Sediment Sampling

Summary

This video script details the process of collecting sediment samples from a water body using a unique tool resembling a 'soda straw'. The narrator explains the method of trapping water and sediment, the importance of selecting the right sample type, and the procedure of extracting and measuring the samples. The script also delves into the significance of such samples in revealing the presence of organic material, soil types, and pollutants like PCBs, providing insights into the ecosystem's health and history.

Takeaways

• 🧪 The script describes a process for collecting sediment and soil samples using a tool that operates like a 'soda straw' to trap water and sediment.
• 🌊 The demonstration takes place at low tide, with the collector being careful to navigate the rocks and selecting a mushy, less rocky sediment for sampling.
• 🔧 The sampling tool has a ball joint mechanism that is operated by a lever to close the space and trap the sample.
• 📏 The depth of the sample is indicated by the lever's movement, and the collected sample is transferred to a table for further examination.
• 💧 After collecting the sample, excess water is poured out, and the sediment is extracted using a dowel.
• 📏 Two samples are taken, with measurements provided: one at approximately 4.5 inches (11.5 cm) and the other at 3.5 inches (8.5 cm).
• 🔬 Sediment samples can reveal the presence of organic material and provide insights into the local ecosystem, including types of soil and possible pollutants.
• 🏭 The script mentions historical industrial activity, such as brick manufacturing, which can be inferred from the presence of eroded brick pieces in the sediment.
• 🌿 The type of soil in the sample is described, with this particular sample having a significant amount of clay and a slightly greasy texture.
• 🚫 Sediment samples are important for detecting pollutants that have settled at the bottom, such as PCBs, which are tested for due to their harmful effects.
• 🦀 Additional items like crab claws and shells can be found in sediment samples, indicating the presence of certain marine life or past activities in the area.

Q & A

What is the purpose of the tool described in the transcript for collecting samples?

The tool is used to collect both soil and sediment samples. It operates similarly to a soda straw, trapping water and sediment inside by closing a ball joint, allowing the sample to be transported to another vessel.

How does the ball joint mechanism work in the described sampling tool?

The ball joint mechanism is controlled by a lever. When the lever is turned, it closes the space in the tool, trapping both water and sediment for sampling.

What precautions are taken while collecting a sediment sample in the field?

The collector ensures they are at low tide, carefully navigates around rocks and logs, and looks for mushy sediment rather than rocky areas to avoid tripping and to effectively collect the sample.

What is the method for extracting the sample from the tool after it has been collected?

The sample is extracted by unscrewing a specific part of the tool, which allows the sediment and water to be released. Excess water is poured out, and a dowel is used to push the sample out of the tube.

Why is it important to measure the depth of the sediment sample collected?

Measuring the depth of the sample provides an indication of the volume and can be useful for analyzing the composition and density of the sediment, which can vary with depth.

What can sediment samples reveal about the environment they are collected from?

Sediment samples can reveal the presence of organic material, types of soil, and pollutants. They can indicate what lives in the area, the history of the environment, and the levels of certain chemicals like PCBs.

What types of organic materials might be found in sediment samples?

Organic materials in sediment samples could include pieces of leaves, wood, and animal material, which can provide insights into the local ecosystem and its decomposition processes.

How can the texture and composition of a sediment sample provide information about the soil type?

The texture and composition, such as the presence of clay or grease, can indicate the types of soils present in the area. For example, a sample that holds its shape well and has a bit of grease might indicate the presence of clay.

What historical insights can be gained from analyzing eroded materials found in sediment samples?

Eroded materials like pieces of brick can suggest past industrial activities or building structures that are no longer present, providing a glimpse into the historical use of the area.

Why are pollutants like PCBs of interest when analyzing sediment samples?

PCBs are harmful chemicals that can accumulate in sediment and affect the health of aquatic life and humans. Analyzing their levels in sediment samples helps to monitor pollution and assess the safety of the environment.

What additional findings, besides sediment, might be discovered during a sampling process?

Besides sediment, one might find shells, claws from crabs, or other animal remains, which can provide information about the local fauna and their interaction with the environment.

Outlines

00:00

🌊 Collecting Sediment Samples with a Unique Tool

The script describes the process of collecting sediment samples using a tool that functions similarly to a soda straw. The tool has a ball joint mechanism that allows for trapping water and sediment when the lever is turned. The narrator demonstrates how to use the tool by inserting it into the water, moving it back and forth to collect the sample, and then closing the joint to secure the sample. The sample is then transferred to a table for examination, where excess water is poured out, and the sediment is measured for depth. The importance of sediment samples is highlighted, as they can reveal the presence of organic material, types of soil, and even clues about the local environment and history, such as eroded pieces of brick indicating past industrial activity.

