Parland’s alligator population has been declining in recent years Ver1

IMO D...
Since fishe's eggs used to hatch in the wholes dug by alligators. But since the alligators population has started decreasing, so there is less number of holes dug by alligators, which in turn has an effect on less no of eggs being hatched.

OA....is D

You, guys, provide the right explanation.

Hi, It looks like there is a slight confusion. Answer in the OG 13 is C and here it is D. I realise that an option is replaced with a new one in OG 13. But this question is directly linked to the same number in the OG diectory which led me to this question.
It will be great if someone changes the options to match the OG 13's

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Interesting......! The answer clearly is Option D (as explained by all the wonderful people above..!! )

The answer is D using the answers provided in the original post, however, the wording of the answer choice D provided here does not match the wording of the answer choice in the actual book.

GMAT Club Answers:
A. The decline in the alligator population has meant that fishers can work in some parts of lakes and rivers that were formerly too dangerous.
B. Over the last few years, Parland’s commercial fishing enterprises have increased the number of fishing boats they use.
C. Many Parlanders who hunt alligators do so because of the high market price of alligator skins, not because of the threat alligators pose to the fish population.
D. During Parland’s dry season, holes dug by alligators remain filled with water long enough to provide a safe place for the eggs of this fish species to hatch.
E. In several neighboring countries through which Parland’s rivers also flow, alligators are at risk of extinction as a result of extensive hunting.

OG 13 Answers:
A. The decline in the alligator population has meant that fishers can work in some parts of lakes and rivers that were formerly too dangerous.
B. Over the last few years, Parland’s commercial fishing enterprises have increased the number of fishing boats they use.
C. The main predator of these fish is another species of fish on which alligators also prey.
D. Many Parlanders who hunt alligators do so because of the high market price of alligator skins, not because of the threat alligators pose to the fish population.
E. In several neighboring countries through which Parland’s rivers also flow, alligators are at risk of extinction as a result of extensive hunting.

Notice in OG 13 the answer regarding eggs is not even present. If you're using the GMAT Club question and answers selections then "D" is the answer. If you're using OG 13 question and answers then "C" is the answer.

Parland’s alligator population has been declining in recent years, primarily because of hunting. Alligators prey heavily on a species of freshwater fish that is highly valued as food by Parlanders, who had hoped that the decline in the alligator population would lead to an increase in the numbers of these fish available for human consumption. Yet the population of this fish species has also declined, even though the annual number caught
for human consumption has not increased.

Which of the following, if true, most helps to explain the decline in the population of the fish species?

A. The decline in the alligator population has meant that fishers can work in some parts of lakes and rivers that were formerly too dangerous.....where they can work is not important.....rather why did the fish decline?
B. Over the last few years, Parland’s commercial fishing enterprises have increased the number of fishing boats they use....but annual number caught has not increased....let them increase boats
C. Many Parlanders who hunt alligators do so because of the high market price of alligator skins, not because of the threat alligators pose to the fish population.........thats fine.... but why did the fish decline?
D. During Parland’s dry season, holes dug by alligators remain filled with water long enough to provide a safe place for the eggs of this fish species to hatch.....clearly a winner as it gives cause for reduction in fishes..... CORRECT
E. In several neighboring countries through which Parland’s rivers also flow, alligators are at risk of extinction as a result of extensive hunting....BUT why did the fish decline?

I think only option B can make test takers fool.

B says number of fishing boats increases. Now no of boats increase doesn't mean the catch has increased. There may be other reasons for increasing the fishing boats.

On the other hand D shows how have the habitats of fish been destroyed by the killing of alligator. If fish can't get safe place for their eggs, the no of fish will eventually decrease.

Even though I have selected the corect answer in both OG13 and in the altered version, I don't understand , why did you change the answer choices. Official questions are best structured, and I don't see any reason to alter them.

We need here some connection between decreasing number of alligators and freshwater fishes + the fact that alligators prey heavily on that type of fishes. This is a Resolve the Paradox Question - so we don't have a conclusion here. In this type of questions both sides are factually correct and we need to explain how the situation came into being or add a piece of Information showing how the two parts can coexist (see CR Bible). To resolve the paradox we must adress ALL the facts -> decreasing number of alligators and fish species + the annual number of fishes caught for human consumption has not increased.

A. The decline in the alligator population has meant that fishers can work in some parts of lakes and rivers that were formerly too dangerous. -> in the argument is clearly stated, the number of fishes for human consumption doesn't change
B. Over the last few years, Parland’s commercial fishing enterprises have increased the number of fishing boats they use. -> in the argument is clearly stated, the number of fishes for human consumption doesn't change
C. Many Parlanders who hunt alligators do so because of the high market price of alligator skins, not because of the threat alligators pose to the fish population. -> it's out of scope and btw. doesn't explain the decreasing number of fish species
D. During Parland’s dry season, holes dug by alligators remain filled with water long enough to provide a safe place for the eggs of this fish species to hatch. -> CORRECT. #of Alligators decreases -> #of the holes decreases -> fewer safe places for the eggs to hatch -> fewer fish species.
E. In several neighboring countries through which Parland’s rivers also flow, alligators are at risk of extinction as a result of extensive hunting. -> It doesn't explain the decreasing number of fish species

