Episode Transcript
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Speaker 1 (00:02):
I first went to South Australia in mid June, at
which point, Yeah, the bloom was in full swing.
Speaker 2 (00:09):
The large number of fish and marine life have been
washing up dead along the shore, including two penguins in
the past week.
Speaker 3 (00:16):
When dead fish began washing up on South Australian beaches
earlier this year, doctor Scott Bennett was alarmed. Scott's a
marin ecologist at the University of Tasmania, and he knew
that dead fish on shore spelled trouble under the surface.
Speaker 1 (00:33):
Nobody was looking under the water, Nobody had seen impacts
on the reef, and in discussion with colleagues in South Australia,
they had really limited capacity to get out.
Speaker 4 (00:44):
There and have a look.
Speaker 3 (00:45):
On a dive in June, Scott came face to face
with the devastating impact of the largest algal bloom Australia
has ever seen.
Speaker 5 (00:54):
The full impact still isn't known.
Speaker 3 (00:56):
But some of Australia's rarest and strangest animals could we
wiped out entirely. I'm Ruby Jones and this is seven
AM today doctor Scott Bennett on what caused.
Speaker 5 (01:11):
The algal bloom and what it.
Speaker 3 (01:12):
Means for the fate of the ocean. It's Wednesday, August thirteenth.
Speaker 6 (01:24):
Goals are growing for the Commonwealth to declare an enormous
algal bloom off the coast of South Australia a natural disaster.
It's been described as an underwater bushfire because of the
devastating effect on marine life.
Speaker 3 (01:37):
Scott, You've conducted the only underwater survey of the impacts
of the algal bloom in South Australia, So can you
tell me about what you saw.
Speaker 1 (01:46):
It was one of the most devastating dive trips I've
ever been on, to be honest. So you know, we
do these trips around the country monitoring biodiversity of our
reefs and when we do them, they're you know, typically
really enjoyable trips. Obviously we have just these amazing help
forest ecosystems throughout Southern Australia. Visibility is often really nice.
(02:07):
You can see a lot of life and diversity on
these dives, so they're really exciting trips to go on.
This trip, the whole spect of it was unlike anything
we normally do.
Speaker 2 (02:18):
Beach goers first sounded the alarm about the micro algal
bloom back in March, after dead marine life washed up
along the Flurio Peninsula and surfers reported feeling unwell, you.
Speaker 1 (02:30):
Know, on the first dive. To be honest, kind of
fulfilled our expectations. We actually couldn't see anything. It was
just so turbid and stirred up. But we continued on
and conditions over the day and that week got better.
But the realization of the impacts on the marine life
were really reinforced.
Speaker 6 (02:49):
The algal bloom has spread into the Golfer Saint Vincent,
with smaller mini blooms likely present in the Spencer Gulf too.
Speaker 1 (02:56):
I've never seen so many dead animals on the bottom
of the ocean. Normally, if things die, they get consumed
or washed away or taken away pretty quickly. This wasn't
the case right now. There's a lot of dead, particularly
invertebrate animals, so things like sea stars, crabs dead and
lyned around on the bottom.
Speaker 6 (03:16):
More than twelve thousand animals are estimated to have died
so far, including fish, sting, rays, dolphins, and sharks. Commercial
fishes have been forced to pause their operations indefinitely.
Speaker 1 (03:26):
A lot of fish that you would expect to see
just weren't there. Like a lot of the reefs would
ghost lick quiet. But at the same time, a lot
of the seaweeds and a lot of the reefs were okay,
like reasonably healthy, and so it wasn't a complete apocalypse.
Speaker 3 (03:45):
Okay, Well, tell me more about the algal bloom itself.
What is it exactly and how did it start?
Speaker 1 (03:51):
Yeah, So in this case they have the harmful algal
bloom is a bloom of micro algae harmful micros in
this context. The reported species a lot is Kernia mikimoti,
but it's actually a multiple species that are forming this bloom.
But what's concerning is there's a number of there's types
(04:13):
of toxins, So things like brevy toxins which are being
found in these blooms haven't been recorded in Australia before.
