SPEAKER_00 0:42

You're listening to Word on the Reef. Diving into marine science on the Great Mary Reef and beyond. With Tanya Murphy and Brett Goodman. Good morning everyone, and welcome to Word on the Reef. I'm your host, diver, and marine conservationist, Tanya Murphy. Diving solo today as my trusty dive buddy Brett Goodman is away. Now, today's topic is a really interesting one. We're going to be talking about city slicking fish. What does that mean? Of course, we all know the Great Barrier Reef Marine Park finishes at the shore of Queensland. But did you know that some Great Barrier Reef fish species are spending part of their life cycle right here in the middle of our city? That's right. Marine fish species could be as close as your nearest concrete stormwater drain, swimming among abandoned shopping trolleys and discarded beer bottles. And that makes sense because the city of Cairns was built on reclaimed mangrove swamps and tidal wetlands, which were nurseries for many marine fish species. Early settlers cleared the mangroves and raised the land level by two to four metres using dredge soil from Trinity Inlet and leftover rox and soil from building the Cairns Piranda Railway. They channelled the meandering natural waterways into straight, narrow concrete drains, like Lily Creek and the Finlay Creek Drain, which today carry rainfall to Trinity Inlet and also fill partially with salt water during high tide. So, what sorts of animals are still inhabiting these urban waters? What impacts have they suffered as a result of all this change? And what can we do right here in our backyard to help restore their habitat as best we can? To help explore our urban waterways, my guest today is Phil Laycock, manager of the Cairns Saltwater Creek Habitat Restoration Project with Ozfish Unlimited. Good morning, Phil, and welcome to Word on the Reef.

SPEAKER_01 2:49

Good morning, Tanya. Thanks very much for uh having me on the show today.

SPEAKER_00 2:52

It's great to have you here. To start off, can you tell us a little bit about yourself and your background?

SPEAKER_01 2:57

Well, I'm a Cairns boy, born and bred, uh, married a Tully Cane farmer's daughter, went to Uni and Townsell, did marine biology, spent the first half of my career, or so out there on the reef, uh working in tourism and research out there, and then for the Great Barrier Reef Marine Park Authority, worked in a regional role here in Cairns. And then I've spent the time since 2018 providing some consultancy services, focusing on urban water quality mostly. And uh from 2024 uh started working with Osfish Unlimited as a project manager here in Cairns.

SPEAKER_00 3:32

What is Osfish all about and what do they do?

SPEAKER_01 3:34

I think the easiest way to think about Ozfish, because most people are familiar with Land Care Australia. So Osfish is kind of like land care, but it's uh all about the fish, and it was started by fishermen, and it makes that connection between healthy habitat and healthy fish stocks. A lot of other stuff in between that, of course, uh a lot of other environmental benefits, but that's what Ozfish is all about.

SPEAKER_00 4:00

Yeah, so it was started by recreational fishers, which is hugely popular in Queensland. It's estimated around one in five Queenslanders will go fishing at least once in any given year. So that's a hugely important segment of the population. How interested are recreational fishers in being good caretakers and stewards of fish populations and habitats?

SPEAKER_01 4:21

Well, they're very interested, Tanya. Um Osfish Unlimited's got fifty-two chapters all around the country. They're active in every state. Wow. Yeah, lots and lots. And we work across the area. So fishers get it, you know. They d they do understand that good habitat means good fishing, better habitat, better fishing.

SPEAKER_00 4:49

Yeah, absolutely. So you have been a keen recreational fisher for most of your life. What changes have you seen in the fish populations in Cairns waterways over that time?

SPEAKER_01 4:59

Well, some good things and some bad things. I guess some of the little urban creeks that I used to run around in as a kid, uh catching snake-headed gudgeons and turtles and yabbies and those sorts of things have been channelized and changed. But there's still plenty of little nooks and crannies around there that we can help. But some of the positive things are there's more barramundi around now. You know, that started not just on the back of the net free zone here in Cairns, but back in the in the 1980s when uh Fisheries Queensland established a closed season to allow the barramundi to spawn. So we see some good things and some bad things, but uh still able to go and have a great time on the water around Cairns here. Just a lot more people around. So we all need to be good stewards and take care while we're out there. Look after the fish and look after the environment as well.

SPEAKER_00 5:51

Yeah, so speaking of that, you've got a project that you're running here in Cairns. Can you tell us a bit about that?

