scholarly journals Local Environmental Conditions Promote High Turnover Diversity of Benthic Deep-Sea Fungi in the Ross Sea (Antarctica)

2022 ◽  
Vol 8 (1) ◽  
pp. 65
Author(s):  
Giulio Barone ◽  
Cinzia Corinaldesi ◽  
Eugenio Rastelli ◽  
Michael Tangherlini ◽  
Stefano Varrella ◽  
...  
Keyword(s):  
Environmental Conditions ◽  
Deep Sea ◽  
Ross Sea ◽  
Organic Matter Content ◽  
Matter Content ◽  
High Turnover ◽  
Potential Control ◽  
Fungal Abundance ◽  
Order Of Magnitude ◽  
Abundance And Diversity

Fungi are a ubiquitous component of marine systems, but their quantitative relevance, biodiversity and ecological role in benthic deep-sea ecosystems remain largely unexplored. In this study, we investigated fungal abundance, diversity and assemblage composition in two benthic deep-sea sites of the Ross Sea (Southern Ocean, Antarctica), characterized by different environmental conditions (i.e., temperature, salinity, trophic availability). Our results indicate that fungal abundance (estimated as the number of 18S rDNA copies g−1) varied by almost one order of magnitude between the two benthic sites, consistently with changes in sediment characteristics and trophic availability. The highest fungal richness (in terms of Amplicon Sequence Variants−ASVs) was encountered in the sediments characterized by the highest organic matter content, indicating potential control of trophic availability on fungal diversity. The composition of fungal assemblages was highly diverse between sites and within each site (similarity less than 10%), suggesting that differences in environmental and ecological characteristics occurring even at a small spatial scale can promote high turnover diversity. Overall, this study provides new insights on the factors influencing the abundance and diversity of benthic deep-sea fungi inhabiting the Ross Sea, and also paves the way for a better understanding of the potential responses of benthic deep-sea fungi inhabiting Antarctic ecosystems in light of current and future climate changes.

Heavy metal pollution and macrobenthic assemblages in soft sediments in two Sydney estuaries, Australia

1998 ◽  
Vol 49 (6) ◽  
pp. 533 ◽  
Author(s):  
Jonathan S. Stark
Keyword(s):  
Heavy Metals ◽  
Environmental Variables ◽  
Spatial Scales ◽  
Organic Matter Content ◽  
Matter Content ◽  
Soft Sediments ◽  
Lead And Zinc ◽  
Macrobenthic Assemblages ◽  
Order Of Magnitude ◽  
Copper Lead

The influence of heavy metals (copper, lead and zinc) associated with urban runoff, on assemblages of macrofauna in intertidal soft sediments was studied in two estuaries in the Sydney region. The patterns of distribution and abundance of fauna and assemblages was found to vary significantly at several spatial scales: within bays in an estuary, between bays within an estuary and between bays from different estuaries. Significant differences were found in concentrations of heavy metals in sediments, but there was very little difference among bays in other environmental variables: grain-size characteristics and organic matter content of sediments. Bays polluted by heavy metals had significantly different assemblages to unpolluted bays, were generally less diverse and were characterized by an order-of-magnitude greater abundance of capitellids, spionids, nereids and bivalves. Unpolluted bays had greater abundance of crustaceans and several polychaete families, including paraonids and nephtyids and were generally more diverse. There was a significant correlation between patterns of assemblages and concentrations of heavy metals, but not with other environmental variables.

scholarly journals Polychaete fauna from the intertidal zone of the Kneiss Islands (central Mediterranean Sea)

2017 ◽  
Vol 18 (2) ◽  
pp. 215
Author(s):  
N. MOSBAHI ◽  
J.C. DAUVIN ◽  
L. NEIFAR
Keyword(s):  
Mediterranean Sea ◽  
Seasonal Variations ◽  
Organic Matter Content ◽  
Temporal Distribution ◽  
Matter Content ◽  
Central Mediterranean ◽  
Community Patterns ◽  
Central Mediterranean Sea ◽  
Abundance And Diversity ◽  
A Site

