scholarly journals Marine free-living nematodes in semiarid inland waters

2021 ◽  
Vol 33 ◽  
Author(s):  
Fábio Lucas de Oliveira Barros ◽  
Maria Cristina da Silva ◽  
Francisco José Victor de Castro ◽  
Miodeli Nogueira Júnior

Abstract: Aim This study reports the occurrence of five Nematoda genera previously considered as exclusively marine in inland waters. Methods Sediment samples were taken, weekly, during nine weeks, at a small spring at the Horto Florestal Olho D’Água da Bica, Cuité, PB, ca. 130 km away from the shoreline, between March and May 2016 and fixed in 4% formalin. Nematodes were sorted by manual elutriation through sieves with 0.5 and 0.045 mm and slides were prepared. Results The sediment was classified as coarse sand, with organic matter content ranging between 2.73 and 13.32%, temperature between 27-28°C and constant salinity of 6. From 315 nematodes were sampled among which 18 were from five genera previously thought to be exclusively marine were found. Bolbolaimus was the most common, found in 11.1% of the samples, followed by Gomphionema (3.7%), Rynchonema (7.4%), Prorynchonema (7.4%) e Sabatieria (3.7%), representing 5.7% from total of nematofauna. These genera are widely distributed worldwide, but had never been recorded from inland environments. Conclusions This study contributes with the distributional knowledge of free-living nematodes. From literature data, these genera are not restricted by low salinity, and can be found in estuarine and/or brackish water environments and body water with direct connection to the sea. In any case, the presence of marine genera in this region which is >130 km away from the nearest shoreline is noteworthy, highlighting the importance of studying nematodes from these poorly known semiarid water bodies. These new occurrences raise questionings about the dispersal mechanisms that certified the colonization of these nematodes in the semiarid.

2005 ◽  
Vol 53 (1-2) ◽  
pp. 23-38 ◽  
Author(s):  
Rosebel C. Nalesso ◽  
Jean-Christophe Joyeux ◽  
Cintia O. Quintana ◽  
Evelise Torezani ◽  
Ana Clara Paz Otegui

The present work describes and analyses the structure of the macrobenthic epi- and infaunal assemblage of the estuarine system of Vitória Bay, South-eastern Brazil, from January 1998 to June 1999. Replicated sampling at intertidal and subtidal levels was conducted quarterly at ten stations. Intertidal and subtidal sediment composition was characterised. Water physico-chemical parameters were measured in situ. A total of 10,695 individuals, belonging to 144 taxa, were collected. Molluscs, crustaceans and polychaetes were the most abundant groups. The bivalves Anomalocardia brasiliana, Mytella guyanensis and M. falcata were the most abundant species. Locally, significant discharges of residential and industrial wastewater resulted in high organic content in the sediment (up to 30%) and low dissolved oxygen concentration in the water (< 1mg.l-1). Near the two entrances of the bay, high hydrodynamic activity and coarse sand reduced the detrimental effects of raw and treated sewage inputs. Species richness (S), diversity (H') and total abundance (A) decreased from outer-bay stations (22 < S < 72; 1.99 < H' < 2.85; 320 < A < 1737) towards inner-bay stations (2 < S < 45; 0.59 < H' < 2.67; 2 < A < 1317), where salinity and dissolved oxygen were lowest and organic matter content highest.


1998 ◽  
Vol 38 (11) ◽  
pp. 169-175 ◽  
Author(s):  
D. Bogner ◽  
M. Juracic ◽  
N. Odžak ◽  
A. Baric

The aim of the present work was to study the past and present contamination of the Kaštela bay using chemical analysis of selected trace metals (Cd, Pb, Zn, Cu, Cr, Mn and Ni) in fine grained sediment cores. Sediment samples were taken at three locations with silty sediments. The highest concentrations of Cd, Pb, Cu and Zn and the lowest concentration of Ni were found in the east, the most contaminated part of the Bay. The decrease of Cd, Pb, Cu and Zn concentrations with increased depth, indicates their anthropogenic origin. Homogeneous distribution of Cr, Mn and Ni in the sediment cores indicates their terrigenous origin. The correlation of Zn, Cu and Ni concentration with the organic matter content was determined.


2020 ◽  
Vol 9 (1) ◽  
pp. 19-26
Author(s):  
Narendra Prasidya Wishnu ◽  
Retno Hartati ◽  
Jusup Suprijanto ◽  
Nirwani Soenardjo ◽  
Gunawan Widi Santosa

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.


1961 ◽  
Vol 7 (4) ◽  
pp. 507-513 ◽  
Author(s):  
E. Strzelczyk

This study represents an attempt to correlate the low numbers of Azotobacter in rhizosphere and root-free soils at the Central Experimental Farm, Ottawa, with the incidence of bacterial and actinomycete antagonists of this organism. Wheat, radish, and onion were grown in the greenhouse in two soils varying greatly in fertility and organic matter content, and isolations of bacteria and actinomycetes were made periodically for testing against Azotobacter. It was found that rhizosphere soil contained greater numbers of microorganisms antagonistic to Azotobacter than root-free soil. Of the three crops used wheat exerted the least effect. In all the tests numbers of antagonists were greater in the fertile Granby sandy loam than in the infertile Upland sand. The results correlated well with the Azotobacter populations in these soils as reported in the first paper of this series.