SPEAKER_01 5:57

Uh the key project I think that we're going to focus on today is uh the habitat restoration project that's focusing on the Saltwater Creek catchment. That includes Lily Creek, uh the Cannes Central Swamp Area, Fernley Street drain. I wish we had a better name for that. Just remember everybody that drains are actually creeks. So they look like a a drain or a gutter, but they were once creeks and they've just been changed. They've just been straightened, sometimes concrete lined, but they are creeks. So let's start calling them creeks. So, yeah, in that in that area we've got lots of uh concrete, but we've also got some areas of habitat that haven't been lined with concrete, and some of those areas have got lots of weeds in them, that sort of stuff, not much shade. Uh they get cleaned out by the council using machinery to maintain the the flood control that we need to do in there. And our project's about doing that better. So it's about planting trees on the bank, it's about doing some uh hands-on uh weed management. So with more shade, we get cooler water, less weeds. It means in the longer term we'll be needing to go in less with those mechanical kind of weed management options. We're creating more habitat, so multi-dimension habitat. I mean, a lot of our little urban waterways that are very open, we've just got one dimension and we tend to see tilapia dominating those. But when we find waterways where we've got bankside cover, shades, controlled weed growth, that sort of stuff, we get a lot more diversity of fish species in those areas. So trees, weeds, litter are the focus of that project.

SPEAKER_00 7:38

When and how did this urban waterway restoration project start?

SPEAKER_01 7:44

So Ozfish began in 2016, so we're ten years old in Australia. I kicked off the chapter here in Cairns in 2018. Um we did a few litter cleanups, a bit of tilapia work, but we had an opportunity at the time to get involved in a process that the Cairns Regional Council was doing, focusing on Saltwater Creek. Uh Lynn Powell was there at the time. And uh with our interests and the interest that the council had, we were able to uh find some funding to provide greater capacity for council and Lynn to do more community engagement. We held a few workshops, we came up with some solutions for water quality, and uh from those solutions Osfisher were able to develop some project ideas and we were able to uh start to get out there and look for some funding. We were lucky enough to get a commitment a couple of elections back for some funding for that work in Saltwater Creek. You know, the Labour government did win that election, we did get that funding coming through the Department of Environment, Climate Change and Water, and it's on the back of that that we've really built our capacity here in Cairns since 2024 to get in there and do some really serious work.

SPEAKER_00 9:01

One aspect of your project involves monitoring fish and water quality in these Cairns waterways. How do you go about doing that and what have you discovered?

SPEAKER_01 9:10

Well, one of the first things that the chapter did in Cairns, way back in 2018, was scrape together a few dollars and get the wonderful Brendan Ebner, uh who's one of the most uh respected freshwater fish biologists that we have here in the tropics of Australia. And uh Eb went and did some surveys for us, and uh we started to build our knowledge about what fish are living in the waterways. Understanding that helps you understand what you can do for the fish, obviously, and uh the consequences of that are also improving the habitat. So since 2018 we've been using a variety of methodologies to uh monitor the waterways, everything from camera traps, so we drop little GoPro cameras in, set them for standard times, go through the footage once a year or so. We do a uh more thorough survey with electro fishing equipment. So that's using a battery backpack, puts a charge into the water. The fish uh are stunned momentarily, come to the surface. It's a good way of getting a a really good understanding of the diversity of life. And then we use a mixture of sort of traps and small sains and scoops and visual observations as well. So from that, uh since 2018, uh we've recorded over sixty species in our urban waterways, from the estuarine areas right up to the foot of the ranges here, fish species. Five or six introduced species, tilapia, garamis, uh plates, and a few things like that, but everything else is native to our area.

SPEAKER_00 10:41

Where do all those introduced species come from? Did they escape from people's aquariums?

SPEAKER_01 10:47

Yeah, mostly aquarium escapees. There's a long story behind the tilapia. They sort of first arrived in North Queensland, uh, introduced in the nineteen eighties by someone who thought they were doing the right thing to control, I think, weeds in the lakes at the Sheridan Mirage when they were being built in the mid-1980s. And since then they've been sort of accidentally and sometimes purposely uh relocated in the our rivers and streams, and uh they're pretty much well established now.

SPEAKER_00 11:17

Ah, I had no idea it was another case of the sort of cane toad where they introduced it on purpose to try and control something else, a native a natively occurring thing, and then it just became a massive problem.

