diversity) will increase in the future, but that the fraction of alien species (alien species abundance) will remain stable.

 

Besides performing risk assessment several management measures, such as ballast water control, regulations regarding the trade of aquatic alien species and further insight in invaded ecosystems are necessary to reduce the further spread and minimise the impact of invasive alien species.

Wednesday, May 22, 2013

Stranded minke whale

On March 10th, a minke whale (Balaenoptera acutorostrata) (3.5 m) stranded in Nieuwpoort. This is the fourth reported stranding of a minke whale at the Belgian coast. This specimen was named Eugene and transported to the University of Liège for autopsy where they found 400g of plastic in its stomach. 

 

Subsequently, researchers from the Museum of Morphology transported Eugene to Ghent for further anatomical investigation and processing. They aim to preserve the skeleton. Because of the young age of the animal (1 year), the skeleton contains a lot of cartilage, challenging the conservation.

 

The Museum of Morphology also preserved the mandible of the fin whale (Balaenoptera physalus) which stranded in the summer of 2009 on the beach of Sint-Anneke, and parts of the sperm whale (Physeter macrocephalus) Theofiel which stranded last year in Heist. 

Wednesday, May 22, 2013

The designation of marine protected areas

The regulatory framework of marine protected areas in the Belgian part of the North Sea have been evaluated by the Maritime Institute and LDR lawyers. They determined whether the existing protection under Belgian jurisdiction was in accordance with international obligations. Recommendations were made. The designation of the site 'Vlakte van de Raan' has been discussed, as well as the tension between fisheries and Marine Protected Areas. 

 

Read more about this in the paper "The conservation of Belgian marine Natura 2000 sites' (Cliquet A., & Schoukens H.) 

 

Tuesday, May 21, 2013

Fieldwork in the Antarctic Peninsula

From 18 January till 18 March 2013, Freija Hauquier, PhD student at the Marine Biology Section of Ghent University, participated in an international research campaign to the Antarctic Peninsula.

 

The overall objective was to gather samples in the Larsen A/B/C area at the eastern side of the Peninsula where large parts of the original ice shelves calved off in the past two decades as a consequence of recent regional warming. Freija spent two months onboard the German icebreaker FS Polarstern, operated by the Alfred Wegener Institute for Marine and Polar Research in Bremerhaven. Together with 50 scientists and the captain and crew of Polarstern, they sailed from Punta Arenas in Chile to the Peninsula. Upon their arrival, however, they had to conclude that reaching the Larsen area, hence the sampling objective, was not feasible due to heavy seasonal sea-ice conditions. As an alternative a new integrative concept was developed onboard the vessel with all participating institutes. With the collaboration of the oceanographers, a series of sampling sites in regions with different water mass influences east and west of the Peninsula were selected. From the ice in the Weddell Sea, to the island surroundings in the Bransfield Strait and the open waters of the Drake Passage, a gradient in surface productivity could be observed as well as differences in continental shelf topography and fauna.

 

While most biologists gathered around the big Agassiz trawl for the collection of larger animals such as holothurians, starfish and sponges, Freija and her colleague Gritta Veit-Köhler from Senckenberg Institute in Wilhelmshaven were interested in the smallest animals living in the seafloor, the nematodes and copepods. Together with the sailors they spent several hours working on deck with a multicorer device to haul sediment cores in which their small objects of interest flourish.

 

Boxes with samples are on their way to the respective labs as we speak and will arrive soon to be analysed to get an idea on the relationship between surface productivity, water mass characteristics and benthic faunal communities. In the meantime, all participants are left with a new set of impressions of one of the world’s most astonishing places… icy landscapes, stormy waters, amazing wildlife and new friendships and collaborations are just some of the memories to cherish.

