Jove
Visualize
Contact Us
JoVE
x logofacebook logolinkedin logoyoutube logo
ABOUT JoVE
OverviewLeadershipBlogJoVE Help Center
AUTHORS
Publishing ProcessEditorial BoardScope & PoliciesPeer ReviewFAQSubmit
LIBRARIANS
TestimonialsSubscriptionsAccessResourcesLibrary Advisory BoardFAQ
RESEARCH
JoVE JournalMethods CollectionsJoVE Encyclopedia of ExperimentsArchive
EDUCATION
JoVE CoreJoVE BusinessJoVE Science EducationJoVE Lab ManualFaculty Resource CenterFaculty Site
Terms & Conditions of Use
Privacy Policy
Policies

Related Concept Videos

Stream Function01:20

Stream Function

2.1K
In two-dimensional incompressible fluid flow, the continuity equation is essential for ensuring mass conservation, meaning that any change in fluid entering or exiting a region is balanced by a corresponding change elsewhere. For incompressible flow, where density remains constant, this requirement simplifies to the condition that the divergence of the velocity field must be zero. Mathematically, this is expressed as,
2.1K
What is an Electrochemical Gradient?01:26

What is an Electrochemical Gradient?

127.5K
Adenosine triphosphate, or ATP, is considered the primary energy source in cells. However, energy can also be stored in the electrochemical gradient of an ion across the plasma membrane, which is determined by two factors: its chemical and electrical gradients.
The chemical gradient relies on differences in the abundance of a substance on the outside versus the inside of a cell and flows from areas of high to low ion concentration. In contrast, the electrical gradient revolves around an...
127.5K
Spanning Openings in Brick Walls01:20

Spanning Openings in Brick Walls

565
In brick wall construction, supporting structures are crucial for openings like windows and doors to maintain the integrity and support the weight of the wall above. These supports include lintels, corbels, and arches, each serving specific structural purposes.
Lintels are primary supports used to span openings and can be crafted from materials such as reinforced concrete, steel-reinforced brick masonry, or simple steel angles. These are straightforward to install and are typically concealed...
565
Steady Flow of a Fluid Stream01:27

Steady Flow of a Fluid Stream

690
Consider a control volume, such as a pipe with solid boundaries, through which fluid flows and changes direction due to the impulse exerted by the resulting force from the pipe walls. In steady flow, the mass of fluid entering the control volume at a given time, t, with velocity v1, is equal to the mass leaving after infinitesimal time dt, with velocity v2.
During this process, the momentum of the fluid within the control volume remains constant over the time interval dt. By applying the...
690
Energy Line and Hydraulic Gradient Line01:27

Energy Line and Hydraulic Gradient Line

2.1K
Based on Bernoulli's equation, the energy line (EL) and hydraulic grade line (HGL) provide graphical representations of energy distribution in a fluid flow system. For steady, incompressible, inviscid flows, Bernoulli's equation is expressed as:
2.1K
Gradient and Del Operator01:14

Gradient and Del Operator

4.4K
In mathematics and physics, the gradient and del operator are fundamental concepts used to describe the behavior of functions and fields in space. The gradient is a mathematical operator that gives both the magnitude and direction of the maximum spatial rate of change. Consider a person standing on a mountain. The slope of the mountain at any given point is not defined unless it is quantified in a particular direction. For this reason, a "directional derivative" is defined, which is a vector...
4.4K

You might also read

Related Articles

Articles linked to this work by shared authors, journal, and citation graph.

Sort by
Same author

Predator traits influence uptake and trophic transfer of nanoplastics in aquatic systems-a mechanistic study.

Microplastics and nanoplastics·2024
Same author

Resolving 500 Years of Anthropogenic Impacts in a Mesotrophic Lake: Nutrients Outweigh Other Drivers of Lake Change.

Environmental science & technology·2022
Same author

Disentangling the influence of microplastics and their chemical additives on a model detritivore system.

Environmental pollution (Barking, Essex : 1987)·2022
Same author

Multigenerational exposure to increased temperature reduces metabolic rate but increases boldness in <i>Gambusia affinis</i>.

Ecology and evolution·2022
Same author

A bacterial index to estimate lake trophic level: National scale validation.

The Science of the total environment·2021
Same author

Towards more ecologically relevant investigations of the impacts of microplastic pollution in freshwater ecosystems.