SPEAKER_01 11:29

I think the tilapia thing means that a lot of people, they're very visible, the tilapia. Their nature is to sort of be out, they school together, they've been quite effective at colonising our waterways. So a lot of people ride off our urban waterways, our local Because they see those everywhere. Yeah, our local drains. Remember, we're calling them creeks, so I'm going to call them creeks now. And so they see those and they think, oh, there's nothing in there but tilapia. But as I said before, if we build a more complex habitat, if we've got sort of a bit of edge vegetation, shade, snags, some little deeper zones in there, patches of uh running water or riffles and those sorts of things, we get a lot more rooms, if you like, in the habitat for different species to occupy. So tilapia are not a predator, but they are very territorial and they tend to chase other fish away from their area. So having more rooms, now the tilapia like those softer bottoms, open areas where they can filter the detritus and that sort of stuff. We have more rooms in the habitat, we get more fish species. And that's what we're trying to do. Create more room, more spaces in the habitat to get more species.

SPEAKER_00 12:37

Ah, more hidey holes.

SPEAKER_01 12:39

That's it, absolutely.

SPEAKER_00 12:40

So for any listeners who aren't familiar, tilapia are uh stripey, aren't they? Sort of silver with black stripes.

SPEAKER_01 12:47

Browny, stripey, and spotty. We've got two species here. One is more stripey and one is more spotty. One tends to be a little lower down, has a bit of a higher alinity tolerance than the other one. And they grow to about 35, 40 centimetres. They're the most farmed fish in the world, interestingly.

SPEAKER_00 13:06

Oh, so do people actually eat them in some places?

SPEAKER_01 13:10

Lots of people eat them in some places. People eat them in cans. I know people that fish for them in some of our larger rivers and things like that. We're not supposed to keep them. We're supposed to, if we catch them, we're supposed to dispose of them humanely and discard them away from the water. But we're not supposed to retain them under the fisheries rules and regulations.

SPEAKER_00 13:28

You mean you're not supposed to throw them back?

SPEAKER_01 13:30

Not supposed to release them and not supposed to take them home because uh they are a mouth brooder at a stage in their life. So we might take a fish home, take the fillets off it, throw the backbone into another waterway, and those eggs or larvae might still be alive, and then that's how we can start a new uh population of tilapia. Yeah.

SPEAKER_00 13:52

Hmm. Okay. Good tips for anyone, because uh even young kids are out there just throwing lines in and not really knowing what they're doing sometimes.

SPEAKER_01 14:00

I see plenty of people down at Lily Creek deliberately targeting the tilapia and dispatching of them humanely, and it's a good thing. It's a fun thing to do, lots of fun for the kids. I'd like to talk about some of the cool fish that live in the waterways. What cool fish are they? Like I said, we don't want to get confused and just think, oh, what's the point of looking after these water wives? They're just full of tilapia. Our fish surveys, let's look at Lily Creek, for example. Right there at the end of Gatton Street, electrofishing there, we've caught barramundi over 500 millimetres in length. We've had people report barramundi to 700 millimetres of length in there.

SPEAKER_00 14:34

Wow.

SPEAKER_01 14:34

We regularly catch three size classes of barramundi when we do our surveys in there. So 120, 270, and 500 mil sort of fish, so one, two, and three-year-old fish. So that waterway is working as a really important nursery environment. Once it was a chain of wetlands, so we would have had more space, more juvenile barramundi, but now we've sort of got a channel, so again, that's really cool. Mangrove jacks, uh, lots of mangrove jacks in there, mostly small fish. We see them as small as 20 millimeters, uh, which is about the size where you can start seeing them reasonably with your eyes. Up to 300 or even 400 millimetres in those little waterways. But again, we're looking at a juvenile fish, and and that's the classic, I guess, fish that connects the reef to our urban waterways. So we'll talk a little bit about mangrove jacks, if that's all right. So mangrove jacks that we catch in those waterways, if we go fishing in Trinity Inlet and we catch a nice 40 centimetre mangrove jack and we take that home for a meal. None of those fish have actually sexually matured. They're all still juveniles. And are up here in Cairns at around about that sort of 45 to 50 centimetre size range in the wet season, they they migrate out to the reef, and that's where they mature sexually. They'll grow to seven or eight kilos out there, uh occasionally uh bigger than that, but that's where they spawn. They spawn out there on the deep water pinnacles, and then their larvae come back inshore on the trade winds and uh on the northeast winds that we get over the summer, and those little fish then swim up those urban waterways, and uh they start to grow and mature in there. So it just shows you how connected we are to the reef through our urban waterways. You know, there's other species, think about some of the batfish species as well, things like milkfish, tarpon that are uh near shore water, but I see milkfish right out there on the outer edge of the reef as well. Trinity Inlet is home to juvenile luchanids or tropical snappers, so nanny guys, if you like, uh letharyanids, so sweet lips, so tricky snappers, and things like that. Um while those fish mightn't get up into our urban waterways, they're still influenced by what's happening in there. So we're really connected. And if we take one link out of that chain, take water quality out of there, take habitat out of there, overfish the spawning stock out on the reef, we start to see those populations collapsing. So looking after those urban waterways is one thing we can do as fishers to help water quality, what we do in our backyard, picking up litter, planting some trees, all of those sorts of things, as well as being uh responsible when we're out on the water and taking what we need, respecting the rules, uh using fish-friendly gear, so if we do get a fish that swies the hook right down, we can better off cutting the line and letting it go, and we'll get rid of it, rather than trying to dig it out, those sorts of things, some good practices there for the fishermen.

