1,721,345 research outputs found
The Natural History of the Crustacea Volume 10 Ecology and Conservation
Full text linkAbstract
This is the last volume of a ten-volume series on The Natural History of the Crustacea. The chapters in this volume synthesize our current understanding of the diverse topics in ecology and conservation of crustaceans. The first section summarizes the role of crustaceans as food for higher trophic levels, as consumers of plant and animal prey, and it examines their contribution to the processing of dead organic material as scavengers and detritivores. The following chapters evaluate how crustaceans modify the structure of ecosystems and the availability of habitat and other resources as bioengineers through, for example, bioturbation. Non-trophic interactions involving crustaceans are synthesized in the following chapters, including parasitism and competition for space and food as well as the importance of crustacean biodiversity and disparity for the structure and functioning of ecosystems. The second section identifies threats to crustaceans in a changing world, such as the effects of habitat loss and fragmentation, global climate change, human land and water use, contaminants, and the impacts of species invasions. The third section of this volume summarizes conservation strategies for endangered crustacean species and habitats and how these strategies can benefit from modern molecular biological technologies and global digital databases. Examples will be given for the successful recovery of crustacean populations in protected areas and how crustaceans are considered in legislative frameworks in, for example, nature conservation and fishery policies. The fourth section addresses the role of crustaceans in human society as a species, as food but also in media and pop culture.</jats:p
Marine Anthropogenic Litter
No full textThis book describes how manmade litter, primarily plastic, has spread into the remotest parts of the oceans and covers all aspects of this pollution problem from the impacts on wildlife and human health to socio-economic and political issues. Marine litter is a prime threat to marine wildlife, habitats and food webs worldwide.
The book illustrates how advanced technologies from deep-sea research, microbiology and mathematic modelling as well as classic beach litter counts by volunteers contributed to the broad awareness of marine litter as a problem of global significance. The authors summarise more than five decades of marine litter research, which receives growing attention after the recent discovery of great oceanic garbage patches and the ubiquity of microscopic plastic particles in marine organisms and habitats.
In 16 chapters, authors from all over the world have created a universal view on the diverse field of marine litter pollution, the biological impacts, dedicated research activities, and the various national and international legislative efforts to combat this environmental problem. They recommend future research directions necessary for a comprehensive understanding of this environmental issue and the development of efficient management strategies. This book addresses scientists, and it provides a solid knowledge base for policy makers, NGOs, and the broader public
Marine Litter as Habitat and Dispersal Vector
No full textFloating anthropogenic litter provides habitat for a diverse community of marine organisms. A total of 387 taxa, including pro- and eukaryotic micro-organisms, seaweeds and invertebrates, have been found rafting on floating litter in all major oceanic regions. Among the invertebrates, species of bryozoans, crustaceans, molluscs and cnidarians are most frequently reported as rafters on marine litter. Microorganisms are also ubiquitous on marine litter although the composition of the microbial community seems to depend on specific substratum characteristics such as the polymer type of floating plastic items. Sessile suspension feeders are particularly well-adapted to the limited autochthonous food resources on artificial floating substrata and an extended planktonic larval development seems to facilitate colonization of floating litter at sea. Properties of floating litter, such as size and surface rugosity, are crucial for colonization by marine organisms and the subsequent succession of the rafting community. The rafters themselves affect substratum characteristics such as floating stability, buoyancy, and degradation. Under the influence of currents and winds marine litter can transport associated organisms over extensive distances. Because of the great persistence (especially of plastics) and the vast quantities of litter in the world’s oceans, rafting dispersal has become more prevalent in the marine environment, potentially facilitating the spread of invasive species
Hydrolysis rates of bio-based polymers
No full textBio-degradation assays were performed for bio-based polymers under environmental conditions with controlled temperature and pH using pH Stat titration. Suspensions of PLA and PBS microparticles, produced by e.g. cryo-milling, were incubated with proteolytic and lipolytic enzymes. Rates of hydrolysis, as determined by counter-titration with a diluted base (NaOH), was recorded for two hours. The thermal profile of PLA hydrolysis by protease was investigated. All measurements were conducted under controlled laboratory conditions
Master track of HEINCKE cruise HE632 in 1 sec resolution (zipped, 8 MB)
No full textRaw data acquired by position sensors on board RV Heincke during expedition HE632 were processed to receive a validated master track which can be used as reference of further expedition data. During HE632 the inertial navigation system IXSEA PHINS III and the GPS receivers Trimble Marine SPS461 and SAAB R5 SUPREME NAV were used as navigation sensors. Data were downloaded from DAVIS SHIP data base (https://dship.awi.de) with a resolution of 1 sec. Processed data are provided as a master track with 1 sec resolution derived from the position sensors' data selected by priority and a generalized track with a reduced set of the most significant positions of the master track
Master tracks in different resolutions of HEINCKE cruise HE632, Bremerhaven - Bremerhaven, 2023-11-13 - 2023-11-15
No full textRaw data acquired by position sensors on board RV Heincke during expedition HE632 were processed to receive a validated master track which can be used as reference of further expedition data. During HE632 the inertial navigation system IXSEA PHINS III and the GPS receivers Trimble Marine SPS461 and SAAB R5 SUPREME NAV were used as navigation sensors. Data were downloaded from DAVIS SHIP data base (https://dship.awi.de) with a resolution of 1 sec. Processed data are provided as a master track with 1 sec resolution derived from the position sensors' data selected by priority and a generalized track with a reduced set of the most significant positions of the master track
Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
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