Thursday, May 2, 2013

Defended PhD by Joke Van Tomme (Marine Biology)

Sandy beaches are the largest coastal ecosystem on earth, covering 70% of all continental margins. As more people interact directly with beaches than with any other type of shoreline worldwide, beaches are of huge social and cultural importance. Sandy beaches have a multitude of ecological but also economic functions: they are important nursery areas for a variety of marine species and function as natural coastal defence. Beaches are also highly valuable as socio-economic areas since they are key components of many tourist destinations and are important for coastal fisheries. These activities are causing a direct anthropogenic impact and put, together with natural impacts such as sea level rise and beach erosion, a severe pressure on the sandy beach ecosystem.

 

To preserve beaches and their important ecosystem functions, management and conservation have become critical issues, especially in the light of burgeoning global population growth, demographic shifts towards the coast, and economic prosperity. However, to develop a valuable management strategy, sound knowledge of all the aspects of the beach ecosystem is important. As studies on sandy beaches are however poorly represented in scientific literature, there are some critical gaps in basic ecological information. Although patterns on sandy beaches are well-studied, the functional beach ecosystem is largely unknown. Food web dynamics, species interactions and energetic linkages on sandy beaches are barely studied and ecosystem-wide processes as nutrient cycling, cross-system nutrient fluxes, productivity and connectivity among metapopulations on different sandy beaches are undescribed.

 

Thursday, May 2, 2013

Field work in Nuuk, Greenland

PhD student Lorenz Meire from the Marine Biology Research Group is currently doing field work in Nuuk, Greenland, for his research on the acidification of the ocean. Increased emissions of carbondioxide cause an increased uptake of this carbondioxide by the oceans, resulting in acidification. This is likely to have a strong impact on marine life worldwide. 

 

Research has already shown that Arctic oceans take up large amounts of carbondioxide, as is also the case in Godthåbsfjord in Greenland. This research aims to understand the driving forces of the high carbondioxide uptake and the relation with the accelerated melting of glaciers. To this end, a year-round sampling campaign in this fjord systems is set up.    

 

Thursday, May 2, 2013

Paper on extraction techniques for microplastics

Published paper on extraction techniques for microplastics by the Laboratory of Environmental Toxicology and Aquatic Ecology.

 

Microplastics have been reported in marine environments worldwide. Accurate assessment of quantity and type is therefore needed. Here, new techniques for extracting microplastics from sediment and invertebrate tissue are proposed.

 

The method developed for sediments involves a volume reduction of the sample by elutriation, followed by density separation using a high density NaI solution. Comparison of this methods' efficiency to that of a widely used technique indicated that the new method has a considerably higher extraction efficiency. For fibres and granules an increase of 23% and 39% was noted, extraction efficiency of PVC increased by 100%. The second method aimed at extracting microplastics from animal tissues based on chemical digestion. Extraction of microspheres yielded high efficiencies (94–98%). For fibres, efficiencies were highly variable (0–98%), depending on polymer type. The use of these two techniques will result in a more complete assessment of marine microplastic concentrations.

 

Monday, April 29, 2013

(Micro)plastic in the ocean - Environmental Toxicology Research Group

Marine debris is an increasing and worldwide problem, which is mainly caused by a growing global plastic production and the continuing improper disposal of waste in our ‘disposable society’. Moreover, plastic is (almost) not degradable, resulting in the accumulation of this debris in our world’s seas and oceans. Of all marine debris, 60 to 80% is estimated to be plastic. This debris is not only aesthetically displeasing, but it also poses a serious threat to marine organisms and even humans.

 

In the last decade, it has been discovered that the large pieces of plastic debris degrade into smaller pieces called microplastics, which can be as small as 20 µm. Because of their small dimensions these microplastics (plastic pieces smaller than 1 mm) pose a new kind of threat to small organisms at the bottom of the food chain as these particles can be ingested and transported to the tissues of these animals.

 

A quantitative monitoring study of marine debris on the seabed, sea-surface and the beach along the Belgian shore reported over 64000 items per km, representing a weight of 92.7 kg of litter per km of beach. These are some of the highest reported numbers worldwide. On every sampled beach, microplastics were present.

