scholarly journals Influence of seasonality on macroinvertebrate diversity associated with the aquatic fern Salvinia biloba Raddi

2020 ◽  
Vol 13 ◽  
pp. e0889
Author(s):  
Rennan Leite Martins Coutinho ◽  
Isabella Rodrigues Lancellotti ◽  
Arthur Ribeiro Flores ◽  
Marcelo Guerra Santos

Abstract. The genus Salvinia is composed of fast-growing floating ferns, capable of surviving in different environmental conditions. Some authors suggest that the relationships between this genus and macroinvertebrates may serve as water quality indicators. The present study aimed to determine the influence of seasonality and water quality on macroinvertebrate diversity associated with the Salvinia biloba Raddi. Water and fern were collected in rainy and dry seasons and was conducted a microbiological analysis of the water, as well as, the area of fern cover on the water, richness, and density of macroinvertebrates. Microbiological analysis of the water detected > 5,700 CFU/mL (rainy season) and 175 CFU/mL (dry season) of heterotrophic bacteria and was positive for total thermotolerant coliforms. The S. biloba cover on the water surface was 100% in the rainy and 30% in the dry season. In the rainy season, 142 macroinvertebrates were identified, divided into 12 morphospecies, with a density of 434 individuals/m3. In the dry season, there were 419 individuals in 14 morphospecies, with a density of 2,076 individuals/m3 exhibited. The highest species density recorded in the rainy season was for Chironomidae sp.1 (Diptera) (57.71%) and Odonata Zygoptera sp.1 (17.44%), and in the dry season, Chironomidae sp.2 (73.98%) followed by Gerromorpha sp.1 (Hemiptera), with 9.54%. The Sørensen similarity index between the two seasons was 53.84%. The higher density of Gerromorpha sp.1 in the dry season may indicate an increase in environmental integrity. 

Author(s):  
Maria Alexandra Endara ◽  
Demián Hinojosa-Garró

Pindo Grande River water quality was analyzed during rainy seasons of 2014 and 2017 and dry seasons of 2015 and 2016. Specimens were collected using surber net, kick net and manual stone collection, from five different sites along the river. In the laboratory, specimens were identified to the lowest possible taxonomic level. Taxon richness, abundance, diversity, trophic niches, and Biological Monitoring Working Party for Colombia (BMWP/Col) index were assessed. A total of 1,695 specimens belonging to 95 taxa were collected, including 57 taxa in rainy seasons and 38 taxa in dry seasons. Class Insecta was the most abundant (98.6%). Richness was highest (3,427) at M1000 collection sites in rainy and dry seasons and varied from moderate to high (13–35) at other sites. All sampling sites had medium diversity, and organisms belonged to three trophic categories: herbivores, detritivores, and predators. Environmental water quality was medium at most sites (BMWP/Col = 102–150). All sites exhibited good conservation status (BMWP/Col = 192–152) in the rainy season; only two sites presented medium conservation status (BMWP/col = 93–67) in the dry season. Principal component analysis indicated that main variables associated with sites were NO3 and COD in upstream areas in the rainy season and O2 in the dry season. Downstream areas were grouped based on depth and width of the river in the rainy season and on pH, PO4, and conductivity in the dry season. According to analysis, the Pindo Grande River has preserved epibenthic communities; it is an oxygenated stream, but its habitats have been gradually affected by anthropogenic activities.


