Finding Plastic Patches in Coastal Waters using Optical Satellite Data

Satellites collecting optical data offer a unique perspective from which to observe the problem of plastic litter in the marine environment, but few studies have successfully demonstrated their use for this purpose. For the first time, we show that patches of floating macroplastics are detectable in optical data acquired by the European Space Agency (ESA) Sentinel-2 satellites and, furthermore, are distinguishable from naturally occurring materials such as seaweed. We present case studies from four countries where suspected macroplastics were detected in Sentinel-2 Earth Observation data. Patches of materials on the ocean surface were highlighted using a novel Floating Debris Index (FDI) developed for the Sentinel-2 Multi-Spectral Instrument (MSI). In all cases, floating aggregations were detectable on sub-pixel scales, and appeared to be composed of a mix of seaweed, sea foam, and macroplastics. Building first steps toward a future monitoring system, we leveraged spectral shape to identify macroplastics, and a Naïve Bayes algorithm to classify mixed materials. Suspected plastics were successfully classified as plastics with an accuracy of 86

Toward the Integrated Marine Debris Observing System

Plastics and other artificial materials pose new risks to the health of the ocean. Anthropogenic debris travels across large distances and is ubiquitous in the water and on shorelines, yet, observations of its sources, composition, pathways, and distributions in the ocean are very sparse and inaccurate. Total amounts of plastics and other man-made debris in the ocean and on the shore, temporal trends in these amounts under exponentially increasing production, as well as degradation processes, vertical fluxes, and time scales are largely unknown. Present ocean circulation models are not able to accurately simulate drift of debris because of its complex hydrodynamics. In this paper we discuss the structure of the future integrated marine debris observing system (IMDOS)thatisrequiredtoprovidelong-termmonitoringofthestateofthisanthropogenic pollution and support operational activities to mitigate impacts on the ecosystem and on the safety of maritime activity. The proposed observing system integrates remote sensing and in situ observations. Also, models are used to optimize the design of the system and, in turn, they will be gradually improved using the products of the system. Remote sensing technologies will provide spatially coherent coverage and consistent surveying time series at local to global scale. Optical sensors, including high-resolution imaging, multi- and hyperspectral, fluorescence, and Raman technologies, as well as SAR will be used to measure different types of debris. They will be implemented in a variety of platforms, from hand-held tools to ship-, buoy-, aircraft-, and satellite-based sensors. A network of in situ observations, including reports from volunteers, citizen scientists and ships of opportunity, will be developed to provide data for calibration/validation of remote sensors and to monitor the spread of plastic pollution and other marine debris. IMDOS will interact with other observing systems monitoring physical, chemical, and biological processes in the ocean and on shorelines as well as the state of the ecosystem, maritime activities and safety, drift of sea ice, etc. The synthesized data will support innovative multi-disciplinary research and serve a diverse community of users

Towards Public Domain Management of Liberation Movement Heritage Records in Eastern and Southern Africa

This article reports on research into the management of liberation movement archives in Eastern and Southern Africa. It is based on a systematic review of literature on the subject, content analysis of national archival legislations in relation to the management of liberation movement archives, inspection visits to such archives in the region, and qualitative content analysis of the responses to an open-ended survey questionnaire administered on the heads of national archival institutions of the countries in the region. The study found out that the archival legislation dealing with the management of private archives is outdated, lacks clarity and are punctuated by latent passivity, and that the available regulatory instruments are inadequate to ensure appropriate acquisition for long term public domain management of the liberation movement archives that are currently managed ineffectively by various private archives in the region. The study recommends that such archives, because of their national heritage importance, should be decommissioned from private custody and managed by the various national archival institutions for the benefit of posterity

The State of Archival Appraisal Practices in the ESARBICA Region

When archivists appraise records, they make a determination as to what to keep and destroy. In other words, they decide who has voice and who remains voiceless. Appraisal involves value prescription to records, and is one of the most important responsibilities of archivists. The future research potential of records is a variable that is difficult to determine, and this serves to highlight the delicateness of the appraisal task. Wrong appraisal decisions constitute a barrier to accessing records and archives. A variety of methodologies exist for archival appraisal, but for the East and Southern Africa Regional Branch of the International Council on Archives (ESARBICA), many archival institutions employ the value based approach. Despite this fact, the archival process is not being conducted in a professional manner which threatens the future of historical research, corporate memory and national heritage of the member states of ESARBICA. This is evidenced by the archaic legislation in place, and the lack of both expertise and defined standards to carry out the process. African Journal of Library Archives and Information Science Vol. 17 (1) 2007: pp. 59-6

