scholarly journals Fishing in the Water: Effect of Sampled Water Volume on Environmental DNA-Based Detection of Macroinvertebrates

2015 ◽  
Vol 50 (1) ◽  
pp. 305-312 ◽  
Author(s):  
Elvira Mächler ◽  
Kristy Deiner ◽  
Fabienne Spahn ◽  
Florian Altermatt
2021 ◽  
Author(s):  
Salome Stauffer ◽  
Meret Jucker ◽  
Thomas Keggin ◽  
Virginie Marques ◽  
Marco Andrello ◽  
...  

Quantifying the diversity of species in rich tropical marine environments remains challenging. Environmental DNA (eDNA) metabarcoding is a promising tool to face this challenge through the filtering, amplification, and sequencing of DNA traces from water samples. However, the reliability of biodiversity detection from eDNA samples can be low in marine environments because eDNA density is low and certainly patchy in this vast, heterogenous and dynamic environment. So, the number of sampling replicates and filtered volume necessary to obtain accurate estimates of biodiversity in rich tropical marine environments using eDNA metabarcoding is still unknown. Here, we used a paired sampling design of 30L per replicate on 68 reef transects from 8 sites in three tropical regions and identified fish Molecular Taxonomic Units (MOTUs) using a 12S marker. We quantified local biodiversity variation as MOTU richness, compositional turnover and compositional nestedness between replicated pairs of seawater samples. We report strong turnover of MOTUs between replicated pairs of samples undertaken in the same location, time, and conditions. Paired samples contained non-overlapping assemblages rather than subsets of one-another. As a result, localised diversity accumulation curves showed that even 6 replicates (180L) in the same location underestimated local diversity (for an area <1km). However, sampling of regional diversity using ~25 replicates in variable locations (often covering 10s of km) achieved saturation of biodiversity accumulation curves. Our results demonstrate high variability of diversity estimates perhaps arising from heterogeneous and local distribution of eDNA distribution in seawater or highly skewed frequencies of eDNA traces. This high compositional variability has consequences for using eDNA to monitor temporal and spatial biodiversity changes of local assemblages. Future biomonitoring efforts could be strongly undermined by a high level of false-negative detections under low replication protocols. We reveal the need to increase replicates or increase sampled water volume to better inform management of marine biodiversity using eDNA.


2021 ◽  
Vol 4 ◽  
Author(s):  
Austen Thomas ◽  
Caren Goldberg

With the rise of environmental DNA as a surveillance tool for aquatic species, a need has also arisen for professionally engineered research tools specifically designed for eDNA applications. We created the first portable, purpose-built eDNA sampling system in the form of a backpack smart-pump filtration apparatus and custom made eDNA filter packets for each sample. The eDNA-Sampler (previously ANDe) enables both point-location sampling and mobile sampling over a spatial distance, with the ability to standardize filtration parameters (e.g. flow rate, pressure, water volume, etc.). In this presentation we will describe the evolution of the eDNA sampling backpack and associated components, each designed to help streamline the eDNA sampling process and increase sampling efficiency. We have optimized the platform for mobile sampling by integrating GPS and data logging capabilities, in addition to modifying the chemistry of the eDNA filter packets to minimize the effort required for sample preservation. Results will be presented from a series of pilot studies in which the eDNA-Sampler capabilities were evaluated. Combined, the innovations described herein should help remove barriers to entry for potential eDNA practitioners and also improve overall eDNA data quality.


2021 ◽  
Vol 39 ◽  
pp. 79-105
Author(s):  
Joshua B. Mouser ◽  
Shannon K. Brewer ◽  
Matthew L. Niemiller ◽  
Robert Mollenhauer ◽  
Ronald A. Van Den Bussche

Subterranean habitats represent focal habitats in many conservation strategies; however, these environments are some of the most difficult to sample. New sampling methods, such as environmental DNA (eDNA), show promise to improve stygobiont detection, but sources of sampling bias are poorly understood. Therefore, we determined the factors affecting detection probability using traditional visual surveys and eDNA surveys for both cavefishes and cave crayfishes and demonstrated how detection affects survey efforts for these taxa. We sampled 40 sites (179 visual and 183 eDNA surveys) across the Ozark Highlands ecoregion. We estimated the detection probability of cave crayfishes and cavefishes using both survey methods under varying environmental conditions. The effectiveness of eDNA or visual surveys varied by environmental conditions (i.e., water volume, prevailing substrate, and water velocity) and the target taxa. When sampling in areas with average water velocity, no flow, and coarse substrate, eDNA surveys had a higher detection probability (0.49) than visual surveys (0.35) for cavefishes and visual surveys (0.67) had a higher detection probability than eDNA surveys (0.40) for cave crayfishes. Under the same sampling conditions, 5 visual surveys compared to 10 eDNA surveys would be needed to confidently detect cave crayfishes and 9 visual surveys compared to 4 eDNA surveys for cavefishes. Environmental DNA is a complementary tool to traditional visual surveys; however, the limitations we identified indicate eDNA currently cannot replace visual surveys in subterranean environments. Although sampling designs that account for imperfect sampling are particularly useful, they may not be practical; thus, increasing sampling efforts to offset known detection bias would benefit conservation strategies.