1973 ◽  
Vol 80 (2) ◽  
pp. 269-281 ◽  
Author(s):  
C. Berryman ◽  
T. Batey ◽  
T. H. Caldwell ◽  
D. A. Boyd

SummaryThe fen silts bordering the Wash are among the most important soils for crop production in eastern England. Derived from marine alluvial deposits occurring naturally or as a result of reclamation, they form deep almost stoneless soils containing little coarse sand but much fine sand and silt.Seven textural classes, ranging from loamy fine sand to silty clay, can be distinguished, but these can be grouped into (1) light silts, typically deep very fine sandy loams with a large available water-holding capacity but weakly developed structure; (2) medium silts, silty loams; and (3) heavy silts, silt loams or silty clay loams, less porous and more retentive of moisture than the light silts.Formerly under grass, the silts were at first capable of growing good crops of potatoes with P fertilizer alone, but as their organic-matter content decreased, potatoes became increasingly responsive to N.In 18 potato manurial experiments on silt soils in Holland, Lincolnshire, done between 1953 and 1963, the mean response to N was much larger than on most English soils, but response differed greatly from site to site and year to year; in most trials N was particularly effective in increasing tuber size and yield of ware. With long-continued use of P fertilizer, residues have accumulated and, particularly on light and medium silts, responses were quite small and differed little between sites; P tended to increase tuber numbers, and so to decrease ware percentage. Most silt soils are rich in K, and only small responses to K fertilizer can be expected, but on a few sites on the light silts, identified by soil analysis as being comparatively poor in K, potatoes responded well. Using these experimental results, recommendations are given for the manuring of potatoes on silt soils.Cooking tests showed little consistent effect of manurial treatment on the amount or degree of tuber blackening.


Soil Research ◽  
2001 ◽  
Vol 39 (6) ◽  
pp. 1219 ◽  
Author(s):  
J. D. Oster ◽  
I. Shainberg

Exchangeable sodium and low salinity deteriorate the permeability of soils to air and water. The susceptibility of soils to sodicity and low salinity depend on both the inherent properties of the soils (e.g. texture, mineralogy, pH, CaCO3, sesquioxides, and organic matter content) and extrinsic, time-dependent properties (e.g. cultivation, irrigation method and wetting rate, antecedent water content, and the time since cultivation). Whereas the effect of inherent soil properties on the soil response to sodicity has been studied and modelled, especially under laboratory conditions, the effect of soil management on the physical response of soils to sodicity has been studied very little. Consequently our ability to predict the changes in soil permeability under field conditions is limited. Including the effect of management on the physical response of soils to sodicity and low salinity is the main challenge facing researchers, consultants, and farmers.


2011 ◽  
Vol 11 (2) ◽  
pp. 59-68 ◽  
Author(s):  
Urszula Aleksander-Kwaterczak ◽  
Anna Kostka

Lead in the environment of Lake Wigry (NE Poland)Analysis was performed for lead content in the sediments of Lake Wigry (NE Poland), taking into account lithology, basic chemical component content and physical characteristics of sediment, Several hundred sediment samples from different parts of the lake and peatland around the lake, were collected. Their locations were determined by GPS and the depth of sediment by echosounder. The surface layer (0-10 cm) of sediment and sediment cores were taken to determine the spatial and vertical distribution of Pb. Concentrations of lead in the surface sediment range from 2.52 to 469 mg kg-1. One of the most important factors influencing spatial distribution of Pb is sediment type. The highest content of Pb was found in samples of organic gyttja and the lowest in clastic sediment samples. Strong positive linear correlation (r = 0.7) between organic matter content and Pb concentration in sediment was observed. It may be the result of simple bio-accumulation of lead. A large influence of sediment location on Pb distribution was found. The largest concentration of this element was found in sediment of the Wigry Basin. The major part of Pb accumulates in the surface layer of sediment.


2020 ◽  
Vol 9 (4) ◽  
pp. 423-430
Author(s):  
Gadisza Asmara Yudha ◽  
Chrisna Adhi Suryono ◽  
Adi Santoso

