The difficult path to sustainable aquaculture

If Tasmania wants to lead the world in fish farming it will have to deploy public resources for environmental monitoring.

Salmon pen, south-east Tasmania. PHOTO CSIRO

Humans need food, but producing it is hard work. A long time ago they worked out that most people could avoid such work if they corralled four-legged animals and tilled the soil.

This is farming, which over thousands of years has enabled cities to grow, along with governments, creative arts, science, sport and everything else that adds up to civilisation. But it came at a price.

As hunters and gatherers we moved through the landscape; as farmers we transformed it, draining marshes, clearing forests and making barriers to free movement in the form of fences.

We see clearly now that farming the land has its limits The swamps and forests we saw as obstacles turn out to have their own value as biologically diverse, productive natural habitats, while trees contribute massively to a stable global climate.

Given those limits and the eternal and growing demand for food, where should we turn? Where else but the sea? That story is playing out around Tasmania as various aquaculture interests compete for a share of a rapidly growing market in farmed finfish, mostly Atlantic salmon.

This has not gone unnoticed by the Tasmanian government, whose recently-released Sustainable industry growth plan for the salmon industry described Tasmanian farmed salmon as “not only the largest primary industry in the State… but also the nation’s largest seafood product by volume.”

A written introduction to the plan by primary industries minister Jeremy Rockliff described the government as “a strong supporter of the salmon industry”, pointing out its important contribution to jobs in regional Tasmania.

Tasmania’s biggest producer, Tassal, says the industry employs over 2000 people directly and another 10,000 indirectly. An Australia Institute study commissioned by the abalone industry puts the total at around 1000 jobs, less than the combined total for fishing and shellfish aquaculture.

Tassal’s website points out that its active farming leases amount to just 0.010561 per cent of the area of Tasmania and its territorial waters, which is true as far as it goes. Except that not all bits of land and sea are equal, especially when it comes to living things.

Shellfish like oysters and abalone feed on phytoplankton, which need sunlight to survive. Nearly all that is gone below about 30 metres, so shallow coastal waters are especially important for these wild sea-floor species. There, they have to coexist with fish farms.

It takes a lot of food to grow penned salmon. Much of that, with salmon faeces, falls into water below and to the sea floor. In some places, notably Macquarie Harbour, the waste has been found to cause a marked decline in dissolved oxygen in bottom water, affecting all sea-floor species.

Nearly all Tasmanian fish pens occupy sheltered inshore waterways, with a few in the more open waters of Storm Bay. No location could accurately be described as oceanic or deep-water.

If Tassal, Huon Aquaculture and Petuna are the farmers of the sea, professional and recreational fishers are its hunters and gatherers. Among these are abalone divers, part of an established, lucrative Tasmanian industry with a colourful past which it is now trying to put behind it.

Besides its earning capacity, the abalone industry has one other invaluable attribute. Abalone fishers secure their catch through diving, which means they have more personal knowledge of the undersea environment than any other active industry player.

According to the Tasmanian Abalone Council, the state’s $100 million a year wild abalone export industry, the world’s largest, is under threat from finfish farmers who don’t understand and cannot control the complexities of the natural environment into which they venture.

In its submission on the industry plan, the TAC identified the key impacts on the sea floor of open-cage salmon farming as sustained loads of nutrients and sediments, coming mainly from artificial feed and excreta but also including chemicals used in maintaining the pens.

It recommended an environmental buffer zone separating salmon farms from inshore reef systems to enable pollutants from pens to be diluted and dispersed by natural water movement, and requested a formal role in developing future finfish aquaculture policy.

The international standard for dealing with potential environmental impact is the precautionary principle, requiring transparent decision-making with public input and a clear demonstration, before any proposed activity begins, that it will not damage its natural surroundings.

Instead, the government has agreed with aquaculture companies that “adaptive management” is the way to go, whereby industry players make decisions based on their own monitoring and learning, with the only oversight being from government officers whose positions are funded by the industry.

This is a huge call. Contrary to world’s best practice, and rejecting advice from fishers able to see what is happening on the sea floor, the government has effectively put primary regulatory power into the hands of the finfish farmers themselves.

A genuinely sustainable, well regulated finfish farming industry with widespread public support ought to be eminently feasible. This could include more onshore operations that recycle water and recover waste as fertiliser.

But the best prospects seem to be in moving out of contested coastal waters to deeper, more dynamic waters able to disperse sediments. Huge, self-navigating submersible pens able to sink below damaging waves are already being trialled in North American and European waters.

In a world increasingly hungry for protein, Tasmania’s aquaculture industry can be a global leader, but that will require unimpeachable environmental credentials and informed, transparent regulation that is completely independent of industry, in both funding and operations.