05:02

🔬 Analyzing Sediment for Environmental Insights

This paragraph delves into the analysis of sediment samples, discussing their significance in understanding the environment. The narrator explains that sediment samples can provide information about pollutants, such as PCBs, that have settled at the bottom of bodies of water. The script also touches on the historical aspect of the samples, with the narrator finding and discussing an eroded piece of brick and a crab claw, which indicate past industrial use and the presence of marine life. The summary includes the method of preserving soil samples in a cylindrical form, labeled with the date of collection, and the potential smells associated with the samples, such as briny or methane odors due to decomposing organic matter.

Keywords

💡Soil Sample

A soil sample is a portion of soil that is collected for analysis to determine its properties and composition. In the video, the process of collecting a soil sample is likened to using a 'soda straw' to trap both water and sediment. This method is crucial for understanding the soil's organic content, texture, and potential pollutants, which are vital for environmental assessments.

💡Sediment Sample

Sediment samples are collected to analyze the particles that settle at the bottom of a body of water. These samples can reveal information about the water's quality, the presence of pollutants, and the types of organisms living in the area. In the script, the sediment sample is described as 'mushy' and not too rocky, indicating the type of sediment that is ideal for capturing a representative sample of the underwater environment.

💡Ball Joint

The ball joint in the context of the video refers to a mechanical component of the sampling tool that allows for the collection of liquid and sediment. When the lever is turned, it closes the space within the tool, trapping the sample. This mechanism is essential for ensuring that the sample remains intact and uncontaminated during the collection process.

💡Organic Material

Organic material in the video refers to any substance derived from living organisms, such as leaves, wood, or animal remains. The presence of organic material in sediment samples can provide insights into the ecosystem's health and the types of organisms that inhabit the area. The script mentions that organic material might include 'pieces of leaves or some pieces of wood' found in the sediment.

💡Clay

Clay is a fine-grained natural rock that is a crucial component of soil. In the video, the sediment sample is described as having 'quite a bit of clay,' which is significant for understanding the soil's texture and its ability to retain water and nutrients. The script also mentions the sample's greasy feel and its ability to hold its shape, which are characteristics of clay.

💡Striation

Striation refers to the lines or layers visible in a sedimentary rock or soil, which can indicate different geological periods or environmental conditions. In the script, the mention of 'different colors from striation' suggests that the soil sample contains layers that could provide information about the geological history of the area.

💡Pollutants

Pollutants are substances that contaminate the environment, causing harm to ecosystems and potentially to human health. In the video, the sediment samples are analyzed for pollutants that have settled at the bottom of the water body. The script specifically mentions the testing for chemicals that are harmful, such as PCBs, which are a focus of environmental concern.

💡PCBs (Polychlorinated Biphenyls)

PCBs are a class of organic compounds that were widely used in industrial applications but are now known for their harmful environmental and health effects. The script highlights that the sediment samples will be tested for PCB levels, which can indicate the presence of industrial pollution in the water body and its potential impact on the ecosystem and human health.

💡Erosion

Erosion is the process by which natural forces, such as water or wind, wear away rocks and soil. In the video, the speaker finds 'eroded pieces of brick,' which suggests that the sediment contains materials that have been worn down and transported by natural processes. This can provide clues about the historical use of the area and the types of materials that have been present.

💡Crab Claw

The crab claw mentioned in the script is a biological sample found in the sediment, which indicates the presence of crabs in the area. This finding is significant as it contributes to the biodiversity assessment of the ecosystem. The crab claw is described as a fully formed piece of shell, which is a clear example of the type of organic material that can be discovered through sediment sampling.

Highlights

Introduction of a tool for collecting soil and sediment samples, functioning like a soda straw.

Explanation of the tool's operation, which involves trapping water and sediment by closing a ball joint.

Field demonstration of collecting a sediment sample at low tide, avoiding rocky areas.

Technique for determining the depth of the sample by observing the ball joint lever.

Process of transferring the sample to a table for further examination.

Description of the sample's extraction method, including unscrewing and pouring out excess water.

Measurement of the sample's depth using a dowel, with two samples measured.

Importance of sediment samples for understanding the presence of organic material and local ecology.

Analysis of the sample's composition, including types of soil and organic materials.

Observation of the sample's color and texture, indicating the presence of clay and organic material.

Historical context provided by the discovery of eroded brick pieces in the sample.

Discussion on the industrial history of the area and its impact on the river's sediment.

Collection and preservation of soil samples in a cylindrical form for further study.

Potential discovery of pollutants in sediment samples, such as PCBs from industrial emissions.

Identification of a blue claw crab's claw as an example of larger fauna remains found in the sediment.

The significance of sediment samples in assessing the health of aquatic ecosystems and pollutants.

