Impact of Human Activities on Wetlands

Hey everybody, it's Mr. Smeeds, and welcome to Ape's Video Notes for topic 8.4, which will cover human disturbances to mangroves and to wetlands. Our objective for the day is to be able to describe the human activities that have impacts on wetlands and on mangroves, and the skill that we'll practice at the end of today's video will involve describing a solution to an environmental problem. So wetlands are going to be areas where the soil is submerged in water for all or part of the year. And another important thing to consider is that they have what are called emergent plants or emergent vegetation. And that's where we can see here in the diagram that the plants are going to have their roots anchored in the soil, but part of the plant extends up and out of the water. These plants are also going to be adapted to living in these conditions. So most plants cannot survive with their roots totally submerged in water. They wouldn't be able to get the oxygen they need. Remember back to our agricultural unit that crops can actually get their roots drowned. They can have The oxygen they need basically pushed out of the soil by having too much water in it. But emergent vegetation and the plants that live in these ecosystems, these wetland habitats, are going to be adapted for that. And so why are wetlands so important? Why is it important to understand the impacts we have on them and to protect them? Well, they have a lot of ecosystem services. And so like we mentioned at the beginning, with the estuary habitats, even freshwater wetlands are going to offer a huge host of ecosystem services. So we have provisioning ecosystem services that would be creating habitats for animals and plants that we utilize as food or as raw materials for things. They're also going to provide a regulating ecosystem service. So that's going to be groundwater recharge. They slowly allow groundwater to seep into the soil. We can use that water later for agriculture or for drinking. And it's going to be cleaner. It's going to be filtered by the roots of these plants. They're basically going to trap pollutants. In many cases, they can actually metabolize the pollutants or just... hang on to them so they can't go into the groundwater. And they're also going to sequester carbon dioxide. So they'll store CO2. So the woody plants especially will take that CO2 in and turn it into bark or into other structures. And that prevents it from being in the atmosphere. So it helps mitigate climate change. We also have supporting ecosystem services. So this would be the water filtration I mentioned earlier, where the roots can really trap pollutants and prevent them from recharging or entering the groundwater that's being recharged by runoff. We also have pollinator habitats. And so many of the flowers or the other organisms in a wetland are habitats for pollinators like bees or dragonflies or butterflies that are going to go and pollinate our agricultural crops. That's a huge benefit to farmers and to that sector of the economy. It's also going to help with nutrient recycling. So it's going to take dead organic matter, break it down, return those nutrients to the soil. We can see here that there's peat building up on the bottom. Remember that peat can be utilized as a fuel source. in developing nations. And it's also just going to be really rich organic matter. And then we even have pest control. So a lot of organisms that eat pests, think of spiders or frogs, they are going to thrive in these wetland habitats. And so they can help prevent the spread of disease and prevent damage to crops due to their pest control services that they provide. And then finally, we have cultural ecosystem services. So remember, that would be things like tourism dollars that are flowing into an area because people want to come visit. want to pay for fishing licenses or boating fees, but also just the educational research that's done that could produce new medications or it could just produce, you know, degrees for students that are seeking them and help them earn more wages in the future due to the knowledge they gain from the research. Now we'll take a look at some threats to wetlands as a result of human activities. And so we have already covered in depth the nutrient pollution threat. But remember that there are other pollutants such as sediment, motor oil that drips down from our cars onto pavement and then washes off into our storm drains into our bodies of water, pesticides from agricultural fields. And then we can also have endocrine disruptors. So remember, these are medical compounds that pass through the human body or are improperly flushed down the toilet. Then we have development. So development can be a really big threat to wetlands. Wetlands can actually be filled in or drained. just in order to create stable land that we can develop into homes, parking lots, stores, or agricultural land. And so that can just completely remove them, you know, and that costs animals habitats. It removes all of those ecosystem services that we just talked about. So that's a really big threat. Another threat that doesn't remove them entirely right away, but can lead to their decline is water diversion. So humans divert water from streams and rivers for a variety of reasons. And what that does is basically decreases the water level and eventually the wetland habitats downstream. So we have a great example here in the Everglades. If you look at the diagram on the left, you can see the historical range of the wetlands that surround the Everglades ecosystem. You can see how far that water floods when the river is in its highest velocity or its highest flow. So that's going to be a habitat for tons and tons of organisms. It's going to provide a lot of ecosystem services. But you can see on the right side, all of those little red lines are channels where water is being diverted for all of these different purposes. It could be diverted for agriculture. So farmers could be using it. It could be diverted for drinking water. So as Florida's population grows, they may be using that water to just supply municipalities. They can also be using it for flood control. So they may install dams. to prevent downstream flooding from occurring as urbanization extends, as more homes are built for more people. And so just a huge variety of purposes that are reasons that people may divert water from upstream and again that decreases the amount of water downstream and eventually leads to these watersheds you know becoming lowered or eventually drying up completely. Also we could have hydroelectric power so that would be one other instance where a dam could be used. to block the river, and that's going to really dramatically decrease not only the flow of water downstream, but also the flow of nutrients. So remember that sediment and the nutrients that are vital for the plants living in those wetlands would be caught behind the dam, they would build up, and so that would drastically