Music This lake looks calm, but it's teeming with different kinds of life above and below the surface This is how nature works!

Theme Music Music When you’re out on a lake or river, it seems to go on forever.

But really, fresh water isn’t as plentiful as you’d think.

Out of every hundred drops of water on Earth, only one is fresh and liquid.

The rest are frozen or salty.

All kinds of different creatures live together in lakes, streams, and wetlands.

The lives of all those that live near each other are connected.

Organisms that live together and naturally interact with each other are a community.

Communities in or on water are called aquatic communities.

Aquatic communities can be in salt water or in freshwater.

Those in freshwater are called freshwater communities and there are lots of different kinds.

You find them in ponds, lakes, streams, and wetlands.

Pond communities thrive in shallow water, where the temperature stays fairly even from top to bottom.

When the air gets warmer or colder, so does the pond.

Pond can even freeze solid.

Their bottoms are usually muddy with rooted plants that may grow all the way across.

Rivers and lakes have similar communities living in them.

Lakes are big enough to have waves and layers of different temperatures.

Since most of the Earth's water is salty, it's a wonder there's any freshwater at all.

We owe all of our freshwater to the fact that rain is fresh.

That's because, in the process called evaporation, the sun’s heat changes saltwater into pure water vapor and leaves the salt behind.

The vapor rises, pools, and changes back into droplets of fresh water that gather into clouds.

The clouds move over land and drop rain, ice, or snow that fills lakes and rivers, and eventually flows back into the ocean for the cycle to start all over again.

Once fresh water falls on land, some of it soaks into the ground and remains there as groundwater.

And some of it is absorbed by plant roots and moved to leaves.

From there, the leaves evaporate water into air.

This part of the water cycle is called transpiration.

Forests add enormous amounts of water to the air through tree leaves.

In warm inland places, forests make enough water vapor to produce most of their own rain.

Wetlands are important because they hold water, helping to control floods during and after storms.

They also keep rivers and lakes clean by trapping sediment and pollutants, recycling nutrients, and transforming poisons into safer compounds.

Since wetlands abound with life, they're great places for migratory birds to nest in the summer or over the winter.

There are so many different conditions in and on fresh water, from huge lakes to wetlands.

It's no wonder there are so many different kinds of freshwater communities.

There’s a freshwater marsh in the nature center where Dave and I found lots of interesting plants and animals.

Let's go there and see what we can find this time.

Music Hey, Dave.

Oh, hi Patrice.

Hey, I heard that you found this snapping turtle.

I did, I found this when crossing a road.

Wow.

You can see she's not terribly happy.

Let me just set her down here.

She was crossing the road, so I thought I'd help her the rest of the way down here to the pond.

So are these snapping turtles, like, dangerous?

Well, you have to be careful around them, because you could see when she had her mouth open, she wasn't.

She felt threatened.

She wasn't very happy.

But that's only because her shell, if you look at it, it's great protection on top here.

But she doesn't have much protection underneath, And so she can't pull herself in like a lot of other turtles can.

And so they do have to use that that beak and that long neck to protect themselves.

So what do they eat?

Well, actually, snapping turtles eat a lot of different stuff.

Of course, they are predators or hunters.

They do eat meat of sorts.

A lot of it, though, is in the form of dead stuff.

So they're kind of scavengers.

In fact they’re sometimes called the garbage man of the pond because eat the dead stuff in the water, but they also eat plants too.

In fact, an older a snapping turtle gets, the more plants they eat or the more plants that are in their diet.

So were you just about to put her into the pond?

Yeah, I think we'll do that right now.

Music Wetlands like these have lots of different functions, but certainly one of the most important ones is to provide habitat for a variety of wildlife.

And not just little animals like frogs and snakes, but even bigger things like beavers and muskrats and herons and even the moose.

And of course, the turtles.

But let's take a closer look at wetlands.

Music Wetlands are found all over the world.

Any land area that tends to be regularly wet or flooded, like swamps and marshes, is a wetland.

Some wetlands are temporary, lasting only a few weeks.

Others are always underwater.

Bogs are mossy wetlands found in cold climates.

They have large deposits of decaying plants called peat in them, and most of their water comes from rain and snow.

Water doesn't flow in and out of bogs.

They have low levels of oxygen, and the soil and water in them is very acidic.

Moss, evergreen trees, and shrubs thrive in bogs because they tolerate the acidic soil conditions.

The insect-eating pitcher plant and sundew can also live in the bog, getting some of their nutrients from the insects they eat.

Another bog-like wetland is called a fen.

Fens are like bogs because they have peat deposits in them too, but their water comes from small streams and groundwater.

The main difference between a fen and a bog is that fens have greater water exchange and are less acidic.

In some parts of the country, glaciers left the land covered with indentations.

These indentations fill up with water when it rains and when the snow melts.

Since most of them are in the prairies and they're often round like a pot, we call them prairie potholes.

Some of them are temporary.

Others are permanent, depending on their size and the amount of rainfall.

