oceanic ecosystem
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Foods ◽  
2021 ◽  
Vol 10 (4) ◽  
pp. 880
Author(s):  
Tiptiwa Sampantamit ◽  
Long Ho ◽  
Carl Lachat ◽  
Giles Hanley-Cook ◽  
Peter Goethals

Sustainably feeding a growing human population is one of the greatest food system challenges of the 21st century. Seafood plays a vital role in supporting human wellbeing, by providing bioavailable and nutrient-dense animal-source food. In Thailand, seafood demand is increasing, and wild capture fishery yields have plateaued, due to oceanic ecosystem degradation and fishery stock exploitation. In this study, we investigated the supply trend of fishery products and subsequent seafood-derived nutrient availability over the last decade. In addition, we explored the possibility of predicting seafood availability and consumption levels, including adherence to Thailand’s national food guide and global dietary recommendations for sustainable seafood consumption. Our findings indicate that, at national-level, fishery products supplied between 19% and 35% of the Thai populations recommended dietary protein intake, 4–6% of calcium, 6–11% of iron, and 2–4% of zinc from 1995 to 2015. Nevertheless, our research also reports that if Thailand’s wild-caught seafood production were to decrease by 13%, as is highly likely, by 2030, the country might face a per capita supply deficit of fish and shellfish to meet healthy and sustainable dietary recommendations (28–30 g/day), let alone the current Thai average intake (32 g/day). Although a 1% per year increase in aquaculture production might bridge this supply gap, policymakers and relevant fishery stakeholders must consider the long-term environmental impacts of such an approach in Thailand.


PLoS ONE ◽  
2021 ◽  
Vol 16 (2) ◽  
pp. e0247071
Author(s):  
Lorena Linacre ◽  
Citlalli Sánchez-Robles ◽  
Uriel Mirabal-Gómez ◽  
J. Rubén Lara-Lara ◽  
Carmen Bazán-Guzmán

This study assessed the cell carbon content and biomass for genera of dinoflagellates and diatoms in the oceanic ecosystem of the Southern Gulf of Mexico. Carbon content estimates were based on biovolume calculations derived from linear dimension measurements of individual cells and the approximate geometric body shape of each genus. Then, biomass assessments were performed for both groups in two gulf regions (Perdido and Coatzacoalcos) using these carbon content factors and cell abundances. After four seasonal cruises, 11,817 cells of dinoflagellates and 3,412 cells of diatoms were analyzed. Diverse body shapes and cell sizes were observed among 46 dinoflagellate genera and 37 diatom genera. Nano-cells of dinoflagellates (68% <20 μm) and micro-cells of diatoms (77% 20–200 μm, mostly 50–75 μm) were predominant. According to this cell-size structure, on average, diatoms contained 40% more carbon per cell than dinoflagellates. Contrasting carbon content estimates were observed within the genera of both microalgae. Large carbon averages (>10,000 pg C cell-1) were attributed to Gonyaulacal and some occasional genera of dinoflagellates (e.g., Pyrocystis and Noctiluca) and centric diatoms. In contrast, values up to 3 orders of magnitude lower were found for Peridinial and Gymnodinial dinoflagellates and pennate diatoms. Based on these carbon content estimates, which can be considered representative for most of this oceanic ecosystem, seasonal and regional differences were found in the biomass assessments conducted for these functional groups. Overall, dinoflagellates (mostly low-carbon Gymnodinales) had larger depth-integrated biomass than diatoms (mainly rich-carbon centric forms) within the euphotic zone. An exception to it was the late-summer cruise at the Coatzacoalcos region when a surface bloom of centric diatoms was observed in stations influenced by river runoff. This work contributes useful reference information for future ecological studies and models for understanding the biogeochemical functioning of this open-ocean ecosystem.


2020 ◽  
Vol 7 ◽  
Author(s):  
April B. Cook ◽  
Andrea M. Bernard ◽  
Kevin M. Boswell ◽  
Heather Bracken-Grissom ◽  
Marta D’Elia ◽  
...  

The pelagic Gulf of Mexico (GoM) is a complex system of dynamic physical oceanography (western boundary current, mesoscale eddies), high biological diversity, and community integration via diel vertical migration and lateral advection. Humans also heavily utilize this system, including its deep-sea components, for resource extraction, shipping, tourism, and other commercial activity. This utilization has had impacts, some with disastrous consequences. The Deepwater Horizon oil spill (DWHOS) occurred at a depth of ∼1500 m (Macondo wellhead), creating a persistent and toxic mixture of hydrocarbons and dispersant in the deep-pelagic (water column below 200 m depth) habitat. In order to assess the impacts of the DWHOS on this habitat, two large-scale research programs, described herein, were designed and executed. These programs, ONSAP and DEEPEND, aimed to quantitatively characterize the oceanic ecosystem of the northern GoM and to establish a time-series with which natural and anthropogenic changes could be detected. The approach was multi-disciplinary in nature and included in situ sampling, acoustic sensing, water column profiling and sampling, satellite remote sensing, AUV sensing, numerical modeling, genetic sequencing, and biogeochemical analyses. The synergy of these methodologies has provided new and unprecedented perspectives of an oceanic ecosystem with respect to composition, connectivity, drivers, and variability.