 

On average, over 3100 items per km² were found on the seabed of the Belgian Continental Shelf. Floating marine debris was assessed both visually and with a neuston net, yielding different results, because most floating items were too small to spot from a distance. Based on the neuston net survey, over 3800 items were retrieved per km².

 

Entanglement and stomach content of seabirds were investigated to assess the impacts of macrodebris on marine species. 0.6% of beached birds were found entangled: mostly in fishing gear, but also in six-pack rings, plastic bags, sheets, and plastic cups. Of all Northern Fulmars (Fulmarus glacialis) examined, 95% had ingested some kind of plastic. On average they had 48 pieces of plastic in their stomach. More than half of the birds had more than 0.1 gram of plastic in their stomach (keep their low body weight in mind!), which is well above the level to qualify the North Sea as being clean (OSPAR EcoQO).

 

Additional to the field studies, laboratory experiments were set up to assess the effects of the uptake of microplastics on two invertebrate species: Mytilus edulis, a filter feeder, and Arenicola marina, a deposit feeder. Both species ingested the microplastics, and the smallest particles were even transported into the tissues of the animals. However, no significant adverse effects were detected during short-term exposure experiments.

 

The economic impact of marine litter along the Belgian coast was assessed by supplying questionnaires to 4 key sectors of human activity which are affected: touristic organisations, municipalities, harbours, and sea fisheries. All sectors are negatively affected by the presence of marine debris. The overall annual cost per municipality for removing litter from the beaches is over 32 000 Euros. Removing litter from the harbours yields a yearly average cost of over 4 000 Euros per harbour. The fishing industry suffers greatly from fouling incidents and a loss of income from reduced fishing time due to clearing litter from nets: i.e. 2.16 million euros per year.

 

Read more about this study in the AS-MADE report (Assessment of marine debris on the Belgian continental shelf: occurrence and effects), performed by the Environmental Toxicology Research Group.  

Sunday, April 28, 2013

Published paper: A first AFLP-based genetic linkage map for brine shrimp Artemia franciscana and its application in mapping the sex locus


ArtemiaPublished paper from Marine@UGent member Stephanie De Vos: A first AFLP-based genetic linkage map for brine shrimp Artemia franciscana and its application in mapping the sex locus.

 

We report on the construction of sex-specific linkage maps, the identification of sex-linked genetic markers and the genome size estimation for the brine shrimp Artemia franciscana. Artemia is the most commonly used live food in aquaculture activities, specifically for larval growth of more than 85% of the marine species reared. Fifteen putatively homologous linkage groups, including the sex linkage groups, were identified between the female and male linkage map.

 

Eight sex-linked AFLP marker alleles were inherited from the female parent, supporting the hypothesis of a WZ–ZZ sex-determining system, as has already been found in economically important crustaceans, such as Pacific white shrimp (L. Vannamei), giant tiger prawn (P. monodon) and giant river prawn (M. rosenbergii). The haploid Artemia genome size was estimated to 0.93 Gb by flow cytometry. The produced Artemia linkage maps provide the basis for further fine mapping and exploring of the sex-determining region and are a possible marker resource for mapping genomic loci underlying phenotypic differences among Artemia species. In addition, we expect that forward genetic approaches in Artemia are not only restricted to Artemia-specific traits, but are also valuable for mapping traits such as sex, Vibrio pathogen resistance and growth rate, in commercially important crustaceans. We believe therefore that Artemia could be a useful model species for other crustaceans.