2021 ◽  
Vol 36 (1) ◽  
pp. 93-105
Author(s):  
A.N. Okereke ◽  
J.C. Ike-Obasi

Seasonal effects on microbial load of sediment and water at different locations along Bonny Estuary of Niger Delta was investigated for a period of 12 months. All analyses followed standard procedure. Results revealed that total fungi counts in sediment and water at different locations were not significantly different (p > 0.05) at both wet and dry seasons while hydrocarbon utilizing fungi showed significant differences (p < 0.05) at both seasons in both sediment and water samples. During the wet season, total faecal counts ranged from 5.0 to 10.0 x 105 CFU/g for sediment and 4.0 to 7.0x 105 CFU/g in water. In dry season, the concentration of hydrocarbon utilizing bacteria in the sediment ranged between 0.1 x 105 CFU/ml/g and 8.0 x 105 CFU/ml/g in wet season while in dry season, the concentration in water ranged between 0.1 x 105 CFU/ml/g and 6.0 x 105 CFU/ml/g at Abuloma. At Okwujagu, total heterotrophic bacteria counts in sediment ranged  from 0.1 to 8.0 x 105 CFU/g in dry season. This was higher than the range 0.1 to 6.8.0 x 105 CFU/ recorded in Abuloma, Okwujagu and Slaughter at dry season. The highest vibrio counts in water (11.0 x 105 CFU/ml) for wet and (10.0 x 105 CFU/ml) for dry seasons were recorded at Slaughter. In Oginiba, the feacal count recorded 3.0 x 105 CFU/ml in water during the wet season and 2.0 x 105 CFU/ml for dry season. Generally, there were significant differences (p < 0.05) in the bacterial concentrations in both sediment and water. This showed that different seasons favour the growth of certain microbial types.


2015 ◽  
Vol 19 (2) ◽  
pp. 58-64
Author(s):  
Birendra Gautam ◽  
Rejina Maskey ◽  
Ramesh Prasad Sapkota ◽  
Dharma Raj Dangol

The present research was conducted to study seasonal limnological parameters and record composition pattern of aquatic macro-invertebrates of the Rampur Ghol. GRS-BIOS/ASPT index was used to calculate the water quality class, Shannon Weiner diversity index (H’) and Piélou evenness index (e) were used to determine taxa richness of the macroinvertebrates. Altogether 281 individuals of 14 families and 313 individuals of 18 families were recorded in dry season and rainy season, respectively. Similarly, diversity index and evenness index values were recorded 0.98 and 0.85 in dry season; 1.075 and 0.86 in rainy season. On the basis of different aquatic macro-invertebrates, GRS-BIOS/ASPT Index value of four sampling sites fall in class II (moderately polluted), four sampling sites belong to water quality class IIIII (critically polluted) and remaining two sampling sites belong to water quality class III (heavily polluted). Similarly, in rainy season seven sites fall in water quality class II (moderately polluted) and three sampling sites belong to water quality class II-III (critically polluted).Journal of Institute of Science and Technology, 2014, 19(2): 58-64


Water ◽  
2020 ◽  
Vol 12 (12) ◽  
pp. 3407
Author(s):  
Han-Sun Ryu ◽  
Heejung Kim ◽  
Jin-Yong Lee ◽  
Jiwook Jang ◽  
Sangwook Park

This study analyzed the hydrochemical characteristics and microbial communities of karst water in Samcheok, Korea, and compared water quality results to identify the seasonal characteristics and hydrogeological connectivity of the study areas of Hamaengbang-ri, Gyogok-ri, Yeosam-ri, and the downtown area of Samcheok. Field survey and water quality analysis were performed in July 2019, February 2020, and April 2020. Hydrochemical analysis of karst water (groundwater and surface water) showed that most samples were comprised of Ca-HCO3 and that water–rock interactions were a dominant factor compared to precipitation and evaporation (crystallization). For seasonal characteristics, water–rock interactions appeared more active in the dry season than in the rainy season. Calcite weathering was dominant in the dry season, whereas dolomite weathering dominated the rainy season. Moreover, the saturation indexes for the dry and rainy seasons were less than and greater than 0, respectively, corresponding to an unsaturation (oversaturation) state; thus, white precipitate distributed in the study areas was deposited in the rainy season. Finally, as a result of analyzing the hydraulic characteristics between regions, hydrogeological similarities were identified between Hamaengbang-ri and Yeosam-ri, and between Gyogok-ri and downtown Samcheok, which suggested hydrogeological connectivity between each of the pairs.


2002 ◽  
Vol 62 (2) ◽  
pp. 293-310 ◽  
Author(s):  
N. de L. STRIPARI ◽  
R. HENRY

