Understanding Aquatic Pollution: Sources, Impacts, and Solutions

hi everyone welcome to this PowerPoint on aquatic pollution and litter this is the first PowerPoint in our Aquatic and

terrestrial pollution unit and by this time we're getting to the point of the school year where everything is kind of

coming full circle and we're tying a lot of Concepts together so a lot of these learning objectives will have already

talked about a little bit here and there throughout the school year some of them more so than others and at this point

you really expected to start to pull many of the things that we've talked about together everything from power

plants to biodiversity all coming together to discuss the impacts of pollution

but let's just get right into it we're going to start off with topic 8.1 sources of pollution the enduring

understanding for this is that human activities including the use of resources have physical chemical and

biological consequences for ecosystems and we've seen this again and again throughout the entire school year

and the learning objective is just to be able to differentiate between point source and non-point source pollution

pollutants we're going to skip all the way ahead to topic 8.12 and talk about lethal dose 50

and 8.13 dose response curves and we just really have to Define lethal dose 50 and evaluate dose response curves

there's a couple other learning objectives that we're going to talk about 8.2 human impacts on ecosystems

you'll see that this one is huge but we're not going to talk about every point of this in this PowerPoint many of

these we'll talk about in the next PowerPoint such as heavy metals or oil spills but just Describe the impact of

human activities on aquatic ecosystems we've already talked at length about eutrophication but you should be able to

explain the environmental effects of excess use of fertilizers and detergents on aquatic ecosystems and again we have

talked a lot about eutrophication throughout the entire school year so we'll hit some of the main points here

but a lot of that should be background knowledge but at this point and then we're going to talk about thermal

pollution as well here's the vocabulary and let's just jump right into it with

sources of pollution now like I said pollutants can either be classified as point source or non-point Source

pollutants if it is a point source pollution it's going to originate from a single place it's really easy to see

where these pollutants come from so let's say that we are at a river and we notice that there is a lot of discolored

maybe orangish water with a chemical smell to it and we see very little Aquatic Life we can walk Upstream up

that River until we come to something like this on the upper right these pipes may be coming off of an industrial

Factory and they might be discharging the Industrial Waste from that factory directly into the river

above or Upstream of this of these pipes would be relatively Clear Water one would hope and then Downstream of it is

heavily polluted and we can tell that this is the a single source that that water pollution is coming from okay it's

really easy to identify it it's really easy to control it and it's really easy to regulate it

non-point source pollution comes from kind of everywhere all at once it's coming from many places all at the same

time okay it's therefore going to be very difficult to identify difficult to

regulate difficult to control and difficult for people to take responsibility for

this is an example of a non-source non-point source pollution down at the bottom right let's say that we have a

really large parking lot and at the corner of that parking lot where the entire parking lot drains into the storm

drain you can see the storm drain just right there we notice after a rain we notice an oil

slick so this rainbow colored liquid right there is our oil slick okay now which of the hundreds of cars

in that parking lot had an oil leak or which several of those hundreds car hundreds of cars had an oil leak or

which dozens had a very small oil leak of just a few drips per hour right it's really difficult to regulate it because

it's really difficult to say like what car this oil came from and who to hold responsible and who to hold accountable

so urban and rural runoff are going to be classic examples whenever you see really any type of runoff

chances are it's going to be non-point source pollution unless it's very clearly coming from a single tract of

land that was say deforested and you have all the sediment of rodent off of that land but if you have dozens and

dozens of agricultural Fields all along One River and you detect high levels of a specific pesticide in that River

which of those dozen Farms or dozens of farms did that pesticide come from okay who's who's actually responsible it's

really difficult to tell okay acid rain or any other type of secondary pollutant is another great

example if you want to go with an atmospheric example all right lethal dose 50 percent is

lethal dose 50. I'll just say ld50 or lethodose 50 for now on please note that the 50 is a subscript most of the time

however you will sometimes see it as a full size number you can also in this class usually talk

them um talk about it being lethal concentration 50 or LC 50 but there is some differences between the two lethal

dose 50 is typically internal say the toxin is either injected into a person or it's consumed or it's breathed

in whereas lethal concentration 50 will typically be external so it will be like on the skin or maybe

a frog or a fish swimming through water that has um a certain toxin but if they're

swimming through that water frogs are going to get that toxin being absorbed through the skin and fish into the

bloodstream via the gills so in many cases these are interchangeable and they are often used synonymously in

this class okay but we're going to stick with lethal dose 50 but don't be surprised if you ever see lethal

concentration 50. what lethal dose 50 is is the dose of a toxin that's required to kill