SPEAKER_00 17:34

When I've been out on the outer Great Barrier Reef diving, I sometimes see mangrove jacks, the fully grown ones, and I didn't learn until much later that when I was living in a high-rise apartment building in the middle of the city, just near Gatton Street, that there could also be some just a few hundred metres away from where I was living, but in a much younger stage of their life cycle.

SPEAKER_01 17:56

Oh, it's incredible the numbers that you see uh up the top end of Saltwater Creek at one of our monitoring locations up there. The the numbers of little mangrove jack from twenty millimetres to 120 millimetres is just amazing. Jungle perch is another one that that fishes love. We've recorded eight different species of gudgeons, so everyone's familiar with the snake-headed gudgeon or mud cod. Well, we've got the the sleepy cods, we've got this beautiful spangled gudgeon in there, all sorts of different gudgeon species, rainbow fish, blue eyes, hardy heads, this incredible range. There's these nifty gobies with a big nose, unfortunately called Roman nose gobies that we find. Um, they're just the the number of fish that we see. I did forget to mention that we also are working with uh researchers to develop what we call eDNA monitoring. So this is where you take water samples and everything in the water is going to shed its DNA. So we can take a water sample and get an idea of what fish species are in the water. Um that's proving quite successful. It's matching our electrofishing surveys really well. On the northern beaches of Cairns, we've got really strong signals for Klingobies, which is this really interesting little known goby family that lives at the bottom of waterfalls and these really steep, short coastal catchments. So those urban waterways don't look pretty. They're still doing a really important thing in that fish diversity, maintaining uh what's been here for for millennia. Aaron Ross Powell, Jr.

SPEAKER_00 19:31

It's absolutely amazing. I think if more people realize this, then they would be a bit more respectful towards uh considering them creeks instead of drains, you know, especially with regards to people just sort of littering around them and and litter getting washed into them. So definitely the awareness being raised about that is really important. I mean, hearing about all these incredible species just makes me want to grab a snorkel and jump in the drain, but that probably wouldn't be a good idea, maybe because of the water quality, I guess. What did you discover about the water quality in these waterways?

SPEAKER_01 20:00

Look, we've got a lot of legacy issues. We live in a much more uh enlightened society these days. So things that were uh common practices, you know, industrial areas and waste transfer facilities and those sorts of things, we don't do anymore. But we've got a lot of legacy issues, so a lot of hangover from there. And I guess the key to those things is about minimising disturbance in the habitat. So again, planting trees, getting the the weeds managed so that they're in a natural state, not in this boom bus stuff that we see. We're kind of keeping a lot of that locked in the soil, you know, we're not locked in the surrounds. Obviously, just driving our car around, we're putting stuff onto the roads and that runs in there and that sort of stuff. Keep your car maintained, you know, pick up your dog poo. Simple stuff like that, take your old paint tins to the waste transfer station, don't just dump them in the green bit to go in a landfill. Lots of things that we can do around our homes. It's just me. But what have we got, 160 odd thousand people in the cans and the surrounds right now, you know? Let's say we've got 30,000 households, you know, let's say a thousand paint tins a year go into the landfill. That's a thousand paint tins that we can keep out of landfills, you know, and that will decay away and leach into the system. So lots of stuff that we can do, but to see the diversity of life that we see in there means that we've actually probably got water quality that's a bit better than what a lot of people think.

SPEAKER_00 21:30

Aaron Ross Powell You mentioned that sometimes when it's time to clear them out so that they don't clog up, there's a lot of machinery just digging them up, and that's probably releasing any toxins in the bottom of the creeks.