The spatial and temporal distribution, abundance and assemblage structure of polychaete communities in the Kneiss Islands (central Mediterranean Sea) was studied at 42 stations selected among seagrass Zostera (Zosterella) noltei Hornemann meadows and unvegetated habitats sampled from April 2014 to January 2015. The Kneiss Islands represent a site of international interest in terms of their ornithological diversity (Important Bird Area, Ramsar Site and SPAMI). A total of 18,026 individuals and 92 species of polychaetes belonging to 25 families were identified. Analysis of the trophic structure reveals that the majority of stations are strongly dominated by deposit feeders (51.2%), followed by carnivores (34.8%) and suspension feeders (14%). Polychaete diversity and abundance were higher on the vegetated stations. Four polychaete assemblages are identified using MDS analysis. The distribution of polychaete assemblages are influenced by edaphic factors, particularly sediment structure and organic matter content. Seasonal variations of the polychaete community patterns at 20 stations show a maximum abundance and diversity during spring and summer and a minimum during winter. Seasonal fluctuations follow the seasonal variations of the environmental factors such as temperature and salinity, and correspond also to the lifestyle of the dominant species.

scholarly journals Komunitas Makrozoobentos pada Substrat Dasar Lunak Di Muara Sungai Wulan, Demak

2020 ◽  
Vol 9 (1) ◽  
pp. 19-26
Author(s):  
Narendra Prasidya Wishnu ◽  
Retno Hartati ◽  
Jusup Suprijanto ◽  
Nirwani Soenardjo ◽  
Gunawan Widi Santosa
Keyword(s):  
Random Sampling ◽  
Organic Matter Content ◽  
Matter Content ◽  
Survey Method ◽  
Suitable Habitat ◽  
Diversity Analysis ◽  
Soft Substrate ◽  
Sediment Samples ◽  
Central Java ◽  
Abundance And Diversity

Muara Sungai Wulan yang terletak di Pantai Demak, Jawa Tengah,merupakan habitat yang baik bagi komunitas makrozoobentos. Habitat tersebutdicirikan dengan sedimen pasir, lanau dan lempung, karena pada beberapa tempat merupakan substrat dasar lunak yang didominasi oleh sedimen lanau. Identifikasi jenis makrozoobentos dan analisis keanekaragamannya penting untuk menentukan kondisi ekosistem substrat lunak tersebut.Tujuan dari penelitian ini adalah untuk mengidentifikasi jenis dan mengetahui struktur komunitas makrozoobentos pada substrat lunak di perairan Delta Wulan, Demak. Metode survei eksploratif diaplikasikan pada penelitian ini dan purposive random sampling dilakukan pada saat mengambil sample sedimen pada12 titik penelitian dengan menggunakan van veen grab sampler. Analisa makrozobentos dan ukuran butir dilakukan terhadap sampel sedimen. Penelitian menemukan 24 spesies makrozoobentos yang termasuk dalam 4 filum, yaitu Arthropoda, Cnidaria, Echinodermata dan Moluska. Titik 5 adalah titik dengan nilai kelimpahan dan keanekaragaman tertinggi adalah Anadara. Terdapat dominansi 4 species yang berbeda disemua titik pengambilan sampel, yaitu Anadara sp., Paphia sp., Cominella sp. dan Gemmula sp. Sedimen pada daerah penelitian termasuk klasifikasi lanau komposisi pasir 2,5-22,14%, lanau 67,82-94,79% dan lempung 0-22,86% serta kandungan bahan organik total yang dikategorikan rendah-sedang dengan nilai berkisar 3,0-14,83%. Adanya dominasi jenis tersebut, maka substrat lunak merupakan habitat yang baik untuk moluska, khususnya bivalvia, sehingga daerah tersebut menjadi tempat penangkapan kerang.  Wulan estuary, located in Demak regency, Central Java, is a suitable habitat for the macrozoobenthos community. The habitat is characterized by sand, silt, and clay sediments, which in some places are soft substrates dominated by silt sediments. Identification of macrozoobenthos types and diversity analysis is important to determine the condition of the soft substrate ecosystem. The purpose of this study was to identify species and determine the structure of the macrozoobenthos community on soft substrates in the waters of Delta Wulan, Demak. Explorative survey method was applied in this study while purposive random sampling was carried out to collect the sediment samples at 12 research stations using a Van Veen grab sampler. Macrozoobenthos and grain size analyzes were performed used the sediment samples obtained. The study found 24 species of macrozoobenthos, which included 4 phyla, namely Arthropods, Cnidaria, Echinoderms and Molluscs. Station 5 has the highest value of abundance and diversity Anadara. Four different genera are dominant at all sampling points, namely Anadara sp., Paphia sp., Cominella sp., and Gemmula sp. Sediments in the study area included silt classification in which the composition of sand 2,5-22,14%, the silt of 67,82-94,79%, and loam of 0-22,86% and total organic matter content which was categorized as low-moderate with values ranging from 3,0-14,83%. The dominance evidence in this estuary concluded that soft substrate is a suitable habitat for mollusks, primarily bivalves; therefore this was the capture area of bivalve.