50 of your test population or half of your test population over a specific time frame okay so you're going to have

a specific time frame which we're not going to worry about in this class but 50 of your population or 50 of your

sample size is going to die at this concentration okay so let's just say that you have

um let's say battery cotoxin from poison dart frogs and you give a very very tiny

little bit to some people and nobody dies you know you couldn't use people let's say Lab Rats you give a tiny tiny

little bit to lab rats and nobody dies and then a tiny little bit more to lab rats and none of them die and then a

little bit more and maybe a couple die and a little bit more and a couple more dye and then a little bit more a little

bit more a little bit more a little bit more and then finally you get to that dose where 50 of your

um of your sample dies of your sample population okay

now these toxins are all going to vary based on their lethal dose is going to vary on on their toxic toxic effects

um it's going to vary them on species so some species are going to be more susceptible to different toxins than

others and in general well always whenever you see a small number that's going to be

more lethal that's a smaller concentration kills 50 of your of your test subjects a larger number is going

to be safer meaning that you need a larger concentration like a larger amount to kill 50 of your test subjects

okay so I'll skip down to this bottom part the ld50 of caffeine is about 10 grams so you would have to

for a normal adult let's say me I would have to eat about 10 grams of caffeine for it to be lethal for me but

if I only was exposed or injected with .00012 grams of poison dart frog poison then that would kill me on average right

okay um so a smaller number is more dangerous than a larger number

and what this all measures is what we call acute toxicity these are effects from a substance resulting from a single

exposure okay so one arrow with poison dart frog poison on it or one pill that has 10 grams of caffeine or one

injection of bleach for example um you know maybe assassinate somebody I don't know okay so this is acute

toxicity a single exposure we can contrast acute toxicity with chronic toxicity which we've talked about before

in class and chronic toxicity is exposure over a long period of time okay so exposure over a long period of

time or multiple exposures over a given period of time okay typically with chronic toxicity

you're living with a toxin in the environment for oftentimes years or decades even for

humans so I just have one of the first points about lethal dose 50 versus lethal

concentration 50 and words so you can pause this and just check that out and lethal dose 50 can often be used um

using a dose response curve and that's essentially what I had on that previous slide or two slides ago and the top

right corner was an example of a dose response curve let's look at this one on the bottom right where we have 50

percent and it shows our ld50 so again we give somebody a little bit of that toxin no big deal a little bit of it and

maybe one percent of the population dies and then a little bit more 0.01 what is this

um well 0.01 concentration and 10 percent maybe a little bit less than maybe eight percent of your sample dies

and then eventually you're up to 50 percent but it doesn't stop there you increase

it a little bit more and you're up to 70 percent increase a little bit more up to 90 and then increase a little bit more

maximum effect a hundred percent of your population or your sample size dies or your sample your test subjects your

sample population okay um so this is just a graphical

representation of the effects of a substance on an organism and you typically will compare your effects

what is um response on this graph but effect on

this graph typically on the y-axis are always on the y-axis and your pollutant or your toxin or your drug or whatever

you're exposing your subjects to on the x-axis okay so the effects on the y-axis

and the concentration on the x axis okay now these dose response curves are often

logistic okay so with contaminant B on this graph we typically see a logistic curve for acute toxicity okay and that's

what we call something called the threshold dose response model this is essentially saying that anything above a

certain concentration of a toxin is going to be dangerous whereas anything below that threshold is going to be

considered safe so maybe this threshold they're shown on this graph as right here that threshold is where you first

start to see some individuals die and you don't want any individuals to die so you say that right there is your

threshold anything below that is safe anything above that is toxic okay maybe the threshold they decide is right here

maybe they decide the threshold is right there you know it really kind of depends on the situation and the toxin now this

measures typically acute toxicity okay so the threshold dose response model is typically going to be measuring acute

toxicity and it's typically like I say going to be a logistic curve or an S curve

okay where you have very little response at the beginning and then a period of um of a very rapid increase exponential

growth and then a plateauing or leveling off okay one of the benefits of this is that

it is very it's so much easier to regulate if you put a numerical limitation on the concentration and say

anything below this is okay you know maybe it's something that we need to Monitor and keep an eye on but we'll

just say it's okay for now but anything above it is absolutely dangerous and we have to take action

then it's really good to have that number so that we have a clear delineation of when we need to take

action and anything above that we have to take it legal action for so it's really good for regulation purposes

however it may not be good for chronic toxicity for chronic toxicity we're often looking at

um linear no threshold dose response model or non-threshold dose response model and