2020 ◽  
Vol 64 (4) ◽  
pp. 40407-1-40407-13 ◽  
Author(s):  
Ran Pang ◽  
He Huang ◽  
Tri Dev Acharya

Abstract Yongding River is one of the five major river systems in Beijing. It is located to the west of Beijing. It has influenced culture along its basin. The river supports both rural and urban areas. Furthermore, it influences economic development, water conservation, and the natural environment. However, during the past few decades, due to the combined effect of increasing population and economic activities, a series of changes have led to problems such as the reduction in water volume and the exposure of the riverbed. In this study, remote sensing images were used to derive land cover maps and compare spatiotemporal changes during the past 40 years. As a result, the following data were found: forest changed least; cropland area increased to a large extent; bareland area was reduced by a maximum of 63%; surface water area in the study area was lower from 1989 to 1999 because of the excessive use of water in human activities, but it increased by 92% from 2010 to 2018 as awareness about protecting the environment arose; there was a small increase in the built-up area, but this was more planned. These results reveal that water conservancy construction, agroforestry activities, and increasing urbanization have a great impact on the surrounding environment of the Yongding River (Beijing section). This study discusses in detail how the current situation can be attributed to of human activities, policies, economic development, and ecological conservation Furthermore, it suggests improvement by strengthening the governance of the riverbed and the riverside. These results and discussion can be a reference and provide decision support for the management of southwest Beijing or similar river basins in peri-urban areas.


2020 ◽  
pp. 102-109
Author(s):  
D.KH. DOMULLODZHANOV ◽  
◽  
R. RAHMATILLOEV

The article presents the results of the field studies and observations that carried out on the territory of the hilly, low-mountain and foothill agro landscapes of the Kyzylsu-yuzhnaya (Kyzylsu-Southern) River Basin of Tajikistan. Taking into account the high-altitude location of households and the amount of precipitation in the river basin, the annual volumes of water accumulated with the use of low-cost systems of collection and storage of precipitation have been clarified. The amount of water accumulated in the precipitation collection and storage systems has been established, the volume of water used for communal and domestic needs,the watering of livestock and the amount of water that can be used to irrigate crops in the have been determined. Possible areas of irrigation of household plots depending on the different availability of precipitation have been determined. It has been established that in wet years (with precipitation of about 10%) the amount of water collected using drip irrigation will be sufficient for irrigation of 0.13 hectares, and in dry years (with 90% of precipitation) it will be possible to irrigate only 0.03 ha of the household plot. On the basis of the basin, the total area of irrigation in wet years can be 4497 ha, and in dry years only 1087 ha. Taking into account the forecasts of population growth by 2030 and an increase in the number of households, the total area of irrigation of farmlands in wet years may reach 5703 hectares,and in dry years – 1379 hectares. Growing crops on household plots under irrigation contributes to a significant increase in land productivity and increases the efficiency of water use of the Kyzylsu-yuzhnaya basin.


2020 ◽  
Vol 38 (9A) ◽  
pp. 1373-1383
Author(s):  
Riyadh S. AL- Mukhtar ◽  
Shurooq T. Remedhan ◽  
Marwa N. Hussin

In this work, effluent wastewater treated by using cyclopentane-water Clathrate system to treat water contaminates with phenols at concentrations (300, 250, 200, 150, 100 and 50) ppm in order to investigate the capability of process performance. Clathrate or hydrate are strong crystal structures including water (host particles) and little particles (guest particles). The experiments were conducted at different cyclopentane-water volume ratios (1: 2 and 1: 4). The work was done in a 250 ml glass cell with an electric mixer at a constant speed of 280 cycles per minute. Phenol was highest removal percent at 300ppm at 1: 4volume ratio was (92.3%), while the lowest concentration at 50 ppm and 1: 2volume ratio was (55%). Yield and Enrich factor had the highest values at the lowest concentration 50ppm and 1:2 volume ratio were (85% and 2.42) respectively. The technique of the Clathrate proved that it has a high capacity in the separation and achieve high removal percentage compared to other methods at standard conditions when the pressure of 1 atmosphere and temperature higher than the degree of freezing water and less economic costs compared to other methods.


2019 ◽  
Vol 5 (2) ◽  
Author(s):  
Kirana Sanggrami Sasmitaloka ◽  
Imia Ribka Banurea ◽  
Sri Widowati Widowati

ABSTRACTThe manufacture of food products in an instant form can reduce obstacles in storage and distribution. The purpose of this study was to determine the characteristics of instant yellow rice produced using a cabinet dryer. The research method used was a non factorial Complete Randomized Design, with comparative treatment of rice and cooking water volume (1: 1,1; 1: 1,2; and 1: 1,3) as well as the type of yellow rice seasoning used (instant seasoning and processed seasoning). The best treatment is obtained on instant yellow rice produced using processed seasonings with a comparison of raw materials with cooking water volume of 1: 1,3. This product has a yield characteristic of 98.29%, rehydration time 4.32 minutes, kamba density 0.351 g/ml, water absorption 64.78%, development volume 174.51%, rehydration ratio 3.44, chroma value 30.29 and hue value 96.38.Keywords: instant yellow rice, rehydration time, drying, characteristics ABSTRAKPembuatan produk makanan dalam bentuk instan dapat menekan kendala dalam penyimpanan serta distribusi . Tujuan  penelitian ini adalah untuk mengetahui karakteristik nasi kuning instan yang diproduksi dengan menggunakan cabinet dryer. Metode penelitian yang digunakan adalah Rancangan Acak Lengkap non faktorial, dengan perlakuan perbandingan beras dan volume air pemasakan (1:1,1; 1:1,2; dan 1:1,3) serta jenis bumbu nasi kuning yang digunakan (bumbu instan dan bumbu olahan). Perlakuan terbaik diperoleh pada nasi kuning instan yang diproduksi menggunakan bumbu olahan dengan perbandingan bahan baku dengan volume air pemasakan sebanyak 1:1,3. Produk ini memiliki karakteristik rendemen 98,29%, waktu rehidrasi 4,32 menit, densitas kamba 0,351 g/ml, daya serap air 64,78%, volume pengembangan 174,51%, rasio rehidrasi 3,44, nilai chroma 30,29 dan nilai hue 96,38.Kata kunci: nasi kuning instan, waktu rehidrasi, pengeringan, karakteristik


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