That is not happening. The government, conflating straight-out political opposition with genuine public concern about environmental consequences, seems intent on casting its lot with the farmers. It needs to correct that bias, and the sooner the better.

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In this New Year, what are we celebrating?

A string of calamitous weather events and our rising carbon emissions leave a sense of foreboding for the year to come.

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Celebrating is what we do in the festive season, but it’s hard to feel good about the truly grotesque year we’ve just had, nor about the one that’s to come.

Underlying our unease is a clearly changing global climate. Governments now know there is no legitimate counter to the fact that this is caused by atmospheric pollution, supported as it is by tens of thousands of scientific studies and by all the world’s major scientific institutions.

Science is discovering some disconcerting trends in extreme weather, including more very heavy rainfall events, more intense, longer-lasting heatwaves, more severe fire outbreaks and more dry-lightning storms.

Reflecting this, public concern over exceptional weather events and political responses (or their absence) has grown steadily, to the point of undisguised alarm in some quarters, such as communities on low-lying islands. In 2018, triggers for that concern piled one on top of another.

In the Arctic over a few days last February, when the region is normally at its coldest, temperatures reached 20C above average. Sea ice began to disappear, and in northern Greenland the period of time above freezing on those days was more than three times the year-round average.

Out-of-season fires in Queensland and NSW prompted some local authorities to open the annual bushfire danger season in August – earlier than ever before. In November, a record-breaking hot spell in tropical Queensland fuelled fires of unprecedented severity.

Meanwhile, extreme summer heat across northern countries sparked many large wildfires including a blaze in Greece that killed 100 people and Scandinavian outbreaks north of the Arctic Circle.

California had its worst-ever summer fire season in July and August. Then in November yet more devastating fires obliterated a town called Paradise in the foothills of the Sierra Nevada, killing 85 people.

Major flash flooding events, too numerous to list here, occurred about every two days through 2018. Most involved multiple lives lost and all of them drove people from homes, at incalculable emotional cost and billions in property damage.

Science has affirmed climate links in a multitude of droughts, heatwaves, wildfires, storms and floods over recent years, with ominous implications for humanity, including food shortages, disease, income loss, warfare and forced migration.

A global survey of flooding events published in October by Nature Communications found a rising trend in the incidence of extreme flash floods, markedly higher than indicated by models and well beyond the capacity of existing infrastructure to cope.

The premier climate science authority, the Intergovernmental Panel on Climate Change, reported two months ago that the world has about 12 years to get carbon emissions declining steeply enough to offer reasonable hope of avoiding dangerous climate change.

The IPCC report, requested under the Paris Agreement of 2015, called for coal power to be phased out and transport, energy and industrial systems to be radically transformed by mid-century, a global effort with “no documented historic precedent”.

Current emission trends indicate we’re not about to break that mould. After a brief levelling off in 2014-16, global emissions rose by 1.6 per cent in 2017. In 2018 emissions are expected to rise 2.5 per cent, to a record 37 billion tonnes.

Hugh Saddler’s National Energy Emissions Audit revealed just before Christmas that Australian emissions have been rising steadily for four years, including 2018. Lower electricity emissions have been more than offset by rises in transport and stationary energy.

All this is feeding into public disquiet about government’s response to the clear and embarrassing evidence that climate policies are failing. In our own federal election this year we can expect climate change to figure more prominently than ever before.

As things stand, this can only benefit Labor, whose emissions policies – modest at best when set against the IPCC findings – are streets ahead of what is presently on offer from Scott Morrison.

Yet South Australia has shown that it doesn’t have to be this way. Steven Marshall’s Liberals took power from Labor in March, and despite a contrary stance in the election campaign the new government has taken on its predecessor’s role as a champion of clean energy.

The previous government’s renewable target of 75 per cent by 2025, attacked in Canberra as being too ambitious, is being exceeded by a wide margin. The Australian Energy Market Operator now calculates that the state could achieve 100 per cent renewable energy by then.

Informed by this and by voters’ clear preferences, Marshall’s team knows its electoral future rests heavily on strong support for renewables. It understands what its federal counterparts cannot – that conservatism and renewable energy can happily coexist.

The struggle to contain emissions has lost many good years because politicians could not admit they were wrong. But South Australia is showing us that change can happen quickly. Getting this experience onto a national stage can’t come soon enough.