I'll typically say non-threshold dose response model what this typically means is that you start off with a very small

concentration and you start to feel an effect that effect may not be death okay it's probably actually not going to be

death but you're going to have increasing effects based off of the concentration

that you're exposed to okay and you're like I said you're typically going to use it for chronic toxicity

for chronic toxicity you often are exposed to a very small amount of something over a very long period of

time let's say before doctors really knew about the dangers of x-rays they were exposed to x-rays standing in the

room with the X-ray machine um eight hours a day for you know five days a week that's a

little bit of exaggeration because nobody takes x-rays that long but let's just say and they're exposed to a little

bit of radiation a little bit of radiation a little bit of radiation a little bit of radiation all the way up

to where they get more and more and more and more over time in this case rather than dose or doses

um as a function of time and then they start to get more and more

and more and more effects ultimately leading to cancers Okay so

what the linear no threshold dose response model basically says is that any toxin is a toxin and it doesn't

really matter what um what concentration you're at if especially if you have chronic toxicity

you're going to be developing symptoms over time okay now we're not going to talk about

the hormatic model hermetic model is a little bit weird but essentially you have a your body has a great response to

a low concentration but once that concentration is too high then your body can't respond to it very well okay so

that's the Hermetic model and brief okay so transitioning um we're going to talk about a lot of

different pollutants as we move forward in this PowerPoint and the next one and keep in mind ecological tolerances for

all of us right remember that every species has its own range of um abiotic factors that it um can live

within all those parameters that it can survive in and what happens when we push them out

of those parameters okay and the other thing I want you to keep in mind for the the rest of this

PowerPoint and the next PowerPoint is water quality parameters okay so water quality is the physical chemical and

biological characteristics of water and you're usually looking at it through a specific lens if you were working for

the fish and wildlife department as a fish biologist then you're probably thinking about it as is this the right

water quality for my trout to survive for example if you are working at a water treatment

plant you may be looking at water quality through a different lens of safe drinking water for the populace okay so

we're going to be looking at it through different lenses but the tests that we'll do are basically the same and

we're going to be doing most of these tests not all of them and class so we'll expand on these later but you should

have an idea of what each of these is and what each of them does for water quality and we've pretty much talked

about all of them so far so I'm going to just leave it there for right now now some human impacts on ecosystems

we're not going to talk about all of these um today in fact we're just going to

talk about these ones and this and the rest of this PowerPoint we'll talk about the rest of them on a future power on

the next PowerPoint and these are in no particular order this is not saying that thermal pollution is worse than oil

spills it's not saying that at all it's just no particular order whatsoever it's just the order that I thought

kind of made sense to teach it in and let's start with thermal pollution now thermal pollution is where you add

any any time that you add water to a aquatic system that is a different temperature than that aquatic system is

typically you're going to be releasing hot water into the aquatic system but you may also be releasing cold water

into that aquatic system okay typically though it's going to be hot water and from here on out I'm just going to talk

about it as if it's hot or warm water okay and that's going to have negative effects on anything living in that

Waterway now where can hot water come from typically it's going to be released from power plants or industry if it's

not cooled properly and if it's not cooled to the to the specific temperatures of your waterways okay and

what this is going to release and or what this is going to cause is a increase in ambient water temperature

which is going to decrease the dissolved oxygen or do you'll see do often in this in this class from now on do is

dissolved oxygen so you're reducing the dissolved oxygen concentration which is going to affect the entire ecosystem

especially animals in that system now one correlation that you guys should know in this class is that water

temperature and dissolved gases in that water are correlated and dependent upon each other or rather that the dissolved

gases are dependent on the water temperature if your water temperature increases then

the amount of dissolved gases in your water is going to decrease okay that includes all dissolved gases but the one

that we're most interested in is oxygen because that's what aerobic Marine creatures need to live to do aerobic

cellular respiration right the opposite of this is also true as you decrease water temperature you're going to

increase the dissolved gases in the water so cold water is going to have more dissolved gases specifically