alter the soil fertility of those wetland habitats downstream. Another impact we want to think about is overfishing. If we overfish wetlands, we disrupt the food system there, or the food web, I should say. So we may disrupt predator prey imbalances when we're overfishing. And so that can really disrupt the stability of that ecosystem. And finally, we'll wrap up today by taking a look at the benefits of and the threats to mangrove ecosystems. So I just have to say, sometimes when I'm making these videos and looking for diagrams, I just find something that's almost too good to believe. And so I want to say thank you to the WWF, the World Wildlife Foundation, and the International Union for the Conservation of Nature. It's like someone did my job for me here. This diagram is just perfect. And so I want to start off with the mangrove ecosystem services. So it's estimated that mangrove ecosystem services provide about $800 billion worth of value. So that's an incredibly valuable habitat to protect. And so where do those services come from? Well, developing nations that could be a source of fuel, they could use it for wood, as long as it's sustainably harvested and still left there for future generations. But coastal protection is another huge advantage. So mangroves are really effective at buffering stormwater, at protecting the human habitats behind them. And they're estimated to be five times more effective than building a break wall or a seawall or something like that. And so these natural coastal buffers are just super, super effective. They're going to be really good at water filtration as well. They're going to trap pollutants in their roots and recharge the soil with cleaner groundwater. They're a huge tourist attraction. So people are going to come visit them. They're going to be home to many different fish and shellfish species. Try that one five times fast. So super valuable to the people that fish them and to the habitats that they stabilize. And then climate regulation. They're also very, very effective at sequestering carbon dioxide. And so when we take in all of these factors, they have tremendous, tremendous value. And so what are the threats to them? why are mangroves at risk here? So a lot of reasons, but one would be logging and deforestation. So we clear them oftentimes for development. Now, developing nations may be used as a subsistence fuel, but in developed nations, it's primarily because beachfront property is so valuable. And so we just cut them down to put up condos or resorts. So that's the coastal development point you can see here. It's just really, really valuable real estate for people. And so... We put buildings there and kind of ignore the ecosystem services that they provide. Aquaculture is another reason. And so that would actually be fishing of, or the farming, I should say, of fish or shellfish. Oftentimes it's shrimp. There's a huge demand for that. And so we cut down the mangroves and basically put these nets in the water where we grow all sorts of aquatic species. It could be done for agriculture, so rice paddies. Remember, rice is a crop that grows really well in flooded soils, and so it's prime area to put up a rice paddy as well. And finally, we have pollution. So remember that all of the pollutants in a watershed that drain into a central body of water are going to end up emptying into the ocean at some point, and that's where they could come to rest in these mangrove ecosystems. If they're sediments, they may kind of clog the root systems of these mangroves, but then... prevent them from getting the oxygen they need. They could actually be solutions that are toxic to the mangroves, actually killing their roots. So if there's heavy metal pollution, that's going to be really problematic. So all of these threats to mangroves are reasons that we should consider protecting them and trying to keep this really, really valuable habitat intact. Now we'll take a look at some solutions to these pollutants entering bodies of water. And so if we take a look at C and at A in this diagram, these are two methods that could be used to reduce nutrient inputs from agriculture. So cover crops are a great strategy that you hopefully remember from our sustainable farming unit or our sustainable farming topic back in unit five. But a cover crop is going to be basically using some plant in between the main crops that you're harvesting just to kind of hold the soil in place, anchor it and keep those sediments and the fertilizer in your field from running off into bodies of water. So you can see if you're continually planting a cover crop each season, it's just going to do. phenomenal job of preventing runoff from entering these bodies of water. It traps the runoff, it lets it infiltrate back into the soil, it uses up some of those excess nitrates, and so a really effective solution. You can also try to adopt better animal manure management practices. So this could involve a manure lagoon that's lined better, that has higher banks or berms to kind of contain that manure. It could be a system that even drains it more frequently and turns it into fertilizer pellets. And then if we look at B, another really good generalized strategy is riparian buffers. Riparian habitats or riparian areas refer to the areas alongside a body of water, such as a river. And so when you plant vegetation in riparian habitats, what you're doing is adding in basically a giant sponge or a giant filter so that the runoff entering that body of water has gone through all of this vegetation first. The roots are going to absorb a lot of the water. depending on what kind of plants you use, the roots may be really effective at even trapping pollutants in their root structures and then metabolizing them or just preventing them from making it into that body of water. And so riparian buffers are a really valuable strategy for kind of reducing these pollutants entering bodies of water. If we look at letter D and at letter F, these are both going to target human sewage. And so we can have septic tank upgrades. A septic tank is where you just have a tank in your backyard that collects your waste. and depending on how we optimize the drain field to more slowly you know drain the sewage out it can just allow that to be filtered more naturally by the ground and prevent it from overflowing and contaminating nearby surface waters and then we can also have biological waste removal so that's where there are microbes that are going to be eating a lot of the waste and trying to utilize a lot of those nutrients to prevent those from being released into the river and so just a ton of different options for trying to reduce nutrient and sediment inputs into bodies of water. So for practice FRQ 8.4 today, I want you to describe how one specific human activity can lead to an increase in phosphorus levels in an estuary ecosystem. Then I want you to try to describe one step that could be taken to reduce the phosphorus inputs from the activity you described above.