The invertebrate colonization during decomposition of Eichhornia azurea was observed in a lateral lake in the mouth zone of Paranapanema River into Jurumirim Reservoir in two periods of the year. The litter bags method was used for measuring the decomposition rate as well as to evaluate the invertebrates colonization. Forty-two litter bags, measuring 15 × 20 cm in size and 2 mm mesh net, were incubated "in situ". Six litter bags (three for colonization and three for decomposition measurements) were removed after the 1st, 3rd, 7th, 14th, 28th, 56th and 72nd days of incubation. After each day, the material was carefully cleaned for detritus removal and invertebrate sampling. The biological material was fixed with 4% formaline and then sorted and identified. The remaining plant material was dried in an oven (at 60ºC) and weighed. A fast material loss occurred during the first 24 hours and the decomposition rate was higher during the rainy season than in the dry season. A peak on invertebrate density (110 ind.g.DW--1) on the remaining detritus of Eichhornia azurea was recorded in the 56th day of dry season, when the polyphenol concentration of plant detritus was 0.57 UDO.g.DW--1. In the rainy season, higher density was found in the 28th day of incubation, when the polyphenol concentration was 4.36 UDO.g.DW--1. Apparently, the reduction in the polyphenol concentration was followed by an increase in invertebrate densities. The majority of the species observed in the detritus belongs to the collector group that was dominant after the 7th and 14th days in the rainy and dry seasons, respectively.


2002 ◽  
Vol 18 (5) ◽  
pp. 759-774 ◽  
Author(s):  
Maria Tereza Grombone-Guaratini ◽  
Ricardo Ribeiro Rodrigues

To examine the influence of seasonality on the abundance and composition of species in the community, we studied the seed rain and the seed bank in a seasonal, semi-deciduous forest in south-eastern Brazil. Soil samples (depth 3 cm, 0.25 m2) were collected within a 1-ha plot in the dry seasons of 1996 and 1997 and the rainy season of 1997 (84 samples per collection). Thirty-five seed traps (0.25 m2 each) were placed randomly in the forest from March 1997 to February 1998. The greatest density of seeds in the soil occurred in samples collected during the rainy season, the period which coincides with the main fruiting period in this forest. The Sørensen similarity index values for the seed bank composition among the three periods were high (> 0.50). The fallout of propagules was strongly seasonal, with more than half of the annual total number of seeds being caught in the two months around the end of the dry season and beginning of the rainy season. The mean density of seeds in the soil bank was nearly 86% lower than the seed rain density. There was no clear evidence of seasonal effects on species density and richness in this forest.


2019 ◽  
Vol 19 (1) ◽  
pp. 57-66
Author(s):  
Le Thi Vinh ◽  
Nguyen Hong Thu ◽  
Pham Huu Tam ◽  
Le Trong Dung

The results of three surveys in the O Loan lagoon in the dry season (April 2013) and the rainy season (December 2012 and December 2014) showed that in the rainy season the average concentrations of nutrients in waters (ammonium: 76.8 μgN/l, nitrite: 13.9 μgN/l, nitrate: 55 μgN/l and silicate: 4021 μgSi/l) tended to be higher than those in the dry season (ammonium: 6.0 μgN/l, nitrite: 2.6 μgN/L, nitrate: 35 μgN/l and silicate: 1973 μgSi/l) while phosphate concentraiton did not differ between the two seasons with an average concentration of 66.8 μgP/l in rainy season and 60 μgP/L in dry season. By space, the concentrations of nutrients except nitrate in the lagoon, especially in the southern part, were usually higher than those in the canal connected to the sea. At O Loan lagoon waters, only ammonium (mainly in the southern part of the lagoon) and nitrate (mainly in the canal and southern part of the lagoon) concentrations were higher than the criteria values in the rainy season (December 2014) with pollution coefficient of about 1.2. However, the water quality of O Loan lagoon regarding nutrients always still needs to be monitored because from 1992 to the surveyed time, the concentrations of nutrients containing nitrogen and phosphate had the increasing trend in both seasons.


2016 ◽  
Vol 75 (s1) ◽  
Author(s):  
Owen Lind ◽  
Laura Dávalos-Lind ◽  
Carlos López ◽  
Martin López ◽  
Juli Dyble Bressie