dissolved oxygen then warm water is going to and the reason for that is just basic simple

thermodynamics and and physics as you increase the water temperature the water molecules are vibrating and shaking

faster and faster and they are moving further slightly further away from one another and it's allowing that what that

the gases in that water to escape the Escape being dissolved in that water Escape solution and go up into the

atmosphere okay now the other thing that this does not

only does it decrease the amount of dissolved oxygen if you're adding warm water but it also causes thermal shock

and again remember the ecological tolerances um every aquatic organism is adapted for

a specific temperature range and if there's a fish let's just say that we have a stream

okay a red stream and our stream is Flowing that direction from left to right and we have this pipe removing

releasing hot water right there then a fish that is swimming down this Waterway is going to have cool

water cool water cool water cool water bam super hot water it's going to go into thermal shock and

it's going to potentially die right there at that um right around that that pipe

okay some other sources of hot water can be coming off of um parking lots and other

um like dark asphalt surfaces because right say that we have uh like Colorado we have sunny day and then we have a

very quick rainstorm that comes through and that sunny day is baking that that asphalt it's getting really really warm

and then we have a quick rain that comes through all the water runs off of that parking

lot into the storm drain and then directly into the neighboring Creek and it's taking a lot of that thermal energy

from the asphalt with it and it's becoming warm and it's causing that Creek to warm up so the same thing can

happen due to that but often less severely than if it's just you know boiling hot water coming off of a power

plant that doesn't have a cooling pond So speaking of cooling ponds what are some solutions for this problem

um one is cooling ponds cooling towers at power plants um not just power plants but also other industrial industrial

applications that require hot water right rather than dumping it right into the river you can cool it in a cooling

tower cooling Pond and reuse it or cool it and take it to the ambient temperature of that Waterway and then

dump it uh co-generation is another great option and that water can definitely be reused

and is more often reused than not in terms of urban runoff permeable pavement is great because that water can

just go right into the soil rather than into your waterways and bio retention systems that water can cool as it moves

from this asphalt into the soil and then if it's a high enough amount of water or a large enough amount of water

it will cool as it pools and then goes into the storm drain okay so it's not going directly off of

that asphalt all right that kind of brings us to runoff so we've talked about runoff ad

nauseum in this class but I do want to mention it here because it specifically applies to Aquatic pollution and again

it's in the learning objectives so runoff is water that is running off of the surface

of the ground doesn't matter what the ground surface is it can be asphalt it could be soil it can be a forested

ecosystem where you're typically not going to have much runoff but still any ground surface

water running off of that as it runs off of that ground surface it's going to pick up sediments it's going to pick up

pollutants it's going to pick up nutrients whatever is there that can either be carried by the water or can

dissolve in that water okay now runoff is often going to carry sediments and that is a natural process

okay if you have um you know a rain event or you know anytime that you have precipitation

you're going to ultimately have sediments going into your runoff and into a Waterway and that's a totally

natural process but too much of a good thing is a bad thing right if you have lots and lots of sediments coming off of

a mine if you have lots and lots and lots of sediments coming from construction activity and it's

overwhelming that Waterway it's increasing the it's massively increasing the turbidity of that Waterway then that

is a problem okay so the two pictures that we have um on this uh on the right side of this

is two different waterways in each case one that is you know two tributaries of the same

river one that is relatively clear and one that is very um heavy in sediments has a high

sediment load okay so this tributary is going in and going into that River and there was probably some mining activity

maybe like a heavy rain on a dirt road or some construction or something happening

um that caused all of that sediment to be in that water okay so we see the stark contrast

between the two nutrients can also be a problem okay nutrients are typically coming from

agriculture as I briefly mentioned in the learning objective it can also be coming from

um from detergents from soaps and that is typically phosphates okay so phosphates are often added to

soaps and detergents because they're really good at cleaning stuff okay they're pretty reactive and clean with

things okay so we're talking about fertilizers for nutrients we're talking about detergents for nutrients think

about somebody washing their car with soapy suds and the driveway and that going straight into the storm drain

which goes into your local Creek okay in terms of sediment again that's just

going to increase this the turbidity of that water and may increase the nutrient load depending on what's in that

sediment but if we're talking about fertilizers or anything with nutrients detergents Etc we're going to be

potentially having cultural eutrophication okay and we've talked about this several

times again you guys should know what oligotrophic mesotrophic and eutrophic Waters are this is again a natural

