The Great Lakes in Trouble
For many years, people didn’t worry about the Great Lakes ecosystem. The Great Lakes and its rivers were so large that most people didn’t think human activity could affect them much. By the late 1960s, though, it was clear that there were problems. News articles similar to the one below made people aware that the Great Lakes were heavily polluted.
As you read the article below, list and describe THREE of the issues plaguing the Great Lakes and describe what is causing each problem. Hint: Use the headings to help you.
The Sad State of Our Once-Great Lakes July 28, 1969
The Cuyahoga River in Cleveland, Ohio, looks like a melted chocolate mess. It is mud-brown, with a layer of oil on top. Gases bubble strangely on its surface. So it was not surprising when the filthy river, part of the Lake Erie watershed, burst into flames last month.
A Burning River and Dead Ducks
No one knows exactly what started the Cuyahoga River fire on June 22. It might have been a spark from a passing train. Whatever the source, the spark ignited picnic benches, piles of logs, and other garbage in the river. The burning debris set fire to oil floating on the river’s surface. The flames blazed across the river and up in the air. They reached about five stories in height.
While the Cuyahoga River burned in Cleveland, another event was taking place on the Detroit River. A Detroit official was showing news reporters around the waterfront. As he assured them that the water was not as polluted as it looked, two ducks flew in for a landing. They paddled around the polluted river for a brief moment. Suddenly, they began choking, keeled over, and died.
These events show the terrible condition of the rivers that flow into the Great Lakes. But what of the Great Lakes themselves? Local residents have described the lakes as “cesspools” and “industrial wastebaskets.” They claim that the lakes are used as dumping grounds for every kind of pollutant, from sewage to toxic chemicals.
Out-of-Control Algae
Television ads boast about the long-lasting suds of laundry detergents. Those suds may not cost a lot at the supermarket. But detergents are taking a toll on the Great Lakes.
Visitors to Lake Erie today see large mats of algae near the shore. This algae explosion is caused by phosphorus, a chemical in detergents. Algae need phosphorus to grow, but too much of it causes algae to grow out of control. Lake Erie is covered with algae mats that are up to two feet thick.
Algae mats create many problems. They choke fish. They clog filters in water treatment plants. They cover beaches in slime. And they make lake water taste like rotting vegetation.
DDT Kills More Than Mosquitoes
For years, the pesticide DDT has been used in the Great Lakes region to control insects. It is sprayed on crops and on waterways to kill mosquitoes and other pests. But when DDT enters rivers and streams, it also enters the Great Lakes food web.
Today, America’s national bird, the bald eagle, has almost disappeared from the Great Lakes because of DDT poisoning. The eagles feed on fish that live in water polluted with the pesticide. Over time, a toxic amount of DDT builds up in their bodies.
The DDT doesn’t kill the adult birds. Instead, it weakens the eagles’ eggshells. The shells of eggs laid by female eagles are so thin that most break before the young are ready to hatch. The few eaglets that do hatch may already have DDT in their blood.
Invading Lampreys and Alewives
Bald eagles are not the only disappearing species. For the past century, people have fished the lakes for fun and profit. Fishing boats once harvested millions of pounds of fish every year. Now, due partly to overfishing, whole populations of fish have almost disappeared.
While some fish are disappearing, species that are not native to this area are overrunning the lakes. The invasion of nonnative species began in 1829 when the Welland Canal connected the Great Lakes to the Atlantic Ocean. The canal allowed species from the Atlantic Ocean to swim or be carried by boats to the Great Lakes.
One deadly invader is an eel-like animal known as the sea lamprey. Lampreys act like vampires. They suck the blood out of fish. Over time, sea lampreys have killed most of the whitefish, lake trout, and other fish native to the Great Lakes.
Another invader is the alewife, a type of herring. Alewives are small but have huge appetites. They have devoured entire species of fish. They also compete with other fish for food. The first alewife wasn’t discovered in Lake Michigan until 1949. Yet by the mid-1960s, alewives made up 9 pounds of every 10 pounds of fish swimming in the lake.
Alewives die off in the spring. Every year, tons of dead alewives wash up on lake beaches. Clouds of flies lay eggs on the rotting fish. Soon, the smelly fish are riddled with maggots. As a result, most beaches are unbearable during the die-off season.
Can the Lakes Be Saved?
Scientists today have begun to talk about the death of the Great Lakes. They warn that unless the lakes are cleaned up soon, they may become lifeless ponds. The question is, will people do what is needed to save them?
