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Naturalist: The decline of coral reefs has various causes. One contrib
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08 Mar 2020, 02:39
08 Mar 2020, 02:39
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Naturalist: The decline of coral reefs has various causes. One contributing factor is predation on coral by organisms such as the crown-of-thorns sea star, whose preferred food source is coral polyps. Human fishing practices have decreased the sea star's predators, such as the harlequin shrimp. It is also possible that runoff containing nutrients for phytoplankton has resulted in larger phytoplankton blooms: the crown-of-thorns sea star gladly eats phytoplankton.
Indicate in the table which cause-and-effect sequence would most likely, according to the naturalist, result in coral reef decline. Make only two selections, one in each column.
Indicate in the table which cause-and-effect sequence would most likely, according to the naturalist, result in coral reef decline. Make only two selections, one in each column.
ID: 100398
| Cause | Effect | Statements |
| An increase in phytoplankton | ||
| A decrease in phytoplankton | ||
| An increase in crown-of-thorns sea stars | ||
| A decrease in crown-of-thorns sea stars | ||
| An increase in harlequin shrimp |
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Official Answer
Cause: An increase in phytoplankton
Effect: An increase in crown-of-thorns sea stars
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Re: Naturalist: The decline of coral reefs has various causes. One contrib
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15 Feb 2024, 00:04
15 Feb 2024, 00:04
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laragarg wrote:
How did you draw the correlation between phytoplankton(phytop) and crown-of-thorns sea stars(COT)? Since COT gladly eats phytop, apart from coral reefs, if phytop increases, coral reefs should also increase as COT would be more likely to eat COT (think you meant phytop) instead of preying upon coral reefs.
I want to focus on the phrase at the start of the last sentence of the passage: "It is also possible that"
It is also possible that runoff containing nutrients for phytoplankton has resulted in larger phytoplankton blooms: the crown-of-thorns sea star gladly eats phytoplankton.
Why has the naturalist used the word 'also;
1. Is it another cause for decline of coral reefs?
No.
The first mentioned contributing factor is predation on coral by organisms such as the CoT sea star.
Then the mention of something that CoT sea star thrive on doesn't seem to be a separate cause.
2. Then what does the phrase "it is also possible" go with?
The previous sentence.
Human fishing practices have decreased the sea star's predators, such as the harlequin shrimp. It is also possible that runoff containing nutrients for phytoplankton has resulted in larger phytoplankton blooms: the crown-of-thorns sea star gladly eats phytoplankton.
In the harlequin shrimp sentence, the naturalist is giving a reason for why CoT sea star population might have increased. When I read the last sentence with this piece in my mind, it becomes more clear that the author is giving another possible reason for the CoT sea star population increase.
And why would the naturalist mention possible reasons for the growth of CoT sea star population?
To support why coral reefs decline could be caused by CoT sea star.
Not a perfect analogy, but I'm thinking:
Say a nice famous cafe opens next to one that wasn't doing well. The whole area would get more footfall. And that could get the older cafe to do better than before, even though there's competition next door now.
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Re: Naturalist: The decline of coral reefs has various causes. One contrib
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04 May 2021, 05:22
04 May 2021, 05:22
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Official Explanation
We are asked to provide a sequence of cause and effect that would (according to the naturalist) result in coral reef decline. The question suggests that the answers will be dependent on one another, in that the correct answer for Cause will depend on the correct answer for Effect, and vice versa.
The passage states that one factor contributing to coral reef decline is predation on coral by organisms such as the crown-of-thorns sea star. The preferred food source for this organism is coral polyps, and so a causal sequence that has as its effect an increase in crown-of-thorns sea stars may be likely to produce a decline in coral reefs. This suggests that the third option may be the correct response for Effect. However, this depends on whether one of the other statements in the table describes a cause suggested by the naturalist to produce this effect.
The last sentence of the naturalist’s statement indeed suggests, in the context of the passage, that an increase in phytoplankton blooms would result in greater numbers of crown-of-thorns sea stars. This suggests that the first option may be the correct response for Effect. And indeed, according to the naturalist, the crown-of-thorns sea star’s preferred food source is coral polyps. All of the naturalist’s statement is about possible explanations of the decline of coral reefs. The passage therefore indicates that the naturalist would take an increase in phytoplankton to produce an increase in crown-of-thorns sea stars, and that this causal sequence would result in coral reef decline.
The correct answer is An increase in phytoplankton.
The correct answer is An increase in crown-of-thorns sea stars.
We are asked to provide a sequence of cause and effect that would (according to the naturalist) result in coral reef decline. The question suggests that the answers will be dependent on one another, in that the correct answer for Cause will depend on the correct answer for Effect, and vice versa.
The passage states that one factor contributing to coral reef decline is predation on coral by organisms such as the crown-of-thorns sea star. The preferred food source for this organism is coral polyps, and so a causal sequence that has as its effect an increase in crown-of-thorns sea stars may be likely to produce a decline in coral reefs. This suggests that the third option may be the correct response for Effect. However, this depends on whether one of the other statements in the table describes a cause suggested by the naturalist to produce this effect.
The last sentence of the naturalist’s statement indeed suggests, in the context of the passage, that an increase in phytoplankton blooms would result in greater numbers of crown-of-thorns sea stars. This suggests that the first option may be the correct response for Effect. And indeed, according to the naturalist, the crown-of-thorns sea star’s preferred food source is coral polyps. All of the naturalist’s statement is about possible explanations of the decline of coral reefs. The passage therefore indicates that the naturalist would take an increase in phytoplankton to produce an increase in crown-of-thorns sea stars, and that this causal sequence would result in coral reef decline.
The correct answer is An increase in phytoplankton.
The correct answer is An increase in crown-of-thorns sea stars.