<p>The phrase <em>cyanobacteria bloom</em> implies a transient condition in which one to few species dominates communities. In this paper we describe a condition in which the <em>bloom</em> is of multi-year duration consisting of different morphologies of a single cyanobacteria species. Lake Catemaco, Veracruz, México maintained a year-round massive (10<sup>8</sup> trichomes L<sup>-1</sup>) population of potentially toxin-producing cyanobacteria, <em>Cylindrospermopsis spp.</em> The trichomes are present as straight and coiled morphotypes.  The relative trichome morphology abundance varied with rainy (June – October) and dry seasons (November – May), but total trichome abundance did not vary.  Coiled trichomes and heterocytes (occurring only on coiled trichomes) were significantly more abundant, both absolutely and relatively, during the dry season. Both coiled trichome and heterocyte mean volumes were significantly smaller during the rainy season than during the dry season.  Biovolumes were largest in January when water temperature was 5º C cooler suggesting buoyancy as a morphology-determining factor. However, with a more than three-fold lower TIN concentration during the dry season, we hypothesized that the coiled morphotype became abundant primarily because it formed heterocytes, which the straight morphotype did not. Spatial trichome and heterocyte abundance differences were small among the 15 lake sites (average CV for all dates = 20%). However, there was a pattern of increased heterocyte and coiled trichome abundance from lake inflow, as a nitrogen source, to outflow during the rainy season. The total volume of heterocytes per litre of lake water increased progressively four-fold from a minimum early in the rainy season to a maximum at the end of the dry season. Morphological diversity, as seen in Lake Catemaco, can partially compensate for the lack of species diversity in determination of community structure.</p>


2014 ◽  
Vol 14 (3) ◽  
Author(s):  
Diego Carvalho Viana ◽  
Leandro Almeida Rui ◽  
Amilton Cesar dos Santos ◽  
Maria Angélica Miglino ◽  
Antônio Chaves de Assis Neto ◽  
...  

This study aimed to characterize the morphology of the vas deferens ofKinosteron scorpioides by macroscopic and microscopic analysis. Were used 20 adult male jurarás collected at regular intervals during the year and divided into four experimental groups in the rainy and dry seasons, being processed for light microscopy, scanning electron microscopy and transmission electron microscopy. Morphometry for tubular and luminal diameters and epithelial height were also performed. On rainy season, vas deferens presented pseudostratified epithelium with cylindrical cells, spermatozoids and milky fluid in the lumen, with cytoplasmic organelles and lipid vesicles. On dry season, epithelium was pseudostratified with cuboid cells, with cellular debris and no spermatozoids. There was significant variation (p<0,05) for morphometry of vas deferens, with lower values of tubular and luminal diameters on rainy season, and higher epithelial height on dry season.


2020 ◽  
pp. 1-28
Author(s):  
M. U. Orji ◽  
S. C. Onuorah ◽  
M. O. Ifemeje ◽  
O. R. Umeh

Background: The people of Awka urban show an increasing trend of using well water resulting to unreliable and quality-compromised water supply. Aim: Effects of depth and seasons on the physicochemical and bacteriological quality of selected well water samples in Awka urban, Anambra State was conducted to determine their quality and suitability for domestic uses. A total of thirty shallow and deep well water samples were collected during the rainy and dry seasons. Methods: Physicochemical analysis was carried out using standard analytical methods. The total bacterial count was determined by dilution method. Results: Some of the physicochemical parameters (PH, dissolved oxygen, nitrate, cadmium, lead and arsenic) exceeded the World Health Organization maximum containment levels indicating that the samples were unfit for domestic uses. The bacterial counts ranged from 2.66 to 3.26 logcfu/ml during the rainy season and 2.54 to 3.20 logcfu/ml during the dry season. The total coliform counts also exceeded the W.H.O levels. Citrobacter freundii, Shigella flexneri, Serratia marcescens, Proteus vulgaris, Vibrio cholerae, Salmonella typhi, Pseudomonas aeruginosa, Escherichia coli and Bacillus subtilis were isolated during both seasons and identified using standard analytical procedures. The bacterium that had the highest frequency of occurrence during the rainy season was Citrobacter freundii (16.55%) while Salmonella typhi had the highest frequency of occurrence during the dry season (17.69%) respectively. Proteus vulgaris had the least frequency of occurrence 5.41% and 4.62% during the rainy and dry seasons respectively. The results were analyzed statistically using two-way analysis of variance. Higher bacterial counts were recorded in rainy season and shallow wells than dry season and deeper wells. Conclusion: The presence of these bacteria above admissible limits showed that the water lacked proper water management services and may be harmful to humans. There is therefore a need to monitor the well water quality by employing better sanitary practices and subjecting the waters through various forms of water treatments before use to help prevent disease outbreak.


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