Bulrushes, sedges, and cattails grow on the edges, where they make great hiding places for birds and other animals that use the potholes.

Over half the migratory waterfowl in North America depend on prairie potholes for their survival and reproduction.

Waterfowl also depend heavily on freshwater marshes and swamps in both warm and cold climates.

Snowy egrets, redwing blackbirds, great blue herons, and lots of species of ducks and geese are common in freshwater marshes.

There are many species of flowers and non woody plants, like cattails and bulrushes, that provide shelter for birds, frogs, and turtles, and are food for muskrats, moose, and beavers.

Many species of fish use wetlands along the margins of the lakes and streams to spawn.

Young fish can find plenty of food and hiding places.

The fish are an important part of the food web.

Larger predators like owls, hawks, raccoon, mink, and otter search for prey in the marsh.

Many of the same animals that use the marsh are also found in swamps.

Swamps are wetlands that support wooded vegetation like trees and shrubs.

Throughout the year, the water level varies, covering the ground for the wettest part of the year.

Some of the most common swamp trees are bald cypress, black tupelos, and red maples.

Probably the smallest and most overlooked wetlands are vernal ponds.

They're usually found in wetlands and fill with water from snowmelt and spring rains.

Although the vernal ponds usually dry up by mid-summer, they still play a role as nurseries for amphibians like wood frogs and spotted salamanders.

Because fish can't survive in vernal ponds, frog and salamander tadpoles have fewer predators to avoid.

About half the wetlands that were in the United States two centuries ago are now gone.

Most were drained and used for farmland, or filled and have roads or towns built on them.

This development has put a strain on species that depend on wetlands for survival.

Over one third of the animals and plants on the U.S.

Endangered and Threatened Species List depend on wetlands for at least part of their lifecycle.

Wetlands play an important role in the natural world.

They’re the habitats for many different plants and animals, and they also help control flooding.

The wetlands are like huge sponges.

They absorb water that might otherwise flood areas where people live.

Wetlands are also filters.

They help clean water by capturing pollutants in sediments.

Wetlands can be found over much of the world and, along with lakes and streams, provide opportunities for people to hunt, fish, canoe, and observe nature.

Freshwater communities are important to the survival of so many living things, and there are people who help us keep an eye on the health of our lakes and streams.

That's right, Beth Malcolm is one of those people.

Marissa and Benjamin are going to help inspect the growth of animal and plant life in those communities.

Music I found them.

Music So what kind of things are we looking for here?

Well, we want to make sure that we find a little bit of everything.

The sensitive species, we want to make sure we get some stoneflies, mayflies, and caddisflies.

Those are the most sensitive species.

And they're also really important to the food web.

What do they eat?

Well, there's a lot of different types of macro invertebrates, macro meaning large enough to see with the human eye and invertebrate meaning that they don't have a backbone.

They often eat algae and plant material.

And there are different kinds.

Some are actually predators, and they'll eat other macro invertebrates.

Some are called collectors, where they'll put out a little net in the water and collect algae and floating materials going by.

There's also ones that are known as scrapers.

And they have a jaw part that's very well adapted to scraping.

Let’s see what we got here.

This is exactly what Beth is talking about.

Right here.

That's a good indicator.

Yup, we want to see those.

This is a stonefly.

It’s a stonefly.

Why is that a good indicator?

What do stoneflies show?

They are typically found in very cold, high, oxygenated water with a ripple like this.

I suppose that's why they call them stoneflies.

And, they don't have a very high tolerance for sedimentation and high nutrient low and just generally indicate a pretty clean environment.

All right, this looks good.

I guess we can take this over to shore and dump it out and see what else we have in here.

What we're going to do here is just kind of separate them out a little bit so we can get a look at the different kinds.

So, judging by the organisms that we've seen, what do you think the what do you think they're telling us about the health of the stream that we have here?

Well, from all we've learned today, it's sort of looks as if this is a pretty healthy stream.

It has so many organisms, and they all seem to tell us that this is pretty healthy.

It's true.

Plus, this is a location at the bottom of the watershed.

So everything that's happening along the shores of this river is all coming by this point.

And it's good to see that there are still a lot of these sensitive critters living here.

Music What have we learned today?

Communities in or on water are called aquatic communities.

Freshwater communities include rivers, streams, lakes, ponds, and wetlands.

All the water on Earth moves through the water cycle.

The types of organisms found in aquatic communities depend on conditions like water temperature, depth, and movement.

Now you know how nature works!

Theme Music Major funding for Nature Works was provided by American Honda Foundation.

Additional funding was provided by Alice Freeman Muchnic, Alice J. Reen Charitable Trust, Cogswell Benevolent Trust, the Finisterre Fund, Greater Piscataqua Community Foundation, Morgridge Family Trust, the Natural Areas Wildlife Fund, Rawson L. Wood.

Support for this episode of Nature Works provided by Greater Piscataqua Community Foundation.

Alice Freeman Muchnic, Laudholm Trust.

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