Link: http://www.plosone.org/article/info%3Adoi%2F10.1371%2Fjournal.pone.0057585

Thursday, April 25, 2013

3rd International conference on ship manoeuvring in shallow and confined water with non-exclusive focus on ship behaviour in locks (3 - 5 June 2013)


Upcoming conference organised by Marine@UGent member Marc Van Torre: 3rd International conference on ship manoeuvring in shallow and confined water with non-exclusive focus on ship behaviour in locks; Ghent, 3 – 5 June 2013

 

The main dimensions of ships tend to increase continuously, while navigation areas and port and waterways infrastructure do not expand at the same rate. As a consequence, the hydrodynamic effects that occur when a ship manoeuvres in shallow or confined water continue to be of great importance. The conference provides an international forum to discuss the latest developments both in research and in practice, and will be organised by the Maritime Technology Division of Ghent University (Faculty of Engineering and Architecture), Flanders Hydraulics Research and the Royal Institution of Naval Architects.

 


After successful conferences in Antwerp (2009) and Trondheim (2011), the third edition will pay particular attention to ship behaviour in locks. A significant number of locks for large sea-going vessels are being designed or under construction all over the world. For seagoing vessels, the new Panama Canal locks are the most famous example. In regard to inland shipping, upgrading existing canals requires continuing renovation of locks.

 

Link: http://www.lockeffects.ugent.be

Thursday, April 25, 2013

Marine@UGent member Prof. Janssen elected Chair of EU Committee SCHER

Professor Janssen was - out of over 400 candidates - appointed as one of the 11 members of SCHER (EU Scientific Committee on Health and Environmental Risks), for a 3-year term.

 

He will provide the Commission with independent scientific advice on issues relating to consumer safety, public health and the environment.Following his appointment, Prof. Janssen was then elected by SCHER members to serve as Chair of the Committee.

 

Read more on our website.

Thursday, April 18, 2013

Published paper: Metabolomics enables the structure elucidation of a diatom sex pheromone


Published paper from Marine@UGent members from the Protistology and Aquatic Ecology group: Metabolomics enables the structure elucidation of a diatom sex pheromone.

 

The work presented solves a major gap in understanding life cycle regulation in the diatoms, the most successful marine eukaryotic phytoplankton group, responsible for ~20% of global primary production. While sexual reproduction in most phytoplankton is induced by environmental cues, diatoms make a remarkable exception because they have a unique life cycle in which cell size is the primary control of sexual capability. We show that mating is under the strict control of size-activated chemical signals that allow the cells to sense the presence and readiness of sexual partners. Based on a novel differential metabolomics approach, we identified L-diproline as the attraction pheromone involved. L-diproline is the first ever identified diatom pheromone and is unprecedented as a pheromone signal. Furthermore, transcriptome analysis revealed that in response to cell size and mating, diatoms employ patched-domain genes that are implicated in cell differentiation in animals.

 

Life cycle regulation in marine phytoplankton is crucial to understanding their ecology and ocean functioning in general. Thousands of different microscopically small algae live in the ocean. They contribute nearly half to the total photosynthesis on earth, but still we do not fully understand how they reproduce. Some of these algae - the diatoms - reproduce mainly by cell division, but since they have a rigid cell wall formed from a ‘biological mineral’ they have to reduce their size during reproduction. Beyond a certain critical size threshold, this process ultimately results in death. They can restore their size by sexual reproduction.

 


Our findings reveal that diatoms can escape this faith by employing a sophisticated, size-controlled mating. Cells sense the presence of mature mating partners and only become sexually active themselves if everything is in place: the time of the day, the cell density and the readiness of the partner. With new analytical techniques we were able to identify the compound that attracts the cells to their mating partners. This work opens new perspectives for a better understanding of the ecological and evolutionary success of diatoms but it also shows ways of how to influence mass cultivation that could potentially be used to generate biofuels and the control of fouling organisms on marine surfaces.

 

Link: http://onlinelibrary.wiley.com/doi/10.1002/anie.201208175/abstract

Wednesday, April 17, 2013

Published paper: Extensive cryptic species diversity and fine-scale endemism in the marine red alga Portieria in the Philippines


Published paper from Marine@UGent member Olivier De Clerck: Extensive cryptic species diversity and fine-scale endemism in the marine red alga Portieria in the Philippines

 

Marine species are generally believed to be widespread because they can disperse on ocean currents without any apparent barriers to dispersal in the sea. This assumption has also led to the belief that in order to save marine species from extinction, only a few biodiversity hotspots have to be conserved. We discovered that this assumption is likely to be fallacious.

