#26 - All oceangoing ships carry seawater ballast tanks

[Administrator]

Complete Question Explanation

Assumption. The correct answer choice is (E).

Answer choice (A):

Answer choice (B):

Answer choice (C):

Answer choice (D):

Answer choice (E): This is the correct answer choice.

This explanation is still in progress. Please post any questions below!

[mokkyukkyu]

Is A wrong because it's just repeating what the stimulus says?

[JSLSAT]

I believe it's because it's not necessary - you're not worrying about blocking sea creatures from getting into the tank, you're worrying about blocking them from damaging the environment when they're being pumped out.

I'm having trouble eliminating C - I'm not sure if any LSAT pros have any better ideas.

Thanks all!

[Emily Haney-Caron]

Mokkyukku: A is wrong because it is not required based on the stimulus. Midocean creatures do not need to be incapable "of disturbing the ecology in a new habitat;" they're just incapable of disturbing the ecology of the coastal habitat.

JSLSAT: C goes much further than you need, giving a bunch of extraneous information. Why "after having been deposited there by oceangoing ships?" That seems totally irrelevant, and therefore can't be an assumption. Additionally, that's not the gap in logic we need to fill; we need to know that this plan could work for the ships even though the water needs to be pumped in and out during cargo loading.

Hope that helps!

[srcline@noctrl.edu]

Hello Emily

Would another reason why A is incorrect, is because it use the words "would ensure" I reasoned that this was too strong of language and that the conclusion says only about a viable way, there could be other ways but we don't know this?

Also so when I negating the conclusion I got " there are NO oceangoing ship whose stability could be adequately maintained while emptying and refiling their ballast tanks in midocean.

This would weaken the conclusion b/c the ships cant handle the emptying of their tanks.

Thankyou
Sarah

[Jonathan Evans]

Sarah,

You're correct about (E). If the ships couldn't maintain their stability following this plan mid-ocean, then it is necessarily not a "viable way." (E) definitely passes the Assumption Negation test for this reason.

You're on the right track with (A). What if some creatures capable of disturbing the ecologies of some new habitat do make it into the ballast tanks mid-ocean? This need not make the plan nonviable. Maybe these deep sea creatures could disturb another deep sea habitat if the ship hypothetically released its ballast tanks next in another deep sea part of the ocean. Notice we've introduced a new assumption, new suppositions. This certainly does not pass the Assumption Negation test. Further, "disturbing" and "ecological havoc" are a degree of magnitude different. So maybe these deep sea creatures occasionally disturb the coastal habitat even though they can't survive. So what? Might not be ecological havoc. The plan could still be far better than the status quo.

Good reasoning.

[jennie]

I can't see why C is wrong. I think C addresses the missing link between "since midocean creatures and costal sea creatures usually cannot survive in one another's habitats" and "where they can wreak ecological havoc" by stating that they cannot wreak havoc unless they can survive.

[Adam Tyson]

Hey there jennie, you are right that the author is assuming that these creatures only wreak havoc if they survive, and that dead creatures don't cause a problem. But answer C goes beyond that simple assumption. Does the author have to assume that in the rare cases when they HAVE wreaked havoc in the past, they not only survived but got there by being "deposited there by oceangoing ships"? Or, could they have gotten there some other way, like hitching a ride on a whale or getting swept out there by a storm? I think he would be okay with those situations, and still claim that the mid-ocean ballast tank maneuver is a "viable way of addressing this problem"? That is, would it work and reduce the ecological havoc?

Another problem with C is that it is about what has happened, or not happened, in the past. The author need not assume anything about what has happened before. Maybe sea creatures have caused a lot of havoc after swapping habitats in other ways, or if they died. Maybe they haven't. The author is only arguing about what WILL happen, not what HAS happened in the past. He might be fine with all kinds of past ecological problems and still believe that this proposal will work.

The negation of answer E, though, completely destroys the argument. If no ships exist that can do the proposed maneuver without flipping over and/or sinking, then his proposal is definitely NOT a ""viable way of addressing this problem"! The plan won't work! While C, negated, might hurt the argument, E completely wrecks it, and that makes it the better answer and in fact the best answer of the bunch.

[jennie]

Thanks for pointing out the issue with the tense!

Hey there jennie, you are right that the author is assuming that these creatures only wreak havoc if they survive, and that dead creatures don't cause a problem. But answer C goes beyond that simple assumption. Does the author have to assume that in the rare cases when they HAVE wreaked havoc in the past, they not only survived but got there by being "deposited there by oceangoing ships"? Or, could they have gotten there some other way, like hitching a ride on a whale or getting swept out there by a storm? I think he would be okay with those situations, and still claim that the mid-ocean ballast tank maneuver is a "viable way of addressing this problem"? That is, would it work and reduce the ecological havoc?

Another problem with C is that it is about what has happened, or not happened, in the past. The author need not assume anything about what has happened before. Maybe sea creatures have caused a lot of havoc after swapping habitats in other ways, or if they died. Maybe they haven't. The author is only arguing about what WILL happen, not what HAS happened in the past. He might be fine with all kinds of past ecological problems and still believe that this proposal will work.

The negation of answer E, though, completely destroys the argument. If no ships exist that can do the proposed maneuver without flipping over and/or sinking, then his proposal is definitely NOT a ""viable way of addressing this problem"! The plan won't work! While C, negated, might hurt the argument, E completely wrecks it, and that makes it the better answer and in fact the best answer of the bunch.

[Leela]

Would A be a good answer if this were a justify question and C be a good answer if this were a strengthen question?