SPEAKER_01 21:45

Yeah, potentially so. I think one of the things that you'll see, and I often get people uh sending me a message or asking me about it, when we do disturb that sort of edge vegetation, there's sort of uh a natural decay process going in. You can get what looks like a bit of an oily film on the surface. It's a sort of a natural feature. It's you know that decaying process kind of as the uh vegetation's turning to mush, if you like. We do get fuel pollution in the creeks, so someone does the wrong thing, uh a car has a a prang and the fuel tank leaks, or someone's got a a car that they're not looking after and it drips oil, and we you know, we'll get those sorts of pollutions there. We do sometimes have to use uh chemical methods, you know, so knockdown sprays. We're very careful with how and where we use those sprays, but we'll just be using Those sorts of things at the at the very beginning, really, to get over that hump. And then once we're over the hump, we can start doing the hand weeding work. I spent some time down at Lily Creek near the end of Gatton Street with the Gimoy Wallaboro Yudinji Rangers uh uh about a month ago. And we only worked on around about oh, about 70 metres of the creek bank there, and just on the right on the edge of the bank, just hand weeding, just pulling out paragrass and Singapore daisy and that sort of stuff. It was five cubic metres of stuff. But that's given us an opportunity now to go back there and do a little bit of selective spot spraying. Rather than just spraying the whole lot, we can now go back and do a little bit of selective spot spraying, back that up with ham weeding. I'll work with the council in the next month or so to take the bulkweed out of the middle, and hopefully we can hold that back along that area up to Florence Street for years to come.

SPEAKER_00 23:40

So, Phil, you've been holding regular tree planting events along these urban waterways, and as you already touched on, removing weeds at the same time. What are the benefits of carrying these activities out?

SPEAKER_01 23:52

Um we touched on before the idea of uh building a a more complex habitat, so shade to cool the water during the hot summer, uh making the water more comfortable and tolerable for fish to live in, managing the complexity of the environment, so opening up sort of the deeper holes and and little riffles and those sorts of things. Um we're working on 1.5 kilometres of waterway across the catchment, and our goal is to eventually plant out close to about two hectares of that riparian zone. Long, thin strips, you know, sort of two to four metres wide. Uh there's some needs for maintenance down there, public safety, those sorts of things. So we can't plant a whole forest and turn it back into a uh rainforest creek, but we can stabilize those edges, capture a lot of runoff, create more habitat, and uh shade the water and uh get some great outcomes. So, yeah, 1.5 kilometres of waterways, uh we've just secured some more funding and we'll do another sort of 800 metres on the back of that. So, you know, by the middle of 2028 or so, we should have had about two kilometres of saltwater in Lily Creek with nice riparian vegetation beginning to establish.

SPEAKER_00 25:09

Yeah, so you talked about removing weeds. What damage do weeds do on these urban waterways?

SPEAKER_01 25:16

Weeds really are a part of the environment. So we do want weeds, so we've got something called paragrass here. So paragrass provides that edge vegetation. But what happens where you've got a shady area, it'll be a little bit sparser, it won't grow particularly quickly, and it won't choke out the system. But when you don't have any vegetation, any shade or anything like that, it'll choke out the system. We've got to introduce things like water spinach as well. Singapore daisy to a lesser extent, but the Singapore daisy will tend to creep out on top of the paragrass and the water spinach. And in those open areas it forms such a thick mass that it'll actually effectively work a bit like a dam. If we get a lot of hot weather, the rate of decay of the dead vegetation in the water can take oxygen out of the water, can cause fish deaths due to eutrophication. But the main issue is for our public safety. So, as you said right at the beginning, you know, our local waterways are treated as drains. They do help us live here. They do help us during those heavy rainfall events. So periodically the council needs to remove that bulk weed mass out of the w out of the creek. And we're essentially resetting the creek every time we do that back to a a bare open space. And then over the twelve-month period in some cases, or five-year period in other cases, that will slow recolonize, we'll get a more complex habitat, and then we repeat the process. So we're trying to uh lengthen those periods between those intensive management events. We need to have that so that we can live happily in cans and not be walking around in flood waters. But we do also we can do it in a way that's uh going to help the fish as well.

SPEAKER_00 27:02

Yeah, absolutely. So it might be too early to tell, but does replanting or this vegetation increase the number of fish? It's probably been tested in other locations, right?

SPEAKER_01 27:13

Yeah, look, there's lots of ev evidence, you know. As I said, the motto of of Ozfish is better habitat, better fishing. So go and have a look at a concrete drain, no habitat, no fish. Very few anyway. Go and have a look at a section of uh one of our waterways where we've got a greater complexity of habitat, trees, grasses, those sorts of things, and we're starting to see fish species there. So yes, that's the goal. You know, that's the goal is to at very least help sustain what's in there. Like I said, we've got underwater footage clips and one screenshot with twenty-five plus little juvenile jungle perch in there. We've got screenshots with four or five juvenile mangrove jack in there. There's lots and lots of these juvenile species in our waterways. So at the very least, make it as healthy and sustainable for those fish to live in as it possibly can.