process where you start uh start a lake or a pond with you sorry with oligotrophic Waters so this is like

stage one um stage one up here where it's pretty

clear water there isn't much nutrient load and then move through mesotrophic to eutrophic waterways

and that's a natural process that takes hundreds thousands millions of years okay not a problem in the natural system

where it is a problem is with cultural eutrophication and essentially the steps of your of

cultural eutrophication we're going to have first Let's uh it's not even listed here

but first we have nutrients in our waterways okay so we have a massive amount of

nutrients going into our waterways again that could be from fertilizers that could be from detergents that could be

from a Phosphate Mine so you mining fertilizers it could be just from agricultural

system it could be from raw sewage it could be from um a uh like a kfo discharging its waste

water that carries all that animal manure into the waterways it could be a farmer that just stores his animal

manure too close to the river and then it rains and washes into it however those nutrients get in the water they

get in the water okay now then you're going to have and algal bloom and boom and bust so

you're going to have an algal bloom those algae which you're seeing um right here and here and in this pond

on the left they explode in population size they go through those nutrients quickly okay so

they explode in population size they use up all the available nutrients but once they use up all the available nutrients

they essentially starve of nutrients and they all die this algal bloom is going to use a lot

of D dissolved oxygen so it's going to use a lot of your dissolved oxygen but where most of the

dissolved oxygen is going to is going to uh disappear is in the next step and that's

when you have a massive increase of decomposers so all of your algae have lived and then died and they're going to

provide A Feast for all the decomposers in that water all the bacteria and fungi in that water

so you're going to have a massive population increase of your decomposers they're going to do aerobic cellular

respiration first because most of them like to do aerobic cellular respiration first most of them are facultative

anaerobes and they will use up all the rest of the dissolved oxygen so your dissolved oxygen is going to plummet

resulting in either hypoxic or anoxic conditions hypoxic means low oxygen and toxic means zero oxygen

and you're going to have massive die-offs of all your fish Crustaceans mollusks any of your animals

that rely on oxygen in your water okay the other thing that I should mention with this is that some species

of algae particularly red algae are toxic so they can kill fish just by themselves

just by the fish ingesting them or for them passing by their gills so red algae are typically going to be toxic so when

you see a red algal bloom or a red tide as it's often called those are toxic algae for the most part so here's

another representation of that I'm showing the steps both on the left and on this timeline

so you can pause it here and read through that if you desire all right so we've been talking about dissolved

oxygen a lot and um thermal pollution and runoff brings me to oxygen sag curves now what an

oxygen sag curve does is it plots dissolved oxygen across a distance and that distance

includes a source of pollution okay so in this diagram on the right we have a point source of pollution this could be

the Heat or thermal pollution from a power plant it could be a raw sewage entering a creek it could be animal

manure entering a creek whatever it is it's going to be thermal pollution or nutrient pollution

okay and again this is going to this plot is

going to plot dissolved oxygen and I didn't mention it but also bod biological oxygen demand

and in this plot it's kind of hard to see the dissolved oxygen curve but dissolved

oxygen is pretty high pretty high pretty high pretty high and then bam we hit our pollution source

okay our dissolved oxygen is going to start to plummet either because the water is now hot and it's going to just

come out of solution and evaporate into the atmosphere or it's going to be a nutrient solution and

you're going to have an algal bloom that is in this decomposition so you're going to have an algal bloom those algae are

going to decompose which is creating this decomposition Zone and then a septic Zone if that sounds familiar

that's the same term as in like a septic system like a sewage system um

pretty nasty water typically typically smells pretty bad and then it's going to start to increase

in the recovery zone and then go back to the clean Zone after that water has sort of cleaned itself and purified itself

Downstream far enough from the source of the pollutants now that can be very far Downstream so it's not like that's you

know 12 feet it could be 12 miles Downstream that it finally recovers or is clean

okay the other thing that this is plotting is biological oxygen demand and again you can't really see it very well

so let me Trace over that biological oxygen demand is the demand of oxygen required by your aerobic organisms

and many of those aerobic organisms are decomposers so after you have your algal bloom

and you start to have massive amounts of decomposition your biological oxygen demand is going

to Skyrocket and then it's going to start to decrease As you move further and further away

from the um the the source of pollution the pollution source and what I want you to notice is that the demand of oxygen

throughout the decomposition and septic zones are consistently higher than the supply of oxygen so your supply of

oxygen is in the red color and your demand of oxygen is in the purple and there's just not enough oxygen so you're

going to have end up with having anaerobic cellular respiration going on

decomposition right fish can't do that but many bacteria fungi can

and that's what leads to that septic smell of waterways that like nasty Pond scum type of smell

and then they're going to switch by the recovery zone and then by the clean Zone it's back to the starting conditions

okay and your species can return now that's not to say that there couldn't be another Factory right here and another