So while harmful alva blooms are actually really common around Australia,
we see them in all states. We see them in
some form each year, we've never seen anything of this
magnitude before this scale.
Speaker 3 (04:34):
And so what are the conditions that lead to a
bloom like this? What do you need to have in
the ocean.
Speaker 1 (04:41):
So typically we need warm temperatures, long days like plenty
of light and nutrients and for this bloom, what we
saw was we had a really intense marine heat wave.
That's one of the most intense marine heat waves who
recorded in South Australia, which seems to have been a
real trigger. It obviously occurred in summertime where we still
(05:02):
have long days, and it was on this base of
high nutrient conditions. So the nutrient trigger or the nutrient
source is still unknown, but yeah, certainly nutrients are an
important factor as well as temperature.
Speaker 3 (05:15):
What is it like for you as someone who has
spent their working life in reefs gone on? I'm sure
many dives seen incredible things underwater. What is it like
to do a dive like this and witness the state
of the.
Speaker 5 (05:31):
Reef right now?
Speaker 1 (05:33):
It's really devastating to see the state of the reef
the moment. And for me as a scientist as well,
South Australia is a really unique place for the biodiversity.
Least reef biodiversity. Around seventy percent of the species that
live on the reefs in this area are unique to
(05:53):
the region, unique to Southern Australia. They're unique because they've
been isolated literally for tens of millions of years here
at the bottom of the earth, basically not found anywhere
else on Earth. And until now, South Australia's been a
bit of a refuge for a lot of these unique
temperate species. We've had huge impacts on our east and
(06:13):
west coast of the country due to marine heat waves
and the like, and for whatever reason, South Australia hadn't
suffered those heat waves and those impacts until now, and
so the population levels of some of our most rare
and bizarre organisms were stable or high in South Australia
where they collapsed everywhere else. And now that refuge is
(06:34):
under attack.
Speaker 3 (06:35):
Can you tell me more about those species? What sorts
of creatures are we talking about?
Speaker 1 (06:40):
I mean, there's a whole host of really weird and
wonderful things. I think some of the most iconic species
are like our leafy sea dragons, particularly around the Adelaide
coastline and the fluri O Peninsula plased like Rapid Bay
and Victor Harbor. These are real tourist attractions to come
and see these leafy sea dragons, which you only find
in South Australia and in parts of southwestern Australia across
(07:05):
the Bremer Bay, but in the early days of the bloom,
people were finding dozens of these washed up and they're
not huge populations, so they're obviously a massive concern. Another
massive concern, which is a really live issue at the moment,
are the giant cuttlefish. And each year there's this remarkable
event where just thousands one thousands of cuttlefish come and
(07:27):
aggregate in this small area to mate and lay eggs.
At the moment, the bloom is tracking up the Spencer
Gulf towards these aggregations. Currently, the adults have laid their
eggs and they're now going through their natural senescence phase.
But there's a lot of concern for what will become
(07:48):
of this new cohort that's about to hatch, and if
the bloom continues to move up, it could reach there
in the next weeks. If nothing changes.
Speaker 3 (08:00):
Coming up, what will happen if the cuttlefish and the
bloom collide. Scott The algal bloom in South Australia is
still spreading and it's getting closer and closer to the
(08:24):
gathering of these giant cuttlefish that's happening right now. So
if the bloom does spread to where they are, what
impact will.
Speaker 1 (08:33):
That have well, there's a real risk that we lose
this entire cohort, which means this entire population it is
under genuine and serious threat from the hab There's been
a number of emergency meetings trying discussing possible interventions and
things like this. But the scale of these aggregations and
(08:54):
these breeding events, and the timeframe that we're working with,
which is literally you know now, like things have to
happen immediately, it is significant. Interventions aren't really on the table.
Things like removing eggs and relocating them, you know, just
the feasibility of those things are deemed not possible right now,
and so there is a real risk these populations are
(09:16):
lost or they're going to be severely impacted we would expect.
Speaker 3 (09:20):
And one of the scariest things about this algal bloom
is the scale of it. And it's still spreading, I believe.
