Spring2004-transcript-Green-Zone

The Green Zone with David SuzukiNARRATOR: New Brunswick's Meremashee is a world famous Atlantic salmon river. It's also one of the world's last large accessible watersheds that has not been altered by development. Hydrologist Bob Newberry comes regularly to the Meremashee. Known internationally for his work on river restorations, he has a special appreciation of the importance of rivers and watersheds.BOB NEWBERRY: They play a tremendous cultural, historical role. But even more importantly they probably are essential for our survival. The river gives you transportation, it gives you the mature forests, it gives you cool water, it gives you drinking water, it gives you fertile soils. All of those things that for our species are important to survive are in fact wrapped up in these corridors of river valleys.NARRATOR: (1)Water is a basic element of life. And where water flows, it creates varied and complex habitat. The strip of vegetation along a waterway is called a riparian zone. The riparian zone plays a vital role, protecting the structure of the stream and maintaining water quality. Streams with clean, fresh water are essential for fish like pacific salmon. Fish in turn attract a host of predators. Because it supports such a diversity of species, many scientists believe the riparian area is as vital as the stream itself.___________: Riparian areas are comparatively small compared to other habitats, but their importance far exceeds their size. However, these vital areas are often damaged or destroyed by urban development, industry,logging and agriculture. And the loss of these green zones bears enormous costs.NARRATOR:Riparian vegetation shades the stream, keeping the water cool. The plants provide food and shelter for many animals. Hordes of insects attract predators like spiders and birds. This caterpillar uses elaborate camouflage for protection. The tree frog wears a leaf on its back to blend in with the vegetation. Numerous aquatic animals provide food for many species such as wading birds. A stream and its riparian area are really a single entity. Without riparian vegetation, a stream can support very little life. In cities, the destruction of riparian areas contributes to severe water pollution. Without vegetation acting as a filter, urban waterways become open sewers. A large percentage of all the commercial fish caught in the world depends on streams for reproduction. The dwindling number of pacific salmon is a direct result of the destruction of the streams where the fish spawn. In recent years there has been an increase in severe flooding worldwide. The destruction is caused in part because people ignore the way rivers work.BOB NEWBERRY: When we say a "serious flood", we mean a serious flood for our civilization. For the river it's just a normal event. It's just that we've intruded so closely on the river that when these normal events happen in the river, in fact we think it's some new destructive force that we haven't seen before.NARRATOR: Running water is often associated with fertility and the rippling sound of a flowing stream is one of the most soothing in nature.___________: A stream is almost like a living organism. As it flows, it's constantly varying its form, providing different opportunities for plants and animals. The force that drives this stream is one of the most basic in nature--gravity.NARRATOR: Water is a restless substance. When it moves, it shapes the landscape. It's natural for a stream to twist and turn as it flows. This meandering is regulated by the riparian vegetation.Bob Newberry uses a plastic ribbon to demonstrate how flowing water is constantly moving back and forth across a stream. The dimensions of this curving create a highly predictable pattern. The distance for the flow to cross from one side to the other is always six times the width of the stream. Wherever water flows on earth, it will take this path. It's the force of the water moving back and forth across the channel that creates the meandering pattern. Like a wave, this pattern is constantly moving.BOB NEWBERRY:The wave shape is established on the landscape by the river, by these hydraulic forces. But it's also translating itself down the valley much the same way as a wave goes down a skipping rope when you snap it, and so the whole wave form is travelling down the valley, planing off this valley bottom surface and defining the outer limits of the riparian zone. NARRATOR: At any one time a river will only occupy a small portion of a valley bottom. But as it meanders and periodically overflows, it can dramatically shape within its flood plain. When it moves, the stream leaves behind rich sediments that create fertile soil. Riparian vegetation acts as a regulator of this movement by buffering the rate of erosion.A curving tree is one sign of a healthy riparian area.BOB NEWBERRY: When you see these trees that are curving upwards like this, it means the river is moving at a rate that is slow enough to allow the trees to correct the vertical growth on the tree. Now if you saw straight trees that were falling into the river, you'd know there was an unnatural amount of erosion but in fact this river moves at a pace of this trees' growth. NARRATOR: A stable bank is critical for a healthy stream. Where the water crosses the channel and hits the bank, it digs a pool. If there is no vegetation to hold the bank and deflect the water down, the water will push the bank back. These deep, calm areas are critical for fish to rest and hide. The vegetation above the pool provides cover from predators. Trees and branches that fall into the water also provide important hiding places. As the water crosses between the deep pools, it flows over shallow areas, called ripples. Here the water flows quickly, carrying food for foraging insects like this cattusfly larva. The larvae build cases out of sand and plant material for protection. Some larvae attach their cases to rocks in the ripples.BOB NEWBERRY: This little cattusfly right here--he's built a net. And he's built a little shelter out of the fine nets of woody debris that are coming down the stream. And the flow is going into this little net and he just has to step out and graze off that net.NARRATOR: Insects in the ripples attract many predators. Many species of wading birds feed in the fast-flowing water. Fish rise from the pools to feed on organisms from the ripples. Ripples are also the places where the water is re-oxygenated.BOB NEWBERRY: This is the place where the bubbles are actually swept into the surface of the stream. The water is going so fast that it sweeps the surface air down into the slower moving water here and there isn’t time for the air to escape from the surface so it’s swept right underneath the flow. We call this ripple zone simply because of the noise it makes. It makes this rippling sound, or the rippling pattern in the water. Some people call this the lungs of the stream. They say this is where the stream breathes.NARRATOR: High oxygen levels are critical for many fish species. Atlantic salmon are extremely sensitive to even small changes in water quality. When damage occurs, salmon are one of the first species to disappear. The Meremashee is one of the healthiest salmon rivers in the world. Each fall the sleek powerful adults migrate from the sea to spawn and return to the ocean. Because of their strength and speed, flyfishing for Atlantic salmon is considered the ultimatechallenge for sport fishers. Evereff Taylor is a fishing guide and farmer who grew up on the Meremashee.EVEREFF TAYLOR:No matter where you go basically in the world, if you tell them you're from the Meremashee, somebody who knows anything about salmon fishing will know where you are from, you know. And so it's always a very important thing and an important part of the community.NARRATOR: The Taylors recently built a fishing lodge. It's been estimated that each returning salmon is worth 1,000 dollars to the sport fishing industry. The river is vitally important to the local economy.EVEREFF TAYLOR: The river's been really important, I guess to this whole area, really over the years. It's brought people here to fish from outside of the province for decades. And we have outfitters who have been here in the same business for over 50, 60 years or more and it brings in a lot of money in from outside of the province that normally wouldn't come here. NARRATOR: Evereff's family has farmed along the river for generations. To grow feed for his cattle, he depends on the river flood plain. The annual spring floods bring moisture and nutrients carried in the sediments. Because large sections are used for farming and fishing much of the river is in a natural state. However, in recent years, people have noticed changes.EVEREFF TAYLOR: There are differences in water fluctuation and stuff like we never used to see before we have high extremes and heights of water in spring. Or whenever we have a freshet or heavy rains and then every year it gets lower, you know. You hear people say they’ve never seen the river so low, then the next year it’ll be lower still again than what was the year before. NARRATOR:Changes in the river are the result of human activities in the watershed. The drainage area of the Meremashee is covered in thick forests. The vegetation helps hold water and slows the speed of runoff. Within the watershed there are many bogs and wetlands. They collect large volumes of water during wet periods. This water is then released gradually. Removing vegetation within the watershed disrupts the water cycle.EVEREFF TAYLOR: You always hear logging, being part of, you know, one of the things that are named the ditching and better management of the runoff from wood roads and