And that's where we can see here in the diagram that the plants are going to have their roots anchored in the soil, but part of the plant extends up and out of the water. These plants are also going to be adapted to living in these conditions. So most plants cannot survive with their roots totally submerged in water. They wouldn't be able to get the oxygen they need. Remember back to our agricultural unit that crops can actually get their roots drowned.

They can have The oxygen they need basically pushed out of the soil by having too much water in it. But emergent vegetation and the plants that live in these ecosystems, these wetland habitats, are going to be adapted for that. And so why are wetlands so important?

Why is it important to understand the impacts we have on them and to protect them? Well, they have a lot of ecosystem services. And so like we mentioned at the beginning, with the estuary habitats, even freshwater wetlands are going to offer a huge host of ecosystem services. So we have provisioning ecosystem services that would be creating habitats for animals and plants that we utilize as food or as raw materials for things.

They're also going to provide a regulating ecosystem service. So that's going to be groundwater recharge. They slowly allow groundwater to seep into the soil. We can use that water later for agriculture or for drinking. And it's going to be cleaner.

It's going to be filtered by the roots of these plants. They're basically going to trap pollutants. In many cases, they can actually metabolize the pollutants or just... hang on to them so they can't go into the groundwater.

And they're also going to sequester carbon dioxide. So they'll store CO2. So the woody plants especially will take that CO2 in and turn it into bark or into other structures. And that prevents it from being in the atmosphere. So it helps mitigate climate change.

We also have supporting ecosystem services. So this would be the water filtration I mentioned earlier, where the roots can really trap pollutants and prevent them from recharging or entering the groundwater that's being recharged by runoff. We also have pollinator habitats. And so many of the flowers or the other organisms in a wetland are habitats for pollinators like bees or dragonflies or butterflies that are going to go and pollinate our agricultural crops.

That's a huge benefit to farmers and to that sector of the economy. It's also going to help with nutrient recycling. So it's going to take dead organic matter, break it down, return those nutrients to the soil.