PERSISTENCE AND PHYTOTOXICITY OF DINITROANILINE HERBICIDES IN MANITOBA SOILS

1980 ◽  
Vol 60 (1) ◽  
pp. 5-11 ◽  
Author(s):  
M. K. PRITCHARD ◽  
E. H. STOBBE
Keyword(s):  
Organic Matter ◽  
Environmental Conditions ◽  
Sandy Loam ◽  
Organic Matter Content ◽  
Matter Content ◽  
Soil Types ◽  
Clay Loam ◽  
Crop Injury ◽  
Dinitroaniline Herbicides

The persistence and phytotoxicity of dinitramine (n4, N4-diethyl-α,α,α-trifluoro-3,5-dinitrotoluene-2,4-diamine), fluchloralin (N-(2-chloroethyl)-2, 6-dinitro- N-propyl-4- (trifluoromethyl)aniline), profluralin (N-(cyclopropylmethyl)α,α,α-trifluoro-2, 6-dinitro-N-propyl-p-toluidine), and trifluralin (α,α,α-trifluoro-2,6-dinitro-N-N-dipropyl-p-toluidine) were compared in three Manitoba soils: sandy loam, clay loam and clay. The phytotoxicities of all chemicals decreased with increased organic matter. The phytotoxicities of the dinitroanilines were: dinitramine > trifluralin > profluralin = fluchloralin. Increased organic matter increased the persistence of trifluralin and fluchloralin. Profluralin and dinitramine persistence increased with increased clay and organic matter content. Profluralin was the most persistent chemical over all soil types. Under environmental conditions that retard dinitroaniline loss from Manitoba soils, residues of some of these herbicides may cause crop injury the year after application.

scholarly journals Nitrogen Transformation Processes Taking Place During the Intensive Phase of Composting

2002 ◽  
Vol 51 (1-2) ◽  
pp. 157-166
Author(s):  
László Alexa ◽  
Gy. Füleky
Keyword(s):  
Raw Materials ◽  
Organic Matter Content ◽  
Nitrogen Transformation ◽  
Matter Content ◽  
N Losses ◽  
Total N ◽  
Intensive Phase ◽  
Significant Difference ◽  
Order Of Magnitude ◽  
Transformation Processes

N transformation processes taking place during the intensive phase of composting were analyzed for characteristic compost raw materials in an adiabatic composting bioreactor by analyzing composts (in various stages of maturity), emitted gases and leakage water.  Temperature exhibited a similar curve for all raw materials, with a gradual decrease in compost temperature from day 11-13 on. Measurements of NH 3 indicated a significant difference between the various raw materials, sometimes amounting to an order of magnitude, in the quantitative data of NH 4 volatilization. Analysis of leakage water indicated that ammonification and nitrification processes could be traced satisfactorily, but the quantity of leakage water formed in the adiabatic drum composter and the associated N losses were negligible compared to the total N cycle of compost formation. Analysis of the composts showed that the organic matter content of the samples declined during composting as the result of biodegradation.

scholarly journals Effects of Varying Environmental Conditions on Biological Control of Fusarium Wilt of Tomato by Nonpathogenic Fusarium spp.

