Logical Reasoning

PT152 · S1 · Q13 When so many oysters died

A free, expert breakdown of this official LSAT Logical Reasoning question.

Save & drill this skill — build targeted practice sets from questions like this one
Video walkthroughs — watch every question solved step by step
81 official LSATs — as questions, timed sections & full-length tests

When so many oysters died off the coast of Britain that some native species were threatened with extinction, the fact that the water temperature had recently risen was at first thought to be the cause.

Background

Native oysters were dying / endangered, and TBT was determined to be the cause, so legislation was enacted, which nearly eliminated TBT from the water.

Surprise

The endangered oyster populations have not recovered.

Evaluation / Goal

Given that TBT was the cause of dying and now there's almost no TBT How can we explain why endangered oyster populations haven't been getting bigger?

We would either need to have a way to explain how a tiny amount of TBT remaining in the water could still suppress the endangered oyster populations, or we need some other causal factor that is suppressing the endangered oyster populations (maybe the legislation that banned TBT had some other ramification that affects oysters indirectly).

13.

Which one of the following, if true, most helps to explain the failure of the native oyster populations to recover?

The increase in water temperature
No Impact
Water temp was thought to be a cause at first, but it was determined that TBT was the cause. So we wouldn't really be able to use a story line about water temperature to explain the low oyster population.
3% picked this
Native oysters rely on different
No Impact
If native oysters and barnacles relied on the same food source, then we could potentially say that an uptick in barnacles could mean that there's not enough food left for oyster populations to grow. But this answer says they rely on different sources of food, so it has no impact.
11% picked this
Correct
TBT also killed imported varieties
Why this is right
Since TBT was previously killing imported oysters, now that there's no TBT, we're not killing these imported oysters. Does having these imported oysters around give us a way to explain why the native populations aren't coming back? Yes, because it says that imported oysters flourish at the expense of native oysters. So in the post-TBT warm waters near Britain, we would expect to see populations of imported oysters thriving and populations of native oysters shrinking / being suppressed. This is an example of the TBT-ban legislation having an indirect effect on the endangered oysters: TBT-ban → way less TBT → more imported oysters -> suppressed native oysters
Skill tested: Paradox · how this choice captures the argument's function is the move to repeat next time.
75% picked this
Other chemicals that are used
Out of Scope: other chemicals Opposite
We're not really concerned with other barnacle-removing chemicals. We only cared about TBT because it was determined to be killing our native oysters. And we're trying to explain why in the aftermath of banning TBT we still don't see the native oysters coming back. We might have thought to ourselves, "Maybe after they banned TBT, ships started using a different chemical to get barnacles off the hulls of boats, and those new chemicals are hurting the endangered native oysters", in which case this answer choice does the opposite of what would be useful to us.
2% picked this
TBT is more deadly to
Irrelevant Distinction
Given that there isn't TBT in the water anymore (basically), it doesn't matter where TBT is more deadly. It's not present, so it's not the current reason why native oyster populations are struggling.
9% picked this

Continue the review in LSAT Lab

Save this question, watch the video walkthrough, and drill similar questions in your LSAT Lab account.

Save and practice this skill

LSAT Lab

Turn this review into a targeted study plan.

Save this question, drill more like it, watch the video walkthrough, and track your progress in your LSAT Lab account.

Start practicing free