Waterbug Census on Scope TV

25 September 2017
Duration
3:13
Audio described version
Transcript

Speakers

Narrator – N1 (Priya Crawford-Wilson)
Speaker 1 – S1 (Priya Crawford-Wilson)

[music][Footage: rivers and running water]

N1: It might look like a tranquil river, but lurking beneath the surface is some of the animal kingdom’s most intriguing creatures.

[music][on-screen text: Priya Crawford-Wilson, Waterwatch Coordinator, Melbourne Water][Footage: Priya talking directly to camera with net and bucket in hand beside a creek]

S1: Hi, I’m Priya from Melbourne Water and today I’m going to introduce you to some of the really cool creatures that live in our waterways.

[music][Footage: close up, waterbugs swimming around under water in a river]

N1:  Waterbugs, or macroinvertebrates, are insects, crustaceans, molluscs and other small animals such as worms and spiders that live in the water. Many of these are juveniles or baby forms of the animals. Insects like dragonflies, caddisflies, and fly larvae begin their live in the water, before undergoing metamorphisis, growing wings and leaving the water to live on land.

[music][Footage: Priya collecting waterbug sample in the creek with a net]

S1: Waterbugs are great biological indicators, this means that they can tell us about aquatic health and that’s why it’s part of my job to monitor waterbugs around Melbourne’s waterways.

[music] [Footage: Priya collecting waterbug sample in the creek with a net. Waterbugs under water in a river.]

N1: Different waterbugs have different tolerance to pollution, indicating the health of the ecosystem. For instance, creatures like the stonefly nymph are very sensitive to pollution and are only likely to be found in streams with a healthy ecosystem. Whereas macroinvertebrates that are tolerant to pollution, like fly larvae and crabs, can be found in streams that are degraded.

[music] [Footage: Priya collecting waterbug sample in the creek with a net and emptying net into bucket.]

S1: Collecting waterbugs is really simple. All you need is a net, then we kick and sweep through the water to collect our bugs. Then we just tip our bugs into the bucket and go and see what we’ve got.

[music][Footage: Pouring bugs into trays and bugs up close in trays.]

N1:  So once we’ve collected a good sample, we can start to sort through it to see what we’ve got.

[music][Footage: Priya looking at waterbugs in trays beside the creek, using a spoon to look closely]

S1: We’ve got heaps of different bugs here today. We’ve got caddisflies, beetle larvae, damselflies, snails, crabs and so many more.

[music][Footage: close up look at waterbugs in trays]

N1:  Many waterbugs have very interesting features. Some are interesting because of the way that they breathe.

[music] [Footage: Priya looking at waterbugs in trays beside the creek, using a spoon to look closely. Close up footage of water boatman in spoon.]

S1:  For instance, these little guys are called waterboatmen and they breathe by collecting a bubble of air, which they hold on their chest and use like a scuba tank.

[music][Footage: stoneflies moving under water over rocks and dragonflies hunting under water amongst reeds.]

N1:  Or these stoneflies which have fluffy gills at the end of their body that they wag to get more oxygen. Or dragonflies, which suck water into their bottom and breathe the oxygen through internal gills, then they squirt the water out and use it like a jetpack to travel through the water.

[music][Footage: Priya looking at waterbugs in trays beside the creek, using a spoon to look closely. Close up footage of caddisfly in spoon.]

S1:  Other waterbugs are interesting because of the way that they hunt. For instance, these caddisflies spin a small net between two rocks and wait for their prey to be trapped in it.

[music][Footage: Close up, damselfly in a spoon]

N1:  And damselflies have adapted bottom jaws that they use to grab their prey. It’s almost like an extra arm under their chin.

[music][Footage: Priya sitting with tray of bugs, data sheet and identification book, going through the identification process with a crab. Close up of crab in a spoon. Close up of book. Close up of data sheet.]

S1:  So once I’ve sorted my bugs into a small tray here, I look through my book to find what I’ve got. Take this crab for example, I’ll identify it as a crab and then I’ll mark it down on my data sheet.   

[music][Footage: close up look at waterbugs in trays]

N1:  Once we’ve identified all of the different species present in the sample, we can then put it into a database to help us to assess the health of the waterway.

[music][Footage: Priya sitting beside the creek with a bucket of bugs and net]

S1: So while not knowing what’s lurking beneath might give some people the heebie-jeebies, for others like me they play a really important role in determining the health of our waterways.