The fundamental role of bacteria in global biogeochemical cycles warrants a thorough understanding of the factors controlling bacterial community structure. In this study, the integrated effect of seasonal differences and spatial distribution on bacterial community structure and diversity were investigated at the regional scale. We conducted a comprehensive bacterial survey, with 451 samples of the Scotian Shelf sector of the Northwest Atlantic Ocean during spring and fall of 2014 and 2016, to analyze the effects of physicochemical gradients on bacterial community structure. Throughout the region, Pelagibacteraceae and Rhodobacteraceae were the most common in the free-living fraction, while Flavobacteriia and Deltaproteobacteria were more abundant in the particle-associated fraction. Overall, there was strong covariation of the microbial community diversity from the two size fractions. This relationship existed despite the statistically significant difference in community structure between the free-living and particle-associated size fractions. In both size fractions, distribution patterns of bacterial taxa, and species within taxa, displayed temporal and spatial preferences. Distinct bacterial assemblages specific to season and depth in the water column were identified. These distinct assemblages, consistent for both 2014 and 2016, suggested replicable patterns in microbial communities for spring and fall in this region. Over all sites, temperature and oxygen values were highly correlated with community similarity, and salinity and oxygen values were the most strongly positively- and negatively correlated with alpha diversity, respectively. However, the strengths of these correlations depended on the depth and season sampled. The bathymetry of the Scotian Shelf, the abrupt shelf break to the Scotian Slope and the major ocean currents dominating in the region led to the formation of distinct on-shelf and off-shelf bacterial communities both in spring and fall. The highest species richness was observed at the shelf break, where water masses from the two major currents meet. Our study establishes the baseline for assessing future changes in the bacterial community of the Scotian Shelf waters, a rapidly changing sector of the Atlantic Ocean.
Marine microbes play essential roles in global energy and nutrient cycles. A primary method of determining their diversity and distribution is through sequencing of 16S ribosomal RNA genes from environmental samples. However, the perceived community composition may vary significantly based on differences in methodology, including choice of 16S variable region(s). This study investigated the influence of 16S variable region selection (V4-V5 or V6-V8) on perceived community composition and diversity for bacteria, Archaea and chloroplasts by tag-Illumina sequencing. We used 24 samples from the photic zone of the Scotian Shelf, northwest Atlantic, collected during a spring phytoplankton bloom. Taxonomic assignment and community composition varied greatly depending on the choice of variable regions while observed patterns of beta diversity were reproducible between variable regions. V4-V5 was considered the preferred variable region for future studies based on its superior recognition of Archaea, which has received little attention in bloom dynamics. The V6-V8 region captured more of the bacterial diversity, including the abundant SAR11 clades and, to a lesser extent, that of chloroplasts. However, the magnitude of difference between variable regions for bacteria and chloroplast was less than for Archaea.
The Phoenix Islands Protected Area (PIPA), one of the world’s largest marine protected areas, represents 11% of the exclusive economic zone of the Republic of Kiribati, which earns much of its GDP by selling tuna fishing licenses to foreign nations. We have determined that PIPA is a spawning area for skipjack ( Katsuwonus pelamis ), bigeye ( Thunnus obesus ), and yellowfin ( Thunnus albacares ) tunas. Our approach included sampling larvae on cruises in 2015–2017 and using a biological-physical model to estimate spawning locations for collected larvae. Temperature and chlorophyll conditions varied markedly due to observed ENSO states: El Niño (2015) and neutral (2016–2017). However, larval tuna distributions were similar amongst years. Generally, skipjack larvae were patchy and more abundant near PIPA’s northeast corner, while Thunnus larvae exhibited lower and more even abundances. Genetic barcoding confirmed the presence of bigeye ( Thunnus obesus ) and yellowfin ( Thunnus albacares ) tuna larvae. Model simulations indicated that most of the larvae collected inside PIPA in 2015 were spawned inside, while stronger currents in 2016 moved more larvae across PIPA’s boundaries. Larval distributions and relative spawning output simulations indicated that both focal taxa spawned inside PIPA in all 3 study years, demonstrating that PIPA is protecting viable tuna spawning habitat.
The western and central Pacific Ocean (WCPO) tuna fishery is one of the world's largest fisheries in terms of both catch volume and value, providing nearly 80% of the total Pacific Ocean tuna catch and over half of global tuna catch with a landed value of US $5.84 billion in 2017 (Williams & Reid, 2018). The major species fished are skipjack (Katsuwonus pelamis, Scombridae), yellowfin (Thunnus albacares, Scombridae) and bigeye (T. obesus, Scombridae), with small amounts of albacore (T. alalonga, Scombridae) and Pacific Bluefin (T. orientalis, Scombridae) also caught. The three main species' stocks overlap geographically and are caught by both large-and small-scale fisheries (LSF and SSF, respectively) at different life stages. LSF are typically from Pacific-based domestic fleets or from foreign fleets of developed countries, with their catch and effort being well documented. In the WCPO, they fish both in exclusive economic zones (EEZs) of coastal states (e.g. waters of Pacific nations) and international waters (high seas). SSF are typically from poorly documented domestic coastal fleets, often from
Background: Substantial gains could be made in reducing the cancer burden if current scientific evidence was applied in practice. The World Health Organization estimates that, worldwide, one-third of cancer cases could be prevented and another one-third cured if evidence was consistently implemented and sustained in cancer care. However, moving evidence-based interventions into care has proven a significant challenge. Even when interventions are put into practice, they often fail to become integrated into the long-term routines of organizations. This poor sustainability means many patients do not benefit from the best care possible. There is little empirical data on the factors that influence the sustainability of interventions in clinical settings. Aim: To identify the determinants of, and explore the processes that facilitate, sustainability of interventions in cancer care survivorship. Sustainability was defined as the continued use of an intervention and its associated components and/or the continued achievement of the intended benefits after the initial funding or support period. Methods: We first conducted an environmental scan to identify interventions in cancer survivorship care implemented in Canada. This was followed by a literature review to ascertain the evidence base for each intervention and identify those meeting the US National Cancer Institute's criteria for evidence-based interventions. We then recruited key individuals relevant to the evidence-based interventions for semistructured in-depth interviews to explore issues related to their sustainability. Interview data are being analyzed through an inductive grounded theory approach using constant comparative analysis. Results: Twenty-seven individuals participated in the interviews. Preliminary findings reveal five factors that influenced whether, and the extent to which, interventions were sustained in cancer survivorship care. Participants emphasized (1) access to sufficient resources and funding is critical to sustaining interventions after the initial funding period. The ability of a team or organization to (2) evaluate a new intervention and demonstrate its quality and usefulness was often perceived as necessary to obtain continued funding as well as ongoing buy in and support from key stakeholders. In addition, the (3) extent to which the intervention can be adapted, (4) support of senior management, and (5) existence of an on-the-ground champion to continuously promote, adapt, lead, and spread the intervention were perceived as important factors that contribute to an intervention's sustained use. Conclusion: Research into determinants and processes of sustainability is critical to ensure we plan and act in ways that maximize the sustained use of interventions shown to benefit patients and our cancer systems. Issues related to evaluation, adaptability, and ongoing moral and material supports should be considered before, during, and after implementation efforts.
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