A week ago, two American astronauts became the first humans to walk on the moon. If the United States can accomplish such an incredible feat, then surely Americans can meet the challenge of restoring the Great Lakes.
As you read the article below, list and describe THREE of the issues plaguing the Great Lakes and describe what is causing each problem. Hint: Use the headings to help you.
The Sad State of Our Once-Great Lakes July 28, 1969
The Cuyahoga River in Cleveland, Ohio, looks like a melted chocolate mess. It is mud-brown, with a layer of oil on top. Gases bubble strangely on its surface. So it was not surprising when the filthy river, part of the Lake Erie watershed, burst into flames last month.
A Burning River and Dead Ducks
No one knows exactly what started the Cuyahoga River fire on June 22. It might have been a spark from a passing train. Whatever the source, the spark ignited picnic benches, piles of logs, and other garbage in the river. The burning debris set fire to oil floating on the river’s surface. The flames blazed across the river and up in the air. They reached about five stories in height.
While the Cuyahoga River burned in Cleveland, another event was taking place on the Detroit River. A Detroit official was showing news reporters around the waterfront. As he assured them that the water was not as polluted as it looked, two ducks flew in for a landing. They paddled around the polluted river for a brief moment. Suddenly, they began choking, keeled over, and died.
These events show the terrible condition of the rivers that flow into the Great Lakes. But what of the Great Lakes themselves? Local residents have described the lakes as “cesspools” and “industrial wastebaskets.” They claim that the lakes are used as dumping grounds for every kind of pollutant, from sewage to toxic chemicals.
Out-of-Control Algae
Television ads boast about the long-lasting suds of laundry detergents. Those suds may not cost a lot at the supermarket. But detergents are taking a toll on the Great Lakes.
Visitors to Lake Erie today see large mats of algae near the shore. This algae explosion is caused by phosphorus, a chemical in detergents. Algae need phosphorus to grow, but too much of it causes algae to grow out of control. Lake Erie is covered with algae mats that are up to two feet thick.
Algae mats create many problems. They choke fish. They clog filters in water treatment plants. They cover beaches in slime. And they make lake water taste like rotting vegetation.
DDT Kills More Than Mosquitoes
For years, the pesticide DDT has been used in the Great Lakes region to control insects. It is sprayed on crops and on waterways to kill mosquitoes and other pests. But when DDT enters rivers and streams, it also enters the Great Lakes food web.
Today, America’s national bird, the bald eagle, has almost disappeared from the Great Lakes because of DDT poisoning. The eagles feed on fish that live in water polluted with the pesticide. Over time, a toxic amount of DDT builds up in their bodies.
The DDT doesn’t kill the adult birds. Instead, it weakens the eagles’ eggshells. The shells of eggs laid by female eagles are so thin that most break before the young are ready to hatch. The few eaglets that do hatch may already have DDT in their blood.
Invading Lampreys and Alewives
Bald eagles are not the only disappearing species. For the past century, people have fished the lakes for fun and profit. Fishing boats once harvested millions of pounds of fish every year. Now, due partly to overfishing, whole populations of fish have almost disappeared.
While some fish are disappearing, species that are not native to this area are overrunning the lakes. The invasion of nonnative species began in 1829 when the Welland Canal connected the Great Lakes to the Atlantic Ocean. The canal allowed species from the Atlantic Ocean to swim or be carried by boats to the Great Lakes.
One deadly invader is an eel-like animal known as the sea lamprey. Lampreys act like vampires. They suck the blood out of fish. Over time, sea lampreys have killed most of the whitefish, lake trout, and other fish native to the Great Lakes.
Another invader is the alewife, a type of herring. Alewives are small but have huge appetites. They have devoured entire species of fish. They also compete with other fish for food. The first alewife wasn’t discovered in Lake Michigan until 1949. Yet by the mid-1960s, alewives made up 9 pounds of every 10 pounds of fish swimming in the lake.
Alewives die off in the spring. Every year, tons of dead alewives wash up on lake beaches. Clouds of flies lay eggs on the rotting fish. Soon, the smelly fish are riddled with maggots. As a result, most beaches are unbearable during the die-off season.
Can the Lakes Be Saved?
Scientists today have begun to talk about the death of the Great Lakes. They warn that unless the lakes are cleaned up soon, they may become lifeless ponds. The question is, will people do what is needed to save them?
A week ago, two American astronauts became the first humans to walk on the moon. If the United States can accomplish such an incredible feat, then surely Americans can meet the challenge of restoring the Great Lakes.