We can see here that there's peat building up on the bottom. Remember that peat can be utilized as a fuel source. in developing nations. And it's also just going to be really rich organic matter. And then we even have pest control.

So a lot of organisms that eat pests, think of spiders or frogs, they are going to thrive in these wetland habitats. And so they can help prevent the spread of disease and prevent damage to crops due to their pest control services that they provide. And then finally, we have cultural ecosystem services.

So remember, that would be things like tourism dollars that are flowing into an area because people want to come visit. want to pay for fishing licenses or boating fees, but also just the educational research that's done that could produce new medications or it could just produce, you know, degrees for students that are seeking them and help them earn more wages in the future due to the knowledge they gain from the research. Now we'll take a look at some threats to wetlands as a result of human activities. And so we have already covered in depth the nutrient pollution threat.

But remember that there are other pollutants such as sediment, motor oil that drips down from our cars onto pavement and then washes off into our storm drains into our bodies of water, pesticides from agricultural fields. And then we can also have endocrine disruptors. So remember, these are medical compounds that pass through the human body or are improperly flushed down the toilet. Then we have development. So development can be a really big threat to wetlands.

Wetlands can actually be filled in or drained. just in order to create stable land that we can develop into homes, parking lots, stores, or agricultural land. And so that can just completely remove them, you know, and that costs animals habitats.

It removes all of those ecosystem services that we just talked about. So that's a really big threat. Another threat that doesn't remove them entirely right away, but can lead to their decline is water diversion. So humans divert water from streams and rivers for a variety of reasons. And what that does is basically decreases the water level and eventually the wetland habitats downstream.

So we have a great example here in the Everglades. If you look at the diagram on the left, you can see the historical range of the wetlands that surround the Everglades ecosystem. You can see how far that water floods when the river is in its highest velocity or its highest flow. So that's going to be a habitat for tons and tons of organisms.

It's going to provide a lot of ecosystem services. But you can see on the right side, all of those little red lines are channels where water is being diverted for all of these different purposes. It could be diverted for agriculture. So farmers could be using it. It could be diverted for drinking water.

So as Florida's population grows, they may be using that water to just supply municipalities. They can also be using it for flood control. So they may install dams. to prevent downstream flooding from occurring as urbanization extends, as more homes are built for more people. And so just a huge variety of purposes that are reasons that people may divert water from upstream and again that decreases the amount of water downstream and eventually leads to these watersheds you know becoming lowered or eventually drying up completely.

Also we could have hydroelectric power so that would be one other instance where a dam could be used. to block the river, and that's going to really dramatically decrease not only the flow of water downstream, but also the flow of nutrients. So remember that sediment and the nutrients that are vital for the plants living in those wetlands would be caught behind the dam, they would build up, and so that would drastically alter the soil fertility of those wetland habitats downstream.

Another impact we want to think about is overfishing. If we overfish wetlands, we disrupt the food system there, or the food web, I should say. So we may disrupt predator prey imbalances when we're overfishing. And so that can really disrupt the stability of that ecosystem.

And finally, we'll wrap up today by taking a look at the benefits of and the threats to mangrove ecosystems. So I just have to say, sometimes when I'm making these videos and looking for diagrams, I just find something that's almost too good to believe. And so I want to say thank you to the WWF, the World Wildlife Foundation, and the International Union for the Conservation of Nature.

It's like someone did my job for me here. This diagram is just perfect. And so I want to start off with the mangrove ecosystem services.

So it's estimated that mangrove ecosystem services provide about $800 billion worth of value. So that's an incredibly valuable habitat to protect. And so where do those services come from?

Well, developing nations that could be a source of fuel, they could use it for wood, as long as it's sustainably harvested and still left there for future generations. But coastal protection is another huge advantage. So mangroves are really effective at buffering stormwater, at protecting the human habitats behind them. And they're estimated to be five times more effective than building a break wall or a seawall or something like that.

And so these natural coastal buffers are just super, super effective. They're going to be really good at water filtration as well. They're going to trap pollutants in their roots and recharge the soil with cleaner groundwater.