SPEAKER_00 28:06

Yeah, and it is a nicer area to go, and there's a nice walking path along Lily Creek that I used to enjoy. And you can see a lot of nature, like dragonflies, and there's all the trees have kookaburas, and sometimes you can stand on the bank and look at the fish and think, wow, who knew that this was all right next to the highway?

SPEAKER_01 28:22

I haven't had one person walk past when we've been down there doing whether it's litter clearing or whether it's fish monitoring or whether it's planting trees or weed management. We haven't had one person that hasn't walked past, that hasn't shared how much they love the area and how much they appreciate the work that we're doing. So um there's lots of people in the community that probably aren't aware of these wonderful walking and cycle paths. They follow all of our waterways, they're wonderful places to be.

SPEAKER_00 28:53

Yeah, well, highly recommend to all the all of the listeners out there go and check out the walking paths along Lily Creek and so on. It's a nice little green space right in our backyard of the concrete jungle of the city. Now, you've uh mentioned that another threat to these urban waterways is litter. How bad is the litter problem in these creeks and what sort of litter are you finding the most?

SPEAKER_01 29:15

Urban generated litter. What would you do we expect to find? Ask anyway, what are we going to find today? We're going to find chip packets, we're going to find fast food packets, we're going to find discarded household items, we're going to find bottles, cans, all of that sort of stuff. People unfortunately still dump illegally, so we do get some larger items bikes, shopping trolleys, bed frames, you know, you name it, we've found it.

SPEAKER_00 29:42

That shows a real misunderstanding of the area. People think, oh, it's just a drain, so I'm going to use it as a trash.

SPEAKER_01 29:48

Yeah. Yeah. And I think it says something about the fact that uh you know, a lot of people in the world don't see the the beautiful green, they just see uh a drain, you know. And that's why I think it's so important for us to, whenever we can remind people that they are creeks. You know, they are important to us.

SPEAKER_00 30:04

Yeah. Well, I was I was uh very privileged to join you for one of the clean-ups, and just on that one day we found so much stuff, including a mattress that was a bit of a struggle for you guys to get out of the water and a sofa, and a bicycle and uh a shopping trolley.

SPEAKER_01 30:19

So yeah, it was all the other bits and pieces as well.

SPEAKER_00 30:23

All the other bits and pieces, yeah. Very satisfying to get all that stuff out.

SPEAKER_01 30:26

Good news story about that location, though, Tanya, is that we've been targeting that area. It's a hot spot for us. It's uh there's a walkway traffic, yeah. High foot traffic, walkway crosses there, uh close to uh takeaway food outlets, all of those sorts of things. We've been targeting that area there. And it does it does attract a homeless situation as well. And it's unfortunate that we still live in a world where people are forced to find somewhere other than a home to live in. But the good news is that the last time we went back there during the Clean Up Australia month, we found less litter and to the point where we spent a whole heap of time there and just got one bag of litter. And the first time we went there with less people, we filled two Utes with litter. So by going back a couple of times a a year and doing intensive work in areas, we've kind of got rid of the legacy stuff. So now we're starting to map it. Yeah. So we're we're starting to map those other areas. So we go back there regularly now to plant trees and manage weeds and we do a bit of litter pickup while we're there. So we're sort of staying on top of it there. We need to find those other hotspots around Cairns to get rid of that legacy stuff and have a great impact. So by working together with people like you and other community members, Osfish volunteers and people that that live in the area, we've had a real impact on that zone of the creek. And if you walk along the creek, about eighty percent of the leader is concentrated there. So it's had a big impact, positive impact.

SPEAKER_00 32:10

Yeah, and I think when you are down there and people walk past and talk to you, hopefully it makes them less likely to throw their trash in it after they've seen it all the the effort that you guys have put in to clean it up in the first place.

SPEAKER_01 32:21

Absolutely, absolutely. You know, I think people are starting to uh have conversations amongst themselves. If they see someone hasn't been particularly thoughtful, people can politely remind them about thinking about what they're doing.

SPEAKER_00 32:34

Yeah. So you're sort of in the middle of the the rollout of all this restoration, but do you know what the impact has been so far and what are the goals moving forward?