OG 13 Answers:
A. The decline in the alligator population has meant that fishers can work in some parts of lakes and rivers that were formerly too dangerous -> in the argument is clearly stated, the number of fishes for human consumption doesn't change
B. Over the last few years, Parland’s commercial fishing enterprises have increased the number of fishing boats they use -> in the argument is clearly stated, the number of fishes for human consumption doesn't change
C. The main predator of these fish is another species of fish on which alligators also prey --> CORRECT. #Alligators goes down --> #main Predator fish type goes up --> #freshwater fish species goes down.
D. Many Parlanders who hunt alligators do so because of the high market price of alligator skins, not because of the threat alligators pose to the fish population -> it's out of scope and btw. doesn't explain the decreasing number of fish species
E. In several neighboring countries through which Parland’s rivers also flow, alligators are at risk of extinction as a result of extensive hunting -> It doesn't explain the decreasing number of fish species

no alligators = no holes = no fish. had to read the piece twice and answers twice, but took about 1:45, more than enough time on a toughy such as this. hope this helps!

A. The decline in the alligator population has meant that fishers can work in some parts of lakes and rivers that were formerly too dangerous.- No, this has nothing to do with fish population. It only means they can fish in more areas.

B. Over the last few years, Parland’s commercial fishing enterprises have increased the number of fishing boats they use.- No, this is the opposite of what the paragraph says. Fishing has not increased.

C. Many Parlanders who hunt alligators do so because of the high market price of alligator skins, not because of the threat alligators pose to the fish population.- No, we are not concerned with alligators but fish

D. During Parland’s dry season, holes dug by alligators remain filled with water long enough to provide a safe place for the eggs of this fish species to hatch.Yes!, this clearly explains why the fish are not repopulating despite reduced threat from alligators

E. In several neighboring countries through which Parland’s rivers also flow, alligators are at risk of extinction as a result of extensive hunting.- No, again, we are most concerned with the fish population

wow, there are 2 different patterns of the same topic. I pick D after using POE because I lack of confidence in dealing with any new patter in gmat.

This is really difficult. Took me 5 minutes though
Got it correct

Well, because the holes are not dug anymore by alligators.
No Holes,No place to hatch eggs and therefore,decline in fish population

Alligators were killed to ensure that the freshwater fish can be hunted for food. But it was noticed that with the decline in the population of alligators, the freshwater fish population also declined.

Therefore, there has to be a link between the alligators and freshwater fish apart from the fact the alligators prey on these fishes.

Which of the following, if true, most helps to explain the decline in the population of the fish species?

A. The decline in the alligator population has meant that fishers can work in some parts of lakes and rivers that were formerly too dangerous.
[This does not tell us the reason for the decline in the population of fishes - eliminated]

B. Over the last few years, Parland’s commercial fishing enterprises have increased the number of fishing boats they use.
[Even if the boat are increased, that does not result in the increase of the number of fishes in the lake - eliminated]

C. Many Parlanders who hunt alligators do so because of the high market price of alligator skins, not because of the threat alligators pose to the fish population.
[This gives a reason for hunting alligators, but we are looking for a reason for the decline in the fishes, hence this cannot be the answer.]

D. During Parland’s dry season, holes dug by alligators remain filled with water long enough to provide a safe place for the eggs of this fish species to hatch.
[Now with the alligators gone, the holes are not available, hence there is no safe place for the eggs to hatch which would lead to a decrease in the population of the fishes,
this clearly gives us the reason for the decrease in population of freshwater fishes, hence this has to be the answer.]

E. In several neighboring countries through which Parland’s rivers also flow, alligators are at risk of extinction as a result of extensive hunting.
[Out of Scope: Not interested in knowing if the alligators are on the verge of extinction]

A - decline in alligator population means fishers can work in parts of lakes & rivers that were formerly too dangerous...if fishers can work in more areas of the lake, can it not be inferred that they could catch more freshwater fish? it doesn't have to be for human consumption, this could be "game fish" like swordfish, etc. This could be correct.

B - Commercial fishing enterprises increasing the # of fishing boats they use could be correct b/c commercial fishing not discussed in the passage...passage only refers to the annual # caught for human consumption.

* I don't like (D). Are these "holes" that provide a safe place for eggs to hatch the ONLY safe places for these eggs to hatch? We're told that alligators prey heavily on this species but are not told about anything else in the passage that could decrease the number of these fish.
- No talk about toxic chemicals being poured into the lake to kill the alligators or
- a virus that spread throughout the lake that kills these fish.

This question really angers me - need someone to break apart my argument here and show me how I'm incorrect.

Resolve the paradox; alligators decreased yet fish continued to decrease. Possible explanations, something else is causing the decline of the fish population or alligators benefited the fish in some way.

D follows the second train of thought.

GMATNinjaTwo GMATNinja

Awesome explanation.



Usually you also point out to stress on modifiers/ minute details while reading argument.
But is there any significant role of highlighted portion?

adkikani, glad to see that you're paying attention to the author's word choice and to the details/modifiers!

In this case, the highlighted portion really just gives us some background information to make sense of this answer choice. Water levels will go down during the dry season, reducing the number of safe places for the eggs to hatch. But despite decreased water levels, the alligator holes remain filled.

If we weren't told that there was a dry season, we might not understand why the holes are necessary. Given the highlighted portion, we understand that water levels can decrease seasonally, and this helps explains why the alligator holes are so important.

I hope that helps!