2002 ◽  
Vol 92 (11) ◽  
pp. 1160-1166 ◽  
Author(s):  
Robert P. Larkin ◽  
Deborah R. Fravel
Keyword(s):  
Biological Control ◽  
Fusarium Wilt ◽  
Environmental Conditions ◽  
Growth Parameters ◽  
Disease Incidence ◽  
Organic Matter Content ◽  
Matter Content ◽  
Disease Development ◽  
Temperature Regimes ◽  
Infested Field

The influence of varying environmental and cropping conditions including temperature, light, soil type, pathogen isolate and race, and cultivar of tomato on biological control of Fusarium wilt of tomato by isolates of nonpathogenic Fusarium oxysporum (CS-20 and CS-24) and F. solani (CS-1) was evaluated in greenhouse and growth chamber experiments. Liquid spore suspensions (106/ml) of the biocontrol isolates were applied to soilless potting mix at the time of tomato seeding, and the seedlings were transplanted into pathogen-infested field soil 2 weeks later. Temperature regimes ranging from 22 to 32°C significantly affected disease development and plant physiological parameters. Biocontrol isolate CS-20 significantly reduced disease at all temperature regimes tested, yielding reductions of disease incidence of 59 to 100% relative to pathogen control treatments. Isolates CS-24 and CS-1 reduced disease incidence in the greenhouse and at high temperatures, but were less effective at the optimum temperature for disease development (27°C). Growing plants under shade (50% of full light) versus full light affected some plant growth parameters, but did not affect the efficacy of biocontrol of any of the three bio-control isolates. Isolate CS-20 effectively reduced disease incidence (56 to 79% reduction) in four different field soils varying in texture (sandy to clayey) and organic matter content (0 to 3.2%). Isolate CS-1 reduced disease in the sandy and loamy soils (49 to 66% reduction), but was not effective in a heavy clay soil. Both CS-1 and CS-20 were equally effective against all three races of the pathogen, as well as multiple isolates of each race (48 to 66% reduction in disease incidence). Both isolates, CS-1 and CS-20, were equally effective in reducing disease incidence (66 to 80% reduction) by pathogenic races 1, 2, and 3 on eight different tomato cultivars containing varying levels of inherent resistance to Fusarium wilt (susceptible, resistant to race 1, or resistant to races 1 and 2). These results demonstrate that both these Fusarium isolates, and particularly CS-20, can effectively reduce Fusarium wilt disease of tomato under a variety of environmental conditions and have potential for further development.

Relative palaeointensity and reservoir effect on Lake Esmeralda, Antarctica

2017 ◽  
Vol 29 (4) ◽  
pp. 356-368 ◽  
Author(s):  
M.A. Irurzun ◽  
M.A.E. Chaparro ◽  
A.M. Sinito ◽  
C.S.G. Gogorza ◽  
H. Nuñez ◽  
...  
Keyword(s):  
Mass Spectrometry ◽  
Remanent Magnetization ◽  
Necessary Conditions ◽  
Organic Matter Content ◽  
Natural Remanent Magnetization ◽  
Matter Content ◽  
Global Models ◽  
Reservoir Effect ◽  
Order Of Magnitude ◽  
Rock Magnetics

AbstractFour cores from the bottom sediments of Lake Esmeralda, Vega Island, Antarctica (60°48'S, 57°37'W) were studied. Analysis of rock magnetics indicates that the main carriers of magnetization are ferrimagnetic minerals, predominantly pseudo-single-domain (titano-) magnetite with a small proportion of paramagnetic and antiferromagnetic minerals. The magnetic grain size of the samples is in the range of 1–5 μm and the variation of the interparametric ratios is less than one order of magnitude. Demagnetization of the natural remanent magnetization shows a stable remanent magnetization in most of the samples. Thus, the samples fulfil the necessary conditions to calculate relative palaeointensity (RPI) and the curves obtained correlated with global models enabling dating of the cores. The 250 cm of sediment recovered spans the last 10 200 yr bp. Finally, some samples with high organic matter content were dated by accelerator mass spectrometry 14C. By comparison with the age defined by the RPI curves, a reservoir effect of c. 5200 years is suggested for this region of Vega Island.