They're a huge tourist attraction. So people are going to come visit them. They're going to be home to many different fish and shellfish species. Try that one five times fast. So super valuable to the people that fish them and to the habitats that they stabilize.

And then climate regulation. They're also very, very effective at sequestering carbon dioxide. And so when we take in all of these factors, they have tremendous, tremendous value. And so what are the threats to them? why are mangroves at risk here?

So a lot of reasons, but one would be logging and deforestation. So we clear them oftentimes for development. Now, developing nations may be used as a subsistence fuel, but in developed nations, it's primarily because beachfront property is so valuable.

And so we just cut them down to put up condos or resorts. So that's the coastal development point you can see here. It's just really, really valuable real estate for people. And so...

We put buildings there and kind of ignore the ecosystem services that they provide. Aquaculture is another reason. And so that would actually be fishing of, or the farming, I should say, of fish or shellfish.

Oftentimes it's shrimp. There's a huge demand for that. And so we cut down the mangroves and basically put these nets in the water where we grow all sorts of aquatic species.

It could be done for agriculture, so rice paddies. Remember, rice is a crop that grows really well in flooded soils, and so it's prime area to put up a rice paddy as well. And finally, we have pollution.

So remember that all of the pollutants in a watershed that drain into a central body of water are going to end up emptying into the ocean at some point, and that's where they could come to rest in these mangrove ecosystems. If they're sediments, they may kind of clog the root systems of these mangroves, but then... prevent them from getting the oxygen they need.

They could actually be solutions that are toxic to the mangroves, actually killing their roots. So if there's heavy metal pollution, that's going to be really problematic. So all of these threats to mangroves are reasons that we should consider protecting them and trying to keep this really, really valuable habitat intact. Now we'll take a look at some solutions to these pollutants entering bodies of water. And so if we take a look at C and at A in this diagram, these are two methods that could be used to reduce nutrient inputs from agriculture.

So cover crops are a great strategy that you hopefully remember from our sustainable farming unit or our sustainable farming topic back in unit five. But a cover crop is going to be basically using some plant in between the main crops that you're harvesting just to kind of hold the soil in place, anchor it and keep those sediments and the fertilizer in your field from running off into bodies of water. So you can see if you're continually planting a cover crop each season, it's just going to do. phenomenal job of preventing runoff from entering these bodies of water.

It traps the runoff, it lets it infiltrate back into the soil, it uses up some of those excess nitrates, and so a really effective solution. You can also try to adopt better animal manure management practices. So this could involve a manure lagoon that's lined better, that has higher banks or berms to kind of contain that manure. It could be a system that even drains it more frequently and turns it into fertilizer pellets. And then if we look at B, another really good generalized strategy is riparian buffers.

Riparian habitats or riparian areas refer to the areas alongside a body of water, such as a river. And so when you plant vegetation in riparian habitats, what you're doing is adding in basically a giant sponge or a giant filter so that the runoff entering that body of water has gone through all of this vegetation first. The roots are going to absorb a lot of the water.

depending on what kind of plants you use, the roots may be really effective at even trapping pollutants in their root structures and then metabolizing them or just preventing them from making it into that body of water. And so riparian buffers are a really valuable strategy for kind of reducing these pollutants entering bodies of water. If we look at letter D and at letter F, these are both going to target human sewage.

And so we can have septic tank upgrades. A septic tank is where you just have a tank in your backyard that collects your waste. and depending on how we optimize the drain field to more slowly you know drain the sewage out it can just allow that to be filtered more naturally by the ground and prevent it from overflowing and contaminating nearby surface waters and then we can also have biological waste removal so that's where there are microbes that are going to be eating a lot of the waste and trying to utilize a lot of those nutrients to prevent those from being released into the river and so just a ton of different options for trying to reduce nutrient and sediment inputs into bodies of water.

So for practice FRQ 8.4 today, I want you to describe how one specific human activity can lead to an increase in phosphorus levels in an estuary ecosystem. Then I want you to try to describe one step that could be taken to reduce the phosphorus inputs from the activity you described above.

Transcript for:Impact of Human Activities on Wetlands

Transcript for:
Impact of Human Activities on Wetlands