Transcripts

so we're going to do a soil sample a

sediment sample

and we're going to use this tool it's

actually pretty cool

it works a little bit like a soda straw

when

you put it in some liquid and you put

your finger over the top and then you

lift it and that liquid stays

in that straw then you can move it and

release your finger

and that water or whatever the liquid

was goes into another vessel

so we're going to do that but we're

going to be getting a sediment sample

so this piece of equipment is really

kind of cool

right now it's open

and you can see right through it

however it has a ball joint

right so this is the lever for the ball

joint and

when i turn that lever it

closes that space and that is how we

trap both water and the sediment right

so

i'm going to go ahead out into the water

and

we're at low tide right now but there

are some random rocks

i'm going to be dragging my feet a bit

to make sure

that i don't trip on any of those rocks

and end up in the water

oh there's a big old log right here

so what we're looking for is some

sediment that's

a little bit more mushy not so rocky

so that we can get the end in to

the sediment right so we should be good

right here

i'm going to go ahead and shake my

instrument i'm going to

push it and i'm going to sort of move

back and forth now usually you could

tell how deep you're going

based on the ball joint and how far that

lever for the ball joint goes into the

water

go in a little bit more

and we're going to close that joint

reach down to the bottom put our hand

over the end we're going to release

water that's at the top

okay cool all right now what we're going

to do is we're going to go

over to the table and we're going to

unscrew this area here and this part of

the pipe is going to come down

and we'll be able to check that sample

so the next thing we have to do once we

get it out of the water

is we have to unscrew this particular

piece right here and then

pull up on the tube on the top you can

see it does hold a little water from

where the ball valve was

down so it can get a little bit messy

right i'm going to pour the excess water

out

and then i'm going to use this uh dowel

now i've already taken a different

sample out so we have one sample here

and i'm going to go ahead and take the

second sample

out right now just by pushing on the

dowel through

the tube right we've got our second

sample

all right so one of the things we want

to do is

to measure it

all right so this one will sort of put

this piece back

so this one is approximately four and a

half

inches or eleven and a half centimeters

the second one is

um about three and a half inches about

um eight and a half centimeters

so why do we take sediment samples

sediment samples can tell us a lot first

of all

there may be some organic material in

here and it might

tell us a little bit about what lives

here so organic material that might be

in these sediment samples

it's going to be things like pieces of

leaves or some pieces of wood

there may also be some animal

material in here as well another thing

this oil sample is going to tell us is

a little bit about the types of soils so

this

particular sample has quite a bit of

clay in it

it's a teeny bit greasy but it

definitely holds its shape

really well so you can see that

sometimes we see different colors

from striation in there we don't really

you could see a little bit of off-white

there

that could be part of organic material

but i'm not seeing like a ton of

anything super interesting

in this particular uh sample in the past

these are some of the things that i've

found

so you may not know what that is because

it's it's pretty worn down

but um if you look at the color of it

and think about

what might be around here um or what

might used to have been around here what

might have been traveling down

the river then maybe this will be

something that you can guess you can

pause the video and maybe take a couple

of guesses

but these are eroded pieces of brick

so brick was made all up and down

thoughts of river at one point

um and then also there were buildings

all up and down the river that are no

longer here

a hundred years ago when the hunts river

was way more industrial then

of course we'd have more buildings

around but today there aren't there's

way more recreation

in the area than there is industry

so soil samples are collected in a form

like this

where the we keep that cylindrical form

we label obviously today um

is october 22nd 2020 and we're going to

go ahead and wrap this up so it stays

sort of true to form i'm sure you have

some ideas of what you think it looks

like

i will guarantee it doesn't smell like

that however it might smell a little bit

briny because of the salt or it may

smell

a little bit like methane because of the

decomposing materials in there

sometimes we do find shell sometimes we

find things

a little bit bigger than shell this was

found earlier on the shoreline

so come take a look at this and

you pause the video if you want to kind

of take a guess what you think this

might be from

so if you didn't guess it is the claw

from

a blue claw crab and this is just a

piece obviously so

but it is not a mold it is definitely a

piece of that shell

fully formed so this this particular

animal is probably deceased

one of the nice things about doing these

sediment samples

if you get a good one is that it's going

to tell us about pollutants

that have settled to the bottom so

sometimes pollutants that come from

emissions

will get into the water because of

precipitation

and sometimes pollutants get into the

water because of industry

and one of the things that gets tested

is for

chemicals that are not good obviously

pollutants

and if you want to think about one i'll

give you a couple of clues

the general electric plant is

responsible for a good majority of one

of the pollutants

and this is one you may know because we

talk about it when we talk about

whether or not fish are healthy to eat

all right you may pause the video if you

want

right so the answer is pcbs and

you may or may not have heard about them

but they're definitely

in the sediment and those samples are

going to give us a good idea of where

the levels of pcbs are all up and down

the hudson river during day in the life

of the hudson when people are all

up and down the river on the same exact

day okay cool