scholarly journals Bacterial Composition and Diversity in Deep-Sea Sediments from the Southern Colombian Caribbean Sea

Diversity ◽  
2020 ◽  
Vol 13 (1) ◽  
pp. 10
Author(s):  
Nelson Rivera Franco ◽  
Miguel Ángel Giraldo ◽  
Diana López-Alvarez ◽  
Jenny Johana Gallo-Franco ◽  
Luisa F. Dueñas ◽  
...  
Keyword(s):  
Bacterial Diversity ◽  
Deep Sea ◽  
Organic Matter Content ◽  
Caribbean Sea ◽  
Extreme Environment ◽  
Matter Content ◽  
Rrna Gene ◽  
Organic Carbon Content ◽  
Bacterial Composition ◽  
Deep Sea Sediments

Deep-sea sediments are considered an extreme environment due to high atmospheric pressure and low temperatures, harboring novel microorganisms. To explore marine bacterial diversity in the southern Colombian Caribbean Sea, this study used 16S ribosomal RNA (rRNA) gene sequencing to estimate bacterial composition and diversity of six samples collected at different depths (1681 to 2409 m) in two localities (CCS_A and CCS_B). We found 1842 operational taxonomic units (OTUs) assigned to bacteria. The most abundant phylum was Proteobacteria (54.74%), followed by Bacteroidetes (24.36%) and Firmicutes (9.48%). Actinobacteria and Chloroflexi were also identified, but their dominance varied between samples. At the class-level, Alphaproteobacteria was most abundant (28.4%), followed by Gammaproteobacteria (24.44%) and Flavobacteria (16.97%). The results demonstrated that some bacteria were common to all sample sites, whereas other bacteria were unique to specific samples. The dominant species was Erythrobacter citreus, followed by Gramella sp. Overall, we found that, in deeper marine sediments (e.g., locality CCS_B), the bacterial alpha diversity decreased while the dominance of several genera increased; moreover, for locality CCS_A, our results suggest that the bacterial diversity could be associated with total organic carbon content. We conclude that physicochemical properties (e.g., organic matter content) create a unique environment and play an important role in shaping bacterial communities and their diversity.

Dissolved oxygen and temperature best predict deep-sea fish community structure in the Gulf of California with climate change implications

2020 ◽  
Vol 637 ◽  
pp. 159-180
Author(s):  
ND Gallo ◽  
M Beckwith ◽  
CL Wei ◽  
LA Levin ◽  
L Kuhnz ◽  
...  
Keyword(s):  
Climate Change ◽  
Community Structure ◽  
Community Composition ◽  
Environmental Conditions ◽  
Deep Sea ◽  
Gulf Of California ◽  
Fish Community ◽  
Demersal Fish ◽  
Fish Community Structure ◽  
Explained Variance

Natural gradient systems can be used to examine the vulnerability of deep-sea communities to climate change. The Gulf of California presents an ideal system for examining relationships between faunal patterns and environmental conditions of deep-sea communities because deep-sea conditions change from warm and oxygen-rich in the north to cold and severely hypoxic in the south. The Monterey Bay Aquarium Research Institute (MBARI) remotely operated vehicle (ROV) ‘Doc Ricketts’ was used to conduct seafloor video transects at depths of ~200-1400 m in the northern, central, and southern Gulf. The community composition, density, and diversity of demersal fish assemblages were compared to environmental conditions. We tested the hypothesis that climate-relevant variables (temperature, oxygen, and primary production) have more explanatory power than static variables (latitude, depth, and benthic substrate) in explaining variation in fish community structure. Temperature best explained variance in density, while oxygen best explained variance in diversity and community composition. Both density and diversity declined with decreasing oxygen, but diversity declined at a higher oxygen threshold (~7 µmol kg-1). Remarkably, high-density fish communities were observed living under suboxic conditions (<5 µmol kg-1). Using an Earth systems global climate model forced under an RCP8.5 scenario, we found that by 2081-2100, the entire Gulf of California seafloor is expected to experience a mean temperature increase of 1.08 ± 1.07°C and modest deoxygenation. The projected changes in temperature and oxygen are expected to be accompanied by reduced diversity and related changes in deep-sea demersal fish communities.

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