1. During the 1990s the numbers of sea otters fell sharply by about 90%.
2. Sea otters lived near the Aleutian Islands off the coast of Alaska.
3. To find an explanation to this huge decrease in the population of the sea otters, scientists discovered that killer whales started eating sea otters.
4. Killer whales usually eat seals and sea lions not much smaller sea otters.
5. Due to over fishing, fish population decreased. And due to the decrease in fish seals and sea lions started to decrease too since they rely on fish.
6. Due to the decrease in seals and sea lions, killer whales started moving from the open ocean into coastal waters and beginning to feed on sea otters.
7. Therefore, sea otters decrease by 90%.
8. The population of sea urchins increases dramatically because there are so few otters to feed on the sea urchins.
9. Kelp forest is then eaten by a large number of sea urchins
10. Due to the decrease in the population of the kelp forest. A lot of species are affected since they used to feed from the kelp forest. These species include ducks, gulls, eagles, fishes, sea stars & mussels.
11. So we could conclude from the otters’ story that the slightest change in the food web can make changes in all the parts of the food web.
12. In a food web, all organisms survive by gaining food energy from the trophic level below it.
13. The population size of each species depends on the food supply and the consumers that use it as a food.
14. In addition, species may compete over food resources with others in its own trophic level.
15. There are four factors that determine carrying capacity. They are Materials and Energy, Food Chain, Competition, and Density.
16. Materials and Energy: all organisms are ultimately limited by the amount of usable energy from the sun, water, carbon….etc.
17. Food Chain: population size is limited by the biomass in all the levels below it. In the words they are limited by their food supply.
18. Competition: all organisms demand for resources (food, water, mates, and space) results in completion among individuals for these resources. Competition among members of the same species is called intraspecific competition. Competition between species is called interspecific competition.
19. Density: depending on their size, environment and way of life, different species have different needs for space. The need for space can determine an organism’s population density. If the population density increases beyond the suitable level, it produces conditions that tend to limit further growth in numbers.
20. Factors that increase in significance as a population grows are called density-dependent factors. Factors that limit the population are called independent factors.
2. Sea otters lived near the Aleutian Islands off the coast of Alaska.
3. To find an explanation to this huge decrease in the population of the sea otters, scientists discovered that killer whales started eating sea otters.
4. Killer whales usually eat seals and sea lions not much smaller sea otters.
5. Due to over fishing, fish population decreased. And due to the decrease in fish seals and sea lions started to decrease too since they rely on fish.
6. Due to the decrease in seals and sea lions, killer whales started moving from the open ocean into coastal waters and beginning to feed on sea otters.
7. Therefore, sea otters decrease by 90%.
8. The population of sea urchins increases dramatically because there are so few otters to feed on the sea urchins.
9. Kelp forest is then eaten by a large number of sea urchins
10. Due to the decrease in the population of the kelp forest. A lot of species are affected since they used to feed from the kelp forest. These species include ducks, gulls, eagles, fishes, sea stars & mussels.
11. So we could conclude from the otters’ story that the slightest change in the food web can make changes in all the parts of the food web.
12. In a food web, all organisms survive by gaining food energy from the trophic level below it.
13. The population size of each species depends on the food supply and the consumers that use it as a food.
14. In addition, species may compete over food resources with others in its own trophic level.
15. There are four factors that determine carrying capacity. They are Materials and Energy, Food Chain, Competition, and Density.
16. Materials and Energy: all organisms are ultimately limited by the amount of usable energy from the sun, water, carbon….etc.
17. Food Chain: population size is limited by the biomass in all the levels below it. In the words they are limited by their food supply.
18. Competition: all organisms demand for resources (food, water, mates, and space) results in completion among individuals for these resources. Competition among members of the same species is called intraspecific competition. Competition between species is called interspecific competition.
19. Density: depending on their size, environment and way of life, different species have different needs for space. The need for space can determine an organism’s population density. If the population density increases beyond the suitable level, it produces conditions that tend to limit further growth in numbers.
20. Factors that increase in significance as a population grows are called density-dependent factors. Factors that limit the population are called independent factors.
My eco-bottle update picture: 
Good! Keep this up!
ReplyDelete