So as you watch that happen, what is that telling
you about the fate of our oceans more broadly?
Speaker 1 (09:36):
Yes, I think one of the scary things about this
is the scale of the impact. This is the largest
harmful algal bloom that we've seen in Australia and most devastating.
It's spanning across tens of thousands of square kilometers of
reef of marine habitat, and we don't expect this to
be an isolated or unique event to South Australia. This
(09:58):
is quite symptomatic the impacts of climate change that we're
seeing throughout our coastlines around Australia. I mean, it was
only this summer that northwestern Australia, up off Ningaloo, the
roly Shoal, some of our most iconic coral reefs, suffered
some of the most devastating bleaching events that they've ever
experienced as well. So this is happening in parallel with
(10:19):
the have down here. We know in southeastern Australia these
synergistic or compounding impacts of really rapid rates of warming
down the coast of Tasmania eastern Victoria. That's bringing new
species further and further south. And so in the case
of Tasmania, it's bringing this long spine sea itch and
further south. And these long spine search is overgrazing that
(10:43):
they're voracious herbivores. They feed on kelp and seaweeds and
they create these large baron areas that are devoid of
vegetation and those barren areas are spreading really rapidly through Tasmania,
Eastern Victoria, in the far south of New South Wales.
Now another one of these synergistic effects of climate change
(11:03):
that we're seeing on our coast that's affecting thousands of
kilometers and the future of hundreds of thousands of reef species.
Speaker 3 (11:11):
So with all of that already happening, what could be
done now to protect this marine life?
Speaker 1 (11:18):
Yes, so the have was really triggered by the intense
marine heat wave we had in South Australia. We know
heat waves are becoming more frequent and more intense with
climate change, and so we really need to act on
climate change as an Australian community, as a global community,
reduce our carbon emissions immediately. We can't avoid or get
(11:40):
around that. That has to be our number one priority.
It's also obviously a long game. There's so much inertia
in the system, and so at a more regional local
context there are things we can also do. So looking
after our coastal waterways and minimizing nutrient pollution is really
important and there are several ways we can do that.
So we know our marine habitats play a really crucial
(12:03):
role in filtering the water. So kelp forests, seagrasses and
oyster reefs amazing filters of the water. They uptake nutrients
and keep our coastal water waste clear. So maintaining healthy
habitats is one of the best things we can do
to bolster the resilience of our coastal systems.
Speaker 5 (12:22):
And if those changes don't happen, what's at stake here?
Speaker 1 (12:26):
This have has really shown what's at stake. You know,
the alga bloom in South Australia is just crippled local
fishing industry, it's crippled the tourism industry, and it's had
an enormous emotional psychological effect on South Australian people and
the Australian society more broadly. And these impacts are very
(12:48):
real at a human level, They're very real and they
affect us personally. At an ecological environmental scale, we could
be losing thousands upon thousands of species that are unique,
that have been swimming these waters for literally tens of
millions of years, and they could be gone on our.
Speaker 3 (13:07):
What well, Scott, thank you so much for speaking with
me today.
Speaker 1 (13:13):
Thanks very much.
Speaker 4 (13:13):
Ruby also in the news.
Speaker 3 (13:26):
The Reserve Bank Board has delivered an interest rate cut
of twenty five basis points from three point eighty five
to three point six percent.
Speaker 4 (13:35):
The move comes.
Speaker 3 (13:35):
After an unexpected decision last month to leave interest rates
on hold.
Speaker 5 (13:41):
And Mark Latham has an abusive.
Speaker 3 (13:43):
Obsession with a fellow MP, A court has heard. Independent
MP Alex Greenwich made the comments in court yesterday as
his legal fight against Latham continues. Last year, Greenwich sued
Latham for homosexual vilification and workplace harassment in one receiving
one hundred and forty thousand dollars in damages. Greenwich's lawyer
told the court yesterday that since then the independent MP
(14:04):
has been subject to further hatred and ridicule. Latham denies
breaching the new South Wales Anti Discrimination Act.
Speaker 5 (14:11):
I'm Ruby Jones.
Speaker 4 (14:12):
This is seven am. Thanks for listening.