stuff that makes its way to the streams quicker. Shooter swamps, you know, have been cut to a certain extent so that there's as not much marsh or bog that slowly seeps out into the river system. NARRATOR: The river is only one part of a huge habitat needed by Atlantic salmon. In recent years the number of fish returning has declined dramatically. The reason is unknown. But it’s of grave concern.EVEREFF TAYLOR: As far as producing the young salmon, like far and small??to go out to the ocean, the rivers are still doing a good job. But it seems to be that they are not returning once they go out to the ocean, you know, but as far as the habitat of the river itself it's remained healthy over the years.NARRATOR:Rivers like the Meremashee that exist in a relatively natural state are becoming increasingly rare. There are few left in the world.BOB NEWBERRY:With some of the forestry practices in South America, we’re losing huge amounts of river basin that would have been there for us. As we move north in Canada, we move into large power projects which have had tremendous effects. And as you move across Europe, there are no natural rivers left. They’ve all been altered in some way. So we don’t have a large stock left anymore.NARRATOR: (2)This loss of natural rivers and streams has led to many efforts at restoration. Along the eastern slopes of the Rockies, many rivers and streams flow down from the mountains. Out on the arid prairies, streamside vegetation is especially important. Riparian areas are critical for migrating birds.Many of the flyways follow river valleys, particularly those running north and south. Other streams form a network of stopovers providing food, shelter and a place to rest. Most prairie animals could not survive without the fresh water, food and shelter of riparian zone. On the prairies eighty percent of the animals require riparian areas for all or part of their life cycles. In the mountains and foothills many animals move down into river valleys from high summer ranges for shelter during the winter.The amount of water flowing across the land fluctuates in an annual cycle. Evaporation and precipitation produce pure fresh water. In winter this moisture accumulates, locked in snow and ice. Warm spring temperatures begin to release the frozen winter moisture. Almost immediately, migrants arrive to take advantage of the open water. Gradually large volumes of water begin to move down the stream. A river at a flood stage has forces similar to a tornado. Riparian vegetation holds the river’s bank against the force of the water. When the stream overflows out of the flood plain, the vegetation holds the soil, slowing the water and allowing sediments to settle out. Without healthy riparian vegetation, spring floods cause severe damage.This creek has only a few of mature trees to protect it. The shallow water is too warm for most fish species because there is little shade. The large number of falling trees indicates the banks are subject to excessive erosion. The uncontrolled erosion makes a creek that is wide and flat rather than the deep pools and ripples. It’s not uncommon for banks in this condition to move several meters a year.Loren Fitch is a fish and wildlife biologist with the Alberta government. Barry Adams works for the provincial Ministry of Agriculture. Part of their jobs is to restore damaged riparian habitat like this. The creek was damaged because it was used continuously for a nearly century to feed and shelter cattle. The few remaining trees are remnants from when the cattle first arrived. All the younger trees that would have grown have been replaced by shallow-rooted grasses.BOB NEWBERRY: To blunt, or to dissipate or to steal the energy that moving water has, you need vegetation. You need a root mass that holds the bank together. In a situation like this, we’ve got very shallow-rooted vegetation, stuff that doesn’t have deep penetrating roots, and doesn’t have that fibrous mass that will hold all the soil particles and all the gravels together to make them resistant to the horse power that the stream has.NARRATOR:To allow a new generation of trees to grow the creek was fenced off. The few remaining trees became seeds stock for the next generation. In the first year cottonwood seedlings began to appear.This small creek was fenced off about 10 years ago. The vegetation quickly engulfed the stream. With vegetation squeezing in on the creek, the channel became deeper and narrower. This confinement of the creek extends the benefits of the water far out onto the dry land.BOB NEWBERRY: When vegetation holds streams together, where does this stream go? Where does the water go? It probably cannot go down because it’s meeting some resistant layer like gravel. So th e water’s got to go up. The water column goes up like this. And as it goes up vertically, it goes out horizontally. And it merely