School lesson: Mangrove adaptations - video transcript
This page is a transcript of the School lesson: Mangrove adaptions video on Brisbane City Council's YouTube channel. The video is nearly 8 minutes long.
[intro music]
>> JACKIE: We are down here at Nudgee Beach, at the Tabbil ban dhagun mangrove boardwalk which means, a place of saltwater.
>> MIKE: And today we are going to look at six different mangrove species, and we are going to look at their adaptations to dealing with this environment.
>> JACKIE: When we talk about adaptations, we are talking about unique features which enable a plant or an animal to survive in a particular environment or habitat.
>> MIKE: Yeah, so these particular mangroves have to deal with a high amount of salinity, so we are going to look at a few different ways they deal with that.
>> JACKIE: Absolutely, it’s a very challenging environment, but our mangrove species are up to the challenge. Let’s have a look at species number one.
>> MIKE: Let’s do it. Our first mangrove we are going to look at today is a, milky mangrove.
>> JACKIE: Also known as the blind your eye mangrove because you don’t want to get this sap in your eye.
>> MIKE: Where will we find this mangrove?
>> JACKIE: It’s found more at the high tide mark, so it doesn’t get full inundation with saltwater like some of our other mangrove species, but it still has to cope with a certain amount of saltwater. How does it do this? It’s a salt concentrator, so it concentrates the salt in its older leaves, and then those leaves drop off, and that’s its ways of getting excess salt in the plant.
>> MIKE: Sort of like a sacrificial leaf.
>> JACKIE: That’s right, yeah.
>> MIKE: Introducing the yellow mangroves, so obviously the tell-tale sign it’s a yellow mangrove is that yellowish-green colour. Another tell-tale sign is that the leaves always point upwards in this mangrove species. They have buttress roots, meaning their roots can sit above the surface in the mud and that helps them to stabilise. The cool thing with these guys is they have what we call, propagules, and that’s their seed pod. These long bits sticking here and what they will do is, they’ll break off and land in the water, and they always float vertically. Ok, so once they float, find some mud and actually grow a new plant from there.
>> JACKIE: Over here we have the river mangrove which has a very specialised adaptation of dealing with the saltwater environment. If you have a really close look at the leaves, you’ll notice some fine salt crystals all over the leaves. That’s part of the adaptation for the plant, it extrudes salt from its leaves, so, therefore, getting rid of salt from the plant. It also concentrates salt in the old leaves as well. The river mangrove gets some pretty white flowers that have a smell of ripe bananas and animals such as bats are good pollinators for the river mangrove.
[music]
>> JACKIE: So down here, we have a beautiful example of the iconic mangrove species the red mangrove. They have this really iconic prop roots which are really obvious and distinguish them from some of the other mangrove species.
>> MIKE: And they get their name red mangrove from the red colour on the roots and a cool adaptation is the big waxy leaves and that helps them to retain some of the moisture.
>> JACKIE: Their strategy of dealing with the saltwater environment is that they’re blocking salt uptake from their roots and also concentrating salt into the older leaves and getting rid of it that way.
>> MIKE: They also have their seed pods which they call propagules and they’re really long on this species, kind of like a cigar shape and they actually float vertically, much like the yellow mangrove.
>> JACKIE: This is probably my favourite mangrove, this is the large-leaved orange mangrove. They are really beautiful, aren’t they? They’ve got this big large green glossy leaves and they’re quite waxy, that helps to retain water, and their strategy is an adaptation for dealing with salt is to exclude salt at the roots and also again concentrated in the old leaves to get rid of it that way.
>> MIKE: One thing I really love about the orange mangrove is the way their sea pods, or, remember that word, propagule, grow, They kind of look like a little octopus. What will happen, the propagule will grow from the middle and will drop off and start the red mangrove and the yellow mangrove, it will float around until it finds a suitable spot in the mud or the sand to grow a whole new mangrove. It’s really cool.
[music]
>> MIKE: Hey, check this out.
>> JACKIE: Yeah, that’s an impressive hollow.
>> MIKE: It is an impressive hollow. So this is in a grey mangrove. Once they get to this larger size, they develop hollows and really, really, really good habitat.
>> JACKIE: Absolutely, there are all kinds of species in the mangroves here that will utilise a piece of real estate like a tree hollow like this. You might find snakes living in there, you might find different birds, possums, animals like that. They all love hollows as shelter in their habitat.
[music]
>> MIKE: So the most dominant species of mangrove in the Boondall Wetlands is the grey mangrove which you can see all around us. Now, this is a pioneer species and what that means is that it’s the first species of mangrove to grow in this area. This guy is pretty big and they can grow to a very, very ripe old age indeed.
>> JACKIE: The thing that you will notice about the grey mangrove is all this little peg or pencil white things sticking up from the mud, that’s part of its roots system called, pneumatophores. They help the grey mangrove to breathe essentially to absorb oxygen and exchange gas even though they’re down in the mud. So, it gets those roots up out of the mud to enable gas exchange.
[music]
>> MIKE: So, as you can see, mangroves are really, really important for the wildlife.
>> JACKIE: Absolutely, habitat but as well as that, they are a carbon sink, they protect against erosion, and they are really important filtering all kinds of pollutants. So, how can we work together to protect mangroves?
>> MIKE: We can act to keep our dog on a leash.
>> JACKIE: Absolutely.
>> MIKE: We were just saying at the Environmental Centre and that’s take three for the sea and what that means is if you can take three pieces of rubbish every day, you're going to be doing your part to helping a wetland like this. Well, that’s it from us guys. Make sure you come out and experience the Boondall Wetlands, in particular, walk the Tabbil ban dhagun Track here at Nudgee Beach.
>> JACKIE: Hope to see you soon, see you later.
[outro music]