Fern Hames, Murray Darling Basin Authority Native Fish Strategy Co-Ordinator for Victoria, explains that because of the change of river flows eccasioned by human water usage and the introduction of non-native fish species, there has been a 90% reduction of native fish numbers since the 1860 Burke and Wills expedition passed this area.
Fern shows us the most common "good" and "bad" fish of the Murray Darling. Some of the fish she discusses are the native silver perch and Murray cod, as well as the introduced carp and weather loach.
This was videoed in Kerang.
For more on the imact of carp on river health listen to the audio Drought Stories Excerpt 14
Further Information
TRANSCRIPT
-My name's Fern Hames. I'm kind of known as the Fish Lady, but my actual title is the Murray-Darling Basin Authority Native Fish Strategy Coordinator for Victoria, which is a crazily long title. So people call me the Fish Lady.
And what I'm really interested in is the fact that we've lost a lot of our native fish. Back when Burke and Wills came through this country, there were a lot of native fish throughout our systems. We now think we're down to about 10% of what was here when Burke and Wills came through. So we're trying to get those populations back up to about 60% of what they were then.
Now, some fish have suffered more than others in those years. And I want to tell you about a couple of those and about some of the things that have happened for native fish in these systems.
First one I want to tell you about is silver perch. Now, they don't look exactly like this, but this is our idea of our toy friend silver perch. And they are about this size. They are a silvery color.
And right here in Kerang is pretty much the hot spot for silver perch in the world. They're threatened everywhere else. Silver perch really like to move around. They like to move up and down rivers to breed. And in a lot of our rivers, we've got dams and weirs that they can't do that.
In this part of the river, we've actually got a nice big, long stretch and they can move around a bit. And silver perch are going OK here. So if you want to see a silver perch, this is where you find them. When we commissioned the fishway here just a few months ago, we caught one kind of fish in there, little silver perch, which was fantastic.
Another fish I want to tell you about-- this one. Big fish. This one's called a Murray cod. This is an icon species for the Murray Darling system.
This is the top predator in the system. This is a fish that is an ambush predator. It'll hang around in the rivers, under a snag or under some rocks, and it'll jump out and catch little fish going past. Some people say that our system is a system of lazy rivers and energetic fish. They all like to swim a long way, and sometimes they leap out and catch little fish.
This is a big fish. This fish can get to 1.4 or 1.2-- depends. We get different theories, different varying ideas-- meters long. That's a big fish, and we know they can get to 48 years old. Perhaps older, but the one that we've aged was at 48 years old.
So these are the big fish. These are the top-order apex predator of the system. And they're not doing very well all over the system. There are some parts of the Murray Darling Basin where they're going OK, but there are plenty of places where Murray cod are in decline. And we're doing a lot of things to try and support that.
One of the problems for native fish is fish like this one. This is a carp. And if you've hung around in any of the rivers in the Murray Darling Basin, you've probably seen this guy.
Carp forage around in substrate, and they disturb the substrate, the bottom of the rivers. They make it turbid. They eat native vegetation that's in the rivers. And they can be real problem. They can also, in that foraging, eat some of our native fish eggs.
There are lots of them in the system. And you might have noticed, if you've ever been at a weir or a dam on one of our rivers, you might see fish jumping, trying to get up over the weir. That'll be carp. Carp can jump 1.8 meters high, which is a lot taller than me, and they're pretty good at jumping.
Native fish never do that. Native fish never jump. Only carp. And that's actually given us a really good tool to try and get carp out of the rivers. Because we've put special traps in at some of the weirs that sort the fish out based on that jumping capacity. So carp jump into the trap, native fish don't, and we can pull the carp out. So that's giving us a really good tool to try and manage carp in our rivers.
This is a little face. It's called a weather loach, and we find them around here quite a lot. Weather loach are not a native fish. Like the carp, they're an introduced fish. And they're starting to become a bit of a problem. More and more and more weather loach in the system.
I wanted to show you this one and the Murray cod to show you that there's all kind of fish in our rivers. We've got big ones, like the Murray cod, we've got little ones like this, and there are some native fish that are really, really tiny.
But they all have different requirements. They all live in our rivers. When they're under the water, it's hard to see them. It's hard to sort of remember the needs for native fish.
But this one, keep an eye out for it. It looks a bit like a catfish. It's not a catfish. If you find a weather loach, take him out. They're not very good.
So that's all the fish that I've got to show you today. I hope that you'll go down to a river near your place and enjoy just being by the river. And if you're lucky, you might see a native fish. That'd be great.