extends the value of that riparian zone. In fact it’s irrigating a much wider area.NARRATOR: Healthy prairie creeks and rivers provide precious moisture to agricultural crops. For over a century and a half, ranchers have used valley bottoms in the foothills to feed and shelter cattle. In many places this constant use has caused severe damage. Stream degradation has become an ex plosive political issue. Blaming cattle for problems with streams doesn’t sit well with progressive ranchers like Clay Chatoway.CLAY CHATOW AY:That’s not so much that cattle abuse the resource as people abuse the resource.NARRATOR:Many ranchers have dramatically reduced the access cattle have to the stream. Some streams are fenced off. Others are used sparingly. After the cattle are removed the valley bottoms are given long periods to recover. By responding to public pressure, most ranchers are acknowledging they have a responsibility to protect streams that cross their land.CLAY CHATOW AY: They are our most productive lands but they have a high value to many different publics for any number of reasons, say, the fish habitat, the water quality downstream. If you follow the continuum from the top of the mountain clean to the ocean it’s a big environmental issue that’s going on in our streams and rivers.NARRATOR:The ability of a river to support wildlife is an indicator of the health of the watershed. In western Canada, rugged terrain and plentiful precipitation generate fast flowing creeks and rivers. Virtually every stream west of the Continental Divide was a breeding area for pacific salmon. Today many of the salmon runs are extinct. This is the Salmon River in central British Columbia. Today it supports only a tiny fraction of the salmon that once returned here. Biologist Mike Wallace.MIKE W ALLACE: We then had perhaps a hundred thousand sockeye returning to this river hundreds of years ago on a regular basis to spawn. And in the present situation we have virtually no sockeye, and, in all, combining all the salmon species we have perhaps a thousand, or two thousand salmon returning to the river to spawn.NARRATOR:Mike Wallace works for a citizens’ grou p in the Salmon River valley. Mike Crowe is a biologist with the Federal Department of Fisheries and Oceans. They are part of the project involving local farmers, loggers and other landowners to improve water quality and fish habitat in the Salmon River. The Salmon River watershed is typical of many in B. C. Much of the forest has been cleared by logging and for agriculture. Removing the vegetation has destroyed fish and wildlife habitat and many banks are severely eroded. Along this 150-meter stretch, nearly a hectare of land was swept away in one flood. The wide shallow channel indicates a river in trouble. To repair the damage whole trees are buried into the bank. These deflect the water away and prevent further erosion. After the bank is stabilized, trees and shrubs are planted. In the time it takes for the logs underneath to rot, the trees will grow enough to permanently hold the bank. It’s a slow process.MIKE CROWE: When we want to talk about true stream restoration and try to provide many of the habitat features you will find in a river system, such as scour pools, and, large woody debris, and logjams. That’s going to take at least a hundred years. So it’s a very long-term process to actually develop what we would call a successful restoration project. It’s not going to occur in our lifetime.NARRATOR:Many of the benefits of improved water quality and wildlife habitat can be regained. But the historical runs of sockeye are extinct and not likely to return. Still some hope for a recovery.MIKE CROWE: W e are not capable of recovering a river, but what we’re doing is we are taking the actions that we can take locally, that we’ll enable Mother Nature to do her own repair. If we do this, here, and similar actions are taken elsewhere, there is very strong possibility that ecological recovery will occur, that the processes of ecological recovery will be triggered. And for example, we may see a much larger return of salmon come back to this river. All we need to do is make ready the habitat for that and make sure that the gauntlet that fish have to run between here and the ocean and back again is just not too severe.NARRATOR: When people try to restore a lost element to the natural world, they usually come to realize the intricate complexity of nature. For centuries people in the valley of the Nile depended on the annual floods to grow their crops. The fertility of the Nile supported a rich and powerful society.