2020 ◽  
Vol 157 (5) ◽  
pp. 701-706 ◽  
Author(s):  
Shiming Wan ◽  
Youbin Sun ◽  
Kana Nagashima

AbstractProduction, transport and deposition of aeolian dust from land to sea closely interact with regional environment and global climate. This Special Issue addresses transport of aeolian dust from the Asian inland to the Loess Plateau and North Pacific Ocean and their possible links to oceanic ecosystem, global climate and even human activity, over various timescales. The papers in this volume are multidisciplinary in nature and include sedimentology, mineralogy, geochemistry, environmental magnetism and climate modelling on multi-timescales from interannual, glacial–interglacial to tectonic timescales. Based on modern observation, geological records and modelling, this Special Issue offers new insights especially into aeolian provenance, dynamics controls on dust production, a novel marine aeolian proxy, as well as long-term aeolian input to the marginal basins of NE Asia and its influence on oceanic productivity. This issue provides a good example for future comprehensive studies of source-to-sink processes of Asian dust from land to sea.


2019 ◽  
Vol 9 (1) ◽  
Author(s):  
D. P. Gavin ◽  
F. J. Reen ◽  
J. Rocha-Martin ◽  
I. Abreu-Castilla ◽  
D. F. Woods ◽  
...  

AbstractMicrobial enzymes from pristine niches can potentially deliver disruptive opportunities in synthetic routes to Active Pharmaceutical Ingredients and intermediates in the Pharmaceutical Industry. Advances in green chemistry technologies and the importance of stereochemical control, further underscores the application of enzyme-based solutions in chemical synthesis. The rich tapestry of microbial diversity in the oceanic ecosystem encodes a capacity for novel biotransformations arising from the chemical complexity of this largely unexplored bioactive reservoir. Here we report a novel ω-transaminase discovered in a marine sponge Pseudovibrio sp. isolate. Remote stereoselection using a transaminase has been demonstrated for the first time using this novel protein. Application to the resolution of an intermediate in the synthesis of sertraline highlights the synthetic potential of this novel biocatalyst discovered through genomic mining. Integrated chemico-genomics revealed a unique substrate profile, while molecular modelling provided structural insights into this ‘first in class’ selectivity at a remote chiral centre.


Crustaceana ◽  
2019 ◽  
Vol 92 (3) ◽  
pp. 335-351 ◽  
Author(s):  
Juliana Gaeta ◽  
Raúl Cruz

Abstract Lobsters are recognizable faunal elements that play an important role as top predator in the trophic webs in benthic ecosystems and have an economic importance due to the intensive and valuable fishery. In Rocas Atoll (03°51′S 33°48′W) the presence of five species of lobsters in low tide pools was observed by visual census. These were: Enoplometopus antillensis Lütken, 1865; Palinurellus gundlachi Von Martens, 1878; Panulirus argus (Latreille, 1804); Panulirus echinatus Smith, 1869; and Parribacus antarcticus (Lund, 1793). This atoll appears to be dominated by P. echinatus followed by P. argus, P. antarcticus, P. gundlachi and E. antillensis, respectively. We also observed the presence of some potential predators that perhaps feed on lobster species and control these populations in the atoll. This work and future information could help to better understand the variability of lobster diversity and density in this unique atoll.


Crustaceana ◽  
2019 ◽  
Vol 92 (2) ◽  
pp. 221-232 ◽  
Author(s):  
Juliana Gaeta ◽  
Raúl Cruz

Abstract In Rocas Atoll (03°51′S 033°48′W) a most abundant population of Panulirus echinatus Smith, 1869 was observed during free dives. Numbers of males and females were almost the same, with an overall sex ratio M : F = 1.1. In addition, males are larger than females, with a mean male carapace length (CL) of 92.6 ± 1.8 mm, while the female mean CL was 72.7 ± 1.0 mm and for both sex combined the mean CL was 83.1 ± 1.4 mm. The percentage of females breeding, i.e., with a spermatophore mass or eggs, was 75.1%. More information is needed to better understand the fluctuation in densities over a year cycle, the reproduction period, and differences in CL between males and females, as well as other aspects of the biology of this species. The present work and future information could help to formulate fisheries policies aimed at protecting P. echinatus stocks.


mBio ◽  
2018 ◽  
Vol 9 (2) ◽  
Author(s):  
Daria Tashyreva ◽  
Galina Prokopchuk ◽  
Jan Votýpka ◽  
Akinori Yabuki ◽  
Aleš Horák ◽  
...  