Factory further Downstream and your stream never gets into that clean zone or you have agricultural field after

field after field after field for the entire length of the river down to the ocean and it never reaches that clean

Zone okay we're seeing that a lot around the world nowadays this water with little to no oxygen

reaching the ocean brings me to Oceanic dead zones so let's imagine for E's sake um for for an example's sake the

Mississippi River Watershed right the Mississippi water river Watershed is going to drain I probably draw it really

poorly but it's going to drain about a third or a little bit more of the continental United States okay all the

way down to the Gulf of Mexico where it discharges around New Orleans now imagine all of those agricultural fields

in Iowa Kentucky Nebraska Kansas all the runoff coming from those fields

and going into the Mississippi River imagine all the industry that's in Minnesota Southern Michigan Ohio that's

going where that runoff is going into the Mississippi River and the Mississippi River has

really low oxygen throughout much of the summer when um when fertilizer use is very high on

these agricultural fields all along its length especially the further Downstream you go where they concentrate and

concentrate and then all of those fertilizers are getting dropped off right there in the Gulf of Mexico

and where that gets dropped off you have these algal blooms every summer in the

Gulf of Mexico and you end up with an oceanic dead zone what that essentially is is an area in

the ocean typically around the mouth of a river or a lot of Coastline that is hypoxic or anoxic again I have these

defined for you hypoxic low oxygen and anoxic zero oxygen and this is going to result in low levels of life or a dead

zone okay you're going to have less fish there you're going to have less Crustaceans more less anything that

requires oxygen okay you'll notice that it's where they're distributed around the world and your industrial and

agricultural centers of the United States same thing around with Europe

Agricultural and Industrial centers and starting to get them in East Asia as well okay they're starting to pop up all

over the world the most famous one and the one that you need to know is the Gulf of Mexico dead zone

the one I used as an example okay now this is not to say that these can't be natural in origin but they're typically

more and more anthropogenic because we're the ones pumping in so much fertilizers and so much um Industrial

Waste into the rivers all right and the last thing that we'll talk about in this PowerPoint is litter

this is just Solid Waste that's been disposed of improperly so not in a landfills or recycled or anything like

that improperly now this can be either intentional or accidental okay and I'm going to include

illegal dumping in with litter okay so accidental litter is a plastic bag accidentally flies off of the back of a

garbage truck right a plastic bag accidentally flies out of your car window while you're driving and you just

can't slam on the brakes and stop and go get it right totally accidental about half of the litter in the U.S is

accidental now the other half is intentional though and part of that is illegal dumping but

part of it is accident um is uh just litter okay so let's just say like somebody smokes a cigarette and then

throws down the cigarette butt onto the ground cigarette butts are plastic they're the most littered

um item in the world and they just throw them on the ground right that is litter that's intentional letter it could be

that your disposal fees for tires are too um too great or you have to go all the

way down to the dump or all the way to the tire shop like Big O to um to dispose of them properly and they charge

you a fee for it so instead your dad goes to an isolated uh bit of bit of Road and just throws them out of the

back of the car into the ditch okay that would be legal dumping or intentional litter and there's a lot of reasons for

it it could be that it's just inconvenient to dispose of something properly it could be that proper

disposal is um is too costly it could be that somebody has a sense of

entitlement and is like oh somebody else will pick this up not my problem to be honest I see that all around at