 

Studies focussing on the widespread red seaweed Portieria hornemannii show that it is not one species but rather consists of at least 21 look-alike species with very small distribution ranges within the Philippine archipelago. Besides the remarkable discovery of 20 new species in one go, this result indicates that marine species-level diversity can be structured at a spatial scale of kilometres rather than hundreds or thousands of kilometres. The finding of fine-scale endemism implies that conservation efforts in archipelagos will need to focus on all islands rather than on a few presumed biodiversity hotspots.

Tuesday, April 2, 2013

WECwakes project with record breaking Wave Energy Converter array

This project, 'Large scale experiments on wave energy converter farms to study the near-field effects between the converters and the far-field effects on other users in the coastal area' is coordinated by professor Peter Troch in a consortium of 7 international partners. It is testing a record breaking array of wave energy converters: the largest array worldwide (25 individual Wave Energy Converters or WECs in an array set-up) is under testing in the Danish Hydraulic Institute wave tank.

 

Wave Energy Converters (WECs) extract energy from ocean waves and have the potential to produce a significant contribution of electricity from renewable sources. Commercial exploitation of wave energy will require installation of large numbers of WECs arranged in an array or a farm, using a particular geometrical layout.

 

The operational behaviour (i.e. the energy production) of a single WEC in a WEC array will be affected by the behaviour of the neighbouring WECs in the array. As a result, the production of the array may be smaller or larger than the superposition of the individual WECs. Therefore, the deployment of wave energy for practical energy production requires an accurate understanding of these WEC interactions in a wave farm. With this understanding, the optimal geometrical farm layout can be determined, and ultimately the cost of energy will be reduced significantly.

 

Several numerical studies on both small and large WEC arrays have already been performed, and have provided some initial indications of the WEC interactions. However, there has been very limited validation of these numerical models using physical scale models of WEC arrays. This project has been launched with the objective to perform large scale experiments in the Shallow Water Wave Basin in Denmark, on large arrays of point absorbers (up to 25 WECs) for a range of layout configurations and wave conditions.

 

The physical model of a large array of 25 individual WECs is tested at the wave tank, which is 50 m wide and 30 m long, with 22 m of wave paddles along one side of the wave tank. Water depth is 0.7 m, and a range of wave conditions (using regular, irregular long-crested and short-crested waves) is used. This experimental set-up of 25 individual WEC units in array layout placed in this large wave tank is a record breaking achievement: it is worldwide the largest set-up of its kind studying the important effects of WEC interactions and WEC wake effects.

 

The obtained results from these experimental tests will be very useful to validate and extend the recently developed numerical models, as well as to optimize the geometrical layout of WEC arrays for real applications.

Friday, March 15, 2013

Marine Art

Marine Art was a unique outreach event and a collaboration between Flanders Marine Institute, the Academy of Fine Arts Ghent and researchers from the Marine@UGent consortiumTwenty-three marine topics, from pollution to building at sea, and ocean acidification served as inspiration for more than 1200 artists from the Academy, aged 6 to 85.

 

The project comprised of 3 stages: 

(1) Art teachers visited the professo, specialised in a topic they were interested in, and were provided with detailed information

(2) Professors, research assistants and scientists presented their research topic in classrooms, or alternatively, students and teachers visited the lab or  made a research trip with the RV Simon Stevin

(3) After being inspired by the science, the art teachers and students transformed the science into art. 

 

More than 1250 pieces of art were presented at the 5-day exhibition in Ghent. Disciplines included painting, mixed media, sculpture and drawing. 

 

In brief: Marine Art, 1200 students, 40 scientists, 23 marine research topics, more than 1250 pieces of art, 8400 people visited the exhibition. 

 

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