ABSTRACT Diplonemids represent a hyperdiverse and abundant yet poorly studied group of marine protists. Here we describe two new members of the genus Diplonema (Diplonemea, Euglenozoa), Diplonema japonicum sp. nov. and Diplonema aggregatum sp. nov., based on life cycle, morphology, and 18S rRNA gene sequences. Along with euglenozoan apomorphies, they contain several unique features. Their life cycle is complex, consisting of a trophic stage that is, following the depletion of nutrients, transformed into a sessile stage and subsequently into a swimming stage. The latter two stages are characterized by the presence of tubular extrusomes and the emergence of a paraflagellar rod, the supportive structure of the flagellum, which is prominently lacking in the trophic stage. These two stages also differ dramatically in motility and flagellar size. Both diplonemid species host endosymbiotic bacteria that are closely related to each other and constitute a novel branch within Holosporales , for which a new genus, “ Candidatus Cytomitobacter” gen. nov., has been established. Remarkably, the number of endosymbionts in the cytoplasm varies significantly, as does their localization within the cell, where they seem to penetrate the mitochondrion, a rare occurrence. IMPORTANCE We describe the morphology, behavior, and life cycle of two new Diplonema species that established a relationship with two Holospora -like bacteria in the first report of an endosymbiosis in diplonemids. Both endosymbionts reside in the cytoplasm and the mitochondrion, which establishes an extremely rare case. Within their life cycle, the diplonemids undergo transformation from a trophic to a sessile and eventually a highly motile swimming stage. These stages differ in several features, such as the presence or absence of tubular extrusomes and a paraflagellar rod, along with the length of the flagella. These morphological and behavioral interstage differences possibly reflect distinct functions in dispersion and invasion of the host and/or prey and may provide novel insight into the virtually unknown function of diplonemids in the oceanic ecosystem.


2017 ◽  
Vol 3 (6) ◽  
pp. 387
Author(s):  
Bram Setyadji ◽  
Asep Priatna

Planktonmerupakan komponen penting dalamkehidupan akuatik karena fungsi biologisnya yang penting sebagaimata rantai paling dasar dalam rantai makanan dan merupakan organisme yang menduduki kunci utama di dalam ekosistem bahari. Penelitian ini dilakukan pada bulanMei, Juli, dan Nopember 2010 yangmewakili musimperalihan I, musim timur dan musim barat dengan tujuan mengetahui distribusi kelimpahan spasial dan temporal fitoplankton dan zooplankton di Teluk Tomini. Kelimpahan fitoplankton dan zooplankton tertinggi terdapat pada musim barat sebesar 177.666 sel/m3 dan 7.088 ind/m3, sedangkan terendah pada musim timur sebesar 4.878 sel/m3 dan 1.118 ind/ m3. Tingkat indek keaneka-ragaman (H) baik fitoplankton dan zooplankton sedang, indek keseragaman (E) rendah hingga sedang, dan tidak ditemukan jenis tertentu yang dominan. Chaetoceros, Coscinodiscus, dan Rhizosolenia dari kelas Bacillariophyceae merupakan fitoplankton yangmempunyai frekuensi kehadiran yang tinggi, sedangkan Crustaceae merupakan zooplankton yang dominan. Konsentrasi sebaran terdapat dimulut teluk dan tersebar relatif sesuai dengan musim. Plankton plays important role in aquatic life due to its significant biological function as basic food chain in oceanic ecosystem. This studywas conducted on May, July, and November representing north-west monsoon, east monsoon, and west monsoon, respectively. The purposed of this study is to know the spatial and temporal distribution and the abundance of phytoplankton and zooplankton in Tomini Bay. Results showed that the highest abundance of phytoplankton and zooplankton were 177.667 cell/m3 and 7.088 ind/m3 that appeared at north-west monsoon, while the lowest were 4.878 cell/m3 and 1.118 ind/m3 that shown in south-east monsoon. The diversity index (H) for both Phytoplankton and Zooplankton were in medium (1<H<3), while the eveness index (E) range from low (d”1) to medium. There were no dominance species found. However, Chaetoceros, Coscinodiscus and Rhizosolenia that representing Bacillariophyceae showed a high frequency of appearance, while Crustaceae group were the dominance of zooplankton. The distribution of plankton concentrated in the mouth of the bay and relatively distributed according to seasons.


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