Grandview High School all the time where somebody just throws a plastic bag onto the ground inside or outside the school

and expect somebody else to clean it up pisses me off now some litter is going to be

biodegradable that essentially means that it will decompose paper cardboard decompose eventually

it's an eyesore until it does decompose and it shouldn't be littered anyway and it's often going to have other

pollutants in it like persistent organic pollutants or chlorine molecule pollutants or um or plastic like tape on

cardboard that shouldn't be there and isn't going to decompose so it's still classified as litter most litter is

going to remain an environment for millions of years your glasses your metals and your Plastics are going to

slowly degrade if degrade at all there's a kind of a running joke among environmentalists that the generation

between 1950 and 1990 or 2000 is going to be known as the aluminum can or Tin Can generation

because of all of the littered Coke cans that are going to be there forever right you're just going to have this

sedimentary layer of Coke cans around the world and it will easily be able to date the second half of the 20th century

okay right now the same thing can be said for Plastics and Plastics are interesting

because they don't decompose most of them are very stable and don't decompose readily rather they just mechanically or

physically get broken into smaller and smaller and smaller pieces and once they become a certain size

um very tiny size they're considered microplastics and we'll talk about

microplastics at length on another day we'll do a lab on microplastics so you don't really need to have that size

category for right now and there's because microplastics are a relatively new deal there is varying definitions of

what size category defines a microplastic so what are the negative effects of

litter well some types of litter can Leach toxic chemicals into your soil and waterways tires are a great example

before the before batteries before auto stores had a um had a battery exchange program bat car batteries used to be

littered all the time and you would just see battery dumps and they're just leaking out the sulfuric acid or

whatever is inside of those batteries the heavy metals as well okay so you can leech out toxic chemicals like acids

heavy metals persistent organic pollutants Plastics into the soil um

you can have organisms that consume different types of litter Plastics is especially problematic with that and

that leads to gastrointestinal blockages so a blockage is when a piece of plastic blocks the

um different Valves and different uh how to um like sphincters of an organism um sphincter doesn't just apply to the

opening of the anus it's also like you have a sphincter between your stomach and your small intestine that opens and

closes to let uh you know partially dissolve digested bits of food go from your stomach into your intestines those

can get blocked Say by a plastic bottle cap or a plastic lighter that a bird accidentally

um identifies as a piece of food okay you can have entanglement of animals so this duck and this sea lion are both

entangled and different types of plastics and they can introduce toxins into your food chain right especially

microplastics and it's estimated that 90 of marine fish just marine organisms have ingested Plastics that includes

microplastics and that includes 70 percent of deep sea fish and you've probably heard the stat that the average

human in the United States eats about a credit card's worth of plastic every year so think of the size of a credit

card and you would never know that you eat it but these microplastics do build up

and when these Plastics get into the ocean they often end up in these Oceanic garbage patches now how they get into

the ocean is varied there's a lot of ways that plastic can get into the ocean or litter in general but I'm

specifically talking about plastic here and that's you know there's there's

different ways right it can directly go into the ocean say from a Coastal Community or from you know being on a

ship it's estimated that about a quarter anywhere between a quarter and a third of all plastic in the ocean is actually

discarded fishing gear such as lines or Nets um

old broken fishing buoys Inflatables all of that type of stuff um Plastics can travel down an ocean or

sorry down a river into the ocean so a plastic found sorry a plastic discarded Upstream can make itself make its way

down into the into the ocean via a river Plastics especially microplastics can just become airborne and be deposited

directly into the ocean via the air there's so many ways that Plastics can get into the ocean including illegal

dumping directly into the ocean once they get into the ocean they get brought into these Oceanic currents and

in each of the world's oceans there are these circular currents called gyres okay these circular gyres are due to

um their circular currents that are due to the prevailing wind patterns so recall at the equator all of the Winds

typically Blow from east to west and then around 30 degrees north and south all of the Winds predominant winds

typically Blow from west to east okay the equatorial winds are the trade winds

and the um the uh the jet streams are at the 30 degrees north and south and that creates

these diff like different directions and the uh the gyres themselves this rotating current

okay once a plastic gets caught up in those they can concentrate in the middle of these gyres

um kind of think about toilet bowl flushing and how everybody how everything concentrates into the middle

of that toilet bowl essentially the same thing is happening here where they just spiral into the middle of these gyres

the largest of these Oceanic garbage patches is the Great Pacific Garbage Patch which you have probably heard of

very famous there's actually two zones of it they're both north of Hawaii um but there's kind of a more easterly