Pantai Kartini merupakan salah satu kawasan wisata di Kabupaten Jepara. Berbagai aktifitas masyarakat serta infrastruktur perairan menjadi kebutuhan yang sangat krusial dengan letak Pantai Kartini. Adanya aktivitas dan bangunan dapat menyebabkan perubahan sebaran ukuran butir dan kandungan bahan organik. Penelitian ini memiliki tujuan untuk mengetahui jenis dan klasifikasi sedimen serta jumlah kandungan bahan organik yang terdapat dalam sedimen di Pantai Kartini, Jepara. Pengambilan data pada penelitian ini yaitu pengambilan data primer yang berupa sampel sedimen dengan menggunakan sediment core. Dilanjutkan dengan analisis sampel sedimen dan analisis kandungan bahan organik. Hasil penelitian menunjukkan bahwa di perairan Pantai Kartini, Jepara memiliki jenis sedimen pasir (sand) dimana nilai ukuran butir tersebut berkisar dari 81-96%, yang mana pada Stasiun 1 rata-rata sebesar 91,6-96%, Stasiun 2 rata-rata sebesar 93,5-96,9%, dan Stasiun 3 rata-rata sebesar 81,4-92,9%. Sedangkan, Kandungan Bahan Organik yang terdapat di perairan tersebut memiliki konsentrasi berkisar dari 5-14% yang termasuk dalam kriteria rendah-sedang, dimana pada Stasiun 1 rata-rata sebesar 10,9-13,3%, Stasiun 2 rata-rata sebesar 5,92-10,18%, dan Stasiun 3 rata-rata sebesar 7,7-14%. Kartini Beach is one of the tourist areas in Jepara Regency. Various community activities and water infrastructure have become crucial needs in Kartini Beach. The existence of activities and buildings can cause changes in the distribution of grain size and content of organic matter. This study aims to determine the type and classification of sediments and the amount of organic matter content contained in sediments in Kartini Beach, Jepara. Data collection in this study is primary data collection in the form of sediment samples using sediment cores. Followed by analysis of sediment samples and analysis of organic matter content. The results showed that in Kartini Coast waters, Jepara had a sand sediment type where the grain size values ranged from 81-96%, which at Station 1 averaged 91,6-96%, Station 2 on average amounted to 93,5-96,9%, and Station 3 averaged 81,4-92,9%. Meanwhile, the content of organic matter contained in these waters has concentrations ranging from 5-14% which are included in the criteria of low-moderate, where at Station 1 an average of 10,9-13,3%, Station 2 an average of 5,92-10,18%, and Station 3 averaging 7,7-14%. 


PeerJ ◽  
2018 ◽  
Vol 6 ◽  
pp. e5720 ◽  
Author(s):  
Aline Nonato de Sousa ◽  
Giovana Bertini ◽  
Fabiano Gazzi Taddei ◽  
Rogério Caetano da Costa ◽  
Thiago Elias da Silva ◽  
...  

This is the first study to examine how different environmental factors may influence the distribution of swimming crab Achelous spinimanus across geographically distant and distinct habitats. We analyzed the influence of bottom water temperature and salinity, sediment texture and organic matter content on the spatiotemporal distribution of A. spinimanus. The crabs were collected from January 1998 until December 1999 by trawling with a shrimp fishing boat outfitted with double-rig nets. The sampling took place in Ubatumirim (UBM), Ubatuba (UBA) and Mar Virado (MV) bays, located in the northern coast of São Paulo State (Brazil). These three bays were chosen as they differed in many physiographic features. We captured 1,911 crabs (UBM = 351; UBA = 1,509; MV = 51), and there were significant differences in abundance between bays and between stations. The distribution of A. spinimanus was primarily associated with sediment features: abundance was higher in stations with sandy sediments classified as gravel, very coarse sand, and intermediate sand. Portunoidea usually burrow in the sediment for protection against predators and to facilitate the capture of fast prey. In addition, the station with the highest abundance of A. spinimanus was also naturally protected from fishing activities, and composed of heterogeneous sediment, in terms of grain size. Hence, the combination of a favorable sediment heterogeneity and protection from fishery activities seemed to be effective modulators of the abundance and distribution of A. spinimanus in these bays.


Author(s):  
Olga Konechnaya ◽  
Christina Schwanen ◽  
Jan Schwarzbauer

Abstract The tremendous increase of plastic production, its intensive usage in packaging, as transport material and the insufficient management of plastic garbage lead to a rise of microplastic particles as anthropogenic contaminant in our environment. To develop appropriate management and remediation strategies for this global pollution problem, reliable and consistent analytical procedures for measuring plastics in the complex matrices need to be designed. The applicability of an easy, robust and fast multi-step approach was tested on three sediment samples from riverine, beach and backwater areas of varying origin, grain size and organic matter content is reported here. The optimized method included grain size fractionation, density separation and μ-FTIR analyses. Identification was based on two complementary methods of μ -FTIR measurements, the Image mode for small microplastics (&lt;1 mm) and the ATR method for bigger (1–5 mm) particles. The analyses revealed the identification of several polymers in various grain sizes at different pollution levels. Major findings are the dominance of PET particles and the highest frequency of microplastic particles in the midsize fraction of 100–500 μm. Generally, the method was able to reliably detect microplastic particles in several grain size fractions and down to very low contamination levels of approximately. ten particles per 50 g of sediments with different organic matter content and various grain size characteristics. Moreover, the presented multi-step approach represents a fast, easy and less cost-effective method as alternative to more expensive and time-consuming methods.


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