The Science of the total environment·2021
Same journal

A double endocrine-disrupting effect of PFAS on intra- and extra-thyroid targets: inhibition of iodide uptake and interference with MCT8-mediated T3 transport in vitro.

Environmental pollution (Barking, Essex : 1987)·2026
Same journal

Impacts of Sewage Treatment Works versus Diffuse Pollution on Bacterial Water Quality at Rural Wild Swimming Sites.

Environmental pollution (Barking, Essex : 1987)·2026
Same journal

Unveiling primary and secondary sources of PM<sub>2.5</sub> in a Chinese megacity using detailed organic and inorganic speciation and receptor modelling.

Environmental pollution (Barking, Essex : 1987)·2026
Same journal

Aquatic ecosystem degradation attributed to tire wear particles in urban roadway runoff.

Environmental pollution (Barking, Essex : 1987)·2026
Same journal

Fate of the nitrification inhibitor 3,4-dimethylpyrazole in sandy arable soils: Low leachability mainly due to sorption in topsoil.

Environmental pollution (Barking, Essex : 1987)·2026
Same journal

Different chronic effects of conventional PET and biodegradable PLA microplastics: Insights from apical and transcriptomic responses in Daphnia magna.

Environmental pollution (Barking, Essex : 1987)·2026
See all related articles

Related Experiment Video

Updated: Jan 26, 2026

Separation and Identification of Conventional Microplastics from Farmland Soils
14:10

Separation and Identification of Conventional Microplastics from Farmland Soils

Published on: March 21, 2025

3.2K

Microplastic pollution in streams spanning an urbanisation gradient.

Nadezhda Dikareva1, Kevin S Simon1

  • 1School of Environment, University of Auckland, Auckland, New Zealand.

Environmental Pollution (Barking, Essex : 1987)
|April 20, 2019
PubMed
Summary
This summary is machine-generated.

Small streams are polluted with microplastics, similar to larger water bodies. Local factors, not just human population, influence plastic levels in these vital freshwater ecosystems.

Keywords:
Catchment parametersFreshwater pollutionMicroplasticUrban streams

More Related Videos

Accumulation and Distribution of Fluorescent Microplastics in the Early Life Stages of Zebrafish
06:46

Accumulation and Distribution of Fluorescent Microplastics in the Early Life Stages of Zebrafish

Published on: July 4, 2021

5.4K
Sampling and Identification of Microplastics in Groundwater
08:27

Sampling and Identification of Microplastics in Groundwater

Published on: November 7, 2025

1.1K

Related Experiment Videos

Last Updated: Jan 26, 2026

Separation and Identification of Conventional Microplastics from Farmland Soils
14:10

Separation and Identification of Conventional Microplastics from Farmland Soils

Published on: March 21, 2025

3.2K
Accumulation and Distribution of Fluorescent Microplastics in the Early Life Stages of Zebrafish
06:46

Accumulation and Distribution of Fluorescent Microplastics in the Early Life Stages of Zebrafish

Published on: July 4, 2021

5.4K
Sampling and Identification of Microplastics in Groundwater
08:27

Sampling and Identification of Microplastics in Groundwater

Published on: November 7, 2025

1.1K

Area of Science:

  • Environmental Science
  • Ecotoxicology
  • Freshwater Ecology

Background:

  • Microplastic pollution is a growing concern in marine environments, with increasing evidence of its presence in freshwater systems.
  • Research has primarily focused on large rivers and lakes, overlooking the role of small streams as crucial land-water interfaces.

Purpose of the Study:

  • To investigate the quantity and types of microplastics in small streams along an urbanization gradient.
  • To identify factors influencing microplastic abundance in these headwater ecosystems.

Main Methods:

  • Sampling microplastics in water and sediment from small streams across varying urbanization levels.
  • Analyzing microplastic characteristics (size, form, chemical type) and correlating abundance with catchment-scale parameters.

Main Results:

  • All studied streams contained microplastics, with concentrations comparable to larger freshwater systems.
  • Fragments and small particles (63-500 μm) were the most common types; chemical composition varied unpredictably.
  • Microplastic abundance showed high variation, with weak correlations to human population density, stormwater overflows, or residential land cover.

Conclusions:

  • Small streams act as significant conduits for microplastic pollution.
  • Local-scale factors appear to be more influential than broad catchment-scale processes in determining microplastic levels in small streams.
  • Further research into localized sources and pathways is needed to mitigate freshwater microplastic contamination.