next we come to wetlands destruction the cartoon here shows somebody building like a weekend cottage in the sand dunes next to the ocean which happens but there's lots more to wetlands destruction than just that coastal wetlands do include sand dunes beaches tidal flats salt marshes stuff like that but there are way more different wetlands inland away from the ocean fresh water not salt water there are swamps marshes bogs fens innumerable other varieties of wetlands they're all under serious threat for a variety of reasons how serious is the damage well let's take a look at this map which shows the percentage of wetlands state by state that have been destroyed the dark blue color here or where the wetlands are in pretty good condition Alaska you see 1/10 of 1% of the wetlands there have been damaged wetlands basically intact well that's no great surprise Alaska is huge it is wet and very few people live there you see the same color up in the far corners of New England here but if you look at the number you'll see that one more percent of wetlands lost and it doesn't qualify for that color anymore so that basically the light blues represent one-third destruction of wetlands the green half the yellow two-thirds and the red these are the states with the really serious wetland losses okay and you see this group in the Midwest here of approaching 90% and then here's California leading the pack with over 90% of our wetlands destroyed if you average all of these together the less than half the house the more than half serious ones if you average them all together they average out at around 50% loss for the nation as a whole by the way there's that number again 50% loss of capital I'd like you to remember that also and never mind the 1 try to remember that in California the loss of wetlands is about 90 percent here's a demonstration of how bad the wetlands losses are for California this is a map of the Central Valley and never mind the yellow that wasn't wet but the various green and blue colors here represent wetlands look where they aren't now pretty much 100% gone Wow are we destroying all these wetlands what do you think you're probably thinking urbanization draining them to build homes shopping malls everything we do around here well that's around here what about most of California take a look back at these two maps that's the Central Valley what are we using the Central Valley for total agriculture how about those states in the Midwest the ones in red Indiana Illinois nearby states are they so urbanized that there's nowhere to build new homes on dry land without draining a swamp absolutely not they have a few big cities but those are basically agricultural states there's oodles of dry land and when you look back at that map again check the dates much of this damage took place in the 19th and early 20th centuries back in those days wetlands were seen as useless unproductive land worse mosquito ridden disease prone and the federal government had a subsidy program the federal government paid landowners to dig ditches drain swamps and plaque or improve the nation's economy raise up very successful program as the map shows you almost 90 percent of the formerly extensive swamps across those Midwestern states were completely destroyed today we know that that was a great mistake we know that wetlands are very important Wow what a wetlands good well let's see first of all biodiversity which is important to our survival wetlands are their very own ecosystem there are animals and plants that live in wetlands can only live in wetlands we call them endemic species that are confined to a specific habitat then there are numerous other species animals and birds in particular that aren't confined to wetlands they don't have to live there but they visit they visit regularly they need to visit for food shelter stuff like that so that's a very important aspect what else the wetlands good for well they provide water we need water what is the plan not only that water purification this could be a huge topic of its own it's complex when water flows into a wetland there's physical filtration through materials and particles are there there's chemical processes involving the soil and the water there are biochemical processes involving plants and microorganisms bottom line you can flow dirty water into a wetland and clean water comes out you should look up the story of Arcata it's in the textbook a small town in Northern California which many years ago got rid of their traditional concrete and steel sewage treatment plant built a wetland they flow the city's sewage into the wet and natural processes take care of it and clean water comes out it was and you don't have to burn any fuel to make it happen so we have more and more of a problem with water pollution in the United States and what have we done we've destroyed overall about 50% of nature's ability to clean up our water fifty percent over all of nature's ability to clean up our water not smart let's see what else [Music] flood control when a whole lot of rain falls it all flows into rivers and sets off down those rivers and a day or two later the river rises stays high for a day or so and then falls again if you look to that news item that I posted about the dam up in Michigan the reporter was standing there saying floods rising isn't it nice to have beautiful sunshine the rain moves two days before with a long river like the Mississippi it can be several weeks after the rainfall in another geographic area before the Mississippi River suddenly Rises and a two days later falls basically a wave of water is travelling down the river it gets to you passes on but while it's there the river rises to a dangerous level over tops the banks and everybody near living near is flooded up a wetland is like a giant sponge if you have wetlands along the course of that River all that pulse of rainwater flows into the wetland and the wetland lets it go a little bit at the time so instead of all that flood water going down the river in one day it's now spread out over two weeks and the river rises one foot instead of 30 feet and there's no damage coastal wetlands help also with protection from storms when we have a big storm even a hurricane jan 12 2008 section due to the incoming waves damp stand-down reduces them and all our infrastructure behind that coastal strip of wetlands undamaged we could probably think of one or two more things but you get the picture wetlands are not useless unproductive land something to be destroyed they are a vital ecosystem that we need to preserve