Zone and a more Westerly zone of the Great Pacific Garbage Patch but there is a there is a garbage patch in the middle

of the North Atlantic the South Atlantic the South Pacific the Indian Ocean as well okay all of them have their own

garbage patches and when people hear about these garbage patches they typically think about them

as being just these islands of trash where you can just go out there and See For Miles and Miles

um just floating trash plastic bottles and floating bits of Styrofoam and all of

that stuff that's due to um poorly labeled and misidentified

pictures on the internet that are typically of coastal communities or the trash around Coastal communities it's

typically microplastics in these garbage patches so you're not going to see a floating

island of plastic now some of the plastic that you'll see out in these areas and these are vast areas right but

some of it you're going to see is more intact large salt pieces of plastic but most of it is going to be

microplastics okay we also have detected for the first time

microplastics in um in the air and these are typically tiny fibers that are swept up into the air and fall with

precipitation there's an article that I'm thinking about having you guys read it's very short about microplastics

being detected in a very isolated part of Rocky Mountain National Park where virtually nobody ever goes and the only

way that this scientist hypothesizes that they can get there is falling via precipitation okay so tiny little

particulates like a polyester fiber can get swept up by the wind get deposited via rain and they're being found in all

of these untouched areas around the world okay and then this picture down on the

bottom right is from a National Geographic article that I'm thinking about having you guys read about

Plastics and you see a little fish larva surrounded by pieces of microplastic all right that's it we're gonna I'm

gonna skip this uh we'll show it in class hopefully but if you're not gonna be in class feel free to watch it all

right let's go let's review the learning objectives and the Essential Knowledge real quick so point source versus

non-point Source pretty easy simple um point source is going to be a single Smoke Stack a single effluent pipe or

discharge pipe non-point Source really difficult to identify and control because it can be any number of

agricultural Fields with pesticide runoff or Urban runoff Etc okay lethal does 50 dose response curves I think

that's pretty straightforward you can see the definitions of those this human impacts on ecosystems uh this

first one is talking about ecological tolerances so I feel like we have talked about that not only with ecological

tolerances and several times between our biodiversity unit and now but also in this

um we did not talk right here about coral reefs and we're not going to talk about them on the next um one either the

next PowerPoint either because I've we've talked about them um before we we had an entire PowerPoint

on the human impacts of coral reefs so if you don't remember that go back to that PowerPoint the human impacts of

coral reefs Mangrove forests and wetlands I forget what order I talked about them in

oil spills we will talk about next class or next PowerPoint rather we did talk about Oceanic dead zones

oxygen sag curves we will not talk about heavy metals in this one we'll talk about that one in

the next PowerPoint we did talk about litter we did talk about sediment and we did not talk about

heavy metals or Mercury okay so for the ones that we did talk about um you know Oceanic dead zones are due

to low oxygen and the world's oceans due to increased nutrient pollution from the riverways and Coastal communities

your oxygen sag curves plot dissolved oxygen levels versus biological oxygen demand sorry dissolved oxygen levels and

biological oxygen Demand versus the distance from a pollution source and you're going to have changes in your

aquatic communities based off of the amount of dissolved oxygen in those ecosystems or in those ecosystems okay

we talked about litter yes litter is unsightly but that's really not the the major issue here the major issues are

that they create intestinal blockages in animals they create choking hazards for animals and they introduce toxic toxic

substances into the food chain animals can also become entangled in them as well

um increase sediment and waterways can reduce light and filtration so it increases turbidity which negatively

affects primary production and visual Predators so your um any organism that requires on site is not

going to be able to hunt very well in turbid waters that's the same thing with prey if your prey organisms are relying

on site to identify Predator they're not going to be able to see a predator in turbot waters

okay so a lot in that learning objective let's move on to eutrophication we have

talked again about eutrophication at length and I even had this same learning objective in the nitrogen cycle

PowerPoint I believe is the nitrogen cycle one now eutrophication occurs when a body of water is enriched in nutrients

we are mostly concerned with cultural eutrophication here okay the increase of

nutrients causes an algal bloom that algal the algae then die as they run through the nutrients decomposition uses

most of the dissolved oxygen in the water and then dissolved oxygen plummets okay so the basic steps of

eutrophication and that hypoxic waterways are those low in dissolved oxygen anoxic waterways are

going to be with zero oxygen okay and then we have talked about um

oligotrophic mesotrophic and eutrophic natural ponds and lakes previously so I'm not gonna I didn't talk about them

too much here but barely mentioned them and then the um the the sources of eutrophication

agricultural runoff and Wastewater all right anywhere where you're going to have nutrients that nutrients can be

fecal matter animals or humans or it can be nutrients from detergents from um from agriculture or from you know

your front front yard and your dad right and then we talked about thermal pollution as well sources and effects