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Earthrise: the moment that revealed the point of it all

Looking back over 50 years to the exhilarating and sobering experience of seeing our planet from afar

Four Earthrises (from top): Lunar Orbiter, 23 August 1966; Anders’s Photo 1, Apollo 8, 24 December 1968; NASA’s colour enhancement of AP1; Anders’s iconic colour image, 24 December 1968. PHOTOS NASA

Four Earthrises (from top): Lunar Orbiter, 23 August 1966; Anders’s first photograph, Apollo 8, 24 December 1968; NASA’s colour enhancement of above; Anders’s iconic colour image, 24 December 1968. PHOTOS NASA


Earthrise. The whole idea is other-worldly. Down here on terra firma, rising is done by the sun and the moon and the stars. But Earth?

It takes an effort to get the head around an Earthrise. You have to imagine being on another celestial body, able to see the whole of our planet as it appears over the horizon. No-one thought about it much until NASA started to capture images in space.

In August 1966 NASA’s first unmanned Lunar Orbiter spacecraft transmitted to the world an image of a crescent Earth coming into view above the surface of the moon – our first Earthrise.

A year later another Lunar Orbiter looked back on its way to the moon to capture the first photograph of the whole planet, showing Africa, the Middle East and the Indian Ocean under swirling cloud.

Both those transmitted images were streaky, grainy and colourless. We knew they were real and that was truly wondrous, but something much better was just over the horizon, so to speak.

Fifty years ago, on 21 December 1968, the US launched Apollo 8, the first manned moon flight. It didn’t land (the Apollo 11 mission would do that seven months later) but it did make nine orbits of the moon through that Christmas.

On Christmas Eve Bill Anders, one of Apollo 8’s three astronauts, was recording the moon’s surface using black-and-white film (no digital then) in a medium-format camera. During a rolling manoeuvre he saw something that made him catch his breath and exclaim, “Oh my God.”

Coming up over the barren lunar horizon was the sparkling blue and white orb of Earth. Anders swung the camera and snapped an image of Earth appearing above the horizon, then called for colour film as his home planet seemed to soar into the heavens.

Jim Lovell, best-known now as commander of the ill-fated Apollo 13, shared his crewmate’s excitement as he found colour film. “I think we missed it” said Anders as the spaceship continued to roll. “Hey I’ve got it right here,” called Lovell, looking out another window.

The voices reveal that the two men knew this was something very special. A pause on the voice recording as Anders loads colour film into the camera is followed by a satisfied “Okay”, then from an anxious Lovell, “Now vary the exposure a little bit.”

Anders: “I did. I took two of ’em.” Lovell: “You sure you got it now.” Anders: “Yeah… well it’ll come up again I think.” As it happened Earth didn’t “come up again” on that mission, but it didn’t matter – Anders had “got it”.

In 1999 Time and Life magazines rated the colour image by Anders as one of the 20th century’s great photographs. It has been called “the most influential environmental photograph ever taken”.

The “pale blue dot” that is Earth can be seen in the upper band on this Voyager image from 23 August 1966. PHOTO NASA

The “pale blue dot” that is Earth can be seen in the upper band on this image captured by Voyager in 1990. PHOTO NASA


There’s a postscript to this story. In 1990 the unmanned spacecraft Voyager 1 was six billion kilometres from Earth when, at the request of the eminent physicist Carl Sagan, NASA directed its camera back toward its home planet.

The resulting pictures, which took three months to transmit back to Earth, included another iconic space image of our planet. No outlines of continents or swirling clouds this time. Earth was a tiny blue speck – in Sagan’s words, “a mote of dust suspended in a sunbeam”.

“That’s here,” wrote Sagan. “That’s home. That’s us. On it everyone you love, everyone you know, everyone you ever heard of, every human being who ever was, lived out their lives.”

In their different ways, both pictures provide compelling guidance to a post-Apollo, post-Voyager age. In them we see our home as we might see other heavenly bodies in a Hubble space image, isolated and finite; in the words of Anders, an “oasis in the vastness of space”.

Bill Anders wrote of his life-changing Apollo experience, “We came all this way to explore the moon, and the most important thing is that we discovered the Earth.”

In our quest to grasp what it is to inhabit Spaceship Earth, Anders and a handful of astronauts – the only people ever to have seen our planet’s orb in all its splendour – have the advantage over us.

But I have a small sense of what he means. I have been privileged to live for two short periods in magnificent, desolate Antarctica. And yes, I am aware that Antarctic travel, like space travel, comes at a large cost in energy and resources. It’s arguable that humans should not go there at all.

Memorable as those Antarctic experiences were, I took away from them something much better: a renewed sense of our great good fortune to live in this wonderful part of our precious mote of dust.

Now we need to find the incentive to stop trashing it. Those 50-year-old Earthrise images are a pretty good place to start.

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