SPEAKER_01 32:46

So we've pretty much done 75% of the planting that we aim to do along Lily Creek. And we've uh completed most of that in the first months of this year. We try to coincide our planting with the with the wet season, so those new plants have got water coming from the sky, nothing like water from the sky, to uh to get a plant established. Over the coming months, we're starting to plan or our planning beginning on the first rains at the end of the year around the upper end of Saltwater Creek, around Jensen Street Park. We'll be doing some up there. We're also going to work through some of these drier months. You'll notice a lot of the waterways and in cairns, a lot of the creeks and cairns have got one bank with trees on and one bank that's open, and that's to allow council access. But you do see on those open banks the bank tends to slump, and that adds sediment. It means you've got to go back there and dig the sediment out again. So we're working with a number of species, uh, mangrove holly and mangrove fern. We've found that we can propagate the mangrove holly in particular quite well. And we're working with council and we hope to plant a lot of mangrove holly along the toe of the bank. So that's the part of the bank that it's just right down at water level. And mangrove holly, as the name suggests, are uh are a mangrove associate. They tend to grow at the upper end of the tidal systems, and by planting those mangrove holly along the toe, we're creating habitat, we're stabilizing the bank. The council can still get over the top to do their maintenance after a flood event or something like that. So not all of what we do is pretty trees and but still having great outcomes for the environment. Moving sediment, creating edge vegetation, creating a more complex habitat. So that's what we'll be doing under this current project over the next 18 months or so. Finishing off Lily Creek, mostly up around Florence Street, is the work that we'll do. Bit of infield planning there, lots of weed management, and starting these new new plannings. Uh, as I said, we've got some additional funding, take us through until about mid-2028 on this project.

SPEAKER_00 34:53

Yeah, awesome project. Are there any other aspects to the creek restoration work that you'd like to talk about which we haven't already covered?

SPEAKER_01 34:59

Follow Ozfish Cans on Facebook and we advertise all of our events along there. We invite people to come along to our monitoring events, our tree planting events, our litter cleanup events. We advertise all of those on our Facebook page. So get involved, go to the Ozfish website and become a member. That'll help us out a lot. In a couple of weeks' time, BCF, who's our main sponsor for Osfish Australia, they hold a weekend where they promote donations to Osfish. It's called Small Change for Big Change. It's the weekend of the 6th and 7th of June. So if you're out and about and you're jumping into a BCF store while you're in there, you can round up to the nearest dollar, and that money will go into Osfish. We'll be in the stores. So you can come and have a chat to us there. We'll have a QR code. You can sign up to a digital membership for free. And yeah, get involved. Give us a hand.

SPEAKER_00 35:57

Awesome. Go and check it out, everyone. So, Phil, I understand you're interested in doing some shellfish reef restoration here in Cairns, and there's a really good precedent because the Whoppaburra First Nations people in Keppel Island on the southern end of the Great Barry Reef Marine Park have already carried out a shellfish reef restoration project in their sea country. Can you tell us a bit about that?

SPEAKER_01 36:23

Yeah, so uh shellfish reefs, um, they can be oysters, depending on where you are in Australia, mussels, all sorts of hard encrusting organisms as well in those areas. So for about the last eight years, Osfish chapters all around the country from the Swan River where they're uh facilitating the growth of mussel reefs. Uh Morton Bay was the sort of birthplace of our shellfish revolution, as we call it. And we now see uh these projects playing a big role in South Australia with the uh algae bloom down there. So the Osfish are doing a lot of work with shellfish reefs down there because they're great filters for the environment. And here in the Great Barrier Reef catchment area, we've got funding to uh build shellfish reefs in our harbours from Gladstone up here to Cairns over the next couple of years. And I met with Ports North and uh Gimoy Wallabara Yadingji traditional owners on Tuesday this week to finalise where we're going to uh start this project. So yeah, yeah. So we'll be we're looking at that area from about wharf one down to the Marlin Jetty and we'll be starting off with about 40 metres of foundations for uh oyster colonisation. People say there's already oysters down there. Yeah, but there's no reef structures down there. If you have a real good look down there, what you'll see is yep, there's oysters on the pylons, the nice vertical pylons, the really old pylons. Uh the oysters on the newer pylons, they tend to get removed as part of the maintenance for the port. That's that's okay. We need to do that. But the rocks themselves that the rock wall is built of are generally very flat surfaces, and you'll notice the oysters just grow on the edges. And um that's because the flat surfaces uh get really hot. They're granite rocks, obviously, they get really hot, and it's not a great habitat. So we're going to introduce a basket structure called a quilted oyster duna. And a module of an oyster duna is uh about a metre long, three modules around about uh 150-200 miles wide and about the same height, and we fill that up with oyster shells, and that gives us this nice three-dimensional habitat that stays a bit cooler, we attach them with uh masonry anchors to the rocks and allow the oysters to colonize. Um reefs were part of all of our coastal ecosystems once upon a time. When Europeans first came to Cairns and Settled Cairns, we would have had oyster reefs around that area that we're working in today. You know, we look at shell middens and things like that from the traditional owners, lots and lots of oysters in there, you know. And not just the species that we see growing from commonly on the mangrove roots, other species, you know. So oyster reefs would grow on the edge of muddy flats once upon a time, and they would form big structures. If anyone's ever been up to Marpoon, you'll see some massive oyster reefs up there. But those oyster reefs were mined literally by the early Europeans here, crushed, they were burnt, and that was an important ingredient in making cement. So some of the old foundations or some of the old buildings here, you can see shell and coral and all sorts of stuff in there. And uh we lost all our oyster reefs, so now we're trying to uh reintroduce them to our environment.

