Claire Corlett

Fish Food, Fish Tanks, and More
Salmon Growing in Tasmania

Salmon Growing in Tasmania


(instrumental music) Well, welcome to Huon Aquaculture. My name’s David Whyte. I’m the Group Technical Manager here at our operations base
here at Hideaway Bay. I’ve been working here
for around ten years. (instrumental music) Well, we farm fish to feed
the growing world population. In 2012, we had 7 billion
people in the world. We then look at that and
say that of that proportion 1.2 billion have seafood as
a primary source of protein, and that equates to 17.2 kilos per person. That’s the amount of seafood that we need on an annual basis. (instrumental music) So this is a life cycle of a salmon. The eggs are incubated. After a certain amount of degree days, which is around 250 days,
the eggs will hatch out. They’re alevins. They have their own yolk sac. They then transfer to sea water for the sea water part
of their life cycle. So up until now they’re in freshwater, then they go to sea water. They will grow up for a
couple of years with us. They will then be stripped so they’ll have the eggs and
the sperm taken from them. That will fertilize the egg which then goes through
this process again. So we talk about closing
the cycle in aquaculture which means we can take eggs,
grow them all the way around to parent fish, and then
get another generation. That’s called vertical integration when you can go from eggs
all the way back around. It means that you’re
vertically integrated. It also is a term we use for explaining that we go all the way from
egg to plate in aquaculture. (instrumental music) We have a world fish
supply which is constrained around 117 to 120 million ton. 45% at that point, which is 2012, was supplied by aquaculture. Now it’s closer to 50%
so we’ve got to the point where we’re farming more
than we’re catching. So 100 kilos of feed
produces 13 kilos of pork, 20 kilos of chicken, but a
whopping 65 kilos of salmon. How does that compare
in terms of efficiency? You can only retain 47% of
sheep after you kill it, 72% of a pig, 66% of a chicken, and 86% of a fish. Once again, our salmon
are looking pretty good. It takes seven kilos of wild
fish to grow a five kilo salmon out there on the farm. How many kilos do you think
it takes for a wild salmon to grow to five kilos in weight? The answers 50. So wild salmon are a lot less sustainable in terms of the use of marine resources than farm salmon are. Each 4 kilos of wild fish
becomes one kilo of fishmeal. Each kilo of fishmeal,
we need 210 grams of it or we needed 210 grams of it
to make our kilo of fish feed. So of the fish feed, we need
1.4 kilos to make a kilo salmon so that’s how we get up to our numbers. Over my shoulder are our
research and development panes. Huon are pretty unique in
that we have 34 small panes, which are exact copies of
full scale production panes. They have the nets. They have the flotation collars, and they also have the
center-mounted feeders. So in those panes, we can
run a small number of fish between 200 and 500. We can do lots of trials on things like different feed ingredients, different feed energy
levels, different folates, how long the day length is
that the fish are experiencing. We’ve even done vaccine trials, and we’ve done all sorts
of other things to. It allows us to try some pretty new things in a very, very controlled environment with good scientific replication without putting full production panes under that kind of stress so it’s the key to our success here is
being able to try things before we do them. First thing you have
to do as a fish farmer is you have to keep your fish alive. The second thing you have
to do as a fish farmer is keep them in one place. Behind me is one of our production panes, it’s a 168 meter pane. That’s the circumference of the pane. That’s how we measure our panes
and how we categorize them. So what we’re gonna do is
we’re gonna have a look at this pane. We’re gonna see what the challenges are that we’ve tried to
solve with this design, and then we’re gonna try
and give you a little bit of insight into the
important things for us so that if you were
redesigning one of these panes what you might have to
take into consideration. The panes made up of
three main components. First component is the flotation collar. That’s what keeps the
whole rig on the surface. Then we have the net
which contains the fish, and also protects the fish
from external predators. Then we have the bird net
which goes over top of the net, which again protects the fish from birds, and out in the middle
is a floating hopper. That floating hopper
is computer controlled, and it basically feeds the
fish when they want to be fed. So it’s an integral part of the pane. It holds up the bird net,
but it also carries the feed that we need to feed the fish. Predators are trying to eat fish. They’re trying to interrupt
the fishes normal behaviors in order to eat them. The challenge for us a few years
ago was to have very tight, high fences that the
seals couldn’t jump over. But despite our best efforts, the seals would pull the net down. They’d try and get up
the inside of the net. They would target any weakness. They’ll learn very quickly from each other so very, very inventive and
very, very persistent animals. So this is state of the
art or was state of the art probably around four years ago, but it’s clear that
improvements have to be made. So one of the things that we’d
like you guys to think about is how would you make those improvements. How would you keep the fish
as far away from the seals as you possibly could? How would you prevent
them from climbing over, and how would you make the whole thing a safer working environment
for people who work here? So that’s the challenge,
and it’s the challenge we face every day. (instrumental music)

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