A Framework for an Investigation into the Management of Former National Liberation Movements' Records and Archives by National and Private Archival Institutions in Eastern and Southern Africa

This contribution seeks to highlight the plight of liberation movement records in eastern and southern Africa in an endeavour to raise awareness on the need for their sound management as they constitute an irreplaceable heritage. The struggle to liberate the eastern and southern African region was an important epoch in contemporary history. It follows then that this history needs to be accurately captured for posterity's sake. The archives generated were of differing types and status which reflected the diverse nature of the struggle itself. As a result, records were created from within and outside Africa to document this historic epoch from the 1950s to the 1990s and these records have to be made available to the public for research, scholarship and general interest as they are a treasured national asset. The main thrust of our argument is that in carrying out the documentation of these records, efforts should be made to ensure that a continuum of care is provided in terms of records' identification and acquisition, intellectual control, access and physical control. Keywords: Liberation movements, Records management, Archives management; Records lifecycle, Records continuum ESARBICA Vol. 27 2008: pp. 147-17

Archives in the trenches: repatriation of African National Congress liberation archives in diaspora to South Africa

Please access the full-text of this article at the doi link at the top of this record.The African National Congress (ANC) liberation archives were created in countries all over the world. These liberation archives form part of the national archival heritage of South Africa as they bridge the gap of undocumented history of people who were previously marginalised by the apartheid government. After the ban on liberation movements was lifted in South Africa, the ANC embarked on the process of identification and repatriation of the records that were fragmented throughout the world. This study investigated the approaches followed by the ANC in identifying and repatriating its liberation archives from the trenches to make them accessible. Qualitative data were collected through interviews with purposively selected employees of the African National Congress, MultiChoice, Africa Media Online and the Nelson Mandela Foundation who were involved in the repatriation of the liberation archives. Interview data were augmented through content analysis of ANC documents such as policies, websites and annual reports, as well as observation of the storage conditions of the liberation archives. The key findings revealed that the ANC stablished an archives management committee that played an important role in the identification, repatriation and, ultimately, digitisation of liberation archives. The committee utilised former liberation struggle members to identify records in ANC hosts in various countries. It was established that, although the ANC was aware of where its records were abroad, not all its records were repatriated to South Africa after the unbanning of the liberation movements. For example, there were host nations, like Italy, that disputed the return of the ANC liberation archives to South Africa. The liberation archives are in the custody of the Fort Hare University as a chosen official repository for the ANC. It is concluded that the repatriation of the liberation archives is an ongoing process, as not all records have been repatriated to South Africa. As the ANC is in power at the time of writing, this is the opportunity for the organisation to negotiate with countries that still have custody of its liberation archives, such as Italy, to repatriate such records to South Africa. A further study on legal ownership and copyright, digitisation and ensuring the authenticity of the ANC liberation archives is recommended. This study can be extended to other liberation movements in southern Africa.Information Scienc

CLOCKS: Northern Cascadia: Extent of locked zone, prism deformation, slip-to-toe, and the edge of subduction, and CASCADIA CO2: Seismic multi-parameter study at a possible site for CO2 storage in basalt in the Cascadia Basin utilizing shear wave events (secondary user), Cruise No. SO294, 13.09. 2022 - 27.10. 2022, Vancouver (Canada) - Port Hueneme (USA), ReSEAt

The research cruise M187 with the RV METEOR sailed January 25 th to March 4 th 2023 from Walvis Bay to Walvis Bay (Namibia), with a focus on investigating the biogeochemical gradients that exist between the Benguela Upwelling zone and the South Atlantic Subtropical Gyre. In order to achieve this, the two specific foci of the research cruise were to (i) track upwelling filaments as they advect offshore and interact with the subtropical gyre, and (ii) perform a high-resolution transect from upwelling sites to the subtropical gyre. On the research cruise, two filaments were successfully mapped from cold water upwelling sites near or over the Namibian shelf through to warmer waters offshore. This was followed by a transect of twelve stations outwards into the subtropical gyre, reaching a maximum westward position of 5 °W. Sampling stations were conducted to a maximum depth of 1000 m and involved an array of deployments to investigate the biogeochemistry of the water column. Further nutrient addition bioassay experiments were conducted throughout the research cruise to assess the nutrients (co-)limiting to phytoplankton growth. Collectively our research will shed light on key mechanisms establishing the major oceanic biogeochemical gradients between upwelling and subtropical gyre regions, so that they can be included in models used to predict the impacts of climate change