SPEAKER_00 39:37

It's terribly sad how they were all lost, but it's very exciting how you're reintroducing them.

SPEAKER_01 39:41

Aaron Ross Powell, you don't know what you don't know, though. In 1880, it was a resource. We didn't have the knowledge we have today. So we can be sad about the loss. We can't be critical of the people at the time who didn't know what we know today.

SPEAKER_00 39:55

Yeah. And and like you said, the indigenous people used to that was their supermarket. They just walk down the coast and they could get oysters. I mean, how much we pay to eat oysters nowadays because they're a delicacy, but there used to be a lot more that they could just grab off the seashore. And unfortunately a lot of them are lost, so it's really good to hear that there's this methodology that's proven effective for getting them to come back. So it's so you fill up the frames with oyster shells because oyster shells attract other oysters.

SPEAKER_01 40:25

Yeah, it's a perfect environment. If you look at an oyster shell, it's quite rough. There's lots of little nooks and crannies. So if you're an oyster larvae or an encrusting tube worm, or uh a leaf oyster larvae, or something like that, you know, there's a nice little nook that you can anchor yourself into. Even some of the sponges and uh, you know, we still get a few corals growing in it in the inlet, those sorts of things. It's a perfect habitat. And because we've got that sort of three-dimensionality, we don't have a big flat, wide, smooth surface facing the sun, they're cooler, and it's just the best way to do it. We also use robust oyster baskets in other parts of Australia, which are kind of triangle-shaped baskets, as well. So it's the way. We'll be we're just kicking off that project here, so keep an eye out. We'll be publicizing that. We'll be looking for oyster shell supplies from restaurants, and that's just kicking off now.

SPEAKER_00 41:18

Yeah. Well, amazing. Yeah, I was going to ask where you're gonna get all the oyster shells, but obviously you'll be partnering with restaurants.

SPEAKER_01 41:23

So restaurants and uh seafood processes, all of that sort of stuff. And uh yeah, we need a supply of shell to to create the foundations.

SPEAKER_00 41:33

Yeah, and so do you think that'll have a benefit to the water quality in the inlet?

SPEAKER_01 41:37

Yeah, look, I mean, you know, we probably need uh Green Island reef size oyster reef to uh make a big change in water quality. But yeah, look, the more oysters, the more filters we've got out there, the more water that's that's going through. Oysters process huge volumes of water in a day. So they will have a role, particularly in those edges around the port where probably a lot of those sorts of pollutants are are concentrated.

SPEAKER_00 42:06

Yeah, yeah well it's a good start, and then yeah, if that goes well, maybe we can we can put more oyster beds.

SPEAKER_01 42:12

But habitat too. Great habitat, food, the food chain, the whole thing, not just about water quality, but its habitat as well.

SPEAKER_00 42:19

Yeah. Well, it's a really exciting project. Sadly, we're uh just about to come up to the 11 o'clock news. So that's all we have time for today. Bill Layock, manager of the Cairns Saltwater Creek Habitat Restoration Project with Ozfish Unlimited. Thanks for all your amazing work and thanks for joining us on Word on the Reef today.

SPEAKER_01 42:39

Thanks, Tanya. It was great to be here and uh we'll catch up again sometime and we'll uh give an update. And uh we've got a few other projects going on I'd love to talk about as well.

SPEAKER_00 42:47

Is there any last comments that you'd like to make before we sign on?

SPEAKER_01 42:50

Look, Seagrass, we're we're sort of doing some work with dropwater around seagrass. We've got a partnership out at the airport uh helping reconnect mangroves. Part of the Saltwater Creek project is improving the water exchange between the wetlands at the base of the Yellow Arrow in Saltwater Creek, so we don't get water trapped in there and fish kills. Lots of stuff going on.

SPEAKER_00 43:11

Thanks listeners for joining us on Word on the Reef. With me, Tonya Murphy. We'll be back next week with more marine science adventures. This show is broadcast live from the Kansas Fem Studio, which is on the land of the NIG people. We'd like to extend our respect to elders past and present. That's all for this week. Best fishes, and see you next time.