# Feedback on a Kelp Forest Presentation: answers and explanations

Testmigo Practice Test 2, Listening Part 3

Source: Written by Testmigo.

## Answer key

| Q | Answer | Proof |
| --- | --- | --- |
| 21 | C | What set yours apart was the order of ideas |
| 22 | B | you described the holdfast as the kelp's roots ... A holdfast only grips the rock |
| 23 | A | make it clear that's the most it can manage when conditions are perfect |
| 24 | C | the audience assumed missing otters explained the losses there too |
| 25 | B | The red abalone fishery closed in 2018 ... Hannah's point fits into one sentence, so go with that |
| 26 | A | thirty seconds would do the same job |
| 27 | E | terms like trophic cascade and gonad index |
| 28 | B | nothing showed where that figure came from |
| 29 | C | it was the best thing in the whole talk |
| 30 | D | Put it before the case study |

## Why these answers are right

**21. C.** Siobhan says what set the talk apart was the order of ideas, moving from what kelp is to how the forest works to what has gone wrong. That ordering is the logical sequence of the content in option C.

**22. B.** The slide called the holdfast the kelp's roots. Siobhan explains that roots take in water and nutrients, while a holdfast only grips the rock, so the description of the holdfast was inaccurate, which is option B.

**23. A.** Hannah settles on the forty-five centimetre figure and says they will make clear it is the most kelp can manage when conditions are perfect. Siobhan agrees. The most it can manage when conditions are perfect is an upper limit under the best circumstances, option A.

The why and the trap for questions 24 onwards are free with an account on the [answers page](https://testmigo.com/ielts/listening/feedback-on-a-kelp-forest-presentation/answers).

## Transcript

**Announcer:** Part 3. You will hear a marine biology tutor called Siobhan giving two students, Jake and Hannah, feedback on their presentation about kelp forests.

**Announcer:** First, you have some time to look at questions 21 to 25.

**Announcer:** Now listen carefully and answer questions 21 to 25.

**Siobhan:** Come in, both of you. So, overall, Thursday's talk was a really solid piece of work.

**Jake:** Thanks. I guess the photos went down well? They took ages to find.

**Siobhan:** They were lovely, Jake, but to be honest, most groups had good pictures.

**Siobhan:** What set yours apart was the order of ideas. You moved from what kelp is, to how the forest works, to what's gone wrong.

**Hannah:** That's good to hear. I felt I was speaking way too fast.

**Siobhan:** A little, but that's not a big worry. Let's start with the science.

**Siobhan:** You were careful to call kelp a brown alga rather than a plant, which is good.

**Siobhan:** But on your second slide, you described the holdfast as the kelp's roots.

**Jake:** Well, it does look like a tangle of roots.

**Siobhan:** It does, but roots take in water and nutrients. A holdfast only grips the rock; the blades absorb what kelp needs from the seawater.

**Hannah:** Should we have said more about the floats as well?

**Siobhan:** No, your part on the gas-filled bladders lifting the blades towards the light was perfectly clear.

**Siobhan:** Now, you said giant kelp grows a metre a day. Where's that from?

**Jake:** An online textbook. It said kelp grows anything from two centimetres to a metre a day.

**Siobhan:** Right, so a metre is the top of a range covering every species. NOAA, the American ocean agency, says kelp grows up to eighteen inches a day, about forty-five centimetres, and only in ideal conditions.

**Jake:** Maybe we should just drop the number and say it grows incredibly fast.

**Siobhan:** I'd keep a number. Audiences remember numbers.

**Hannah:** We could give the whole range, then, from two centimetres up to a metre?

**Siobhan:** That would only confuse people, since most of that range is other species.

**Hannah:** OK, so we use the forty-five centimetres, and make it clear that's the most it can manage when conditions are perfect.

**Siobhan:** Exactly. Say up to, and say ideal conditions.

**Siobhan:** Next, the otters. Your food chain was right, otters eat urchins and urchins graze kelp, and calling otters a keystone species was spot on.

**Siobhan:** But you went straight from there to the northern California case study, so the audience assumed missing otters explained the losses there too.

**Hannah:** And they didn't?

**Siobhan:** Otters were hunted off that coast in the fur trade, long before any of this. Today they live in central California, not the north.

**Jake:** So the urchin predator that actually disappeared up there was the sunflower sea star.

**Siobhan:** Right. Sea star wasting disease struck in 2013, then came the marine heatwave, at its worst from 2014 to 2016, and purple urchins took over.

**Jake:** I'd love to add a graph of urchin numbers. They rose sixty-fold in 2015.

**Siobhan:** Striking, but you already mention it. What's missing is why non-biologists should care.

**Hannah:** What about the abalone? The red abalone fishery closed in 2018 because so many had starved.

**Jake:** Or a map of the more than three hundred and fifty kilometres of coast where the kelp canopy collapsed?

**Siobhan:** No time for another slide, Jake. Hannah's point fits into one sentence, so go with that.

**Announcer:** Before you hear the rest of the conversation, you have some time to look at questions 26 to 30.

**Announcer:** Now listen and answer questions 26 to 30.

**Siobhan:** Right, let's go through the parts one by one, starting with the opening video.

**Hannah:** I was thinking we'd cut it. It felt self-indulgent.

**Siobhan:** No, it drew everyone in. But it ran nearly two minutes, and thirty seconds would do the same job.

**Jake:** Fair enough. And the urchin barrens section? Did that drag on as well?

**Siobhan:** The length was fine. The trouble was terms like trophic cascade and gonad index, which half the audience didn't know.

**Siobhan:** Just saying the starving urchins are almost empty inside makes the point in plain words.

**Hannah:** OK. Then there's the restoration section, with the commercial divers clearing urchins at Noyo Bay.

**Siobhan:** Good example. But you said bull kelp reached twenty per cent of its historical density after fifteen months, and nothing showed where that figure came from.

**Jake:** It's from a Reef Check report. I'll add the reference.

**Jake:** To be honest, I thought you'd call the urchin ranching part a gimmick.

**Siobhan:** Quite the opposite, it was the best thing in the whole talk. Fattening starving urchins in tanks for eight to ten weeks so their roe can be sold really woke the room up.

**Hannah:** And the sunflower sea star slide? At the moment it's right near the end.

**Siobhan:** That needs moving. Put it before the case study, so people know about the missing predator before they see the barrens.

**Hannah:** Great. Thanks, Siobhan.

**Announcer:** That is the end of Part 3. You now have 30 seconds to check your answers.

[Practice Feedback on a Kelp Forest Presentation](https://testmigo.com/ielts/listening/feedback-on-a-kelp-forest-presentation)