___________: The natural abundance of rivers and streams has played an important role in human history. The valleys of the Nile, the Tigris and the Euphrates rivers nurtured some of the earliest and most elaborate civilizations. Today much of the world’s population lives along waterways. It’s a sad irony that the natural wealth of the rivers and flood plains is threatened by the people it attracts.NARRATOR:(3)The Dawn River in Toronto is an example of how humans affect rivers. Running through a city of over two million people, the Dawn Valley is a busy transportation corridor. Parts of the Lower Dawn have been straightened to accommodate roads. At its mouth the river has been turned sharply to make a harbor and fill in a marsh. The headwaters of the Dawn are in a glacial moraine north of the city. The porous gravel absorbs rain and snowmelt. The moraine is dotted with springs fed by underground aquifers. The water trickles down to form cool, clear creeks. When Europeans arrived, the lakefront was sand beach and wetlands. Where the Dawn River emptied into Lake Ontario, there was a large marsh. As more settlers arrived, the Dawn valley was stripped of timber. The land was then taken over for farms. Quickly the city expanded into the watershed. To accommodate the growing population, an elaborate network of roads was constructed. Wetlands along the waterfront were drained and filled in. By the early part of the 20th century, much of the southern portion of the watershed was covered with buildings and paved roads. These created an impervious surface where water couldn't seep into the ground. The natural cycle of flooding became an increasingly frequent and destructive occurrence.__________: In the fall of 1954, after a week of unusually heavy rain, weather forecasters watched a tropical storm as it moved north through the eastern United States. Suddenly it veered further inland and crossing Lake Ontario, picked up moisture and increased intensity. When hurricane hazel hit Toronto, it dramatically changed the way people in the area viewed the rivers and streams. The heaviest rains began late in the afternoon.NARRATOR: (4)Over the next few hours, nearly 15 centimeters poured down. With the ground saturated, the water went on a rampage. In the darkness, 82 people lost their lives. Entire communities were swept away. Daylight brought the horrific realization of the power of surging water. Rescuers did what they could. The water smashed bridges and washed out roads. Many houses were torn apart. The destruction and loss of life led to the formation of an elaborate flood-control system. The Metropolitan Toronto and Region Conservation Authority was formed the year after the hurricane hazel. They constructed two large dams with enormous reservoirs to collect floodwater. Many of the flood vulnerable creek and river valleys were purchased. In some areas large concrete channel s were constructed to move water away as quickly as possible.Hundreds of millions of dollars were spent on these projects. They did provide flood protection, but they also created serious unforeseen problems. During the time of construction, the city continued to expand into the watershed, even reaching parts of the headwaters in the moraine. The reduction of water-absorbing ground meant that each rainfall or snowmelt brought increasing amounts of water into the rivers. The water was also becoming severely polluted. The rain washed chemicals from cars and other pollutants into the waterways. Each rainfall created toxic soup that was straining the capacity of even the most elaborate and expensive flood-control installations. Faced with a rising cost and dangerous pollution problems, a more natural approach was adopted. Conservation Authority coordinator for the Dawn River, Adell Freeman.ADELL FREEMAN: We recognize that flooding is a natural phenomenon. Water is going to flow, and we want to work with the water system and the hydrology that's here rather than trying to work against it.NARRATOR:The authority owned most of the creek and river valley lands. They decided to return as much of this land as possible to its natural state. Riparian vegetation was replanted to act as a filter for pollutants and to slow down runoff. Working with nature has proved effective and has led to ambitious rehabilitation projects. This was a quarry near the Lower Dawn that supplied clay for a brick works. When the pit was exhausted, the brick works was shut down and the conservation authority gained possession of the property. At one time, a small creek crossed this land. It was taken out of a pipe and now flows into a series of large wet land ponds. Dozens of species of native vegetation were planted on the site. The plants help purify the water, filtering out sediments and taking out extra nutrients. The regeneration projects have spawned an urban wildlife recovery. Many animals thought to be gone from the city forever have returned. Some, making remarkable adaptations. Many species of birds use the restored habitat to rear their young. Others use the valleys as migration flyways. Using natural methods still provides flood protection and the return of wildlife has added an important element to city life.ADELL FREEMAN: I believe the real value of having wildlife in the city is so that people have a real sense of being a part of a natural system rather than apart from it. I don't believe that people will understand natural systems removed in terms of Algonquin park or wonderful natural parks up in the Arctic if they don't have some first-hand experience with animals and wildlife right here in their own backyard.NARRATOR:One goal of the restoration is to improve water quality to the point where a diversity of fish species returns to the watershed.