Title: Ecosystems in the Brink
By: Carl Zimmer
Notes:
Summary:
Ecosystems are changing a great deal. Why? the reason is due to our human activity. Scientists tried to put bass to change back the ecosystem in Peter's Lake, it worked for a while but then went back to it's normal routine of having only fathead minnows, pumpkinseeds and other small fishes. Scientist states that many of the top predators are disappearing which changes the whole food web of the ecosystem in that certain area. The species/organisms that the top predators (that not longer exist in the environment) was free to flourish and it's difficult to bring the top predators back to their original state.
Reflection:
This article was very interesting to read because I didn't know that it was that hard to bring back the top predators After reading the article, it was interesting to read that eliminating the top predator has a big impact on the food web and this causes the little things like the fathead minnows, pumpkinseeds and smaller fishes to flourish. This happens mostly because of our human actvity like fishing, pollution, and converting the land (taking their habitat away). This damages the ecosystems and a the other species living in it.
- One by one, they dropped 12 largemouth bass into the water. Then they headed for home, leaving behind sensors that could measure water clarity every five minutes, 24 hours a day.
- Carpenter triggered the switch over on purpose, as part of an experiment he is running on the factors that lead to persistent changes in the mix of organisms eating and being eaten by one another.
- Hungry snails and fungi are overrunning coastal marshes in North Carolina, causing them to disintegrate. In the northwestern Atlantic, lobsters are proliferating while cod have crashed.
- To make sense of the snarls, ecologists have turned food webs into mathematical models. They write an equation for the growth of one species by linking its reproduction rate to how much food it can obtain and how often it gets eaten by other species.
- Two species are strongly linked if they interact a lot, such as a predator that consistently devours huge numbers of a single prey. Species that are weakly linked interact occasionally: a predator snacks every now and then on various species
- Food webs may be dominated by numerous weak links because that arrangement is more stable over the long term.
- In the 1960s, for example, theoreticians proposed that predators at the top of a food web exerted a surprising amount of control over the size of populations of other species—including species they did not directly attack.
- Most food webs consist of many weak links rather than a few strong ones. Two species are strongly linked if they interact a lot, such as a predator that consistently devours huge numbers of a single prey.
- After falling to as low as 1 percent of their precrash levels, the cod have risen in recent years to 30 percent.
- If cod can return to their former levels, they will be able to keep the populations of forage fish down once more.
- Ecologists realized that changes in certain predators had massive impacts on food webs.
- The equations that he and his colleagues have developed suggest that some disturbances will be so dramatic and fast that they will not leave time for ecologists to notice that trouble is coming.
Summary:
Ecosystems are changing a great deal. Why? the reason is due to our human activity. Scientists tried to put bass to change back the ecosystem in Peter's Lake, it worked for a while but then went back to it's normal routine of having only fathead minnows, pumpkinseeds and other small fishes. Scientist states that many of the top predators are disappearing which changes the whole food web of the ecosystem in that certain area. The species/organisms that the top predators (that not longer exist in the environment) was free to flourish and it's difficult to bring the top predators back to their original state.
Reflection:
This article was very interesting to read because I didn't know that it was that hard to bring back the top predators After reading the article, it was interesting to read that eliminating the top predator has a big impact on the food web and this causes the little things like the fathead minnows, pumpkinseeds and smaller fishes to flourish. This happens mostly because of our human actvity like fishing, pollution, and converting the land (taking their habitat away). This damages the ecosystems and a the other species living in it.