___________: Fish are always seen as a bellwether of the health of streams and rivers. In British Columbia salmon have great economic importance, but they are also part of the culture. The rate of the salmon's decline has alarmed not only fishers and fisheries officers but people from all walks of life.NARRATOR: On a cold, wet Sunday morning, dozens of people gather along a small creek in the city of Burnaby. Teacher and naturalist, Mark Angelo, is one of the organizers of the event. The volunteers are restoring a creek that was buried for decades.___________: This creek used to be covered and paved over. And when some of the new development occurred here, we had an opportunity to daylight it or literally open it up again, so slowly but surely we're bringing this creek back to life.NARRATOR: This project is part of B. C. Rivers Day. Started as a small celebration of rivers and streams, in 18 years it has grown into a large annual event.MARK ANGELO: We have more than a hundred projects going on around the province, projects ranging from stream cleanups and fish enhancement projects and stream-side planting initiated like this one. Right on through the educational tours and riverside celebrations and we probably have about 25,000 people doing work like this on streams all around the province. NARRATOR: Great Vancouver straddles the Fraser River. At one time it supported one of the largest salmon runs in the world. There was a time when city residents complained that the sound of spawning salmon kept them awake at night. People could catch fish in their backyards or at the end of their street. Today within the Vancouver area virtually no salmon runs remain.__________: Or I say at least three quarters of the urban streams left in the lower mainland are classified as endangered. The rest are largely threatened. Looking at Vancouver also, we've lost more than 50 streams in the last century that have been covered and paved over, and that represents more than 700 kilometers in waterway. So we've lost a lot of urban streams and those that remain, a number of those are troubled.NARRATOR: A primary cause of stream damage is that much of the protective riparian vegetation has been removed. Many of the structures used to divert and control water pose impenetrable obstacles to fish. The Vancouver area is one of the fastest-growing urban centers in North America. The demand for housing and industrial development has meant that much of the watershed has been paved. The steep slopes and abundant rainfall magnify the problems of the urban runoff. Despite the odds against them, people involved in restoration have produced some remarkable results. This is Still Creek in Burnaby. It was one of the most-damaged waterways in Great Vancouver. After years of planting by volunteers and lobbying by activists, some sections are being reestablished. This section has a 600-meter-wide riparian zone.__________: I think it's important that we look at our urban streams differently than we have in the past. There are wonderful futures of our community. I look at this particular creek, the recreational values, the natural values associated with it, the cultural values as well. And I think people are starting to appreciate urban streams like this more so than was the case in the past. And I think that'll be certainly important in terms of doing a better job of managing these creeks in future.NARRATOR: One of the Rivers' Day events took place on the Allawet. After years of work some of the river has been reestablished. In a park besides the river first nations people prepare a salmon barbecue. It's a celebration of the benefits they can flow from a healthy river._________: It's a good time to let them go, although; it's happy, right?NARRATOR: One of the highlights was the release of an eagle. The young bird suffered an eye injury in an area battle with a bald eagle._____________: Bald eagle. About four years old. Male.NARRATOR: Local volunteers nursed the bird back to health. The eagle was confined for 18 months. For those who looked after the bird and the others watching it, it was an emotional event. There is no guarantee the eagle will readapt to life in the wild. But because it has a habitat, clean water and food, there is a good chance he will survive.。